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
 161    void (*InvalidateState)( GLcontext *ctx, GLbitfield new_state );
 162
 163    /**
 164     * When the NewState mask intersects these masks, we invalidate the
 165     * Point/Line/Triangle function pointers below.
 166     */
 167    /*@{*/
 168    GLbitfield InvalidatePointMask;
 169    GLbitfield InvalidateLineMask;
 170    GLbitfield InvalidateTriangleMask;
 171    /*@}*/
 172
 173    /**
 174     * Device drivers plug in functions for these callbacks.
 175     * Will be called when the GL state change mask intersects the above masks.
 176     */
 177    /*@{*/
 178    void (*choose_point)( GLcontext * );
 179    void (*choose_line)( GLcontext * );
 180    void (*choose_triangle)( GLcontext * );
 181    /*@}*/
 182
 183    /**
 184     * Current point, line and triangle drawing functions.
 185     */
 186    /*@{*/
 187    swrast_point_func Point;
 188    swrast_line_func Line;
 189    swrast_tri_func Triangle;
 190    /*@}*/
 191
 192    /**
 193     * Placeholders for when separate specular (or secondary color) is
 194     * enabled but texturing is not.
 195     */
 196    /*@{*/
 197    swrast_point_func SpecPoint;
 198    swrast_line_func SpecLine;
 199    swrast_tri_func SpecTriangle;
 200    /*@}*/
 201
 202    /**
 203     * Typically, we'll allocate a sw_span structure as a local variable
 204     * and set its 'array' pointer to point to this object.  The reason is
 205     * this object is big and causes problems when allocated on the stack
 206     * on some systems.
 207     */
 208    SWspanarrays *SpanArrays;
 209    SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
 210
 211    /**
 212     * Used to buffer N GL_POINTS, instead of rendering one by one.
 213     */
 214    SWspan PointSpan;
 215
 216    /** Internal hooks, kept up to date by the same mechanism as above.
 217     */
 218    blend_func BlendFunc;
 219    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 220
 221    /** Buffer for saving the sampled texture colors.
 222     * Needed for GL_ARB_texture_env_crossbar implementation.
 223     */
 224    GLfloat *TexelBuffer;
 225
 226    validate_texture_image_func ValidateTextureImage;
 227
 228    /** State used during execution of fragment programs */
 229    struct gl_program_machine FragProgMachine;
 230
 231 } SWcontext;
 232
 233
 234 extern void
 235 _swrast_validate_derived( GLcontext *ctx );
 236
 237 extern void
 238 _swrast_update_texture_samplers(GLcontext *ctx);
 239
 240
 241 /** Return SWcontext for the given GLcontext */
 242 static INLINE SWcontext *
 243 SWRAST_CONTEXT(GLcontext *ctx)
 244 {
 245    return (SWcontext *) ctx->swrast_context;
 246 }
 247
 248 /** const version of above */
 249 static INLINE const SWcontext *
 250 CONST_SWRAST_CONTEXT(const GLcontext *ctx)
 251 {
 252    return (const SWcontext *) ctx->swrast_context;
 253 }
 254
 255
 256 /**
 257  * Called prior to framebuffer reading/writing.
 258  * For drivers that rely on swrast for fallback rendering, this is the
 259  * driver's opportunity to map renderbuffers and textures.
 260  */
 261 static INLINE void
 262 swrast_render_start(GLcontext *ctx)
 263 {
 264    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 265    if (swrast->Driver.SpanRenderStart)
 266       swrast->Driver.SpanRenderStart(ctx);
 267 }
 268
 269
 270 /** Called after framebuffer reading/writing */
 271 static INLINE void
 272 swrast_render_finish(GLcontext *ctx)
 273 {
 274    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 275    if (swrast->Driver.SpanRenderFinish)
 276       swrast->Driver.SpanRenderFinish(ctx);
 277 }
 278
 279
 280
 281 /**
 282  * Size of an RGBA pixel, in bytes, for given datatype.
 283  */
 284 #define RGBA_PIXEL_SIZE(TYPE)                                     \
 285          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
 286           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
 287            : 4 * sizeof(GLfloat)))
 288
 289
 290
 291 /*
 292  * Fixed point arithmetic macros
 293  */
 294 #ifndef FIXED_FRAC_BITS
 295 #define FIXED_FRAC_BITS 11
 296 #endif
 297
 298 #define FIXED_SHIFT     FIXED_FRAC_BITS
 299 #define FIXED_ONE       (1 << FIXED_SHIFT)
 300 #define FIXED_HALF      (1 << (FIXED_SHIFT-1))
 301 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
 302 #define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
 303 #define FIXED_EPSILON   1
 304 #define FIXED_SCALE     ((float) FIXED_ONE)
 305 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
 306 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
 307 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
 308 #define IntToFixed(I)   ((I) << FIXED_SHIFT)
 309 #define FixedToInt(X)   ((X) >> FIXED_SHIFT)
 310 #define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
 311 #define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
 312 #define FixedFloor(X)   ((X) & FIXED_INT_MASK)
 313 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
 314 #define PosFloatToFixed(X)      FloatToFixed(X)
 315 #define SignedFloatToFixed(X)   FloatToFixed(X)
 316
 317
 318
 319 /*
 320  * XXX these macros are just bandages for now in order to make
 321  * CHAN_BITS==32 compile cleanly.
 322  * These should probably go elsewhere at some point.
 323  */
 324 #if CHAN_TYPE == GL_FLOAT
 325 #define ChanToFixed(X)  (X)
 326 #define FixedToChan(X)  (X)
 327 #else
 328 #define ChanToFixed(X)  IntToFixed(X)
 329 #define FixedToChan(X)  FixedToInt(X)
 330 #endif
 331
 332
 333 /**
 334  * For looping over fragment attributes in the pointe, line
 335  * triangle rasterizers.
 336  */
 337 #define ATTRIB_LOOP_BEGIN                                \
 338    {                                                     \
 339       GLuint a;                                          \
 340       for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
 341          const GLuint attr = swrast->_ActiveAttribs[a];
 342
 343 #define ATTRIB_LOOP_END } }
 344
 345
 346
 347 #endif