src/mesa/swrast/s_context.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.3
   4  *
   5  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file swrast/s_context.h
  28  * \brief Software rasterization context and private types.
  29  * \author Keith Whitwell <keith@tungstengraphics.com>
  30  */
  31
  32 /**
  33  * \mainpage swrast module
  34  *
  35  * This module, software rasterization, contains the software fallback
  36  * routines for drawing points, lines, triangles, bitmaps and images.
  37  * All rendering boils down to writing spans (arrays) of pixels with
  38  * particular colors.  The span-writing routines must be implemented
  39  * by the device driver.
  40  */
  41
  42
  43 #ifndef S_CONTEXT_H
  44 #define S_CONTEXT_H
  45
  46 #include "main/mtypes.h"
  47 #include "shader/prog_execute.h"
  48 #include "swrast.h"
  49 #include "s_span.h"
  50
  51
  52 typedef void (*texture_sample_func)(GLcontext *ctx,
  53                                     const struct gl_texture_object *tObj,
  54                                     GLuint n, const GLfloat texcoords[][4],
  55                                     const GLfloat lambda[], GLfloat rgba[][4]);
  56
  57 typedef void (_ASMAPIP blend_func)( GLcontext *ctx, GLuint n,
  58                                     const GLubyte mask[],
  59                                     GLvoid *src, const GLvoid *dst,
  60                                     GLenum chanType);
  61
  62 typedef void (*swrast_point_func)( GLcontext *ctx, const SWvertex *);
  63
  64 typedef void (*swrast_line_func)( GLcontext *ctx,
  65                                   const SWvertex *, const SWvertex *);
  66
  67 typedef void (*swrast_tri_func)( GLcontext *ctx, const SWvertex *,
  68                                  const SWvertex *, const SWvertex *);
  69
  70
  71 typedef void (*validate_texture_image_func)(GLcontext *ctx,
  72                                             struct gl_texture_object *texObj,
  73                                             GLuint face, GLuint level);
  74
  75
  76 /**
  77  * \defgroup Bitmasks
  78  * Bitmasks to indicate which rasterization options are enabled
  79  * (RasterMask)
  80  */
  81 /*@{*/
  82 #define ALPHATEST_BIT           0x001   /**< Alpha-test pixels */
  83 #define BLEND_BIT               0x002   /**< Blend pixels */
  84 #define DEPTH_BIT               0x004   /**< Depth-test pixels */
  85 #define FOG_BIT                 0x008   /**< Fog pixels */
  86 #define LOGIC_OP_BIT            0x010   /**< Apply logic op in software */
  87 #define CLIP_BIT                0x020   /**< Scissor or window clip pixels */
  88 #define STENCIL_BIT             0x040   /**< Stencil pixels */
  89 #define MASKING_BIT             0x080   /**< Do glColorMask or glIndexMask */
  90 #define MULTI_DRAW_BIT          0x400   /**< Write to more than one color- */
  91                                         /**< buffer or no buffers. */
  92 #define OCCLUSION_BIT           0x800   /**< GL_HP_occlusion_test enabled */
  93 #define TEXTURE_BIT             0x1000  /**< Texturing really enabled */
  94 #define FRAGPROG_BIT            0x2000  /**< Fragment program enabled */
  95 #define ATIFRAGSHADER_BIT       0x4000  /**< ATI Fragment shader enabled */
  96 #define CLAMPING_BIT            0x8000  /**< Clamp colors to [0,1] */
  97 /*@}*/
  98
  99 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|   \
 100                                 _NEW_SCISSOR|   \
 101                                 _NEW_COLOR|     \
 102                                 _NEW_DEPTH|     \
 103                                 _NEW_FOG|       \
 104                                 _NEW_PROGRAM|   \
 105                                 _NEW_STENCIL|   \
 106                                 _NEW_TEXTURE|   \
 107                                 _NEW_VIEWPORT|  \
 108                                 _NEW_DEPTH)
 109
 110
 111 /**
 112  * \struct SWcontext
 113  * \brief  Per-context state that's private to the software rasterizer module.
 114  */
 115 typedef struct
 116 {
 117    /** Driver interface:
 118     */
 119    struct swrast_device_driver Driver;
 120
 121    /** Configuration mechanisms to make software rasterizer match
 122     * characteristics of the hardware rasterizer (if present):
 123     */
 124    GLboolean AllowVertexFog;
 125    GLboolean AllowPixelFog;
 126
 127    /** Derived values, invalidated on statechanges, updated from
 128     * _swrast_validate_derived():
 129     */
 130    GLbitfield _RasterMask;
 131    GLfloat _BackfaceSign;      /** +1 or -1 */
 132    GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
 133    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
 134    GLboolean _TextureCombinePrimary;
 135    GLboolean _FogEnabled;
 136    GLboolean _DeferredTexture;
 137    GLenum _FogMode;  /* either GL_FOG_MODE or fragment program's fog mode */
 138
 139    /** List/array of the fragment attributes to interpolate */
 140    GLuint _ActiveAttribs[FRAG_ATTRIB_MAX];
 141    /** Same info, but as a bitmask */
 142    GLbitfield _ActiveAttribMask;
 143    /** Number of fragment attributes to interpolate */
 144    GLuint _NumActiveAttribs;
 145    /** Indicates how each attrib is to be interpolated (lines/tris) */
 146    GLenum _InterpMode[FRAG_ATTRIB_MAX]; /* GL_FLAT or GL_SMOOTH (for now) */
 147
 148    /* Accum buffer temporaries.
 149     */
 150    GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */
 151    GLfloat _IntegerAccumScaler; /**< Implicit scale factor */
 152
 153    /* Working values:
 154     */
 155    GLuint StippleCounter;    /**< Line stipple counter */
 156    GLuint PointLineFacing;
 157    GLbitfield NewState;
 158    GLuint StateChanges;
 159    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
 160    GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
 161
 162    void (*InvalidateState)( GLcontext *ctx, GLbitfield new_state );
 163
 164    /**
 165     * When the NewState mask intersects these masks, we invalidate the
 166     * Point/Line/Triangle function pointers below.
 167     */
 168    /*@{*/
 169    GLbitfield InvalidatePointMask;
 170    GLbitfield InvalidateLineMask;
 171    GLbitfield InvalidateTriangleMask;
 172    /*@}*/
 173
 174    /**
 175     * Device drivers plug in functions for these callbacks.
 176     * Will be called when the GL state change mask intersects the above masks.
 177     */
 178    /*@{*/
 179    void (*choose_point)( GLcontext * );
 180    void (*choose_line)( GLcontext * );
 181    void (*choose_triangle)( GLcontext * );
 182    /*@}*/
 183
 184    /**
 185     * Current point, line and triangle drawing functions.
 186     */
 187    /*@{*/
 188    swrast_point_func Point;
 189    swrast_line_func Line;
 190    swrast_tri_func Triangle;
 191    /*@}*/
 192
 193    /**
 194     * Placeholders for when separate specular (or secondary color) is
 195     * enabled but texturing is not.
 196     */
 197    /*@{*/
 198    swrast_point_func SpecPoint;
 199    swrast_line_func SpecLine;
 200    swrast_tri_func SpecTriangle;
 201    /*@}*/
 202
 203    /**
 204     * Typically, we'll allocate a sw_span structure as a local variable
 205     * and set its 'array' pointer to point to this object.  The reason is
 206     * this object is big and causes problems when allocated on the stack
 207     * on some systems.
 208     */
 209    SWspanarrays *SpanArrays;
 210    SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
 211
 212    /**
 213     * Used to buffer N GL_POINTS, instead of rendering one by one.
 214     */
 215    SWspan PointSpan;
 216
 217    /** Internal hooks, kept up to date by the same mechanism as above.
 218     */
 219    blend_func BlendFunc;
 220    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 221
 222    /** Buffer for saving the sampled texture colors.
 223     * Needed for GL_ARB_texture_env_crossbar implementation.
 224     */
 225    GLfloat *TexelBuffer;
 226
 227    validate_texture_image_func ValidateTextureImage;
 228
 229    /** State used during execution of fragment programs */
 230    struct gl_program_machine FragProgMachine;
 231
 232 } SWcontext;
 233
 234
 235 extern void
 236 _swrast_validate_derived( GLcontext *ctx );
 237
 238 extern void
 239 _swrast_update_texture_samplers(GLcontext *ctx);
 240
 241
 242 /** Return SWcontext for the given GLcontext */
 243 static INLINE SWcontext *
 244 SWRAST_CONTEXT(GLcontext *ctx)
 245 {
 246    return (SWcontext *) ctx->swrast_context;
 247 }
 248
 249 /** const version of above */
 250 static INLINE const SWcontext *
 251 CONST_SWRAST_CONTEXT(const GLcontext *ctx)
 252 {
 253    return (const SWcontext *) ctx->swrast_context;
 254 }
 255
 256
 257 /**
 258  * Called prior to framebuffer reading/writing.
 259  * For drivers that rely on swrast for fallback rendering, this is the
 260  * driver's opportunity to map renderbuffers and textures.
 261  */
 262 static INLINE void
 263 swrast_render_start(GLcontext *ctx)
 264 {
 265    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 266    if (swrast->Driver.SpanRenderStart)
 267       swrast->Driver.SpanRenderStart(ctx);
 268 }
 269
 270
 271 /** Called after framebuffer reading/writing */
 272 static INLINE void
 273 swrast_render_finish(GLcontext *ctx)
 274 {
 275    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 276    if (swrast->Driver.SpanRenderFinish)
 277       swrast->Driver.SpanRenderFinish(ctx);
 278 }
 279
 280
 281
 282 /**
 283  * Size of an RGBA pixel, in bytes, for given datatype.
 284  */
 285 #define RGBA_PIXEL_SIZE(TYPE)                                     \
 286          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
 287           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
 288            : 4 * sizeof(GLfloat)))
 289
 290
 291
 292 /*
 293  * Fixed point arithmetic macros
 294  */
 295 #ifndef FIXED_FRAC_BITS
 296 #define FIXED_FRAC_BITS 11
 297 #endif
 298
 299 #define FIXED_SHIFT     FIXED_FRAC_BITS
 300 #define FIXED_ONE       (1 << FIXED_SHIFT)
 301 #define FIXED_HALF      (1 << (FIXED_SHIFT-1))
 302 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
 303 #define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
 304 #define FIXED_EPSILON   1
 305 #define FIXED_SCALE     ((float) FIXED_ONE)
 306 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
 307 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
 308 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
 309 #define IntToFixed(I)   ((I) << FIXED_SHIFT)
 310 #define FixedToInt(X)   ((X) >> FIXED_SHIFT)
 311 #define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
 312 #define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
 313 #define FixedFloor(X)   ((X) & FIXED_INT_MASK)
 314 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
 315 #define PosFloatToFixed(X)      FloatToFixed(X)
 316 #define SignedFloatToFixed(X)   FloatToFixed(X)
 317
 318
 319
 320 /*
 321  * XXX these macros are just bandages for now in order to make
 322  * CHAN_BITS==32 compile cleanly.
 323  * These should probably go elsewhere at some point.
 324  */
 325 #if CHAN_TYPE == GL_FLOAT
 326 #define ChanToFixed(X)  (X)
 327 #define FixedToChan(X)  (X)
 328 #else
 329 #define ChanToFixed(X)  IntToFixed(X)
 330 #define FixedToChan(X)  FixedToInt(X)
 331 #endif
 332
 333
 334 /**
 335  * For looping over fragment attributes in the pointe, line
 336  * triangle rasterizers.
 337  */
 338 #define ATTRIB_LOOP_BEGIN                                \
 339    {                                                     \
 340       GLuint a;                                          \
 341       for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
 342          const GLuint attr = swrast->_ActiveAttribs[a];
 343
 344 #define ATTRIB_LOOP_END } }
 345
 346
 347
 348 #endif