[mesa.git] / src / mesa / main / mtypes.h

/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * \file mtypes.h
 * Main Mesa data structures.
 *
 * Please try to mark derived values with a leading underscore ('_').
 */

#ifndef MTYPES_H
#define MTYPES_H


#include <stdint.h>             /* uint32_t */
#include <stdbool.h>
#include "c11/threads.h"

#include "main/glheader.h"
#include "main/config.h"
#include "glapi/glapi.h"
#include "math/m_matrix.h"      /* GLmatrix */
#include "glsl/nir/shader_enums.h"
#include "main/formats.h"       /* MESA_FORMAT_COUNT */


#ifdef __cplusplus
extern "C" {
#endif


/**
 * \name 64-bit extension of GLbitfield.
 */
/*@{*/
typedef GLuint64 GLbitfield64;

/** Set a single bit */
#define BITFIELD64_BIT(b)      ((GLbitfield64)1 << (b))
/** Set all bits up to excluding bit b */
#define BITFIELD64_MASK(b)      \
   ((b) == 64 ? (~(GLbitfield64)0) : BITFIELD64_BIT(b) - 1)
/** Set count bits starting from bit b  */
#define BITFIELD64_RANGE(b, count) \
   (BITFIELD64_MASK((b) + (count)) & ~BITFIELD64_MASK(b))


/**
 * \name Some forward type declarations
 */
/*@{*/
struct _mesa_HashTable;
struct gl_attrib_node;
struct gl_list_extensions;
struct gl_meta_state;
struct gl_program_cache;
struct gl_texture_object;
struct gl_debug_state;
struct gl_context;
struct st_context;
struct gl_uniform_storage;
struct prog_instruction;
struct gl_program_parameter_list;
struct set;
struct set_entry;
struct vbo_context;
/*@}*/


/** Extra draw modes beyond GL_POINTS, GL_TRIANGLE_FAN, etc */
#define PRIM_MAX                 GL_PATCHES
#define PRIM_OUTSIDE_BEGIN_END   (PRIM_MAX + 1)
#define PRIM_UNKNOWN             (PRIM_MAX + 2)

/**
 * Determine if the given gl_varying_slot appears in the fragment shader.
 */
static inline GLboolean
_mesa_varying_slot_in_fs(gl_varying_slot slot)
{
   switch (slot) {
   case VARYING_SLOT_PSIZ:
   case VARYING_SLOT_BFC0:
   case VARYING_SLOT_BFC1:
   case VARYING_SLOT_EDGE:
   case VARYING_SLOT_CLIP_VERTEX:
   case VARYING_SLOT_LAYER:
   case VARYING_SLOT_TESS_LEVEL_OUTER:
   case VARYING_SLOT_TESS_LEVEL_INNER:
      return GL_FALSE;
   default:
      return GL_TRUE;
   }
}

/**
 * Indexes for all renderbuffers
 */
typedef enum
{
   /* the four standard color buffers */
   BUFFER_FRONT_LEFT,
   BUFFER_BACK_LEFT,
   BUFFER_FRONT_RIGHT,
   BUFFER_BACK_RIGHT,
   BUFFER_DEPTH,
   BUFFER_STENCIL,
   BUFFER_ACCUM,
   /* optional aux buffer */
   BUFFER_AUX0,
   /* generic renderbuffers */
   BUFFER_COLOR0,
   BUFFER_COLOR1,
   BUFFER_COLOR2,
   BUFFER_COLOR3,
   BUFFER_COLOR4,
   BUFFER_COLOR5,
   BUFFER_COLOR6,
   BUFFER_COLOR7,
   BUFFER_COUNT
} gl_buffer_index;

/**
 * Bit flags for all renderbuffers
 */
#define BUFFER_BIT_FRONT_LEFT   (1 << BUFFER_FRONT_LEFT)
#define BUFFER_BIT_BACK_LEFT    (1 << BUFFER_BACK_LEFT)
#define BUFFER_BIT_FRONT_RIGHT  (1 << BUFFER_FRONT_RIGHT)
#define BUFFER_BIT_BACK_RIGHT   (1 << BUFFER_BACK_RIGHT)
#define BUFFER_BIT_AUX0         (1 << BUFFER_AUX0)
#define BUFFER_BIT_AUX1         (1 << BUFFER_AUX1)
#define BUFFER_BIT_AUX2         (1 << BUFFER_AUX2)
#define BUFFER_BIT_AUX3         (1 << BUFFER_AUX3)
#define BUFFER_BIT_DEPTH        (1 << BUFFER_DEPTH)
#define BUFFER_BIT_STENCIL      (1 << BUFFER_STENCIL)
#define BUFFER_BIT_ACCUM        (1 << BUFFER_ACCUM)
#define BUFFER_BIT_COLOR0       (1 << BUFFER_COLOR0)
#define BUFFER_BIT_COLOR1       (1 << BUFFER_COLOR1)
#define BUFFER_BIT_COLOR2       (1 << BUFFER_COLOR2)
#define BUFFER_BIT_COLOR3       (1 << BUFFER_COLOR3)
#define BUFFER_BIT_COLOR4       (1 << BUFFER_COLOR4)
#define BUFFER_BIT_COLOR5       (1 << BUFFER_COLOR5)
#define BUFFER_BIT_COLOR6       (1 << BUFFER_COLOR6)
#define BUFFER_BIT_COLOR7       (1 << BUFFER_COLOR7)

/**
 * Mask of all the color buffer bits (but not accum).
 */
#define BUFFER_BITS_COLOR  (BUFFER_BIT_FRONT_LEFT | \
                            BUFFER_BIT_BACK_LEFT | \
                            BUFFER_BIT_FRONT_RIGHT | \
                            BUFFER_BIT_BACK_RIGHT | \
                            BUFFER_BIT_AUX0 | \
                            BUFFER_BIT_COLOR0 | \
                            BUFFER_BIT_COLOR1 | \
                            BUFFER_BIT_COLOR2 | \
                            BUFFER_BIT_COLOR3 | \
                            BUFFER_BIT_COLOR4 | \
                            BUFFER_BIT_COLOR5 | \
                            BUFFER_BIT_COLOR6 | \
                            BUFFER_BIT_COLOR7)

/**
 * Framebuffer configuration (aka visual / pixelformat)
 * Note: some of these fields should be boolean, but it appears that
 * code in drivers/dri/common/util.c requires int-sized fields.
 */
struct gl_config
{
   GLboolean rgbMode;
   GLboolean floatMode;
   GLuint doubleBufferMode;
   GLuint stereoMode;

   GLboolean haveAccumBuffer;
   GLboolean haveDepthBuffer;
   GLboolean haveStencilBuffer;

   GLint redBits, greenBits, blueBits, alphaBits;       /* bits per comp */
   GLuint redMask, greenMask, blueMask, alphaMask;
   GLint rgbBits;               /* total bits for rgb */
   GLint indexBits;             /* total bits for colorindex */

   GLint accumRedBits, accumGreenBits, accumBlueBits, accumAlphaBits;
   GLint depthBits;
   GLint stencilBits;

   GLint numAuxBuffers;

   GLint level;

   /* EXT_visual_rating / GLX 1.2 */
   GLint visualRating;

   /* EXT_visual_info / GLX 1.2 */
   GLint transparentPixel;
   /*    colors are floats scaled to ints */
   GLint transparentRed, transparentGreen, transparentBlue, transparentAlpha;
   GLint transparentIndex;

   /* ARB_multisample / SGIS_multisample */
   GLint sampleBuffers;
   GLint samples;

   /* SGIX_pbuffer / GLX 1.3 */
   GLint maxPbufferWidth;
   GLint maxPbufferHeight;
   GLint maxPbufferPixels;
   GLint optimalPbufferWidth;   /* Only for SGIX_pbuffer. */
   GLint optimalPbufferHeight;  /* Only for SGIX_pbuffer. */

   /* OML_swap_method */
   GLint swapMethod;

   /* EXT_texture_from_pixmap */
   GLint bindToTextureRgb;
   GLint bindToTextureRgba;
   GLint bindToMipmapTexture;
   GLint bindToTextureTargets;
   GLint yInverted;

   /* EXT_framebuffer_sRGB */
   GLint sRGBCapable;
};


/**
 * \name Bit flags used for updating material values.
 */
/*@{*/
#define MAT_ATTRIB_FRONT_AMBIENT           0 
#define MAT_ATTRIB_BACK_AMBIENT            1
#define MAT_ATTRIB_FRONT_DIFFUSE           2 
#define MAT_ATTRIB_BACK_DIFFUSE            3
#define MAT_ATTRIB_FRONT_SPECULAR          4 
#define MAT_ATTRIB_BACK_SPECULAR           5
#define MAT_ATTRIB_FRONT_EMISSION          6
#define MAT_ATTRIB_BACK_EMISSION           7
#define MAT_ATTRIB_FRONT_SHININESS         8
#define MAT_ATTRIB_BACK_SHININESS          9
#define MAT_ATTRIB_FRONT_INDEXES           10
#define MAT_ATTRIB_BACK_INDEXES            11
#define MAT_ATTRIB_MAX                     12

#define MAT_ATTRIB_AMBIENT(f)  (MAT_ATTRIB_FRONT_AMBIENT+(f))  
#define MAT_ATTRIB_DIFFUSE(f)  (MAT_ATTRIB_FRONT_DIFFUSE+(f))  
#define MAT_ATTRIB_SPECULAR(f) (MAT_ATTRIB_FRONT_SPECULAR+(f)) 
#define MAT_ATTRIB_EMISSION(f) (MAT_ATTRIB_FRONT_EMISSION+(f)) 
#define MAT_ATTRIB_SHININESS(f)(MAT_ATTRIB_FRONT_SHININESS+(f))
#define MAT_ATTRIB_INDEXES(f)  (MAT_ATTRIB_FRONT_INDEXES+(f))  

#define MAT_INDEX_AMBIENT  0
#define MAT_INDEX_DIFFUSE  1
#define MAT_INDEX_SPECULAR 2

#define MAT_BIT_FRONT_AMBIENT         (1<<MAT_ATTRIB_FRONT_AMBIENT)
#define MAT_BIT_BACK_AMBIENT          (1<<MAT_ATTRIB_BACK_AMBIENT)
#define MAT_BIT_FRONT_DIFFUSE         (1<<MAT_ATTRIB_FRONT_DIFFUSE)
#define MAT_BIT_BACK_DIFFUSE          (1<<MAT_ATTRIB_BACK_DIFFUSE)
#define MAT_BIT_FRONT_SPECULAR        (1<<MAT_ATTRIB_FRONT_SPECULAR)
#define MAT_BIT_BACK_SPECULAR         (1<<MAT_ATTRIB_BACK_SPECULAR)
#define MAT_BIT_FRONT_EMISSION        (1<<MAT_ATTRIB_FRONT_EMISSION)
#define MAT_BIT_BACK_EMISSION         (1<<MAT_ATTRIB_BACK_EMISSION)
#define MAT_BIT_FRONT_SHININESS       (1<<MAT_ATTRIB_FRONT_SHININESS)
#define MAT_BIT_BACK_SHININESS        (1<<MAT_ATTRIB_BACK_SHININESS)
#define MAT_BIT_FRONT_INDEXES         (1<<MAT_ATTRIB_FRONT_INDEXES)
#define MAT_BIT_BACK_INDEXES          (1<<MAT_ATTRIB_BACK_INDEXES)


#define FRONT_MATERIAL_BITS     (MAT_BIT_FRONT_EMISSION |       \
                                 MAT_BIT_FRONT_AMBIENT |        \
                                 MAT_BIT_FRONT_DIFFUSE |        \
                                 MAT_BIT_FRONT_SPECULAR |       \
                                 MAT_BIT_FRONT_SHININESS |      \
                                 MAT_BIT_FRONT_INDEXES)

#define BACK_MATERIAL_BITS      (MAT_BIT_BACK_EMISSION |        \
                                 MAT_BIT_BACK_AMBIENT |         \
                                 MAT_BIT_BACK_DIFFUSE |         \
                                 MAT_BIT_BACK_SPECULAR |        \
                                 MAT_BIT_BACK_SHININESS |       \
                                 MAT_BIT_BACK_INDEXES)

#define ALL_MATERIAL_BITS       (FRONT_MATERIAL_BITS | BACK_MATERIAL_BITS)
/*@}*/


/**
 * Material state.
 */
struct gl_material
{
   GLfloat Attrib[MAT_ATTRIB_MAX][4];
};


/**
 * Light state flags.
 */
/*@{*/
#define LIGHT_SPOT         0x1
#define LIGHT_LOCAL_VIEWER 0x2
#define LIGHT_POSITIONAL   0x4
#define LIGHT_NEED_VERTICES (LIGHT_POSITIONAL|LIGHT_LOCAL_VIEWER)
/*@}*/


/**
 * Light source state.
 */
struct gl_light
{
   struct gl_light *next;       /**< double linked list with sentinel */
   struct gl_light *prev;

   GLfloat Ambient[4];          /**< ambient color */
   GLfloat Diffuse[4];          /**< diffuse color */
   GLfloat Specular[4];         /**< specular color */
   GLfloat EyePosition[4];      /**< position in eye coordinates */
   GLfloat SpotDirection[4];    /**< spotlight direction in eye coordinates */
   GLfloat SpotExponent;
   GLfloat SpotCutoff;          /**< in degrees */
   GLfloat _CosCutoff;          /**< = MAX(0, cos(SpotCutoff)) */
   GLfloat ConstantAttenuation;
   GLfloat LinearAttenuation;
   GLfloat QuadraticAttenuation;
   GLboolean Enabled;           /**< On/off flag */

   /** 
    * \name Derived fields
    */
   /*@{*/
   GLbitfield _Flags;           /**< Mask of LIGHT_x bits defined above */

   GLfloat _Position[4];        /**< position in eye/obj coordinates */
   GLfloat _VP_inf_norm[3];     /**< Norm direction to infinite light */
   GLfloat _h_inf_norm[3];      /**< Norm( _VP_inf_norm + <0,0,1> ) */
   GLfloat _NormSpotDirection[4]; /**< normalized spotlight direction */
   GLfloat _VP_inf_spot_attenuation;

   GLfloat _MatAmbient[2][3];   /**< material ambient * light ambient */
   GLfloat _MatDiffuse[2][3];   /**< material diffuse * light diffuse */
   GLfloat _MatSpecular[2][3];  /**< material spec * light specular */
   /*@}*/
};


/**
 * Light model state.
 */
struct gl_lightmodel
{
   GLfloat Ambient[4];          /**< ambient color */
   GLboolean LocalViewer;       /**< Local (or infinite) view point? */
   GLboolean TwoSide;           /**< Two (or one) sided lighting? */
   GLenum ColorControl;         /**< either GL_SINGLE_COLOR
                                 *    or GL_SEPARATE_SPECULAR_COLOR */
};


/**
 * Accumulation buffer attribute group (GL_ACCUM_BUFFER_BIT)
 */
struct gl_accum_attrib
{
   GLfloat ClearColor[4];       /**< Accumulation buffer clear color */
};


/**
 * Used for storing clear color, texture border color, etc.
 * The float values are typically unclamped.
 */
union gl_color_union
{
   GLfloat f[4];
   GLint i[4];
   GLuint ui[4];
};


/**
 * Color buffer attribute group (GL_COLOR_BUFFER_BIT).
 */
struct gl_colorbuffer_attrib
{
   GLuint ClearIndex;                      /**< Index for glClear */
   union gl_color_union ClearColor;        /**< Color for glClear, unclamped */
   GLuint IndexMask;                       /**< Color index write mask */
   GLubyte ColorMask[MAX_DRAW_BUFFERS][4]; /**< Each flag is 0xff or 0x0 */

   GLenum DrawBuffer[MAX_DRAW_BUFFERS]; /**< Which buffer to draw into */

   /** 
    * \name alpha testing
    */
   /*@{*/
   GLboolean AlphaEnabled;              /**< Alpha test enabled flag */
   GLenum AlphaFunc;                    /**< Alpha test function */
   GLfloat AlphaRefUnclamped;
   GLclampf AlphaRef;                   /**< Alpha reference value */
   /*@}*/

   /** 
    * \name Blending
    */
   /*@{*/
   GLbitfield BlendEnabled;             /**< Per-buffer blend enable flags */

   /* NOTE: this does _not_ depend on fragment clamping or any other clamping
    * control, only on the fixed-pointness of the render target.
    * The query does however depend on fragment color clamping.
    */
   GLfloat BlendColorUnclamped[4];               /**< Blending color */
   GLfloat BlendColor[4];               /**< Blending color */

   struct
   {
      GLenum SrcRGB;             /**< RGB blend source term */
      GLenum DstRGB;             /**< RGB blend dest term */
      GLenum SrcA;               /**< Alpha blend source term */
      GLenum DstA;               /**< Alpha blend dest term */
      GLenum EquationRGB;        /**< GL_ADD, GL_SUBTRACT, etc. */
      GLenum EquationA;          /**< GL_ADD, GL_SUBTRACT, etc. */
      /**
       * Set if any blend factor uses SRC1.  Computed at the time blend factors
       * get set.
       */
      GLboolean _UsesDualSrc;
   } Blend[MAX_DRAW_BUFFERS];
   /** Are the blend func terms currently different for each buffer/target? */
   GLboolean _BlendFuncPerBuffer;
   /** Are the blend equations currently different for each buffer/target? */
   GLboolean _BlendEquationPerBuffer;
   /*@}*/

   /** 
    * \name Logic op
    */
   /*@{*/
   GLboolean IndexLogicOpEnabled;       /**< Color index logic op enabled flag */
   GLboolean ColorLogicOpEnabled;       /**< RGBA logic op enabled flag */
   GLenum LogicOp;                      /**< Logic operator */

   /*@}*/

   GLboolean DitherFlag;                /**< Dither enable flag */

   GLboolean _ClampFragmentColor; /** < with GL_FIXED_ONLY_ARB resolved */
   GLenum ClampFragmentColor; /**< GL_TRUE, GL_FALSE or GL_FIXED_ONLY_ARB */
   GLenum ClampReadColor;     /**< GL_TRUE, GL_FALSE or GL_FIXED_ONLY_ARB */

   GLboolean sRGBEnabled;    /**< Framebuffer sRGB blending/updating requested */
};


/**
 * Current attribute group (GL_CURRENT_BIT).
 */
struct gl_current_attrib
{
   /**
    * \name Current vertex attributes (color, texcoords, etc).
    * \note Values are valid only after FLUSH_VERTICES has been called.
    * \note Index and Edgeflag current values are stored as floats in the 
    * SIX and SEVEN attribute slots.
    * \note We need double storage for 64-bit vertex attributes
    */
   GLfloat Attrib[VERT_ATTRIB_MAX][4*2];

   /**
    * \name Current raster position attributes (always up to date after a
    * glRasterPos call).
    */
   GLfloat RasterPos[4];
   GLfloat RasterDistance;
   GLfloat RasterColor[4];
   GLfloat RasterSecondaryColor[4];
   GLfloat RasterTexCoords[MAX_TEXTURE_COORD_UNITS][4];
   GLboolean RasterPosValid;
};


/**
 * Depth buffer attribute group (GL_DEPTH_BUFFER_BIT).
 */
struct gl_depthbuffer_attrib
{
   GLenum Func;                 /**< Function for depth buffer compare */
   GLclampd Clear;              /**< Value to clear depth buffer to */
   GLboolean Test;              /**< Depth buffering enabled flag */
   GLboolean Mask;              /**< Depth buffer writable? */
   GLboolean BoundsTest;        /**< GL_EXT_depth_bounds_test */
   GLfloat BoundsMin, BoundsMax;/**< GL_EXT_depth_bounds_test */
};


/**
 * Evaluator attribute group (GL_EVAL_BIT).
 */
struct gl_eval_attrib
{
   /**
    * \name Enable bits 
    */
   /*@{*/
   GLboolean Map1Color4;
   GLboolean Map1Index;
   GLboolean Map1Normal;
   GLboolean Map1TextureCoord1;
   GLboolean Map1TextureCoord2;
   GLboolean Map1TextureCoord3;
   GLboolean Map1TextureCoord4;
   GLboolean Map1Vertex3;
   GLboolean Map1Vertex4;
   GLboolean Map2Color4;
   GLboolean Map2Index;
   GLboolean Map2Normal;
   GLboolean Map2TextureCoord1;
   GLboolean Map2TextureCoord2;
   GLboolean Map2TextureCoord3;
   GLboolean Map2TextureCoord4;
   GLboolean Map2Vertex3;
   GLboolean Map2Vertex4;
   GLboolean AutoNormal;
   /*@}*/
   
   /**
    * \name Map Grid endpoints and divisions and calculated du values
    */
   /*@{*/
   GLint MapGrid1un;
   GLfloat MapGrid1u1, MapGrid1u2, MapGrid1du;
   GLint MapGrid2un, MapGrid2vn;
   GLfloat MapGrid2u1, MapGrid2u2, MapGrid2du;
   GLfloat MapGrid2v1, MapGrid2v2, MapGrid2dv;
   /*@}*/
};


/**
 * Fog attribute group (GL_FOG_BIT).
 */
struct gl_fog_attrib
{
   GLboolean Enabled;           /**< Fog enabled flag */
   GLboolean ColorSumEnabled;
   GLfloat ColorUnclamped[4];            /**< Fog color */
   GLfloat Color[4];            /**< Fog color */
   GLfloat Density;             /**< Density >= 0.0 */
   GLfloat Start;               /**< Start distance in eye coords */
   GLfloat End;                 /**< End distance in eye coords */
   GLfloat Index;               /**< Fog index */
   GLenum Mode;                 /**< Fog mode */
   GLenum FogCoordinateSource;  /**< GL_EXT_fog_coord */
   GLfloat _Scale;              /**< (End == Start) ? 1.0 : 1.0 / (End - Start) */
   GLenum FogDistanceMode;     /**< GL_NV_fog_distance */
};


/** 
 * Hint attribute group (GL_HINT_BIT).
 * 
 * Values are always one of GL_FASTEST, GL_NICEST, or GL_DONT_CARE.
 */
struct gl_hint_attrib
{
   GLenum PerspectiveCorrection;
   GLenum PointSmooth;
   GLenum LineSmooth;
   GLenum PolygonSmooth;
   GLenum Fog;
   GLenum TextureCompression;   /**< GL_ARB_texture_compression */
   GLenum GenerateMipmap;       /**< GL_SGIS_generate_mipmap */
   GLenum FragmentShaderDerivative; /**< GL_ARB_fragment_shader */
};


/**
 * Lighting attribute group (GL_LIGHT_BIT).
 */
struct gl_light_attrib
{
   struct gl_light Light[MAX_LIGHTS];   /**< Array of light sources */
   struct gl_lightmodel Model;          /**< Lighting model */

   /**
    * Front and back material values.
    * Note: must call FLUSH_VERTICES() before using.
    */
   struct gl_material Material;

   GLboolean Enabled;                   /**< Lighting enabled flag */
   GLboolean ColorMaterialEnabled;

   GLenum ShadeModel;                   /**< GL_FLAT or GL_SMOOTH */
   GLenum ProvokingVertex;              /**< GL_EXT_provoking_vertex */
   GLenum ColorMaterialFace;            /**< GL_FRONT, BACK or FRONT_AND_BACK */
   GLenum ColorMaterialMode;            /**< GL_AMBIENT, GL_DIFFUSE, etc */
   GLbitfield _ColorMaterialBitmask;    /**< bitmask formed from Face and Mode */


   GLboolean _ClampVertexColor;
   GLenum ClampVertexColor;             /**< GL_TRUE, GL_FALSE, GL_FIXED_ONLY */

   /** 
    * Derived state for optimizations: 
    */
   /*@{*/
   GLboolean _NeedEyeCoords;            
   GLboolean _NeedVertices;             /**< Use fast shader? */
   struct gl_light EnabledList;         /**< List sentinel */

   GLfloat _BaseColor[2][3];
   /*@}*/
};


/**
 * Line attribute group (GL_LINE_BIT).
 */
struct gl_line_attrib
{
   GLboolean SmoothFlag;        /**< GL_LINE_SMOOTH enabled? */
   GLboolean StippleFlag;       /**< GL_LINE_STIPPLE enabled? */
   GLushort StipplePattern;     /**< Stipple pattern */
   GLint StippleFactor;         /**< Stipple repeat factor */
   GLfloat Width;               /**< Line width */
};


/**
 * Display list attribute group (GL_LIST_BIT).
 */
struct gl_list_attrib
{
   GLuint ListBase;
};


/**
 * Multisample attribute group (GL_MULTISAMPLE_BIT).
 */
struct gl_multisample_attrib
{
   GLboolean Enabled;
   GLboolean _Enabled;   /**< true if Enabled and multisample buffer */
   GLboolean SampleAlphaToCoverage;
   GLboolean SampleAlphaToOne;
   GLboolean SampleCoverage;
   GLboolean SampleCoverageInvert;
   GLboolean SampleShading;

   /* ARB_texture_multisample / GL3.2 additions */
   GLboolean SampleMask;

   GLfloat SampleCoverageValue;
   GLfloat MinSampleShadingValue;

   /** The GL spec defines this as an array but >32x MSAA is madness */
   GLbitfield SampleMaskValue;
};


/**
 * A pixelmap (see glPixelMap)
 */
struct gl_pixelmap
{
   GLint Size;
   GLfloat Map[MAX_PIXEL_MAP_TABLE];
};


/**
 * Collection of all pixelmaps
 */
struct gl_pixelmaps
{
   struct gl_pixelmap RtoR;  /**< i.e. GL_PIXEL_MAP_R_TO_R */
   struct gl_pixelmap GtoG;
   struct gl_pixelmap BtoB;
   struct gl_pixelmap AtoA;
   struct gl_pixelmap ItoR;
   struct gl_pixelmap ItoG;
   struct gl_pixelmap ItoB;
   struct gl_pixelmap ItoA;
   struct gl_pixelmap ItoI;
   struct gl_pixelmap StoS;
};


/**
 * Pixel attribute group (GL_PIXEL_MODE_BIT).
 */
struct gl_pixel_attrib
{
   GLenum ReadBuffer;           /**< source buffer for glRead/CopyPixels() */

   /*--- Begin Pixel Transfer State ---*/
   /* Fields are in the order in which they're applied... */

   /** Scale & Bias (index shift, offset) */
   /*@{*/
   GLfloat RedBias, RedScale;
   GLfloat GreenBias, GreenScale;
   GLfloat BlueBias, BlueScale;
   GLfloat AlphaBias, AlphaScale;
   GLfloat DepthBias, DepthScale;
   GLint IndexShift, IndexOffset;
   /*@}*/

   /* Pixel Maps */
   /* Note: actual pixel maps are not part of this attrib group */
   GLboolean MapColorFlag;
   GLboolean MapStencilFlag;

   /*--- End Pixel Transfer State ---*/

   /** glPixelZoom */
   GLfloat ZoomX, ZoomY;
};


/**
 * Point attribute group (GL_POINT_BIT).
 */
struct gl_point_attrib
{
   GLfloat Size;                /**< User-specified point size */
   GLfloat Params[3];           /**< GL_EXT_point_parameters */
   GLfloat MinSize, MaxSize;    /**< GL_EXT_point_parameters */
   GLfloat Threshold;           /**< GL_EXT_point_parameters */
   GLboolean SmoothFlag;        /**< True if GL_POINT_SMOOTH is enabled */
   GLboolean _Attenuated;       /**< True if Params != [1, 0, 0] */
   GLboolean PointSprite;       /**< GL_NV/ARB_point_sprite */
   GLboolean CoordReplace[MAX_TEXTURE_COORD_UNITS]; /**< GL_ARB_point_sprite*/
   GLenum SpriteRMode;          /**< GL_NV_point_sprite (only!) */
   GLenum SpriteOrigin;         /**< GL_ARB_point_sprite */
};


/**
 * Polygon attribute group (GL_POLYGON_BIT).
 */
struct gl_polygon_attrib
{
   GLenum FrontFace;            /**< Either GL_CW or GL_CCW */
   GLenum FrontMode;            /**< Either GL_POINT, GL_LINE or GL_FILL */
   GLenum BackMode;             /**< Either GL_POINT, GL_LINE or GL_FILL */
   GLboolean _FrontBit;         /**< 0=GL_CCW, 1=GL_CW */
   GLboolean CullFlag;          /**< Culling on/off flag */
   GLboolean SmoothFlag;        /**< True if GL_POLYGON_SMOOTH is enabled */
   GLboolean StippleFlag;       /**< True if GL_POLYGON_STIPPLE is enabled */
   GLenum CullFaceMode;         /**< Culling mode GL_FRONT or GL_BACK */
   GLfloat OffsetFactor;        /**< Polygon offset factor, from user */
   GLfloat OffsetUnits;         /**< Polygon offset units, from user */
   GLfloat OffsetClamp;         /**< Polygon offset clamp, from user */
   GLboolean OffsetPoint;       /**< Offset in GL_POINT mode */
   GLboolean OffsetLine;        /**< Offset in GL_LINE mode */
   GLboolean OffsetFill;        /**< Offset in GL_FILL mode */
};


/**
 * Scissor attributes (GL_SCISSOR_BIT).
 */
struct gl_scissor_rect
{
   GLint X, Y;                  /**< Lower left corner of box */
   GLsizei Width, Height;       /**< Size of box */
};
struct gl_scissor_attrib
{
   GLbitfield EnableFlags;      /**< Scissor test enabled? */
   struct gl_scissor_rect ScissorArray[MAX_VIEWPORTS];
};


/**
 * Stencil attribute group (GL_STENCIL_BUFFER_BIT).
 *
 * Three sets of stencil data are tracked so that OpenGL 2.0,
 * GL_EXT_stencil_two_side, and GL_ATI_separate_stencil can all be supported
 * simultaneously.  In each of the stencil state arrays, element 0 corresponds
 * to GL_FRONT.  Element 1 corresponds to the OpenGL 2.0 /
 * GL_ATI_separate_stencil GL_BACK state.  Element 2 corresponds to the
 * GL_EXT_stencil_two_side GL_BACK state.
 *
 * The derived value \c _BackFace is either 1 or 2 depending on whether or
 * not GL_STENCIL_TEST_TWO_SIDE_EXT is enabled.
 *
 * The derived value \c _TestTwoSide is set when the front-face and back-face
 * stencil state are different.
 */
struct gl_stencil_attrib
{
   GLboolean Enabled;           /**< Enabled flag */
   GLboolean TestTwoSide;       /**< GL_EXT_stencil_two_side */
   GLubyte ActiveFace;          /**< GL_EXT_stencil_two_side (0 or 2) */
   GLboolean _Enabled;          /**< Enabled and stencil buffer present */
   GLboolean _WriteEnabled;     /**< _Enabled and non-zero writemasks */
   GLboolean _TestTwoSide;
   GLubyte _BackFace;           /**< Current back stencil state (1 or 2) */
   GLenum Function[3];          /**< Stencil function */
   GLenum FailFunc[3];          /**< Fail function */
   GLenum ZPassFunc[3];         /**< Depth buffer pass function */
   GLenum ZFailFunc[3];         /**< Depth buffer fail function */
   GLint Ref[3];                /**< Reference value */
   GLuint ValueMask[3];         /**< Value mask */
   GLuint WriteMask[3];         /**< Write mask */
   GLuint Clear;                /**< Clear value */
};


/**
 * An index for each type of texture object.  These correspond to the GL
 * texture target enums, such as GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP, etc.
 * Note: the order is from highest priority to lowest priority.
 */
typedef enum
{
   TEXTURE_2D_MULTISAMPLE_INDEX,
   TEXTURE_2D_MULTISAMPLE_ARRAY_INDEX,
   TEXTURE_CUBE_ARRAY_INDEX,
   TEXTURE_BUFFER_INDEX,
   TEXTURE_2D_ARRAY_INDEX,
   TEXTURE_1D_ARRAY_INDEX,
   TEXTURE_EXTERNAL_INDEX,
   TEXTURE_CUBE_INDEX,
   TEXTURE_3D_INDEX,
   TEXTURE_RECT_INDEX,
   TEXTURE_2D_INDEX,
   TEXTURE_1D_INDEX,
   NUM_TEXTURE_TARGETS
} gl_texture_index;


/**
 * Bit flags for each type of texture object
 */
/*@{*/
#define TEXTURE_2D_MULTISAMPLE_BIT (1 << TEXTURE_2D_MULTISAMPLE_INDEX)
#define TEXTURE_2D_MULTISAMPLE_ARRAY_BIT (1 << TEXTURE_2D_MULTISAMPLE_ARRAY_INDEX)
#define TEXTURE_CUBE_ARRAY_BIT (1 << TEXTURE_CUBE_ARRAY_INDEX)
#define TEXTURE_BUFFER_BIT   (1 << TEXTURE_BUFFER_INDEX)
#define TEXTURE_2D_ARRAY_BIT (1 << TEXTURE_2D_ARRAY_INDEX)
#define TEXTURE_1D_ARRAY_BIT (1 << TEXTURE_1D_ARRAY_INDEX)
#define TEXTURE_EXTERNAL_BIT (1 << TEXTURE_EXTERNAL_INDEX)
#define TEXTURE_CUBE_BIT     (1 << TEXTURE_CUBE_INDEX)
#define TEXTURE_3D_BIT       (1 << TEXTURE_3D_INDEX)
#define TEXTURE_RECT_BIT     (1 << TEXTURE_RECT_INDEX)
#define TEXTURE_2D_BIT       (1 << TEXTURE_2D_INDEX)
#define TEXTURE_1D_BIT       (1 << TEXTURE_1D_INDEX)
/*@}*/


/**
 * Texture image state.  Drivers will typically create a subclass of this
 * with extra fields for memory buffers, etc.
 */
struct gl_texture_image
{
   GLint InternalFormat;        /**< Internal format as given by the user */
   GLenum _BaseFormat;          /**< Either GL_RGB, GL_RGBA, GL_ALPHA,
                                 *   GL_LUMINANCE, GL_LUMINANCE_ALPHA,
                                 *   GL_INTENSITY, GL_DEPTH_COMPONENT or
                                 *   GL_DEPTH_STENCIL_EXT only. Used for
                                 *   choosing TexEnv arithmetic.
                                 */
   mesa_format TexFormat;         /**< The actual texture memory format */

   GLuint Border;               /**< 0 or 1 */
   GLuint Width;                /**< = 2^WidthLog2 + 2*Border */
   GLuint Height;               /**< = 2^HeightLog2 + 2*Border */
   GLuint Depth;                /**< = 2^DepthLog2 + 2*Border */
   GLuint Width2;               /**< = Width - 2*Border */
   GLuint Height2;              /**< = Height - 2*Border */
   GLuint Depth2;               /**< = Depth - 2*Border */
   GLuint WidthLog2;            /**< = log2(Width2) */
   GLuint HeightLog2;           /**< = log2(Height2) */
   GLuint DepthLog2;            /**< = log2(Depth2) */
   GLuint MaxNumLevels;         /**< = maximum possible number of mipmap
                                       levels, computed from the dimensions */

   struct gl_texture_object *TexObject;  /**< Pointer back to parent object */
   GLuint Level;                /**< Which mipmap level am I? */
   /** Cube map face: index into gl_texture_object::Image[] array */
   GLuint Face;

   /** GL_ARB_texture_multisample */
   GLuint NumSamples;            /**< Sample count, or 0 for non-multisample */
   GLboolean FixedSampleLocations; /**< Same sample locations for all pixels? */
};


/**
 * Indexes for cube map faces.
 */
typedef enum
{
   FACE_POS_X = 0,
   FACE_NEG_X = 1,
   FACE_POS_Y = 2,
   FACE_NEG_Y = 3,
   FACE_POS_Z = 4,
   FACE_NEG_Z = 5,
   MAX_FACES = 6
} gl_face_index;


/**
 * Sampler object state.  These objects are new with GL_ARB_sampler_objects
 * and OpenGL 3.3.  Legacy texture objects also contain a sampler object.
 */
struct gl_sampler_object
{
   mtx_t Mutex;
   GLuint Name;
   GLint RefCount;
   GLchar *Label;               /**< GL_KHR_debug */

   GLenum WrapS;                /**< S-axis texture image wrap mode */
   GLenum WrapT;                /**< T-axis texture image wrap mode */
   GLenum WrapR;                /**< R-axis texture image wrap mode */
   GLenum MinFilter;            /**< minification filter */
   GLenum MagFilter;            /**< magnification filter */
   union gl_color_union BorderColor;  /**< Interpreted according to texture format */
   GLfloat MinLod;              /**< min lambda, OpenGL 1.2 */
   GLfloat MaxLod;              /**< max lambda, OpenGL 1.2 */
   GLfloat LodBias;             /**< OpenGL 1.4 */
   GLfloat MaxAnisotropy;       /**< GL_EXT_texture_filter_anisotropic */
   GLenum CompareMode;          /**< GL_ARB_shadow */
   GLenum CompareFunc;          /**< GL_ARB_shadow */
   GLenum sRGBDecode;           /**< GL_DECODE_EXT or GL_SKIP_DECODE_EXT */
   GLboolean CubeMapSeamless;   /**< GL_AMD_seamless_cubemap_per_texture */
};


/**
 * Texture object state.  Contains the array of mipmap images, border color,
 * wrap modes, filter modes, and shadow/texcompare state.
 */
struct gl_texture_object
{
   mtx_t Mutex;      /**< for thread safety */
   GLint RefCount;             /**< reference count */
   GLuint Name;                /**< the user-visible texture object ID */
   GLchar *Label;               /**< GL_KHR_debug */
   GLenum Target;              /**< GL_TEXTURE_1D, GL_TEXTURE_2D, etc. */
   gl_texture_index TargetIndex; /**< The gl_texture_unit::CurrentTex index.
                                      Only valid when Target is valid. */

   struct gl_sampler_object Sampler;

   GLenum DepthMode;           /**< GL_ARB_depth_texture */
   bool StencilSampling;       /**< Should we sample stencil instead of depth? */

   GLfloat Priority;           /**< in [0,1] */
   GLint BaseLevel;            /**< min mipmap level, OpenGL 1.2 */
   GLint MaxLevel;             /**< max mipmap level, OpenGL 1.2 */
   GLint ImmutableLevels;      /**< ES 3.0 / ARB_texture_view */
   GLint _MaxLevel;            /**< actual max mipmap level (q in the spec) */
   GLfloat _MaxLambda;         /**< = _MaxLevel - BaseLevel (q - p in spec) */
   GLint CropRect[4];          /**< GL_OES_draw_texture */
   GLenum Swizzle[4];          /**< GL_EXT_texture_swizzle */
   GLuint _Swizzle;            /**< same as Swizzle, but SWIZZLE_* format */
   GLboolean GenerateMipmap;   /**< GL_SGIS_generate_mipmap */
   GLboolean _BaseComplete;    /**< Is the base texture level valid? */
   GLboolean _MipmapComplete;  /**< Is the whole mipmap valid? */
   GLboolean _IsIntegerFormat; /**< Does the texture store integer values? */
   GLboolean _RenderToTexture; /**< Any rendering to this texture? */
   GLboolean Purgeable;        /**< Is the buffer purgeable under memory
                                    pressure? */
   GLboolean Immutable;        /**< GL_ARB_texture_storage */
   GLboolean _IsFloat;         /**< GL_OES_float_texture */
   GLboolean _IsHalfFloat;     /**< GL_OES_half_float_texture */

   GLuint MinLevel;            /**< GL_ARB_texture_view */
   GLuint MinLayer;            /**< GL_ARB_texture_view */
   GLuint NumLevels;           /**< GL_ARB_texture_view */
   GLuint NumLayers;           /**< GL_ARB_texture_view */

   /** Actual texture images, indexed by [cube face] and [mipmap level] */
   struct gl_texture_image *Image[MAX_FACES][MAX_TEXTURE_LEVELS];

   /** GL_ARB_texture_buffer_object */
   struct gl_buffer_object *BufferObject;
   GLenum BufferObjectFormat;
   /** Equivalent Mesa format for BufferObjectFormat. */
   mesa_format _BufferObjectFormat;
   /** GL_ARB_texture_buffer_range */
   GLintptr BufferOffset;
   GLsizeiptr BufferSize; /**< if this is -1, use BufferObject->Size instead */

   /** GL_OES_EGL_image_external */
   GLint RequiredTextureImageUnits;

   /** GL_ARB_shader_image_load_store */
   GLenum ImageFormatCompatibilityType;
};


/** Up to four combiner sources are possible with GL_NV_texture_env_combine4 */
#define MAX_COMBINER_TERMS 4


/**
 * Texture combine environment state.
 */
struct gl_tex_env_combine_state
{
   GLenum ModeRGB;       /**< GL_REPLACE, GL_DECAL, GL_ADD, etc. */
   GLenum ModeA;         /**< GL_REPLACE, GL_DECAL, GL_ADD, etc. */
   /** Source terms: GL_PRIMARY_COLOR, GL_TEXTURE, etc */
   GLenum SourceRGB[MAX_COMBINER_TERMS];
   GLenum SourceA[MAX_COMBINER_TERMS];
   /** Source operands: GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, etc */
   GLenum OperandRGB[MAX_COMBINER_TERMS];
   GLenum OperandA[MAX_COMBINER_TERMS];
   GLuint ScaleShiftRGB; /**< 0, 1 or 2 */
   GLuint ScaleShiftA;   /**< 0, 1 or 2 */
   GLuint _NumArgsRGB;   /**< Number of inputs used for the RGB combiner */
   GLuint _NumArgsA;     /**< Number of inputs used for the A combiner */
};


/**
 * TexGenEnabled flags.
 */
/*@{*/
#define S_BIT 1
#define T_BIT 2
#define R_BIT 4
#define Q_BIT 8
#define STR_BITS (S_BIT | T_BIT | R_BIT)
/*@}*/


/**
 * Bit flag versions of the corresponding GL_ constants.
 */
/*@{*/
#define TEXGEN_SPHERE_MAP        0x1
#define TEXGEN_OBJ_LINEAR        0x2
#define TEXGEN_EYE_LINEAR        0x4
#define TEXGEN_REFLECTION_MAP_NV 0x8
#define TEXGEN_NORMAL_MAP_NV     0x10

#define TEXGEN_NEED_NORMALS      (TEXGEN_SPHERE_MAP        | \
                                  TEXGEN_REFLECTION_MAP_NV | \
                                  TEXGEN_NORMAL_MAP_NV)
#define TEXGEN_NEED_EYE_COORD    (TEXGEN_SPHERE_MAP        | \
                                  TEXGEN_REFLECTION_MAP_NV | \
                                  TEXGEN_NORMAL_MAP_NV     | \
                                  TEXGEN_EYE_LINEAR)
/*@}*/



/** Tex-gen enabled for texture unit? */
#define ENABLE_TEXGEN(unit) (1 << (unit))

/** Non-identity texture matrix for texture unit? */
#define ENABLE_TEXMAT(unit) (1 << (unit))


/**
 * Texture coord generation state.
 */
struct gl_texgen
{
   GLenum Mode;         /**< GL_EYE_LINEAR, GL_SPHERE_MAP, etc */
   GLbitfield _ModeBit; /**< TEXGEN_x bit corresponding to Mode */
   GLfloat ObjectPlane[4];
   GLfloat EyePlane[4];
};


/**
 * Texture unit state.  Contains enable flags, texture environment/function/
 * combiners, texgen state, and pointers to current texture objects.
 */
struct gl_texture_unit
{
   GLbitfield Enabled;          /**< bitmask of TEXTURE_*_BIT flags */

   GLenum EnvMode;              /**< GL_MODULATE, GL_DECAL, GL_BLEND, etc. */
   GLclampf EnvColor[4];
   GLfloat EnvColorUnclamped[4];

   struct gl_texgen GenS;
   struct gl_texgen GenT;
   struct gl_texgen GenR;
   struct gl_texgen GenQ;
   GLbitfield TexGenEnabled;    /**< Bitwise-OR of [STRQ]_BIT values */
   GLbitfield _GenFlags;        /**< Bitwise-OR of Gen[STRQ]._ModeBit */

   GLfloat LodBias;             /**< for biasing mipmap levels */

   /** Texture targets that have a non-default texture bound */
   GLbitfield _BoundTextures;

   /** Current sampler object (GL_ARB_sampler_objects) */
   struct gl_sampler_object *Sampler;

   /** 
    * \name GL_EXT_texture_env_combine 
    */
   struct gl_tex_env_combine_state Combine;

   /**
    * Derived state based on \c EnvMode and the \c BaseFormat of the
    * currently enabled texture.
    */
   struct gl_tex_env_combine_state _EnvMode;

   /**
    * Currently enabled combiner state.  This will point to either
    * \c Combine or \c _EnvMode.
    */
   struct gl_tex_env_combine_state *_CurrentCombine;

   /** Current texture object pointers */
   struct gl_texture_object *CurrentTex[NUM_TEXTURE_TARGETS];

   /** Points to highest priority, complete and enabled texture object */
   struct gl_texture_object *_Current;

};


/**
 * Texture attribute group (GL_TEXTURE_BIT).
 */
struct gl_texture_attrib
{
   GLuint CurrentUnit;   /**< GL_ACTIVE_TEXTURE */

   /** GL_ARB_seamless_cubemap */
   GLboolean CubeMapSeamless;

   struct gl_texture_object *ProxyTex[NUM_TEXTURE_TARGETS];

   /** GL_ARB_texture_buffer_object */
   struct gl_buffer_object *BufferObject;

   /** Texture coord units/sets used for fragment texturing */
   GLbitfield _EnabledCoordUnits;

   /** Texture coord units that have texgen enabled */
   GLbitfield _TexGenEnabled;

   /** Texture coord units that have non-identity matrices */
   GLbitfield _TexMatEnabled;

   /** Bitwise-OR of all Texture.Unit[i]._GenFlags */
   GLbitfield _GenFlags;

   /** Largest index of a texture unit with _Current != NULL. */
   GLint _MaxEnabledTexImageUnit;

   /** Largest index + 1 of texture units that have had any CurrentTex set. */
   GLint NumCurrentTexUsed;

   struct gl_texture_unit Unit[MAX_COMBINED_TEXTURE_IMAGE_UNITS];
};


/**
 * Data structure representing a single clip plane (e.g. one of the elements
 * of the ctx->Transform.EyeUserPlane or ctx->Transform._ClipUserPlane array).
 */
typedef GLfloat gl_clip_plane[4];


/**
 * Transformation attribute group (GL_TRANSFORM_BIT).
 */
struct gl_transform_attrib
{
   GLenum MatrixMode;                           /**< Matrix mode */
   gl_clip_plane EyeUserPlane[MAX_CLIP_PLANES]; /**< User clip planes */
   gl_clip_plane _ClipUserPlane[MAX_CLIP_PLANES]; /**< derived */
   GLbitfield ClipPlanesEnabled;                /**< on/off bitmask */
   GLboolean Normalize;                         /**< Normalize all normals? */
   GLboolean RescaleNormals;                    /**< GL_EXT_rescale_normal */
   GLboolean RasterPositionUnclipped;           /**< GL_IBM_rasterpos_clip */
   GLboolean DepthClamp;                        /**< GL_ARB_depth_clamp */
   /** GL_ARB_clip_control */
   GLenum ClipOrigin;     /**< GL_LOWER_LEFT or GL_UPPER_LEFT */
   GLenum ClipDepthMode;  /**< GL_NEGATIVE_ONE_TO_ONE or GL_ZERO_TO_ONE */
};


/**
 * Viewport attribute group (GL_VIEWPORT_BIT).
 */
struct gl_viewport_attrib
{
   GLfloat X, Y;                /**< position */
   GLfloat Width, Height;       /**< size */
   GLdouble Near, Far;          /**< Depth buffer range */
};


typedef enum {
   MAP_USER,
   MAP_INTERNAL,

   MAP_COUNT
} gl_map_buffer_index;


/**
 * Fields describing a mapped buffer range.
 */
struct gl_buffer_mapping {
   GLbitfield AccessFlags; /**< Mask of GL_MAP_x_BIT flags */
   GLvoid *Pointer;     /**< User-space address of mapping */
   GLintptr Offset;     /**< Mapped offset */
   GLsizeiptr Length;   /**< Mapped length */
};


/**
 * Usages we've seen for a buffer object.
 */
typedef enum {
   USAGE_UNIFORM_BUFFER = 0x1,
   USAGE_TEXTURE_BUFFER = 0x2,
   USAGE_ATOMIC_COUNTER_BUFFER = 0x4,
   USAGE_SHADER_STORAGE_BUFFER = 0x8,
} gl_buffer_usage;


/**
 * GL_ARB_vertex/pixel_buffer_object buffer object
 */
struct gl_buffer_object
{
   mtx_t Mutex;
   GLint RefCount;
   GLuint Name;
   GLchar *Label;       /**< GL_KHR_debug */
   GLenum Usage;        /**< GL_STREAM_DRAW_ARB, GL_STREAM_READ_ARB, etc. */
   GLbitfield StorageFlags; /**< GL_MAP_PERSISTENT_BIT, etc. */
   GLsizeiptrARB Size;  /**< Size of buffer storage in bytes */
   GLubyte *Data;       /**< Location of storage either in RAM or VRAM. */
   GLboolean DeletePending;   /**< true if buffer object is removed from the hash */
   GLboolean Written;   /**< Ever written to? (for debugging) */
   GLboolean Purgeable; /**< Is the buffer purgeable under memory pressure? */
   GLboolean Immutable; /**< GL_ARB_buffer_storage */
   gl_buffer_usage UsageHistory; /**< How has this buffer been used so far? */

   struct gl_buffer_mapping Mappings[MAP_COUNT];
};


/**
 * Client pixel packing/unpacking attributes
 */
struct gl_pixelstore_attrib
{
   GLint Alignment;
   GLint RowLength;
   GLint SkipPixels;
   GLint SkipRows;
   GLint ImageHeight;
   GLint SkipImages;
   GLboolean SwapBytes;
   GLboolean LsbFirst;
   GLboolean Invert;        /**< GL_MESA_pack_invert */
   GLint CompressedBlockWidth;   /**< GL_ARB_compressed_texture_pixel_storage */
   GLint CompressedBlockHeight;
   GLint CompressedBlockDepth;
   GLint CompressedBlockSize;
   struct gl_buffer_object *BufferObj; /**< GL_ARB_pixel_buffer_object */
};


/**
 * Client vertex array attributes
 */
struct gl_client_array
{
   GLint Size;                  /**< components per element (1,2,3,4) */
   GLenum Type;                 /**< datatype: GL_FLOAT, GL_INT, etc */
   GLenum Format;               /**< default: GL_RGBA, but may be GL_BGRA */
   GLsizei Stride;              /**< user-specified stride */
   GLsizei StrideB;             /**< actual stride in bytes */
   GLuint _ElementSize;         /**< size of each element in bytes */
   const GLubyte *Ptr;          /**< Points to array data */
   GLboolean Enabled;           /**< Enabled flag is a boolean */
   GLboolean Normalized;        /**< GL_ARB_vertex_program */
   GLboolean Integer;           /**< Integer-valued? */
   GLboolean Doubles;       /**< double precision values are not converted to floats */
   GLuint InstanceDivisor;      /**< GL_ARB_instanced_arrays */

   struct gl_buffer_object *BufferObj;/**< GL_ARB_vertex_buffer_object */
};


/**
 * Vertex attribute array as seen by the client.
 *
 * Contains the size, type, format and normalization flag,
 * along with the index of a vertex buffer binding point.
 *
 * Note that the Stride field corresponds to VERTEX_ATTRIB_ARRAY_STRIDE
 * and is only present for backwards compatibility reasons.
 * Rendering always uses VERTEX_BINDING_STRIDE.
 * The gl*Pointer() functions will set VERTEX_ATTRIB_ARRAY_STRIDE
 * and VERTEX_BINDING_STRIDE to the same value, while
 * glBindVertexBuffer() will only set VERTEX_BINDING_STRIDE.
 */
struct gl_vertex_attrib_array
{
   GLint Size;              /**< Components per element (1,2,3,4) */
   GLenum Type;             /**< Datatype: GL_FLOAT, GL_INT, etc */
   GLenum Format;           /**< Default: GL_RGBA, but may be GL_BGRA */
   GLsizei Stride;          /**< Stride as specified with gl*Pointer() */
   const GLubyte *Ptr;      /**< Points to client array data. Not used when a VBO is bound */
   GLintptr RelativeOffset; /**< Offset of the first element relative to the binding offset */
   GLboolean Enabled;       /**< Whether the array is enabled */
   GLboolean Normalized;    /**< Fixed-point values are normalized when converted to floats */
   GLboolean Integer;       /**< Fixed-point values are not converted to floats */
   GLboolean Doubles;       /**< double precision values are not converted to floats */
   GLuint _ElementSize;     /**< Size of each element in bytes */
   GLuint VertexBinding;    /**< Vertex buffer binding */
};


/**
 * This describes the buffer object used for a vertex array (or
 * multiple vertex arrays).  If BufferObj points to the default/null
 * buffer object, then the vertex array lives in user memory and not a VBO.
 */
struct gl_vertex_buffer_binding
{
   GLintptr Offset;                    /**< User-specified offset */
   GLsizei Stride;                     /**< User-specified stride */
   GLuint InstanceDivisor;             /**< GL_ARB_instanced_arrays */
   struct gl_buffer_object *BufferObj; /**< GL_ARB_vertex_buffer_object */
   GLbitfield64 _BoundArrays;          /**< Arrays bound to this binding point */
};


/**
 * A representation of "Vertex Array Objects" (VAOs) from OpenGL 3.1+,
 * GL_ARB_vertex_array_object, or the original GL_APPLE_vertex_array_object
 * extension.
 */
struct gl_vertex_array_object
{
   /** Name of the VAO as received from glGenVertexArray. */
   GLuint Name;

   GLint RefCount;

   GLchar *Label;       /**< GL_KHR_debug */

   mtx_t Mutex;

   /**
    * Does the VAO use ARB semantics or Apple semantics?
    *
    * There are several ways in which ARB_vertex_array_object and
    * APPLE_vertex_array_object VAOs have differing semantics.  At the very
    * least,
    *
    *     - ARB VAOs require that all array data be sourced from vertex buffer
    *       objects, but Apple VAOs do not.
    *
    *     - ARB VAOs require that names come from GenVertexArrays.
    *
    * This flag notes which behavior governs this VAO.
    */
   GLboolean ARBsemantics;

   /**
    * Has this array object been bound?
    */
   GLboolean EverBound;

   /**
    * Derived vertex attribute arrays
    *
    * This is a legacy data structure created from gl_vertex_attrib_array and
    * gl_vertex_buffer_binding, for compatibility with existing driver code.
    */
   struct gl_client_array _VertexAttrib[VERT_ATTRIB_MAX];

   /** Vertex attribute arrays */
   struct gl_vertex_attrib_array VertexAttrib[VERT_ATTRIB_MAX];

   /** Vertex buffer bindings */
   struct gl_vertex_buffer_binding VertexBinding[VERT_ATTRIB_MAX];

   /** Mask indicating which vertex arrays have vertex buffer associated. */
   GLbitfield64 VertexAttribBufferMask;

   /** Mask of VERT_BIT_* values indicating which arrays are enabled */
   GLbitfield64 _Enabled;

   /** Mask of VERT_BIT_* values indicating changed/dirty arrays */
   GLbitfield64 NewArrays;

   /** The index buffer (also known as the element array buffer in OpenGL). */
   struct gl_buffer_object *IndexBufferObj;
};


/** Used to signal when transitioning from one kind of drawing method
 * to another.
 */
typedef enum {
   DRAW_NONE,          /**< Initial value only */
   DRAW_BEGIN_END,
   DRAW_DISPLAY_LIST,
   DRAW_ARRAYS
} gl_draw_method;

/**
 * Enum for the OpenGL APIs we know about and may support.
 *
 * NOTE: This must match the api_enum table in
 * src/mesa/main/get_hash_generator.py
 */
typedef enum
{
   API_OPENGL_COMPAT,      /* legacy / compatibility contexts */
   API_OPENGLES,
   API_OPENGLES2,
   API_OPENGL_CORE,
   API_OPENGL_LAST = API_OPENGL_CORE
} gl_api;

/**
 * Vertex array state
 */
struct gl_array_attrib
{
   /** Currently bound array object. See _mesa_BindVertexArrayAPPLE() */
   struct gl_vertex_array_object *VAO;

   /** The default vertex array object */
   struct gl_vertex_array_object *DefaultVAO;

   /** The last VAO accessed by a DSA function */
   struct gl_vertex_array_object *LastLookedUpVAO;

   /** Array objects (GL_ARB/APPLE_vertex_array_object) */
   struct _mesa_HashTable *Objects;

   GLint ActiveTexture;         /**< Client Active Texture */
   GLuint LockFirst;            /**< GL_EXT_compiled_vertex_array */
   GLuint LockCount;            /**< GL_EXT_compiled_vertex_array */

   /**
    * \name Primitive restart controls
    *
    * Primitive restart is enabled if either \c PrimitiveRestart or
    * \c PrimitiveRestartFixedIndex is set.
    */
   /*@{*/
   GLboolean PrimitiveRestart;
   GLboolean PrimitiveRestartFixedIndex;
   GLboolean _PrimitiveRestart;
   GLuint RestartIndex;
   /*@}*/

   /** One of the DRAW_xxx flags, not consumed by drivers */
   gl_draw_method DrawMethod;

   /* GL_ARB_vertex_buffer_object */
   struct gl_buffer_object *ArrayBufferObj;

   /**
    * Vertex arrays as consumed by a driver.
    * The array pointer is set up only by the VBO module.
    */
   const struct gl_client_array **_DrawArrays; /**< 0..VERT_ATTRIB_MAX-1 */

   /** Legal array datatypes and the API for which they have been computed */
   GLbitfield LegalTypesMask;
   gl_api LegalTypesMaskAPI;
};


/**
 * Feedback buffer state
 */
struct gl_feedback
{
   GLenum Type;
   GLbitfield _Mask;    /**< FB_* bits */
   GLfloat *Buffer;
   GLuint BufferSize;
   GLuint Count;
};


/**
 * Selection buffer state
 */
struct gl_selection
{
   GLuint *Buffer;      /**< selection buffer */
   GLuint BufferSize;   /**< size of the selection buffer */
   GLuint BufferCount;  /**< number of values in the selection buffer */
   GLuint Hits;         /**< number of records in the selection buffer */
   GLuint NameStackDepth; /**< name stack depth */
   GLuint NameStack[MAX_NAME_STACK_DEPTH]; /**< name stack */
   GLboolean HitFlag;   /**< hit flag */
   GLfloat HitMinZ;     /**< minimum hit depth */
   GLfloat HitMaxZ;     /**< maximum hit depth */
};


/**
 * 1-D Evaluator control points
 */
struct gl_1d_map
{
   GLuint Order;        /**< Number of control points */
   GLfloat u1, u2, du;  /**< u1, u2, 1.0/(u2-u1) */
   GLfloat *Points;     /**< Points to contiguous control points */
};


/**
 * 2-D Evaluator control points
 */
struct gl_2d_map
{
   GLuint Uorder;               /**< Number of control points in U dimension */
   GLuint Vorder;               /**< Number of control points in V dimension */
   GLfloat u1, u2, du;
   GLfloat v1, v2, dv;
   GLfloat *Points;             /**< Points to contiguous control points */
};


/**
 * All evaluator control point state
 */
struct gl_evaluators
{
   /** 
    * \name 1-D maps
    */
   /*@{*/
   struct gl_1d_map Map1Vertex3;
   struct gl_1d_map Map1Vertex4;
   struct gl_1d_map Map1Index;
   struct gl_1d_map Map1Color4;
   struct gl_1d_map Map1Normal;
   struct gl_1d_map Map1Texture1;
   struct gl_1d_map Map1Texture2;
   struct gl_1d_map Map1Texture3;
   struct gl_1d_map Map1Texture4;
   /*@}*/

   /** 
    * \name 2-D maps 
    */
   /*@{*/
   struct gl_2d_map Map2Vertex3;
   struct gl_2d_map Map2Vertex4;
   struct gl_2d_map Map2Index;
   struct gl_2d_map Map2Color4;
   struct gl_2d_map Map2Normal;
   struct gl_2d_map Map2Texture1;
   struct gl_2d_map Map2Texture2;
   struct gl_2d_map Map2Texture3;
   struct gl_2d_map Map2Texture4;
   /*@}*/
};


struct gl_transform_feedback_varying_info
{
   char *Name;
   GLenum Type;
   GLint Size;
};


/**
 * Per-output info vertex shaders for transform feedback.
 */
struct gl_transform_feedback_output
{
   unsigned OutputRegister;
   unsigned OutputBuffer;
   unsigned NumComponents;
   unsigned StreamId;

   /** offset (in DWORDs) of this output within the interleaved structure */
   unsigned DstOffset;

   /**
    * Offset into the output register of the data to output.  For example,
    * if NumComponents is 2 and ComponentOffset is 1, then the data to
    * offset is in the y and z components of the output register.
    */
   unsigned ComponentOffset;
};


/** Post-link transform feedback info. */
struct gl_transform_feedback_info
{
   unsigned NumOutputs;

   /**
    * Number of transform feedback buffers in use by this program.
    */
   unsigned NumBuffers;

   struct gl_transform_feedback_output *Outputs;

   /** Transform feedback varyings used for the linking of this shader program.
    *
    * Use for glGetTransformFeedbackVarying().
    */
   struct gl_transform_feedback_varying_info *Varyings;
   GLint NumVarying;

   /**
    * Total number of components stored in each buffer.  This may be used by
    * hardware back-ends to determine the correct stride when interleaving
    * multiple transform feedback outputs in the same buffer.
    */
   unsigned BufferStride[MAX_FEEDBACK_BUFFERS];

   /**
    * Which transform feedback stream this buffer binding is associated with.
    */
   unsigned BufferStream[MAX_FEEDBACK_BUFFERS];
};


/**
 * Transform feedback object state
 */
struct gl_transform_feedback_object
{
   GLuint Name;  /**< AKA the object ID */
   GLint RefCount;
   GLchar *Label;     /**< GL_KHR_debug */
   GLboolean Active;  /**< Is transform feedback enabled? */
   GLboolean Paused;  /**< Is transform feedback paused? */
   GLboolean EndedAnytime; /**< Has EndTransformFeedback been called
                                at least once? */
   GLboolean EverBound; /**< Has this object been bound? */

   /**
    * GLES: if Active is true, remaining number of primitives which can be
    * rendered without overflow.  This is necessary to track because GLES
    * requires us to generate INVALID_OPERATION if a call to glDrawArrays or
    * glDrawArraysInstanced would overflow transform feedback buffers.
    * Undefined if Active is false.
    *
    * Not tracked for desktop GL since it's unnecessary.
    */
   unsigned GlesRemainingPrims;

   /**
    * The shader program active when BeginTransformFeedback() was called.
    * When active and unpaused, this equals ctx->Shader.CurrentProgram[stage],
    * where stage is the pipeline stage that is the source of data for
    * transform feedback.
    */
   struct gl_shader_program *shader_program;

   /** The feedback buffers */
   GLuint BufferNames[MAX_FEEDBACK_BUFFERS];
   struct gl_buffer_object *Buffers[MAX_FEEDBACK_BUFFERS];

   /** Start of feedback data in dest buffer */
   GLintptr Offset[MAX_FEEDBACK_BUFFERS];

   /**
    * Max data to put into dest buffer (in bytes).  Computed based on
    * RequestedSize and the actual size of the buffer.
    */
   GLsizeiptr Size[MAX_FEEDBACK_BUFFERS];

   /**
    * Size that was specified when the buffer was bound.  If the buffer was
    * bound with glBindBufferBase() or glBindBufferOffsetEXT(), this value is
    * zero.
    */
   GLsizeiptr RequestedSize[MAX_FEEDBACK_BUFFERS];
};


/**
 * Context state for transform feedback.
 */
struct gl_transform_feedback_state
{
   GLenum Mode;       /**< GL_POINTS, GL_LINES or GL_TRIANGLES */

   /** The general binding point (GL_TRANSFORM_FEEDBACK_BUFFER) */
   struct gl_buffer_object *CurrentBuffer;

   /** The table of all transform feedback objects */
   struct _mesa_HashTable *Objects;

   /** The current xform-fb object (GL_TRANSFORM_FEEDBACK_BINDING) */
   struct gl_transform_feedback_object *CurrentObject;

   /** The default xform-fb object (Name==0) */
   struct gl_transform_feedback_object *DefaultObject;
};


/**
 * A "performance monitor" as described in AMD_performance_monitor.
 */
struct gl_perf_monitor_object
{
   GLuint Name;

   /** True if the monitor is currently active (Begin called but not End). */
   GLboolean Active;

   /**
    * True if the monitor has ended.
    *
    * This is distinct from !Active because it may never have began.
    */
   GLboolean Ended;

   /**
    * A list of groups with currently active counters.
    *
    * ActiveGroups[g] == n if there are n counters active from group 'g'.
    */
   unsigned *ActiveGroups;

   /**
    * An array of bitsets, subscripted by group ID, then indexed by counter ID.
    *
    * Checking whether counter 'c' in group 'g' is active can be done via:
    *
    *    BITSET_TEST(ActiveCounters[g], c)
    */
   GLuint **ActiveCounters;
};


union gl_perf_monitor_counter_value
{
   float f;
   uint64_t u64;
   uint32_t u32;
};


struct gl_perf_monitor_counter
{
   /** Human readable name for the counter. */
   const char *Name;

   /**
    * Data type of the counter.  Valid values are FLOAT, UNSIGNED_INT,
    * UNSIGNED_INT64_AMD, and PERCENTAGE_AMD.
    */
   GLenum Type;

   /** Minimum counter value. */
   union gl_perf_monitor_counter_value Minimum;

   /** Maximum counter value. */
   union gl_perf_monitor_counter_value Maximum;
};


struct gl_perf_monitor_group
{
   /** Human readable name for the group. */
   const char *Name;

   /**
    * Maximum number of counters in this group which can be active at the
    * same time.
    */
   GLuint MaxActiveCounters;

   /** Array of counters within this group. */
   const struct gl_perf_monitor_counter *Counters;
   GLuint NumCounters;
};


/**
 * Context state for AMD_performance_monitor.
 */
struct gl_perf_monitor_state
{
   /** Array of performance monitor groups (indexed by group ID) */
   const struct gl_perf_monitor_group *Groups;
   GLuint NumGroups;

   /** The table of all performance monitors. */
   struct _mesa_HashTable *Monitors;
};


/**
 * Names of the various vertex/fragment program register files, etc.
 *
 * NOTE: first four tokens must fit into 2 bits (see t_vb_arbprogram.c)
 * All values should fit in a 4-bit field.
 *
 * NOTE: PROGRAM_STATE_VAR, PROGRAM_CONSTANT, and PROGRAM_UNIFORM can all be
 * considered to be "uniform" variables since they can only be set outside
 * glBegin/End.  They're also all stored in the same Parameters array.
 */
typedef enum
{
   PROGRAM_TEMPORARY,   /**< machine->Temporary[] */
   PROGRAM_ARRAY,       /**< Arrays & Matrixes */
   PROGRAM_INPUT,       /**< machine->Inputs[] */
   PROGRAM_OUTPUT,      /**< machine->Outputs[] */
   PROGRAM_STATE_VAR,   /**< gl_program->Parameters[] */
   PROGRAM_CONSTANT,    /**< gl_program->Parameters[] */
   PROGRAM_UNIFORM,     /**< gl_program->Parameters[] */
   PROGRAM_WRITE_ONLY,  /**< A dummy, write-only register */
   PROGRAM_ADDRESS,     /**< machine->AddressReg */
   PROGRAM_SAMPLER,     /**< for shader samplers, compile-time only */
   PROGRAM_SYSTEM_VALUE,/**< InstanceId, PrimitiveID, etc. */
   PROGRAM_UNDEFINED,   /**< Invalid/TBD value */
   PROGRAM_FILE_MAX
} gl_register_file;


/**
 * Base class for any kind of program object
 */
struct gl_program
{
   mtx_t Mutex;
   GLuint Id;
   GLint RefCount;
   GLubyte *String;  /**< Null-terminated program text */

   GLenum Target;    /**< GL_VERTEX/FRAGMENT_PROGRAM_ARB, GL_GEOMETRY_PROGRAM_NV */
   GLenum Format;    /**< String encoding format */

   struct prog_instruction *Instructions;

   struct nir_shader *nir;

   GLbitfield64 InputsRead;     /**< Bitmask of which input regs are read */
   GLbitfield64 DoubleInputsRead;     /**< Bitmask of which input regs are read  and are doubles */
   GLbitfield64 OutputsWritten; /**< Bitmask of which output regs are written */
   GLbitfield PatchInputsRead;  /**< VAR[0..31] usage for patch inputs (user-defined only) */
   GLbitfield PatchOutputsWritten; /**< VAR[0..31] usage for patch outputs (user-defined only) */
   GLbitfield SystemValuesRead;   /**< Bitmask of SYSTEM_VALUE_x inputs used */
   GLbitfield TexturesUsed[MAX_COMBINED_TEXTURE_IMAGE_UNITS];  /**< TEXTURE_x_BIT bitmask */
   GLbitfield SamplersUsed;   /**< Bitfield of which samplers are used */
   GLbitfield ShadowSamplers; /**< Texture units used for shadow sampling. */

   GLboolean UsesGather; /**< Does this program use gather4 at all? */

   /**
    * For vertex and geometry shaders, true if the program uses the
    * gl_ClipDistance output.  Ignored for fragment shaders.
    */
   unsigned ClipDistanceArraySize;


   /** Named parameters, constants, etc. from program text */
   struct gl_program_parameter_list *Parameters;

   /**
    * Local parameters used by the program.
    *
    * It's dynamically allocated because it is rarely used (just
    * assembly-style programs), and MAX_PROGRAM_LOCAL_PARAMS entries once it's
    * allocated.
    */
   GLfloat (*LocalParams)[4];

   /** Map from sampler unit to texture unit (set by glUniform1i()) */
   GLubyte SamplerUnits[MAX_SAMPLERS];

   /** Bitmask of which register files are read/written with indirect
    * addressing.  Mask of (1 << PROGRAM_x) bits.
    */
   GLbitfield IndirectRegisterFiles;

   /** Logical counts */
   /*@{*/
   GLuint NumInstructions;
   GLuint NumTemporaries;
   GLuint NumParameters;
   GLuint NumAttributes;
   GLuint NumAddressRegs;
   GLuint NumAluInstructions;
   GLuint NumTexInstructions;
   GLuint NumTexIndirections;
   /*@}*/
   /** Native, actual h/w counts */
   /*@{*/
   GLuint NumNativeInstructions;
   GLuint NumNativeTemporaries;
   GLuint NumNativeParameters;
   GLuint NumNativeAttributes;
   GLuint NumNativeAddressRegs;
   GLuint NumNativeAluInstructions;
   GLuint NumNativeTexInstructions;
   GLuint NumNativeTexIndirections;
   /*@}*/
};


/** Vertex program object */
struct gl_vertex_program
{
   struct gl_program Base;   /**< base class */
   GLboolean IsPositionInvariant;
};


/** Tessellation control program object */
struct gl_tess_ctrl_program
{
   struct gl_program Base;   /**< base class */

   /* output layout */
   GLint VerticesOut;
};


/** Tessellation evaluation program object */
struct gl_tess_eval_program
{
   struct gl_program Base;   /**< base class */

   /* input layout */
   GLenum PrimitiveMode; /* GL_TRIANGLES, GL_QUADS or GL_ISOLINES */
   GLenum Spacing;       /* GL_EQUAL, GL_FRACTIONAL_EVEN, GL_FRACTIONAL_ODD */
   GLenum VertexOrder;   /* GL_CW or GL_CCW */
   bool PointMode;
};


/** Geometry program object */
struct gl_geometry_program
{
   struct gl_program Base;   /**< base class */

   GLint VerticesIn;
   GLint VerticesOut;
   GLint Invocations;
   GLenum InputType;  /**< GL_POINTS, GL_LINES, GL_LINES_ADJACENCY_ARB,
                           GL_TRIANGLES, or GL_TRIANGLES_ADJACENCY_ARB */
   GLenum OutputType; /**< GL_POINTS, GL_LINE_STRIP or GL_TRIANGLE_STRIP */
   bool UsesEndPrimitive;
   bool UsesStreams;
};


/** Fragment program object */
struct gl_fragment_program
{
   struct gl_program Base;   /**< base class */
   GLboolean UsesKill;          /**< shader uses KIL instruction */
   GLboolean UsesDFdy;          /**< shader uses DDY instruction */
   GLboolean OriginUpperLeft;
   GLboolean PixelCenterInteger;
   enum gl_frag_depth_layout FragDepthLayout;

   /**
    * GLSL interpolation qualifier associated with each fragment shader input.
    * For inputs that do not have an interpolation qualifier specified in
    * GLSL, the value is INTERP_QUALIFIER_NONE.
    */
   enum glsl_interp_qualifier InterpQualifier[VARYING_SLOT_MAX];

   /**
    * Bitfield indicating, for each fragment shader input, 1 if that input
    * uses centroid interpolation, 0 otherwise.  Unused inputs are 0.
    */
   GLbitfield64 IsCentroid;

   /**
    * Bitfield indicating, for each fragment shader input, 1 if that input
    * uses sample interpolation, 0 otherwise.  Unused inputs are 0.
    */
   GLbitfield64 IsSample;
};


/** Compute program object */
struct gl_compute_program
{
   struct gl_program Base;   /**< base class */

   /**
    * Size specified using local_size_{x,y,z}.
    */
   unsigned LocalSize[3];
};


/**
 * State common to vertex and fragment programs.
 */
struct gl_program_state
{
   GLint ErrorPos;                       /* GL_PROGRAM_ERROR_POSITION_ARB/NV */
   const char *ErrorString;              /* GL_PROGRAM_ERROR_STRING_ARB/NV */
};


/**
 * Context state for vertex programs.
 */
struct gl_vertex_program_state
{
   GLboolean Enabled;            /**< User-set GL_VERTEX_PROGRAM_ARB/NV flag */
   GLboolean _Enabled;           /**< Enabled and _valid_ user program? */
   GLboolean PointSizeEnabled;   /**< GL_VERTEX_PROGRAM_POINT_SIZE_ARB/NV */
   GLboolean TwoSideEnabled;     /**< GL_VERTEX_PROGRAM_TWO_SIDE_ARB/NV */
   /** Computed two sided lighting for fixed function/programs. */
   GLboolean _TwoSideEnabled;
   struct gl_vertex_program *Current;  /**< User-bound vertex program */

   /** Currently enabled and valid vertex program (including internal
    * programs, user-defined vertex programs and GLSL vertex shaders).
    * This is the program we must use when rendering.
    */
   struct gl_vertex_program *_Current;

   GLfloat Parameters[MAX_PROGRAM_ENV_PARAMS][4]; /**< Env params */

   /** Should fixed-function T&L be implemented with a vertex prog? */
   GLboolean _MaintainTnlProgram;

   /** Program to emulate fixed-function T&L (see above) */
   struct gl_vertex_program *_TnlProgram;

   /** Cache of fixed-function programs */
   struct gl_program_cache *Cache;

   GLboolean _Overriden;
};

/**
 * Context state for tessellation control programs.
 */
struct gl_tess_ctrl_program_state
{
   /** Currently bound and valid shader. */
   struct gl_tess_ctrl_program *_Current;

   GLint patch_vertices;
   GLfloat patch_default_outer_level[4];
   GLfloat patch_default_inner_level[2];
};

/**
 * Context state for tessellation evaluation programs.
 */
struct gl_tess_eval_program_state
{
   /** Currently bound and valid shader. */
   struct gl_tess_eval_program *_Current;
};

/**
 * Context state for geometry programs.
 */
struct gl_geometry_program_state
{
   /** Currently enabled and valid program (including internal programs
    * and compiled shader programs).
    */
   struct gl_geometry_program *_Current;
};

/**
 * Context state for fragment programs.
 */
struct gl_fragment_program_state
{
   GLboolean Enabled;     /**< User-set fragment program enable flag */
   GLboolean _Enabled;    /**< Enabled and _valid_ user program? */
   struct gl_fragment_program *Current;  /**< User-bound fragment program */

   /** Currently enabled and valid fragment program (including internal
    * programs, user-defined fragment programs and GLSL fragment shaders).
    * This is the program we must use when rendering.
    */
   struct gl_fragment_program *_Current;

   GLfloat Parameters[MAX_PROGRAM_ENV_PARAMS][4]; /**< Env params */

   /** Should fixed-function texturing be implemented with a fragment prog? */
   GLboolean _MaintainTexEnvProgram;

   /** Program to emulate fixed-function texture env/combine (see above) */
   struct gl_fragment_program *_TexEnvProgram;

   /** Cache of fixed-function programs */
   struct gl_program_cache *Cache;
};


/**
 * Context state for compute programs.
 */
struct gl_compute_program_state
{
   /** Currently enabled and valid program (including internal programs
    * and compiled shader programs).
    */
   struct gl_compute_program *_Current;
};


/**
 * ATI_fragment_shader runtime state
 */
#define ATI_FS_INPUT_PRIMARY 0
#define ATI_FS_INPUT_SECONDARY 1

struct atifs_instruction;
struct atifs_setupinst;

/**
 * ATI fragment shader
 */
struct ati_fragment_shader
{
   GLuint Id;
   GLint RefCount;
   struct atifs_instruction *Instructions[2];
   struct atifs_setupinst *SetupInst[2];
   GLfloat Constants[8][4];
   GLbitfield LocalConstDef;  /**< Indicates which constants have been set */
   GLubyte numArithInstr[2];
   GLubyte regsAssigned[2];
   GLubyte NumPasses;         /**< 1 or 2 */
   GLubyte cur_pass;
   GLubyte last_optype;
   GLboolean interpinp1;
   GLboolean isValid;
   GLuint swizzlerq;
};

/**
 * Context state for GL_ATI_fragment_shader
 */
struct gl_ati_fragment_shader_state
{
   GLboolean Enabled;
   GLboolean _Enabled;                  /**< enabled and valid shader? */
   GLboolean Compiling;
   GLfloat GlobalConstants[8][4];
   struct ati_fragment_shader *Current;
};

/**
 *  Shader subroutine function definition
 */
struct gl_subroutine_function
{
   char *name;
   int index;
   int num_compat_types;
   const struct glsl_type **types;
};

/**
 * A GLSL vertex or fragment shader object.
 */
struct gl_shader
{
   /** GL_FRAGMENT_SHADER || GL_VERTEX_SHADER || GL_GEOMETRY_SHADER_ARB ||
    *  GL_TESS_CONTROL_SHADER || GL_TESS_EVALUATION_SHADER.
    * Must be the first field.
    */
   GLenum Type;
   gl_shader_stage Stage;
   GLuint Name;  /**< AKA the handle */
   GLint RefCount;  /**< Reference count */
   GLchar *Label;   /**< GL_KHR_debug */
   GLboolean DeletePending;
   GLboolean CompileStatus;
   bool IsES;              /**< True if this shader uses GLSL ES */

   GLuint SourceChecksum;       /**< for debug/logging purposes */
   const GLchar *Source;  /**< Source code string */

   struct gl_program *Program;  /**< Post-compile assembly code */
   GLchar *InfoLog;

   unsigned Version;       /**< GLSL version used for linking */

   /**
    * \name Sampler tracking
    *
    * \note Each of these fields is only set post-linking.
    */
   /*@{*/
   unsigned num_samplers;       /**< Number of samplers used by this shader. */
   GLbitfield active_samplers;  /**< Bitfield of which samplers are used */
   GLbitfield shadow_samplers;  /**< Samplers used for shadow sampling. */
   /*@}*/

   /**
    * Map from sampler unit to texture unit (set by glUniform1i())
    *
    * A sampler unit is associated with each sampler uniform by the linker.
    * The sampler unit associated with each uniform is stored in the
    * \c gl_uniform_storage::sampler field.
    */
   GLubyte SamplerUnits[MAX_SAMPLERS];
   /** Which texture target is being sampled (TEXTURE_1D/2D/3D/etc_INDEX) */
   gl_texture_index SamplerTargets[MAX_SAMPLERS];

   /**
    * Number of default uniform block components used by this shader.
    *
    * This field is only set post-linking.
    */
   unsigned num_uniform_components;

   /**
    * Number of combined uniform components used by this shader.
    *
    * This field is only set post-linking.  It is the sum of the uniform block
    * sizes divided by sizeof(float), and num_uniform_compoennts.
    */
   unsigned num_combined_uniform_components;

   /**
    * This shader's uniform/ssbo block information.
    *
    * These fields are only set post-linking.
    *
    * BufferInterfaceBlocks is a list containing both UBOs and SSBOs. This is
    * useful during the linking process so that we don't have to handle SSBOs
    * specifically.
    *
    * UniformBlocks is a list of UBOs. This is useful for backends that need
    * or prefer to see separate index spaces for UBOS and SSBOs like the GL
    * API specifies.
    *
    * ShaderStorageBlocks is a list of SSBOs. This is useful for backends that
    * need or prefer to see separate index spaces for UBOS and SSBOs like the
    * GL API specifies.
    *
    * UniformBlocks and ShaderStorageBlocks only have pointers into
    * BufferInterfaceBlocks so the actual resource information is not
    * duplicated.
    */
   unsigned NumBufferInterfaceBlocks;
   struct gl_uniform_block *BufferInterfaceBlocks;

   unsigned NumUniformBlocks;
   struct gl_uniform_block **UniformBlocks;

   unsigned NumShaderStorageBlocks;
   struct gl_uniform_block **ShaderStorageBlocks;

   struct exec_list *ir;
   struct exec_list *packed_varyings;
   struct exec_list *fragdata_arrays;
   struct glsl_symbol_table *symbols;

   bool uses_builtin_functions;
   bool uses_gl_fragcoord;
   bool redeclares_gl_fragcoord;
   bool ARB_fragment_coord_conventions_enable;

   /**
    * Fragment shader state from GLSL 1.50 layout qualifiers.
    */
   bool origin_upper_left;
   bool pixel_center_integer;

   /**
    * Tessellation Control shader state from layout qualifiers.
    */
   struct {
      /**
       * 0 - vertices not declared in shader, or
       * 1 .. GL_MAX_PATCH_VERTICES
       */
      GLint VerticesOut;
   } TessCtrl;

   /**
    * Tessellation Evaluation shader state from layout qualifiers.
    */
   struct {
      /**
       * GL_TRIANGLES, GL_QUADS, GL_ISOLINES or PRIM_UNKNOWN if it's not set
       * in this shader.
       */
      GLenum PrimitiveMode;
      /**
       * GL_EQUAL, GL_FRACTIONAL_ODD, GL_FRACTIONAL_EVEN, or 0 if it's not set
       * in this shader.
       */
      GLenum Spacing;
      /**
       * GL_CW, GL_CCW, or 0 if it's not set in this shader.
       */
      GLenum VertexOrder;
      /**
       * 1, 0, or -1 if it's not set in this shader.
       */
      int PointMode;
   } TessEval;

   /**
    * Geometry shader state from GLSL 1.50 layout qualifiers.
    */
   struct {
      GLint VerticesOut;
      /**
       * 0 - Invocations count not declared in shader, or
       * 1 .. MAX_GEOMETRY_SHADER_INVOCATIONS
       */
      GLint Invocations;
      /**
       * GL_POINTS, GL_LINES, GL_LINES_ADJACENCY, GL_TRIANGLES, or
       * GL_TRIANGLES_ADJACENCY, or PRIM_UNKNOWN if it's not set in this
       * shader.
       */
      GLenum InputType;
       /**
        * GL_POINTS, GL_LINE_STRIP or GL_TRIANGLE_STRIP, or PRIM_UNKNOWN if
        * it's not set in this shader.
        */
      GLenum OutputType;
   } Geom;

   /**
    * Map from image uniform index to image unit (set by glUniform1i())
    *
    * An image uniform index is associated with each image uniform by
    * the linker.  The image index associated with each uniform is
    * stored in the \c gl_uniform_storage::image field.
    */
   GLubyte ImageUnits[MAX_IMAGE_UNIFORMS];

   /**
    * Access qualifier specified in the shader for each image uniform
    * index.  Either \c GL_READ_ONLY, \c GL_WRITE_ONLY or \c
    * GL_READ_WRITE.
    *
    * It may be different, though only more strict than the value of
    * \c gl_image_unit::Access for the corresponding image unit.
    */
   GLenum ImageAccess[MAX_IMAGE_UNIFORMS];

   /**
    * Number of image uniforms defined in the shader.  It specifies
    * the number of valid elements in the \c ImageUnits and \c
    * ImageAccess arrays above.
    */
   GLuint NumImages;

   struct gl_active_atomic_buffer **AtomicBuffers;
   unsigned NumAtomicBuffers;

   /**
    * Whether early fragment tests are enabled as defined by
    * ARB_shader_image_load_store.
    */
   bool EarlyFragmentTests;

   /**
    * Compute shader state from ARB_compute_shader layout qualifiers.
    */
   struct {
      /**
       * Size specified using local_size_{x,y,z}, or all 0's to indicate that
       * it's not set in this shader.
       */
      unsigned LocalSize[3];
   } Comp;

   /**
     * Number of types for subroutine uniforms.
     */
   GLuint NumSubroutineUniformTypes;

   /**
     * Subroutine uniform remap table
     * based on the program level uniform remap table.
     */
   GLuint NumSubroutineUniformRemapTable;
   struct gl_uniform_storage **SubroutineUniformRemapTable;

   /**
    * Num of subroutine functions for this stage
    * and storage for them.
    */
   GLuint NumSubroutineFunctions;
   struct gl_subroutine_function *SubroutineFunctions;
};


struct gl_uniform_buffer_variable
{
   char *Name;

   /**
    * Name of the uniform as seen by glGetUniformIndices.
    *
    * glGetUniformIndices requires that the block instance index \b not be
    * present in the name of queried uniforms.
    *
    * \note
    * \c gl_uniform_buffer_variable::IndexName and
    * \c gl_uniform_buffer_variable::Name may point to identical storage.
    */
   char *IndexName;

   const struct glsl_type *Type;
   unsigned int Offset;
   GLboolean RowMajor;
};


enum gl_uniform_block_packing
{
   ubo_packing_std140,
   ubo_packing_shared,
   ubo_packing_packed,
   ubo_packing_std430
};


struct gl_uniform_block
{
   /** Declared name of the uniform block */
   char *Name;

   /** Array of supplemental information about UBO ir_variables. */
   struct gl_uniform_buffer_variable *Uniforms;
   GLuint NumUniforms;

   /**
    * Index (GL_UNIFORM_BLOCK_BINDING) into ctx->UniformBufferBindings[] to use
    * with glBindBufferBase to bind a buffer object to this uniform block.  When
    * updated in the program, _NEW_BUFFER_OBJECT will be set.
    */
   GLuint Binding;

   /**
    * Minimum size (in bytes) of a buffer object to back this uniform buffer
    * (GL_UNIFORM_BLOCK_DATA_SIZE).
    */
   GLuint UniformBufferSize;

   /**
    * Is this actually an interface block for a shader storage buffer?
    */
   bool IsShaderStorage;

   /**
    * Layout specified in the shader
    *
    * This isn't accessible through the API, but it is used while
    * cross-validating uniform blocks.
    */
   enum gl_uniform_block_packing _Packing;
};

/**
 * Structure that represents a reference to an atomic buffer from some
 * shader program.
 */
struct gl_active_atomic_buffer
{
   /** Uniform indices of the atomic counters declared within it. */
   GLuint *Uniforms;
   GLuint NumUniforms;

   /** Binding point index associated with it. */
   GLuint Binding;

   /** Minimum reasonable size it is expected to have. */
   GLuint MinimumSize;

   /** Shader stages making use of it. */
   GLboolean StageReferences[MESA_SHADER_STAGES];
};

/**
 * Active resource in a gl_shader_program
 */
struct gl_program_resource
{
   GLenum Type; /** Program interface type. */
   const void *Data; /** Pointer to resource associated data structure. */
   uint8_t StageReferences; /** Bitmask of shader stage references. */
};

/**
 * A GLSL program object.
 * Basically a linked collection of vertex and fragment shaders.
 */
struct gl_shader_program
{
   GLenum Type;  /**< Always GL_SHADER_PROGRAM (internal token) */
   GLuint Name;  /**< aka handle or ID */
   GLchar *Label;   /**< GL_KHR_debug */
   GLint RefCount;  /**< Reference count */
   GLboolean DeletePending;

   /**
    * Is the application intending to glGetProgramBinary this program?
    */
   GLboolean BinaryRetreivableHint;

   /**
    * Indicates whether program can be bound for individual pipeline stages
    * using UseProgramStages after it is next linked.
    */
   GLboolean SeparateShader;

   GLuint NumShaders;          /**< number of attached shaders */
   struct gl_shader **Shaders; /**< List of attached the shaders */

   /**
    * User-defined attribute bindings
    *
    * These are set via \c glBindAttribLocation and are used to direct the
    * GLSL linker.  These are \b not the values used in the compiled shader,
    * and they are \b not the values returned by \c glGetAttribLocation.
    */
   struct string_to_uint_map *AttributeBindings;

   /**
    * User-defined fragment data bindings
    *
    * These are set via \c glBindFragDataLocation and are used to direct the
    * GLSL linker.  These are \b not the values used in the compiled shader,
    * and they are \b not the values returned by \c glGetFragDataLocation.
    */
   struct string_to_uint_map *FragDataBindings;
   struct string_to_uint_map *FragDataIndexBindings;

   /**
    * Transform feedback varyings last specified by
    * glTransformFeedbackVaryings().
    *
    * For the current set of transform feedback varyings used for transform
    * feedback output, see LinkedTransformFeedback.
    */
   struct {
      GLenum BufferMode;
      GLuint NumVarying;
      GLchar **VaryingNames;  /**< Array [NumVarying] of char * */
   } TransformFeedback;

   /** Post-link transform feedback info. */
   struct gl_transform_feedback_info LinkedTransformFeedback;

   /** Post-link gl_FragDepth layout for ARB_conservative_depth. */
   enum gl_frag_depth_layout FragDepthLayout;

   /**
    * Tessellation Control shader state from layout qualifiers.
    */
   struct {
      /**
       * 0 - vertices not declared in shader, or
       * 1 .. GL_MAX_PATCH_VERTICES
       */
      GLint VerticesOut;
   } TessCtrl;

   /**
    * Tessellation Evaluation shader state from layout qualifiers.
    */
   struct {
      /** GL_TRIANGLES, GL_QUADS or GL_ISOLINES */
      GLenum PrimitiveMode;
      /** GL_EQUAL, GL_FRACTIONAL_ODD or GL_FRACTIONAL_EVEN */
      GLenum Spacing;
      /** GL_CW or GL_CCW */
      GLenum VertexOrder;
      bool PointMode;
      /**
       * True if gl_ClipDistance is written to.  Copied into
       * gl_tess_eval_program by _mesa_copy_linked_program_data().
       */
      GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                         0 if not present. */
   } TessEval;

   /**
    * Geometry shader state - copied into gl_geometry_program by
    * _mesa_copy_linked_program_data().
    */
   struct {
      GLint VerticesIn;
      GLint VerticesOut;
      /**
       * 1 .. MAX_GEOMETRY_SHADER_INVOCATIONS
       */
      GLint Invocations;
      GLenum InputType;  /**< GL_POINTS, GL_LINES, GL_LINES_ADJACENCY_ARB,
                              GL_TRIANGLES, or GL_TRIANGLES_ADJACENCY_ARB */
      GLenum OutputType; /**< GL_POINTS, GL_LINE_STRIP or GL_TRIANGLE_STRIP */
      /**
       * True if gl_ClipDistance is written to.  Copied into
       * gl_geometry_program by _mesa_copy_linked_program_data().
       */
      GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                         0 if not present. */
      bool UsesEndPrimitive;
      bool UsesStreams;
   } Geom;

   /** Vertex shader state */
   struct {
      /**
       * True if gl_ClipDistance is written to.  Copied into gl_vertex_program
       * by _mesa_copy_linked_program_data().
       */
      GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                         0 if not present. */
   } Vert;

   /**
    * Compute shader state - copied into gl_compute_program by
    * _mesa_copy_linked_program_data().
    */
   struct {
      /**
       * If this shader contains a compute stage, size specified using
       * local_size_{x,y,z}.  Otherwise undefined.
       */
      unsigned LocalSize[3];
   } Comp;

   /* post-link info: */
   unsigned NumUniformStorage;
   unsigned NumHiddenUniforms;
   struct gl_uniform_storage *UniformStorage;

   /**
    * Mapping from GL uniform locations returned by \c glUniformLocation to
    * UniformStorage entries. Arrays will have multiple contiguous slots
    * in the UniformRemapTable, all pointing to the same UniformStorage entry.
    */
   unsigned NumUniformRemapTable;
   struct gl_uniform_storage **UniformRemapTable;

   /**
    * Size of the gl_ClipDistance array that is output from the last pipeline
    * stage before the fragment shader.
    */
   unsigned LastClipDistanceArraySize;

   /**
    * This shader's uniform/ssbo block information.
    *
    * BufferInterfaceBlocks is a list containing both UBOs and SSBOs. This is
    * useful during the linking process so that we don't have to handle SSBOs
    * specifically.
    *
    * UniformBlocks is a list of UBOs. This is useful for backends that need
    * or prefer to see separate index spaces for UBOS and SSBOs like the GL
    * API specifies.
    *
    * ShaderStorageBlocks is a list of SSBOs. This is useful for backends that
    * need or prefer to see separate index spaces for UBOS and SSBOs like the
    * GL API specifies.
    *
    * UniformBlocks and ShaderStorageBlocks only have pointers into
    * BufferInterfaceBlocks so the actual resource information is not
    * duplicated and are only set after linking.
    */
   unsigned NumBufferInterfaceBlocks;
   struct gl_uniform_block *BufferInterfaceBlocks;

   unsigned NumUniformBlocks;
   struct gl_uniform_block **UniformBlocks;

   unsigned NumShaderStorageBlocks;
   struct gl_uniform_block **ShaderStorageBlocks;

   /**
    * Indices into the BufferInterfaceBlocks[] array for each stage they're
    * used in, or -1.
    *
    * This is used to maintain the Binding values of the stage's
    * BufferInterfaceBlocks[] and to answer the
    * GL_UNIFORM_BLOCK_REFERENCED_BY_*_SHADER queries.
    */
   int *InterfaceBlockStageIndex[MESA_SHADER_STAGES];

   /**
    * Map of active uniform names to locations
    *
    * Maps any active uniform that is not an array element to a location.
    * Each active uniform, including individual structure members will appear
    * in this map.  This roughly corresponds to the set of names that would be
    * enumerated by \c glGetActiveUniform.
    */
   struct string_to_uint_map *UniformHash;

   struct gl_active_atomic_buffer *AtomicBuffers;
   unsigned NumAtomicBuffers;

   GLboolean LinkStatus;   /**< GL_LINK_STATUS */
   GLboolean Validated;
   GLboolean _Used;        /**< Ever used for drawing? */
   GLboolean SamplersValidated; /**< Samplers validated against texture units? */
   GLchar *InfoLog;

   unsigned Version;       /**< GLSL version used for linking */
   bool IsES;              /**< True if this program uses GLSL ES */

   /**
    * Per-stage shaders resulting from the first stage of linking.
    *
    * Set of linked shaders for this program.  The array is accessed using the
    * \c MESA_SHADER_* defines.  Entries for non-existent stages will be
    * \c NULL.
    */
   struct gl_shader *_LinkedShaders[MESA_SHADER_STAGES];

   /** List of all active resources after linking. */
   struct gl_program_resource *ProgramResourceList;
   unsigned NumProgramResourceList;

   /* True if any of the fragment shaders attached to this program use:
    * #extension ARB_fragment_coord_conventions: enable
    */
   GLboolean ARB_fragment_coord_conventions_enable;
};   


#define GLSL_DUMP      0x1  /**< Dump shaders to stdout */
#define GLSL_LOG       0x2  /**< Write shaders to files */
#define GLSL_OPT       0x4  /**< Force optimizations (override pragmas) */
#define GLSL_NO_OPT    0x8  /**< Force no optimizations (override pragmas) */
#define GLSL_UNIFORMS 0x10  /**< Print glUniform calls */
#define GLSL_NOP_VERT 0x20  /**< Force no-op vertex shaders */
#define GLSL_NOP_FRAG 0x40  /**< Force no-op fragment shaders */
#define GLSL_USE_PROG 0x80  /**< Log glUseProgram calls */
#define GLSL_REPORT_ERRORS 0x100  /**< Print compilation errors */
#define GLSL_DUMP_ON_ERROR 0x200 /**< Dump shaders to stderr on compile error */


/**
 * Context state for GLSL vertex/fragment shaders.
 * Extended to support pipeline object
 */
struct gl_pipeline_object
{
   /** Name of the pipeline object as received from glGenProgramPipelines.
    * It would be 0 for shaders without separate shader objects.
    */
   GLuint Name;

   GLint RefCount;

   mtx_t Mutex;

   GLchar *Label;   /**< GL_KHR_debug */

   /**
    * Programs used for rendering
    *
    * There is a separate program set for each shader stage.
    */
   struct gl_shader_program *CurrentProgram[MESA_SHADER_STAGES];

   struct gl_shader_program *_CurrentFragmentProgram;

   /**
    * Program used by glUniform calls.
    *
    * Explicitly set by \c glUseProgram and \c glActiveProgramEXT.
    */
   struct gl_shader_program *ActiveProgram;

   GLbitfield Flags;                    /**< Mask of GLSL_x flags */

   GLboolean EverBound;                 /**< Has the pipeline object been created */

   GLboolean Validated;                 /**< Pipeline Validation status */

   GLchar *InfoLog;
};

/**
 * Context state for GLSL pipeline shaders.
 */
struct gl_pipeline_shader_state
{
   /** Currently bound pipeline object. See _mesa_BindProgramPipeline() */
   struct gl_pipeline_object *Current;

   /* Default Object to ensure that _Shader is never NULL */
   struct gl_pipeline_object *Default;

   /** Pipeline objects */
   struct _mesa_HashTable *Objects;
};

/**
 * Compiler options for a single GLSL shaders type
 */
struct gl_shader_compiler_options
{
   /** Driver-selectable options: */
   GLboolean EmitCondCodes;             /**< Use condition codes? */
   GLboolean EmitNoLoops;
   GLboolean EmitNoFunctions;
   GLboolean EmitNoCont;                  /**< Emit CONT opcode? */
   GLboolean EmitNoMainReturn;            /**< Emit CONT/RET opcodes? */
   GLboolean EmitNoNoise;                 /**< Emit NOISE opcodes? */
   GLboolean EmitNoPow;                   /**< Emit POW opcodes? */
   GLboolean EmitNoSat;                   /**< Emit SAT opcodes? */
   GLboolean LowerClipDistance; /**< Lower gl_ClipDistance from float[8] to vec4[2]? */

   /**
    * \name Forms of indirect addressing the driver cannot do.
    */
   /*@{*/
   GLboolean EmitNoIndirectInput;   /**< No indirect addressing of inputs */
   GLboolean EmitNoIndirectOutput;  /**< No indirect addressing of outputs */
   GLboolean EmitNoIndirectTemp;    /**< No indirect addressing of temps */
   GLboolean EmitNoIndirectUniform; /**< No indirect addressing of constants */
   GLboolean EmitNoIndirectSampler; /**< No indirect addressing of samplers */
   /*@}*/

   GLuint MaxIfDepth;               /**< Maximum nested IF blocks */
   GLuint MaxUnrollIterations;

   /**
    * Optimize code for array of structures backends.
    *
    * This is a proxy for:
    *   - preferring DP4 instructions (rather than MUL/MAD) for
    *     matrix * vector operations, such as position transformation.
    */
   GLboolean OptimizeForAOS;

   GLboolean LowerBufferInterfaceBlocks; /**< Lower UBO and SSBO access to intrinsics. */

   const struct nir_shader_compiler_options *NirOptions;
};


/**
 * Occlusion/timer query object.
 */
struct gl_query_object
{
   GLenum Target;      /**< The query target, when active */
   GLuint Id;          /**< hash table ID/name */
   GLchar *Label;       /**< GL_KHR_debug */
   GLuint64EXT Result; /**< the counter */
   GLboolean Active;   /**< inside Begin/EndQuery */
   GLboolean Ready;    /**< result is ready? */
   GLboolean EverBound;/**< has query object ever been bound */
   GLuint Stream;      /**< The stream */
};


/**
 * Context state for query objects.
 */
struct gl_query_state
{
   struct _mesa_HashTable *QueryObjects;
   struct gl_query_object *CurrentOcclusionObject; /* GL_ARB_occlusion_query */
   struct gl_query_object *CurrentTimerObject;     /* GL_EXT_timer_query */

   /** GL_NV_conditional_render */
   struct gl_query_object *CondRenderQuery;

   /** GL_EXT_transform_feedback */
   struct gl_query_object *PrimitivesGenerated[MAX_VERTEX_STREAMS];
   struct gl_query_object *PrimitivesWritten[MAX_VERTEX_STREAMS];

   /** GL_ARB_timer_query */
   struct gl_query_object *TimeElapsed;

   /** GL_ARB_pipeline_statistics_query */
   struct gl_query_object *pipeline_stats[MAX_PIPELINE_STATISTICS];

   GLenum CondRenderMode;
};


/** Sync object state */
struct gl_sync_object
{
   GLenum Type;               /**< GL_SYNC_FENCE */
   GLuint Name;               /**< Fence name */
   GLchar *Label;             /**< GL_KHR_debug */
   GLint RefCount;            /**< Reference count */
   GLboolean DeletePending;   /**< Object was deleted while there were still
                               * live references (e.g., sync not yet finished)
                               */
   GLenum SyncCondition;
   GLbitfield Flags;          /**< Flags passed to glFenceSync */
   GLuint StatusFlag:1;       /**< Has the sync object been signaled? */
};


/**
 * State which can be shared by multiple contexts:
 */
struct gl_shared_state
{
   mtx_t Mutex;            /**< for thread safety */
   GLint RefCount;                         /**< Reference count */
   struct _mesa_HashTable *DisplayList;    /**< Display lists hash table */
   struct _mesa_HashTable *TexObjects;     /**< Texture objects hash table */

   /** Default texture objects (shared by all texture units) */
   struct gl_texture_object *DefaultTex[NUM_TEXTURE_TARGETS];

   /** Fallback texture used when a bound texture is incomplete */
   struct gl_texture_object *FallbackTex[NUM_TEXTURE_TARGETS];

   /**
    * \name Thread safety and statechange notification for texture
    * objects. 
    *
    * \todo Improve the granularity of locking.
    */
   /*@{*/
   mtx_t TexMutex;              /**< texobj thread safety */
   GLuint TextureStateStamp;            /**< state notification for shared tex */
   /*@}*/

   /** Default buffer object for vertex arrays that aren't in VBOs */
   struct gl_buffer_object *NullBufferObj;

   /**
    * \name Vertex/geometry/fragment programs
    */
   /*@{*/
   struct _mesa_HashTable *Programs; /**< All vertex/fragment programs */
   struct gl_vertex_program *DefaultVertexProgram;
   struct gl_fragment_program *DefaultFragmentProgram;
   /*@}*/

   /* GL_ATI_fragment_shader */
   struct _mesa_HashTable *ATIShaders;
   struct ati_fragment_shader *DefaultFragmentShader;

   struct _mesa_HashTable *BufferObjects;

   /** Table of both gl_shader and gl_shader_program objects */
   struct _mesa_HashTable *ShaderObjects;

   /* GL_EXT_framebuffer_object */
   struct _mesa_HashTable *RenderBuffers;
   struct _mesa_HashTable *FrameBuffers;

   /* GL_ARB_sync */
   struct set *SyncObjects;

   /** GL_ARB_sampler_objects */
   struct _mesa_HashTable *SamplerObjects;

   /**
    * Some context in this share group was affected by a GPU reset
    *
    * On the next call to \c glGetGraphicsResetStatus, contexts that have not
    * been affected by a GPU reset must also return
    * \c GL_INNOCENT_CONTEXT_RESET_ARB.
    *
    * Once this field becomes true, it is never reset to false.
    */
   bool ShareGroupReset;
};



/**
 * Renderbuffers represent drawing surfaces such as color, depth and/or
 * stencil.  A framebuffer object has a set of renderbuffers.
 * Drivers will typically derive subclasses of this type.
 */
struct gl_renderbuffer
{
   mtx_t Mutex; /**< for thread safety */
   GLuint ClassID;        /**< Useful for drivers */
   GLuint Name;
   GLchar *Label;         /**< GL_KHR_debug */
   GLint RefCount;
   GLuint Width, Height;
   GLuint Depth;
   GLboolean Purgeable;  /**< Is the buffer purgeable under memory pressure? */
   GLboolean AttachedAnytime; /**< TRUE if it was attached to a framebuffer */
   /**
    * True for renderbuffers that wrap textures, giving the driver a chance to
    * flush render caches through the FinishRenderTexture hook.
    *
    * Drivers may also set this on renderbuffers other than those generated by
    * glFramebufferTexture(), though it means FinishRenderTexture() would be
    * called without a rb->TexImage.
    */
   GLboolean NeedsFinishRenderTexture;
   GLubyte NumSamples;
   GLenum InternalFormat; /**< The user-specified format */
   GLenum _BaseFormat;    /**< Either GL_RGB, GL_RGBA, GL_DEPTH_COMPONENT or
                               GL_STENCIL_INDEX. */
   mesa_format Format;      /**< The actual renderbuffer memory format */
   /**
    * Pointer to the texture image if this renderbuffer wraps a texture,
    * otherwise NULL.
    *
    * Note that the reference on the gl_texture_object containing this
    * TexImage is held by the gl_renderbuffer_attachment.
    */
   struct gl_texture_image *TexImage;

   /** Delete this renderbuffer */
   void (*Delete)(struct gl_context *ctx, struct gl_renderbuffer *rb);

   /** Allocate new storage for this renderbuffer */
   GLboolean (*AllocStorage)(struct gl_context *ctx,
                             struct gl_renderbuffer *rb,
                             GLenum internalFormat,
                             GLuint width, GLuint height);
};


/**
 * A renderbuffer attachment points to either a texture object (and specifies
 * a mipmap level, cube face or 3D texture slice) or points to a renderbuffer.
 */
struct gl_renderbuffer_attachment
{
   GLenum Type;  /**< \c GL_NONE or \c GL_TEXTURE or \c GL_RENDERBUFFER_EXT */
   GLboolean Complete;

   /**
    * If \c Type is \c GL_RENDERBUFFER_EXT, this stores a pointer to the
    * application supplied renderbuffer object.
    */
   struct gl_renderbuffer *Renderbuffer;

   /**
    * If \c Type is \c GL_TEXTURE, this stores a pointer to the application
    * supplied texture object.
    */
   struct gl_texture_object *Texture;
   GLuint TextureLevel; /**< Attached mipmap level. */
   GLuint CubeMapFace;  /**< 0 .. 5, for cube map textures. */
   GLuint Zoffset;      /**< Slice for 3D textures,  or layer for both 1D
                         * and 2D array textures */
   GLboolean Layered;
};


/**
 * A framebuffer is a collection of renderbuffers (color, depth, stencil, etc).
 * In C++ terms, think of this as a base class from which device drivers
 * will make derived classes.
 */
struct gl_framebuffer
{
   mtx_t Mutex;  /**< for thread safety */
   /**
    * If zero, this is a window system framebuffer.  If non-zero, this
    * is a FBO framebuffer; note that for some devices (i.e. those with
    * a natural pixel coordinate system for FBOs that differs from the
    * OpenGL/Mesa coordinate system), this means that the viewport,
    * polygon face orientation, and polygon stipple will have to be inverted.
    */
   GLuint Name;
   GLint RefCount;

   GLchar *Label;       /**< GL_KHR_debug */

   GLboolean DeletePending;

   /**
    * The framebuffer's visual. Immutable if this is a window system buffer.
    * Computed from attachments if user-made FBO.
    */
   struct gl_config Visual;

   /**
    * Size of frame buffer in pixels. If there are no attachments, then both
    * of these are 0.
    */
   GLuint Width, Height;

   /**
    * In the case that the framebuffer has no attachment (i.e.
    * GL_ARB_framebuffer_no_attachments) then the geometry of
    * the framebuffer is specified by the default values.
    */
   struct {
     GLuint Width, Height, Layers, NumSamples;
     GLboolean FixedSampleLocations;
   } DefaultGeometry;

   /** \name  Drawing bounds (Intersection of buffer size and scissor box)
    * The drawing region is given by [_Xmin, _Xmax) x [_Ymin, _Ymax),
    * (inclusive for _Xmin and _Ymin while exclusive for _Xmax and _Ymax)
    */
   /*@{*/
   GLint _Xmin, _Xmax;
   GLint _Ymin, _Ymax;
   /*@}*/

   /** \name  Derived Z buffer stuff */
   /*@{*/
   GLuint _DepthMax;    /**< Max depth buffer value */
   GLfloat _DepthMaxF;  /**< Float max depth buffer value */
   GLfloat _MRD;        /**< minimum resolvable difference in Z values */
   /*@}*/

   /** One of the GL_FRAMEBUFFER_(IN)COMPLETE_* tokens */
   GLenum _Status;

   /** Whether one of Attachment has Type != GL_NONE
    * NOTE: the values for Width and Height are set to 0 in case of having
    * no attachments, a backend driver supporting the extension
    * GL_ARB_framebuffer_no_attachments must check for the flag _HasAttachments
    * and if GL_FALSE, must then use the values in DefaultGeometry to initialize
    * its viewport, scissor and so on (in particular _Xmin, _Xmax, _Ymin and
    * _Ymax do NOT take into account _HasAttachments being false). To get the
    * geometry of the framebuffer, the  helper functions
    *   _mesa_geometric_width(),
    *   _mesa_geometric_height(),
    *   _mesa_geometric_samples() and
    *   _mesa_geometric_layers()
    * are available that check _HasAttachments.
    */
   bool _HasAttachments;

   /** Integer color values */
   GLboolean _IntegerColor;

   /* ARB_color_buffer_float */
   GLboolean _AllColorBuffersFixedPoint; /* no integer, no float */
   GLboolean _HasSNormOrFloatColorBuffer;

   /**
    * The maximum number of layers in the framebuffer, or 0 if the framebuffer
    * is not layered.  For cube maps and cube map arrays, each cube face
    * counts as a layer. As the case for Width, Height a backend driver
    * supporting GL_ARB_framebuffer_no_attachments must use DefaultGeometry
    * in the case that _HasAttachments is false
    */
   GLuint MaxNumLayers;

   /** Array of all renderbuffer attachments, indexed by BUFFER_* tokens. */
   struct gl_renderbuffer_attachment Attachment[BUFFER_COUNT];

   /* In unextended OpenGL these vars are part of the GL_COLOR_BUFFER
    * attribute group and GL_PIXEL attribute group, respectively.
    */
   GLenum ColorDrawBuffer[MAX_DRAW_BUFFERS];
   GLenum ColorReadBuffer;

   /** Computed from ColorDraw/ReadBuffer above */
   GLuint _NumColorDrawBuffers;
   GLint _ColorDrawBufferIndexes[MAX_DRAW_BUFFERS]; /**< BUFFER_x or -1 */
   GLint _ColorReadBufferIndex; /* -1 = None */
   struct gl_renderbuffer *_ColorDrawBuffers[MAX_DRAW_BUFFERS];
   struct gl_renderbuffer *_ColorReadBuffer;

   /** Delete this framebuffer */
   void (*Delete)(struct gl_framebuffer *fb);
};


/**
 * Precision info for shader datatypes.  See glGetShaderPrecisionFormat().
 */
struct gl_precision
{
   GLushort RangeMin;   /**< min value exponent */
   GLushort RangeMax;   /**< max value exponent */
   GLushort Precision;  /**< number of mantissa bits */
};


/**
 * Limits for vertex, geometry and fragment programs/shaders.
 */
struct gl_program_constants
{
   /* logical limits */
   GLuint MaxInstructions;
   GLuint MaxAluInstructions;
   GLuint MaxTexInstructions;
   GLuint MaxTexIndirections;
   GLuint MaxAttribs;
   GLuint MaxTemps;
   GLuint MaxAddressRegs;
   GLuint MaxAddressOffset;  /**< [-MaxAddressOffset, MaxAddressOffset-1] */
   GLuint MaxParameters;
   GLuint MaxLocalParams;
   GLuint MaxEnvParams;
   /* native/hardware limits */
   GLuint MaxNativeInstructions;
   GLuint MaxNativeAluInstructions;
   GLuint MaxNativeTexInstructions;
   GLuint MaxNativeTexIndirections;
   GLuint MaxNativeAttribs;
   GLuint MaxNativeTemps;
   GLuint MaxNativeAddressRegs;
   GLuint MaxNativeParameters;
   /* For shaders */
   GLuint MaxUniformComponents;  /**< Usually == MaxParameters * 4 */

   /**
    * \name Per-stage input / output limits
    *
    * Previous to OpenGL 3.2, the intrastage data limits were advertised with
    * a single value: GL_MAX_VARYING_COMPONENTS (GL_MAX_VARYING_VECTORS in
    * ES).  This is stored as \c gl_constants::MaxVarying.
    *
    * Starting with OpenGL 3.2, the limits are advertised with per-stage
    * variables.  Each stage as a certain number of outputs that it can feed
    * to the next stage and a certain number inputs that it can consume from
    * the previous stage.
    *
    * Vertex shader inputs do not participate this in this accounting.
    * These are tracked exclusively by \c gl_program_constants::MaxAttribs.
    *
    * Fragment shader outputs do not participate this in this accounting.
    * These are tracked exclusively by \c gl_constants::MaxDrawBuffers.
    */
   /*@{*/
   GLuint MaxInputComponents;
   GLuint MaxOutputComponents;
   /*@}*/

   /* ES 2.0 and GL_ARB_ES2_compatibility */
   struct gl_precision LowFloat, MediumFloat, HighFloat;
   struct gl_precision LowInt, MediumInt, HighInt;
   /* GL_ARB_uniform_buffer_object */
   GLuint MaxUniformBlocks;
   GLuint MaxCombinedUniformComponents;
   GLuint MaxTextureImageUnits;

   /* GL_ARB_shader_atomic_counters */
   GLuint MaxAtomicBuffers;
   GLuint MaxAtomicCounters;

   /* GL_ARB_shader_image_load_store */
   GLuint MaxImageUniforms;

   /* GL_ARB_shader_storage_buffer_object */
   GLuint MaxShaderStorageBlocks;
};


/**
 * Constants which may be overridden by device driver during context creation
 * but are never changed after that.
 */
struct gl_constants
{
   GLuint MaxTextureMbytes;      /**< Max memory per image, in MB */
   GLuint MaxTextureLevels;      /**< Max mipmap levels. */ 
   GLuint Max3DTextureLevels;    /**< Max mipmap levels for 3D textures */
   GLuint MaxCubeTextureLevels;  /**< Max mipmap levels for cube textures */
   GLuint MaxArrayTextureLayers; /**< Max layers in array textures */
   GLuint MaxTextureRectSize;    /**< Max rectangle texture size, in pixes */
   GLuint MaxTextureCoordUnits;
   GLuint MaxCombinedTextureImageUnits;
   GLuint MaxTextureUnits; /**< = MIN(CoordUnits, FragmentProgram.ImageUnits) */
   GLfloat MaxTextureMaxAnisotropy;  /**< GL_EXT_texture_filter_anisotropic */
   GLfloat MaxTextureLodBias;        /**< GL_EXT_texture_lod_bias */
   GLuint MaxTextureBufferSize;      /**< GL_ARB_texture_buffer_object */

   GLuint TextureBufferOffsetAlignment; /**< GL_ARB_texture_buffer_range */

   GLuint MaxArrayLockSize;

   GLint SubPixelBits;

   GLfloat MinPointSize, MaxPointSize;       /**< aliased */
   GLfloat MinPointSizeAA, MaxPointSizeAA;   /**< antialiased */
   GLfloat PointSizeGranularity;
   GLfloat MinLineWidth, MaxLineWidth;       /**< aliased */
   GLfloat MinLineWidthAA, MaxLineWidthAA;   /**< antialiased */
   GLfloat LineWidthGranularity;

   GLuint MaxClipPlanes;
   GLuint MaxLights;
   GLfloat MaxShininess;                     /**< GL_NV_light_max_exponent */
   GLfloat MaxSpotExponent;                  /**< GL_NV_light_max_exponent */

   GLuint MaxViewportWidth, MaxViewportHeight;
   GLuint MaxViewports;                      /**< GL_ARB_viewport_array */
   GLuint ViewportSubpixelBits;              /**< GL_ARB_viewport_array */
   struct {
      GLfloat Min;
      GLfloat Max;
   } ViewportBounds;                         /**< GL_ARB_viewport_array */

   struct gl_program_constants Program[MESA_SHADER_STAGES];
   GLuint MaxProgramMatrices;
   GLuint MaxProgramMatrixStackDepth;

   struct {
      GLuint SamplesPassed;
      GLuint TimeElapsed;
      GLuint Timestamp;
      GLuint PrimitivesGenerated;
      GLuint PrimitivesWritten;
      GLuint VerticesSubmitted;
      GLuint PrimitivesSubmitted;
      GLuint VsInvocations;
      GLuint TessPatches;
      GLuint TessInvocations;
      GLuint GsInvocations;
      GLuint GsPrimitives;
      GLuint FsInvocations;
      GLuint ComputeInvocations;
      GLuint ClInPrimitives;
      GLuint ClOutPrimitives;
   } QueryCounterBits;

   GLuint MaxDrawBuffers;    /**< GL_ARB_draw_buffers */

   GLuint MaxColorAttachments;   /**< GL_EXT_framebuffer_object */
   GLuint MaxRenderbufferSize;   /**< GL_EXT_framebuffer_object */
   GLuint MaxSamples;            /**< GL_ARB_framebuffer_object */

   /**
    * GL_ARB_framebuffer_no_attachments
    */
   GLuint MaxFramebufferWidth;
   GLuint MaxFramebufferHeight;
   GLuint MaxFramebufferLayers;
   GLuint MaxFramebufferSamples;

   /** Number of varying vectors between any two shader stages. */
   GLuint MaxVarying;

   /** @{
    * GL_ARB_uniform_buffer_object
    */
   GLuint MaxCombinedUniformBlocks;
   GLuint MaxUniformBufferBindings;
   GLuint MaxUniformBlockSize;
   GLuint UniformBufferOffsetAlignment;
   /** @} */

   /** @{
    * GL_ARB_shader_storage_buffer_object
    */
   GLuint MaxCombinedShaderStorageBlocks;
   GLuint MaxShaderStorageBufferBindings;
   GLuint MaxShaderStorageBlockSize;
   GLuint ShaderStorageBufferOffsetAlignment;
   /** @} */

   /**
    * GL_ARB_explicit_uniform_location
    */
   GLuint MaxUserAssignableUniformLocations;

   /** geometry shader */
   GLuint MaxGeometryOutputVertices;
   GLuint MaxGeometryTotalOutputComponents;

   GLuint GLSLVersion;  /**< Desktop GLSL version supported (ex: 120 = 1.20) */

   /**
    * Changes default GLSL extension behavior from "error" to "warn".  It's out
    * of spec, but it can make some apps work that otherwise wouldn't.
    */
   GLboolean ForceGLSLExtensionsWarn;

   /**
    * If non-zero, forces GLSL shaders to behave as if they began
    * with "#version ForceGLSLVersion".
    */
   GLuint ForceGLSLVersion;

   /**
    * Allow GLSL #extension directives in the middle of shaders.
    */
   GLboolean AllowGLSLExtensionDirectiveMidShader;

   /**
    * Does the driver support real 32-bit integers?  (Otherwise, integers are
    * simulated via floats.)
    */
   GLboolean NativeIntegers;

   /**
    * Does VertexID count from zero or from base vertex?
    *
    * \note
    * If desktop GLSL 1.30 or GLSL ES 3.00 are not supported, this field is
    * ignored and need not be set.
    */
   bool VertexID_is_zero_based;

   /**
    * If the driver supports real 32-bit integers, what integer value should be
    * used for boolean true in uniform uploads?  (Usually 1 or ~0.)
    */
   GLuint UniformBooleanTrue;

   /**
    * Maximum amount of time, measured in nanseconds, that the server can wait.
    */
   GLuint64 MaxServerWaitTimeout;

   /** GL_EXT_provoking_vertex */
   GLboolean QuadsFollowProvokingVertexConvention;

   /** GL_ARB_viewport_array */
   GLenum LayerAndVPIndexProvokingVertex;

   /** OpenGL version 3.0 */
   GLbitfield ContextFlags;  /**< Ex: GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT */

   /** OpenGL version 3.2 */
   GLbitfield ProfileMask;   /**< Mask of CONTEXT_x_PROFILE_BIT */

   /** OpenGL version 4.4 */
   GLuint MaxVertexAttribStride;

   /** GL_EXT_transform_feedback */
   GLuint MaxTransformFeedbackBuffers;
   GLuint MaxTransformFeedbackSeparateComponents;
   GLuint MaxTransformFeedbackInterleavedComponents;
   GLuint MaxVertexStreams;

   /** GL_EXT_gpu_shader4 */
   GLint MinProgramTexelOffset, MaxProgramTexelOffset;

   /** GL_ARB_texture_gather */
   GLuint MinProgramTextureGatherOffset;
   GLuint MaxProgramTextureGatherOffset;
   GLuint MaxProgramTextureGatherComponents;

   /* GL_ARB_robustness */
   GLenum ResetStrategy;

   /* GL_ARB_blend_func_extended */
   GLuint MaxDualSourceDrawBuffers;

   /**
    * Whether the implementation strips out and ignores texture borders.
    *
    * Many GPU hardware implementations don't support rendering with texture
    * borders and mipmapped textures.  (Note: not static border color, but the
    * old 1-pixel border around each edge).  Implementations then have to do
    * slow fallbacks to be correct, or just ignore the border and be fast but
    * wrong.  Setting the flag strips the border off of TexImage calls,
    * providing "fast but wrong" at significantly reduced driver complexity.
    *
    * Texture borders are deprecated in GL 3.0.
    **/
   GLboolean StripTextureBorder;

   /**
    * For drivers which can do a better job at eliminating unused uniforms
    * than the GLSL compiler.
    *
    * XXX Remove these as soon as a better solution is available.
    */
   GLboolean GLSLSkipStrictMaxUniformLimitCheck;

   /**
    * Always use the GetTransformFeedbackVertexCount() driver hook, rather
    * than passing the transform feedback object to the drawing function.
    */
   GLboolean AlwaysUseGetTransformFeedbackVertexCount;

   /** GL_ARB_map_buffer_alignment */
   GLuint MinMapBufferAlignment;

   /**
    * Disable varying packing.  This is out of spec, but potentially useful
    * for older platforms that supports a limited number of texture
    * indirections--on these platforms, unpacking the varyings in the fragment
    * shader increases the number of texture indirections by 1, which might
    * make some shaders not executable at all.
    *
    * Drivers that support transform feedback must set this value to GL_FALSE.
    */
   GLboolean DisableVaryingPacking;

   /**
    * Should meaningful names be generated for compiler temporary variables?
    *
    * Generally, it is not useful to have the compiler generate "meaningful"
    * names for temporary variables that it creates.  This can, however, be a
    * useful debugging aid.  In Mesa debug builds or release builds when
    * MESA_GLSL is set at run-time, meaningful names will be generated.
    * Drivers can also force names to be generated by setting this field.
    * For example, the i965 driver may set it when INTEL_DEBUG=vs (to dump
    * vertex shader assembly) is set at run-time.
    */
   bool GenerateTemporaryNames;

   /*
    * Maximum value supported for an index in DrawElements and friends.
    *
    * This must be at least (1ull<<24)-1.  The default value is
    * (1ull<<32)-1.
    *
    * \since ES 3.0 or GL_ARB_ES3_compatibility
    * \sa _mesa_init_constants
    */
   GLuint64 MaxElementIndex;

   /**
    * Disable interpretation of line continuations (lines ending with a
    * backslash character ('\') in GLSL source.
    */
   GLboolean DisableGLSLLineContinuations;

   /** GL_ARB_texture_multisample */
   GLint MaxColorTextureSamples;
   GLint MaxDepthTextureSamples;
   GLint MaxIntegerSamples;

   /**
    * GL_EXT_texture_multisample_blit_scaled implementation assumes that
    * samples are laid out in a rectangular grid roughly corresponding to
    * sample locations within a pixel. Below SampleMap{2,4,8}x variables
    * are used to map indices of rectangular grid to sample numbers within
    * a pixel. This mapping of indices to sample numbers must be initialized
    * by the driver for the target hardware. For example, if we have the 8X
    * MSAA sample number layout (sample positions) for XYZ hardware:
    *
    *        sample indices layout          sample number layout
    *            ---------                      ---------
    *            | 0 | 1 |                      | a | b |
    *            ---------                      ---------
    *            | 2 | 3 |                      | c | d |
    *            ---------                      ---------
    *            | 4 | 5 |                      | e | f |
    *            ---------                      ---------
    *            | 6 | 7 |                      | g | h |
    *            ---------                      ---------
    *
    * Where a,b,c,d,e,f,g,h are integers between [0-7].
    *
    * Then, initialize the SampleMap8x variable for XYZ hardware as shown
    * below:
    *    SampleMap8x = {a, b, c, d, e, f, g, h};
    *
    * Follow the logic for sample counts 2-8.
    *
    * For 16x the sample indices layout as a 4x4 grid as follows:
    *
    *            -----------------
    *            | 0 | 1 | 2 | 3 |
    *            -----------------
    *            | 4 | 5 | 6 | 7 |
    *            -----------------
    *            | 8 | 9 |10 |11 |
    *            -----------------
    *            |12 |13 |14 |15 |
    *            -----------------
    */
   uint8_t SampleMap2x[2];
   uint8_t SampleMap4x[4];
   uint8_t SampleMap8x[8];
   uint8_t SampleMap16x[16];

   /** GL_ARB_shader_atomic_counters */
   GLuint MaxAtomicBufferBindings;
   GLuint MaxAtomicBufferSize;
   GLuint MaxCombinedAtomicBuffers;
   GLuint MaxCombinedAtomicCounters;

   /** GL_ARB_vertex_attrib_binding */
   GLint MaxVertexAttribRelativeOffset;
   GLint MaxVertexAttribBindings;

   /* GL_ARB_shader_image_load_store */
   GLuint MaxImageUnits;
   GLuint MaxCombinedShaderOutputResources;
   GLuint MaxImageSamples;
   GLuint MaxCombinedImageUniforms;

   /** GL_ARB_compute_shader */
   GLuint MaxComputeWorkGroupCount[3]; /* Array of x, y, z dimensions */
   GLuint MaxComputeWorkGroupSize[3]; /* Array of x, y, z dimensions */
   GLuint MaxComputeWorkGroupInvocations;

   /** GL_ARB_gpu_shader5 */
   GLfloat MinFragmentInterpolationOffset;
   GLfloat MaxFragmentInterpolationOffset;

   GLboolean FakeSWMSAA;

   /** GL_KHR_context_flush_control */
   GLenum ContextReleaseBehavior;

   struct gl_shader_compiler_options ShaderCompilerOptions[MESA_SHADER_STAGES];

   /** GL_ARB_tessellation_shader */
   GLuint MaxPatchVertices;
   GLuint MaxTessGenLevel;
   GLuint MaxTessPatchComponents;
   GLuint MaxTessControlTotalOutputComponents;
   bool LowerTessLevel; /**< Lower gl_TessLevel* from float[n] to vecn? */
};


/**
 * Enable flag for each OpenGL extension.  Different device drivers will
 * enable different extensions at runtime.
 */
struct gl_extensions
{
   GLboolean dummy;  /* don't remove this! */
   GLboolean dummy_true;  /* Set true by _mesa_init_extensions(). */
   GLboolean dummy_false; /* Set false by _mesa_init_extensions(). */
   GLboolean ANGLE_texture_compression_dxt;
   GLboolean ARB_ES2_compatibility;
   GLboolean ARB_ES3_compatibility;
   GLboolean ARB_arrays_of_arrays;
   GLboolean ARB_base_instance;
   GLboolean ARB_blend_func_extended;
   GLboolean ARB_buffer_storage;
   GLboolean ARB_clear_texture;
   GLboolean ARB_clip_control;
   GLboolean ARB_color_buffer_float;
   GLboolean ARB_compute_shader;
   GLboolean ARB_conditional_render_inverted;
   GLboolean ARB_conservative_depth;
   GLboolean ARB_copy_image;
   GLboolean ARB_depth_buffer_float;
   GLboolean ARB_depth_clamp;
   GLboolean ARB_depth_texture;
   GLboolean ARB_derivative_control;
   GLboolean ARB_draw_buffers_blend;
   GLboolean ARB_draw_elements_base_vertex;
   GLboolean ARB_draw_indirect;
   GLboolean ARB_draw_instanced;
   GLboolean ARB_fragment_coord_conventions;
   GLboolean ARB_fragment_layer_viewport;
   GLboolean ARB_fragment_program;
   GLboolean ARB_fragment_program_shadow;
   GLboolean ARB_fragment_shader;
   GLboolean ARB_framebuffer_no_attachments;
   GLboolean ARB_framebuffer_object;
   GLboolean ARB_enhanced_layouts;
   GLboolean ARB_explicit_attrib_location;
   GLboolean ARB_explicit_uniform_location;
   GLboolean ARB_gpu_shader5;
   GLboolean ARB_gpu_shader_fp64;
   GLboolean ARB_half_float_vertex;
   GLboolean ARB_instanced_arrays;
   GLboolean ARB_internalformat_query;
   GLboolean ARB_map_buffer_range;
   GLboolean ARB_occlusion_query;
   GLboolean ARB_occlusion_query2;
   GLboolean ARB_pipeline_statistics_query;
   GLboolean ARB_point_sprite;
   GLboolean ARB_sample_shading;
   GLboolean ARB_seamless_cube_map;
   GLboolean ARB_shader_atomic_counters;
   GLboolean ARB_shader_bit_encoding;
   GLboolean ARB_shader_clock;
   GLboolean ARB_shader_image_load_store;
   GLboolean ARB_shader_image_size;
   GLboolean ARB_shader_precision;
   GLboolean ARB_shader_stencil_export;
   GLboolean ARB_shader_storage_buffer_object;
   GLboolean ARB_shader_subroutine;
   GLboolean ARB_shader_texture_image_samples;
   GLboolean ARB_shader_texture_lod;
   GLboolean ARB_shading_language_packing;
   GLboolean ARB_shading_language_420pack;
   GLboolean ARB_shadow;
   GLboolean ARB_stencil_texturing;
   GLboolean ARB_sync;
   GLboolean ARB_tessellation_shader;
   GLboolean ARB_texture_border_clamp;
   GLboolean ARB_texture_buffer_object;
   GLboolean ARB_texture_buffer_object_rgb32;
   GLboolean ARB_texture_buffer_range;
   GLboolean ARB_texture_compression_bptc;
   GLboolean ARB_texture_compression_rgtc;
   GLboolean ARB_texture_cube_map;
   GLboolean ARB_texture_cube_map_array;
   GLboolean ARB_texture_env_combine;
   GLboolean ARB_texture_env_crossbar;
   GLboolean ARB_texture_env_dot3;
   GLboolean ARB_texture_float;
   GLboolean ARB_texture_gather;
   GLboolean ARB_texture_mirror_clamp_to_edge;
   GLboolean ARB_texture_multisample;
   GLboolean ARB_texture_non_power_of_two;
   GLboolean ARB_texture_stencil8;
   GLboolean ARB_texture_query_levels;
   GLboolean ARB_texture_query_lod;
   GLboolean ARB_texture_rg;
   GLboolean ARB_texture_rgb10_a2ui;
   GLboolean ARB_texture_view;
   GLboolean ARB_timer_query;
   GLboolean ARB_transform_feedback2;
   GLboolean ARB_transform_feedback3;
   GLboolean ARB_transform_feedback_instanced;
   GLboolean ARB_uniform_buffer_object;
   GLboolean ARB_vertex_attrib_64bit;
   GLboolean ARB_vertex_program;
   GLboolean ARB_vertex_shader;
   GLboolean ARB_vertex_type_10f_11f_11f_rev;
   GLboolean ARB_vertex_type_2_10_10_10_rev;
   GLboolean ARB_viewport_array;
   GLboolean EXT_blend_color;
   GLboolean EXT_blend_equation_separate;
   GLboolean EXT_blend_func_separate;
   GLboolean EXT_blend_minmax;
   GLboolean EXT_depth_bounds_test;
   GLboolean EXT_draw_buffers2;
   GLboolean EXT_framebuffer_multisample;
   GLboolean EXT_framebuffer_multisample_blit_scaled;
   GLboolean EXT_framebuffer_sRGB;
   GLboolean EXT_gpu_program_parameters;
   GLboolean EXT_gpu_shader4;
   GLboolean EXT_packed_float;
   GLboolean EXT_pixel_buffer_object;
   GLboolean EXT_point_parameters;
   GLboolean EXT_polygon_offset_clamp;
   GLboolean EXT_provoking_vertex;
   GLboolean EXT_shader_integer_mix;
   GLboolean EXT_shader_samples_identical;
   GLboolean EXT_stencil_two_side;
   GLboolean EXT_texture_array;
   GLboolean EXT_texture_compression_latc;
   GLboolean EXT_texture_compression_s3tc;
   GLboolean EXT_texture_env_dot3;
   GLboolean EXT_texture_filter_anisotropic;
   GLboolean EXT_texture_integer;
   GLboolean EXT_texture_mirror_clamp;
   GLboolean EXT_texture_shared_exponent;
   GLboolean EXT_texture_snorm;
   GLboolean EXT_texture_sRGB;
   GLboolean EXT_texture_sRGB_decode;
   GLboolean EXT_texture_swizzle;
   GLboolean EXT_transform_feedback;
   GLboolean EXT_timer_query;
   GLboolean EXT_vertex_array_bgra;
   GLboolean OES_standard_derivatives;
   /* vendor extensions */
   GLboolean AMD_performance_monitor;
   GLboolean AMD_pinned_memory;
   GLboolean AMD_seamless_cubemap_per_texture;
   GLboolean AMD_vertex_shader_layer;
   GLboolean AMD_vertex_shader_viewport_index;
   GLboolean APPLE_object_purgeable;
   GLboolean ATI_texture_compression_3dc;
   GLboolean ATI_texture_mirror_once;
   GLboolean ATI_texture_env_combine3;
   GLboolean ATI_fragment_shader;
   GLboolean ATI_separate_stencil;
   GLboolean INTEL_performance_query;
   GLboolean KHR_texture_compression_astc_hdr;
   GLboolean KHR_texture_compression_astc_ldr;
   GLboolean MESA_pack_invert;
   GLboolean MESA_ycbcr_texture;
   GLboolean NV_conditional_render;
   GLboolean NV_fog_distance;
   GLboolean NV_fragment_program_option;
   GLboolean NV_point_sprite;
   GLboolean NV_primitive_restart;
   GLboolean NV_texture_barrier;
   GLboolean NV_texture_env_combine4;
   GLboolean NV_texture_rectangle;
   GLboolean NV_vdpau_interop;
   GLboolean TDFX_texture_compression_FXT1;
   GLboolean OES_EGL_image;
   GLboolean OES_draw_texture;
   GLboolean OES_depth_texture_cube_map;
   GLboolean OES_EGL_image_external;
   GLboolean OES_texture_float;
   GLboolean OES_texture_float_linear;
   GLboolean OES_texture_half_float;
   GLboolean OES_texture_half_float_linear;
   GLboolean OES_compressed_ETC1_RGB8_texture;
   GLboolean extension_sentinel;
   /** The extension string */
   const GLubyte *String;
   /** Number of supported extensions */
   GLuint Count;
   /**
    * The context version which extension helper functions compare against.
    * By default, the value is equal to ctx->Version. This changes to ~0
    * while meta is in progress.
    */
   GLubyte Version;
};


/**
 * A stack of matrices (projection, modelview, color, texture, etc).
 */
struct gl_matrix_stack
{
   GLmatrix *Top;      /**< points into Stack */
   GLmatrix *Stack;    /**< array [MaxDepth] of GLmatrix */
   GLuint Depth;       /**< 0 <= Depth < MaxDepth */
   GLuint MaxDepth;    /**< size of Stack[] array */
   GLuint DirtyFlag;   /**< _NEW_MODELVIEW or _NEW_PROJECTION, for example */
};


/**
 * \name Bits for image transfer operations 
 * \sa __struct gl_contextRec::ImageTransferState.
 */
/*@{*/
#define IMAGE_SCALE_BIAS_BIT                      0x1
#define IMAGE_SHIFT_OFFSET_BIT                    0x2
#define IMAGE_MAP_COLOR_BIT                       0x4
#define IMAGE_CLAMP_BIT                           0x800


/** Pixel Transfer ops */
#define IMAGE_BITS (IMAGE_SCALE_BIAS_BIT |                      \
                    IMAGE_SHIFT_OFFSET_BIT |                    \
                    IMAGE_MAP_COLOR_BIT)

/**
 * \name Bits to indicate what state has changed.  
 */
/*@{*/
#define _NEW_MODELVIEW         (1 << 0)   /**< gl_context::ModelView */
#define _NEW_PROJECTION        (1 << 1)   /**< gl_context::Projection */
#define _NEW_TEXTURE_MATRIX    (1 << 2)   /**< gl_context::TextureMatrix */
#define _NEW_COLOR             (1 << 3)   /**< gl_context::Color */
#define _NEW_DEPTH             (1 << 4)   /**< gl_context::Depth */
#define _NEW_EVAL              (1 << 5)   /**< gl_context::Eval, EvalMap */
#define _NEW_FOG               (1 << 6)   /**< gl_context::Fog */
#define _NEW_HINT              (1 << 7)   /**< gl_context::Hint */
#define _NEW_LIGHT             (1 << 8)   /**< gl_context::Light */
#define _NEW_LINE              (1 << 9)   /**< gl_context::Line */
#define _NEW_PIXEL             (1 << 10)  /**< gl_context::Pixel */
#define _NEW_POINT             (1 << 11)  /**< gl_context::Point */
#define _NEW_POLYGON           (1 << 12)  /**< gl_context::Polygon */
#define _NEW_POLYGONSTIPPLE    (1 << 13)  /**< gl_context::PolygonStipple */
#define _NEW_SCISSOR           (1 << 14)  /**< gl_context::Scissor */
#define _NEW_STENCIL           (1 << 15)  /**< gl_context::Stencil */
#define _NEW_TEXTURE           (1 << 16)  /**< gl_context::Texture */
#define _NEW_TRANSFORM         (1 << 17)  /**< gl_context::Transform */
#define _NEW_VIEWPORT          (1 << 18)  /**< gl_context::Viewport */
/* gap, re-use for core Mesa state only; use ctx->DriverFlags otherwise */
#define _NEW_ARRAY             (1 << 20)  /**< gl_context::Array */
#define _NEW_RENDERMODE        (1 << 21)  /**< gl_context::RenderMode, etc */
#define _NEW_BUFFERS           (1 << 22)  /**< gl_context::Visual, DrawBuffer, */
#define _NEW_CURRENT_ATTRIB    (1 << 23)  /**< gl_context::Current */
#define _NEW_MULTISAMPLE       (1 << 24)  /**< gl_context::Multisample */
#define _NEW_TRACK_MATRIX      (1 << 25)  /**< gl_context::VertexProgram */
#define _NEW_PROGRAM           (1 << 26)  /**< New program/shader state */
#define _NEW_PROGRAM_CONSTANTS (1 << 27)
#define _NEW_BUFFER_OBJECT     (1 << 28)
#define _NEW_FRAG_CLAMP        (1 << 29)
/* gap, re-use for core Mesa state only; use ctx->DriverFlags otherwise */
#define _NEW_VARYING_VP_INPUTS (1 << 31) /**< gl_context::varying_vp_inputs */
#define _NEW_ALL ~0
/*@}*/


/**
 * Composite state flags
 */
/*@{*/
#define _MESA_NEW_NEED_EYE_COORDS         (_NEW_LIGHT |         \
                                           _NEW_TEXTURE |       \
                                           _NEW_POINT |         \
                                           _NEW_PROGRAM |       \
                                           _NEW_MODELVIEW)

#define _MESA_NEW_SEPARATE_SPECULAR        (_NEW_LIGHT | \
                                            _NEW_FOG | \
                                            _NEW_PROGRAM)


/*@}*/




/* This has to be included here. */
#include "dd.h"


/**
 * Display list flags.
 * Strictly this is a tnl-private concept, but it doesn't seem
 * worthwhile adding a tnl private structure just to hold this one bit
 * of information:
 */
#define DLIST_DANGLING_REFS     0x1 


/** Opaque declaration of display list payload data type */
union gl_dlist_node;


/**
 * Provide a location where information about a display list can be
 * collected.  Could be extended with driverPrivate structures,
 * etc. in the future.
 */
struct gl_display_list
{
   GLuint Name;
   GLchar *Label;     /**< GL_KHR_debug */
   GLbitfield Flags;  /**< DLIST_x flags */
   /** The dlist commands are in a linked list of nodes */
   union gl_dlist_node *Head;
};


/**
 * State used during display list compilation and execution.
 */
struct gl_dlist_state
{
   GLuint CallDepth;            /**< Current recursion calling depth */

   struct gl_display_list *CurrentList; /**< List currently being compiled */
   union gl_dlist_node *CurrentBlock; /**< Pointer to current block of nodes */
   GLuint CurrentPos;           /**< Index into current block of nodes */

   GLvertexformat ListVtxfmt;

   GLubyte ActiveAttribSize[VERT_ATTRIB_MAX];
   GLfloat CurrentAttrib[VERT_ATTRIB_MAX][4];
   
   GLubyte ActiveMaterialSize[MAT_ATTRIB_MAX];
   GLfloat CurrentMaterial[MAT_ATTRIB_MAX][4];

   struct {
      /* State known to have been set by the currently-compiling display
       * list.  Used to eliminate some redundant state changes.
       */
      GLenum ShadeModel;
   } Current;
};

/** @{
 *
 * These are a mapping of the GL_ARB_debug_output/GL_KHR_debug enums
 * to small enums suitable for use as an array index.
 */

enum mesa_debug_source {
   MESA_DEBUG_SOURCE_API,
   MESA_DEBUG_SOURCE_WINDOW_SYSTEM,
   MESA_DEBUG_SOURCE_SHADER_COMPILER,
   MESA_DEBUG_SOURCE_THIRD_PARTY,
   MESA_DEBUG_SOURCE_APPLICATION,
   MESA_DEBUG_SOURCE_OTHER,
   MESA_DEBUG_SOURCE_COUNT
};

enum mesa_debug_type {
   MESA_DEBUG_TYPE_ERROR,
   MESA_DEBUG_TYPE_DEPRECATED,
   MESA_DEBUG_TYPE_UNDEFINED,
   MESA_DEBUG_TYPE_PORTABILITY,
   MESA_DEBUG_TYPE_PERFORMANCE,
   MESA_DEBUG_TYPE_OTHER,
   MESA_DEBUG_TYPE_MARKER,
   MESA_DEBUG_TYPE_PUSH_GROUP,
   MESA_DEBUG_TYPE_POP_GROUP,
   MESA_DEBUG_TYPE_COUNT
};

enum mesa_debug_severity {
   MESA_DEBUG_SEVERITY_LOW,
   MESA_DEBUG_SEVERITY_MEDIUM,
   MESA_DEBUG_SEVERITY_HIGH,
   MESA_DEBUG_SEVERITY_NOTIFICATION,
   MESA_DEBUG_SEVERITY_COUNT
};

/** @} */

/**
 * Driver-specific state flags.
 *
 * These are or'd with gl_context::NewDriverState to notify a driver about
 * a state change. The driver sets the flags at context creation and
 * the meaning of the bits set is opaque to core Mesa.
 */
struct gl_driver_flags
{
   /** gl_context::Array::_DrawArrays (vertex array state) */
   uint64_t NewArray;

   /** gl_context::TransformFeedback::CurrentObject */
   uint64_t NewTransformFeedback;

   /** gl_context::TransformFeedback::CurrentObject::shader_program */
   uint64_t NewTransformFeedbackProg;

   /** gl_context::RasterDiscard */
   uint64_t NewRasterizerDiscard;

   /**
    * gl_context::UniformBufferBindings
    * gl_shader_program::UniformBlocks
    */
   uint64_t NewUniformBuffer;

   /**
    * gl_context::ShaderStorageBufferBindings
    * gl_shader_program::ShaderStorageBlocks
    */
   uint64_t NewShaderStorageBuffer;

   uint64_t NewTextureBuffer;

   /**
    * gl_context::AtomicBufferBindings
    */
   uint64_t NewAtomicBuffer;

   /**
    * gl_context::ImageUnits
    */
   uint64_t NewImageUnits;

   /**
    * gl_context::TessCtrlProgram::patch_default_*
    */
   uint64_t NewDefaultTessLevels;
};

struct gl_uniform_buffer_binding
{
   struct gl_buffer_object *BufferObject;
   /** Start of uniform block data in the buffer */
   GLintptr Offset;
   /** Size of data allowed to be referenced from the buffer (in bytes) */
   GLsizeiptr Size;
   /**
    * glBindBufferBase() indicates that the Size should be ignored and only
    * limited by the current size of the BufferObject.
    */
   GLboolean AutomaticSize;
};

struct gl_shader_storage_buffer_binding
{
   struct gl_buffer_object *BufferObject;
   /** Start of shader storage block data in the buffer */
   GLintptr Offset;
   /** Size of data allowed to be referenced from the buffer (in bytes) */
   GLsizeiptr Size;
   /**
    * glBindBufferBase() indicates that the Size should be ignored and only
    * limited by the current size of the BufferObject.
    */
   GLboolean AutomaticSize;
};

/**
 * ARB_shader_image_load_store image unit.
 */
struct gl_image_unit
{
   /**
    * Texture object bound to this unit.
    */
   struct gl_texture_object *TexObj;

   /**
    * Level of the texture object bound to this unit.
    */
   GLuint Level;

   /**
    * \c GL_TRUE if the whole level is bound as an array of layers, \c
    * GL_FALSE if only some specific layer of the texture is bound.
    * \sa Layer
    */
   GLboolean Layered;

   /**
    * Layer of the texture object bound to this unit as specified by the
    * application.
    */
   GLuint Layer;

   /**
    * Layer of the texture object bound to this unit, or zero if the
    * whole level is bound.
    */
   GLuint _Layer;

   /**
    * Access allowed to this texture image.  Either \c GL_READ_ONLY,
    * \c GL_WRITE_ONLY or \c GL_READ_WRITE.
    */
   GLenum Access;

   /**
    * GL internal format that determines the interpretation of the
    * image memory when shader image operations are performed through
    * this unit.
    */
   GLenum Format;

   /**
    * Mesa format corresponding to \c Format.
    */
   mesa_format _ActualFormat;

};

/**
 * Binding point for an atomic counter buffer object.
 */
struct gl_atomic_buffer_binding
{
   struct gl_buffer_object *BufferObject;
   GLintptr Offset;
   GLsizeiptr Size;
};

/**
 * Mesa rendering context.
 *
 * This is the central context data structure for Mesa.  Almost all
 * OpenGL state is contained in this structure.
 * Think of this as a base class from which device drivers will derive
 * sub classes.
 */
struct gl_context
{
   /** State possibly shared with other contexts in the address space */
   struct gl_shared_state *Shared;

   /** \name API function pointer tables */
   /*@{*/
   gl_api API;
   /**
    * The current dispatch table for non-displaylist-saving execution, either
    * BeginEnd or OutsideBeginEnd
    */
   struct _glapi_table *Exec;
   /**
    * The normal dispatch table for non-displaylist-saving, non-begin/end
    */
   struct _glapi_table *OutsideBeginEnd;
   /** The dispatch table used between glNewList() and glEndList() */
   struct _glapi_table *Save;
   /**
    * The dispatch table used between glBegin() and glEnd() (outside of a
    * display list).  Only valid functions between those two are set, which is
    * mostly just the set in a GLvertexformat struct.
    */
   struct _glapi_table *BeginEnd;
   /**
    * Tracks the current dispatch table out of the 3 above, so that it can be
    * re-set on glXMakeCurrent().
    */
   struct _glapi_table *CurrentDispatch;
   /*@}*/

   struct gl_config Visual;
   struct gl_framebuffer *DrawBuffer;   /**< buffer for writing */
   struct gl_framebuffer *ReadBuffer;   /**< buffer for reading */
   struct gl_framebuffer *WinSysDrawBuffer;  /**< set with MakeCurrent */
   struct gl_framebuffer *WinSysReadBuffer;  /**< set with MakeCurrent */

   /**
    * Device driver function pointer table
    */
   struct dd_function_table Driver;

   /** Core/Driver constants */
   struct gl_constants Const;

   /** \name The various 4x4 matrix stacks */
   /*@{*/
   struct gl_matrix_stack ModelviewMatrixStack;
   struct gl_matrix_stack ProjectionMatrixStack;
   struct gl_matrix_stack TextureMatrixStack[MAX_TEXTURE_UNITS];
   struct gl_matrix_stack ProgramMatrixStack[MAX_PROGRAM_MATRICES];
   struct gl_matrix_stack *CurrentStack; /**< Points to one of the above stacks */
   /*@}*/

   /** Combined modelview and projection matrix */
   GLmatrix _ModelProjectMatrix;

   /** \name Display lists */
   struct gl_dlist_state ListState;

   GLboolean ExecuteFlag;       /**< Execute GL commands? */
   GLboolean CompileFlag;       /**< Compile GL commands into display list? */

   /** Extension information */
   struct gl_extensions Extensions;

   /** GL version integer, for example 31 for GL 3.1, or 20 for GLES 2.0. */
   GLuint Version;
   char *VersionString;

   /** \name State attribute stack (for glPush/PopAttrib) */
   /*@{*/
   GLuint AttribStackDepth;
   struct gl_attrib_node *AttribStack[MAX_ATTRIB_STACK_DEPTH];
   /*@}*/

   /** \name Renderer attribute groups
    * 
    * We define a struct for each attribute group to make pushing and popping
    * attributes easy.  Also it's a good organization.
    */
   /*@{*/
   struct gl_accum_attrib       Accum;          /**< Accum buffer attributes */
   struct gl_colorbuffer_attrib Color;          /**< Color buffer attributes */
   struct gl_current_attrib     Current;        /**< Current attributes */
   struct gl_depthbuffer_attrib Depth;          /**< Depth buffer attributes */
   struct gl_eval_attrib        Eval;           /**< Eval attributes */
   struct gl_fog_attrib         Fog;            /**< Fog attributes */
   struct gl_hint_attrib        Hint;           /**< Hint attributes */
   struct gl_light_attrib       Light;          /**< Light attributes */
   struct gl_line_attrib        Line;           /**< Line attributes */
   struct gl_list_attrib        List;           /**< List attributes */
   struct gl_multisample_attrib Multisample;
   struct gl_pixel_attrib       Pixel;          /**< Pixel attributes */
   struct gl_point_attrib       Point;          /**< Point attributes */
   struct gl_polygon_attrib     Polygon;        /**< Polygon attributes */
   GLuint PolygonStipple[32];                   /**< Polygon stipple */
   struct gl_scissor_attrib     Scissor;        /**< Scissor attributes */
   struct gl_stencil_attrib     Stencil;        /**< Stencil buffer attributes */
   struct gl_texture_attrib     Texture;        /**< Texture attributes */
   struct gl_transform_attrib   Transform;      /**< Transformation attributes */
   struct gl_viewport_attrib    ViewportArray[MAX_VIEWPORTS];   /**< Viewport attributes */
   /*@}*/

   /** \name Client attribute stack */
   /*@{*/
   GLuint ClientAttribStackDepth;
   struct gl_attrib_node *ClientAttribStack[MAX_CLIENT_ATTRIB_STACK_DEPTH];
   /*@}*/

   /** \name Client attribute groups */
   /*@{*/
   struct gl_array_attrib       Array;  /**< Vertex arrays */
   struct gl_pixelstore_attrib  Pack;   /**< Pixel packing */
   struct gl_pixelstore_attrib  Unpack; /**< Pixel unpacking */
   struct gl_pixelstore_attrib  DefaultPacking; /**< Default params */
   /*@}*/

   /** \name Other assorted state (not pushed/popped on attribute stack) */
   /*@{*/
   struct gl_pixelmaps          PixelMaps;

   struct gl_evaluators EvalMap;   /**< All evaluators */
   struct gl_feedback   Feedback;  /**< Feedback */
   struct gl_selection  Select;    /**< Selection */

   struct gl_program_state Program;  /**< general program state */
   struct gl_vertex_program_state VertexProgram;
   struct gl_fragment_program_state FragmentProgram;
   struct gl_geometry_program_state GeometryProgram;
   struct gl_compute_program_state ComputeProgram;
   struct gl_tess_ctrl_program_state TessCtrlProgram;
   struct gl_tess_eval_program_state TessEvalProgram;
   struct gl_ati_fragment_shader_state ATIFragmentShader;

   struct gl_pipeline_shader_state Pipeline; /**< GLSL pipeline shader object state */
   struct gl_pipeline_object Shader; /**< GLSL shader object state */

   /**
    * Current active shader pipeline state
    *
    * Almost all internal users want ::_Shader instead of ::Shader.  The
    * exceptions are bits of legacy GLSL API that do not know about separate
    * shader objects.
    *
    * If a program is active via \c glUseProgram, this will point to
    * \c ::Shader.
    *
    * If a program pipeline is active via \c glBindProgramPipeline, this will
    * point to \c ::Pipeline.Current.
    *
    * If neither a program nor a program pipeline is active, this will point to
    * \c ::Pipeline.Default.  This ensures that \c ::_Shader will never be
    * \c NULL.
    */
   struct gl_pipeline_object *_Shader;

   struct gl_query_state Query;  /**< occlusion, timer queries */

   struct gl_transform_feedback_state TransformFeedback;

   struct gl_perf_monitor_state PerfMonitor;

   struct gl_buffer_object *DrawIndirectBuffer; /** < GL_ARB_draw_indirect */
   struct gl_buffer_object *DispatchIndirectBuffer; /** < GL_ARB_compute_shader */

   struct gl_buffer_object *CopyReadBuffer; /**< GL_ARB_copy_buffer */
   struct gl_buffer_object *CopyWriteBuffer; /**< GL_ARB_copy_buffer */

   /**
    * Current GL_ARB_uniform_buffer_object binding referenced by
    * GL_UNIFORM_BUFFER target for glBufferData, glMapBuffer, etc.
    */
   struct gl_buffer_object *UniformBuffer;

   /**
    * Current GL_ARB_shader_storage_buffer_object binding referenced by
    * GL_SHADER_STORAGE_BUFFER target for glBufferData, glMapBuffer, etc.
    */
   struct gl_buffer_object *ShaderStorageBuffer;

   /**
    * Array of uniform buffers for GL_ARB_uniform_buffer_object and GL 3.1.
    * This is set up using glBindBufferRange() or glBindBufferBase().  They are
    * associated with uniform blocks by glUniformBlockBinding()'s state in the
    * shader program.
    */
   struct gl_uniform_buffer_binding
      UniformBufferBindings[MAX_COMBINED_UNIFORM_BUFFERS];

   /**
    * Array of shader storage buffers for ARB_shader_storage_buffer_object
    * and GL 4.3. This is set up using glBindBufferRange() or
    * glBindBufferBase().  They are associated with shader storage blocks by
    * glShaderStorageBlockBinding()'s state in the shader program.
    */
   struct gl_shader_storage_buffer_binding
      ShaderStorageBufferBindings[MAX_COMBINED_SHADER_STORAGE_BUFFERS];

   /**
    * Object currently associated with the GL_ATOMIC_COUNTER_BUFFER
    * target.
    */
   struct gl_buffer_object *AtomicBuffer;

   /**
    * Object currently associated w/ the GL_EXTERNAL_VIRTUAL_MEMORY_BUFFER_AMD
    * target.
    */
   struct gl_buffer_object *ExternalVirtualMemoryBuffer;

   /**
    * Array of atomic counter buffer binding points.
    */
   struct gl_atomic_buffer_binding
      AtomicBufferBindings[MAX_COMBINED_ATOMIC_BUFFERS];

   /**
    * Array of image units for ARB_shader_image_load_store.
    */
   struct gl_image_unit ImageUnits[MAX_IMAGE_UNITS];

   /*@}*/

   struct gl_meta_state *Meta;  /**< for "meta" operations */

   /* GL_EXT_framebuffer_object */
   struct gl_renderbuffer *CurrentRenderbuffer;

   GLenum ErrorValue;        /**< Last error code */

   /**
    * Recognize and silence repeated error debug messages in buggy apps.
    */
   const char *ErrorDebugFmtString;
   GLuint ErrorDebugCount;

   /* GL_ARB_debug_output/GL_KHR_debug */
   mtx_t DebugMutex;
   struct gl_debug_state *Debug;

   GLenum RenderMode;        /**< either GL_RENDER, GL_SELECT, GL_FEEDBACK */
   GLbitfield NewState;      /**< bitwise-or of _NEW_* flags */
   uint64_t NewDriverState;  /**< bitwise-or of flags from DriverFlags */

   struct gl_driver_flags DriverFlags;

   GLboolean ViewportInitialized;  /**< has viewport size been initialized? */

   GLbitfield64 varying_vp_inputs;  /**< mask of VERT_BIT_* flags */

   /** \name Derived state */
   GLbitfield _ImageTransferState;/**< bitwise-or of IMAGE_*_BIT flags */
   GLfloat _EyeZDir[3];
   GLfloat _ModelViewInvScale;
   GLboolean _NeedEyeCoords;
   GLboolean _ForceEyeCoords; 

   GLuint TextureStateTimestamp; /**< detect changes to shared state */

   struct gl_list_extensions *ListExt; /**< driver dlist extensions */

   /** \name For debugging/development only */
   /*@{*/
   GLboolean FirstTimeCurrent;
   /*@}*/

   /**
    * False if this context was created without a config. This is needed
    * because the initial state of glDrawBuffers depends on this
    */
   GLboolean HasConfig;

   /** software compression/decompression supported or not */
   GLboolean Mesa_DXTn;

   GLboolean TextureFormatSupported[MESA_FORMAT_COUNT];

   GLboolean RasterDiscard;  /**< GL_RASTERIZER_DISCARD */

   /**
    * \name Hooks for module contexts.  
    *
    * These will eventually live in the driver or elsewhere.
    */
   /*@{*/
   void *swrast_context;
   void *swsetup_context;
   void *swtnl_context;
   struct vbo_context *vbo_context;
   struct st_context *st;
   void *aelt_context;
   /*@}*/

   /**
    * \name NV_vdpau_interop
    */
   /*@{*/
   const void *vdpDevice;
   const void *vdpGetProcAddress;
   struct set *vdpSurfaces;
   /*@}*/

   /**
    * Has this context observed a GPU reset in any context in the share group?
    *
    * Once this field becomes true, it is never reset to false.
    */
   GLboolean ShareGroupReset;
};


#ifdef DEBUG
extern int MESA_VERBOSE;
extern int MESA_DEBUG_FLAGS;
# define MESA_FUNCTION __func__
#else
# define MESA_VERBOSE 0
# define MESA_DEBUG_FLAGS 0
# define MESA_FUNCTION "a function"
#endif


/** The MESA_VERBOSE var is a bitmask of these flags */
enum _verbose
{
   VERBOSE_VARRAY               = 0x0001,
   VERBOSE_TEXTURE              = 0x0002,
   VERBOSE_MATERIAL             = 0x0004,
   VERBOSE_PIPELINE             = 0x0008,
   VERBOSE_DRIVER               = 0x0010,
   VERBOSE_STATE                = 0x0020,
   VERBOSE_API                  = 0x0040,
   VERBOSE_DISPLAY_LIST         = 0x0100,
   VERBOSE_LIGHTING             = 0x0200,
   VERBOSE_PRIMS                = 0x0400,
   VERBOSE_VERTS                = 0x0800,
   VERBOSE_DISASSEM             = 0x1000,
   VERBOSE_DRAW                 = 0x2000,
   VERBOSE_SWAPBUFFERS          = 0x4000
};


/** The MESA_DEBUG_FLAGS var is a bitmask of these flags */
enum _debug
{
   DEBUG_SILENT                 = (1 << 0),
   DEBUG_ALWAYS_FLUSH           = (1 << 1),
   DEBUG_INCOMPLETE_TEXTURE     = (1 << 2),
   DEBUG_INCOMPLETE_FBO         = (1 << 3)
};

static inline bool
_mesa_active_fragment_shader_has_atomic_ops(const struct gl_context *ctx)
{
   return ctx->Shader._CurrentFragmentProgram != NULL &&
      ctx->Shader._CurrentFragmentProgram->_LinkedShaders[MESA_SHADER_FRAGMENT]->NumAtomicBuffers > 0;
}

#ifdef __cplusplus
}
#endif

#endif /* MTYPES_H */