src/mesa/swrast/s_context.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2004  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  * Authors:
  25  *    Keith Whitwell <keith@tungstengraphics.com>
  26  *    Brian Paul
  27  */
  28
  29 #include "imports.h"
  30 #include "bufferobj.h"
  31 #include "context.h"
  32 #include "colormac.h"
  33 #include "mtypes.h"
  34 #include "program.h"
  35 #include "texobj.h"
  36 #include "nvfragprog.h"
  37
  38 #include "swrast.h"
  39 #include "s_blend.h"
  40 #include "s_context.h"
  41 #include "s_lines.h"
  42 #include "s_points.h"
  43 #include "s_span.h"
  44 #include "s_triangle.h"
  45 #include "s_texture.h"
  46
  47
  48 /**
  49  * Recompute the value of swrast->_RasterMask, etc. according to
  50  * the current context.  The _RasterMask field can be easily tested by
  51  * drivers to determine certain basic GL state (does the primitive need
  52  * stenciling, logic-op, fog, etc?).
  53  */
  54 static void
  55 _swrast_update_rasterflags( GLcontext *ctx )
  56 {
  57    GLuint rasterMask = 0;
  58
  59    if (ctx->Color.AlphaEnabled)           rasterMask |= ALPHATEST_BIT;
  60    if (ctx->Color.BlendEnabled)           rasterMask |= BLEND_BIT;
  61    if (ctx->Depth.Test)                   rasterMask |= DEPTH_BIT;
  62    if (ctx->Fog.Enabled)                  rasterMask |= FOG_BIT;
  63    if (ctx->Scissor.Enabled)              rasterMask |= CLIP_BIT;
  64    if (ctx->Stencil.Enabled)              rasterMask |= STENCIL_BIT;
  65    if (ctx->Visual.rgbMode) {
  66       const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
  67       if (colorMask != 0xffffffff)        rasterMask |= MASKING_BIT;
  68       if (ctx->Color._LogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  69       if (ctx->Texture._EnabledUnits)     rasterMask |= TEXTURE_BIT;
  70    }
  71    else {
  72       if (ctx->Color.IndexMask != 0xffffffff) rasterMask |= MASKING_BIT;
  73       if (ctx->Color.IndexLogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  74    }
  75
  76    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers
  77        && ctx->Color.ColorMask[ACOMP]
  78        && ctx->Color.DrawBuffer != GL_NONE)
  79       rasterMask |= ALPHABUF_BIT;
  80
  81    if (   ctx->Viewport.X < 0
  82        || ctx->Viewport.X + ctx->Viewport.Width > (GLint) ctx->DrawBuffer->Width
  83        || ctx->Viewport.Y < 0
  84        || ctx->Viewport.Y + ctx->Viewport.Height > (GLint) ctx->DrawBuffer->Height) {
  85       rasterMask |= CLIP_BIT;
  86    }
  87
  88    if (ctx->Depth.OcclusionTest || ctx->Occlusion.Active)
  89       rasterMask |= OCCLUSION_BIT;
  90
  91
  92    /* If we're not drawing to exactly one color buffer set the
  93     * MULTI_DRAW_BIT flag.  Also set it if we're drawing to no
  94     * buffers or the RGBA or CI mask disables all writes.
  95     */
  96    if (_mesa_bitcount(ctx->Color._DrawDestMask[0]) != 1) {
  97       /* more than one color buffer designated for writing (or zero buffers) */
  98       rasterMask |= MULTI_DRAW_BIT;
  99    }
 100    else if (ctx->Visual.rgbMode && *((GLuint *) ctx->Color.ColorMask) == 0) {
 101       rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
 102    }
 103    else if (!ctx->Visual.rgbMode && ctx->Color.IndexMask==0) {
 104       rasterMask |= MULTI_DRAW_BIT; /* all color index bits disabled */
 105    }
 106
 107    if (ctx->FragmentProgram._Active) {
 108       rasterMask |= FRAGPROG_BIT;
 109    }
 110
 111    if (ctx->ATIFragmentShader._Enabled) {
 112       rasterMask |= ATIFRAGSHADER_BIT;
 113    }
 114
 115    SWRAST_CONTEXT(ctx)->_RasterMask = rasterMask;
 116 }
 117
 118
 119 /**
 120  * Examine polycon culls tate to compute the _BackfaceSign field.
 121  * _BackfaceSign will be 0 if no culling, -1 if culling back-faces,
 122  * and 1 if culling front-faces.  The Polygon FrontFace state also
 123  * factors in.
 124  */
 125 static void
 126 _swrast_update_polygon( GLcontext *ctx )
 127 {
 128    GLfloat backface_sign = 1;
 129
 130    if (ctx->Polygon.CullFlag) {
 131       backface_sign = 1;
 132       switch(ctx->Polygon.CullFaceMode) {
 133       case GL_BACK:
 134          if(ctx->Polygon.FrontFace==GL_CCW)
 135             backface_sign = -1;
 136          break;
 137       case GL_FRONT:
 138          if(ctx->Polygon.FrontFace!=GL_CCW)
 139             backface_sign = -1;
 140          break;
 141       default:
 142       case GL_FRONT_AND_BACK:
 143          backface_sign = 0;
 144          break;
 145       }
 146    }
 147    else {
 148       backface_sign = 0;
 149    }
 150
 151    SWRAST_CONTEXT(ctx)->_BackfaceSign = backface_sign;
 152 }
 153
 154
 155 /**
 156  * Update the _PreferPixelFog field to indicate if we need to compute
 157  * fog factors per-fragment.
 158  */
 159 static void
 160 _swrast_update_fog_hint( GLcontext *ctx )
 161 {
 162    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 163    swrast->_PreferPixelFog = (!swrast->AllowVertexFog ||
 164                               ctx->FragmentProgram._Active ||
 165                               (ctx->Hint.Fog == GL_NICEST &&
 166                                swrast->AllowPixelFog));
 167 }
 168
 169
 170
 171 /**
 172  * Update the swrast->_AnyTextureCombine flag.
 173  */
 174 static void
 175 _swrast_update_texture_env( GLcontext *ctx )
 176 {
 177    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 178    GLuint i;
 179    swrast->_AnyTextureCombine = GL_FALSE;
 180    for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
 181       if (ctx->Texture.Unit[i].EnvMode == GL_COMBINE_EXT ||
 182           ctx->Texture.Unit[i].EnvMode == GL_COMBINE4_NV) {
 183          swrast->_AnyTextureCombine = GL_TRUE;
 184          return;
 185       }
 186    }
 187 }
 188
 189
 190 /**
 191  * Update swrast->_FogColor and swrast->_FogEnable values.
 192  */
 193 static void
 194 _swrast_update_fog_state( GLcontext *ctx )
 195 {
 196    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 197
 198    /* convert fog color to GLchan values */
 199    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[RCOMP], ctx->Fog.Color[RCOMP]);
 200    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[GCOMP], ctx->Fog.Color[GCOMP]);
 201    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[BCOMP], ctx->Fog.Color[BCOMP]);
 202
 203    /* determine if fog is needed, and if so, which fog mode */
 204    swrast->_FogEnabled = GL_FALSE;
 205    if (ctx->FragmentProgram._Active) {
 206       if (ctx->FragmentProgram._Current->Base.Target==GL_FRAGMENT_PROGRAM_ARB) {
 207          const struct fragment_program *p
 208             = (struct fragment_program *) ctx->FragmentProgram._Current;
 209          if (p->FogOption != GL_NONE) {
 210             swrast->_FogEnabled = GL_TRUE;
 211             swrast->_FogMode = p->FogOption;
 212          }
 213       }
 214    }
 215    else if (ctx->Fog.Enabled) {
 216       swrast->_FogEnabled = GL_TRUE;
 217       swrast->_FogMode = ctx->Fog.Mode;
 218    }
 219 }
 220
 221
 222 /**
 223  * Update state for running fragment programs.  Basically, load the
 224  * program parameters with current state values.
 225  */
 226 static void
 227 _swrast_update_fragment_program( GLcontext *ctx )
 228 {
 229    if (ctx->FragmentProgram._Active) {
 230       struct fragment_program *program = ctx->FragmentProgram._Current;
 231       _mesa_load_state_parameters(ctx, program->Parameters);
 232    }
 233 }
 234
 235
 236
 237 #define _SWRAST_NEW_DERIVED (_SWRAST_NEW_RASTERMASK |   \
 238                              _NEW_TEXTURE |             \
 239                              _NEW_HINT |                \
 240                              _NEW_POLYGON )
 241
 242 /* State referenced by _swrast_choose_triangle, _swrast_choose_line.
 243  */
 244 #define _SWRAST_NEW_TRIANGLE (_SWRAST_NEW_DERIVED |             \
 245                               _NEW_RENDERMODE|                  \
 246                               _NEW_POLYGON|                     \
 247                               _NEW_DEPTH|                       \
 248                               _NEW_STENCIL|                     \
 249                               _NEW_COLOR|                       \
 250                               _NEW_TEXTURE|                     \
 251                               _SWRAST_NEW_RASTERMASK|           \
 252                               _NEW_LIGHT|                       \
 253                               _NEW_FOG |                        \
 254                               _DD_NEW_SEPARATE_SPECULAR)
 255
 256 #define _SWRAST_NEW_LINE (_SWRAST_NEW_DERIVED |         \
 257                           _NEW_RENDERMODE|              \
 258                           _NEW_LINE|                    \
 259                           _NEW_TEXTURE|                 \
 260                           _NEW_LIGHT|                   \
 261                           _NEW_FOG|                     \
 262                           _NEW_DEPTH |                  \
 263                           _DD_NEW_SEPARATE_SPECULAR)
 264
 265 #define _SWRAST_NEW_POINT (_SWRAST_NEW_DERIVED |        \
 266                            _NEW_RENDERMODE |            \
 267                            _NEW_POINT |                 \
 268                            _NEW_TEXTURE |               \
 269                            _NEW_LIGHT |                 \
 270                            _NEW_FOG |                   \
 271                            _DD_NEW_SEPARATE_SPECULAR)
 272
 273 #define _SWRAST_NEW_TEXTURE_SAMPLE_FUNC _NEW_TEXTURE
 274
 275 #define _SWRAST_NEW_TEXTURE_ENV_MODE _NEW_TEXTURE
 276
 277 #define _SWRAST_NEW_BLEND_FUNC _NEW_COLOR
 278
 279
 280
 281 /**
 282  * Stub for swrast->Triangle to select a true triangle function
 283  * after a state change.
 284  */
 285 static void
 286 _swrast_validate_triangle( GLcontext *ctx,
 287                            const SWvertex *v0,
 288                            const SWvertex *v1,
 289                            const SWvertex *v2 )
 290 {
 291    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 292
 293    _swrast_validate_derived( ctx );
 294    swrast->choose_triangle( ctx );
 295
 296    if (ctx->Texture._EnabledUnits == 0
 297        && NEED_SECONDARY_COLOR(ctx)
 298        && !ctx->FragmentProgram._Active) {
 299       /* separate specular color, but no texture */
 300       swrast->SpecTriangle = swrast->Triangle;
 301       swrast->Triangle = _swrast_add_spec_terms_triangle;
 302    }
 303
 304    swrast->Triangle( ctx, v0, v1, v2 );
 305 }
 306
 307 /**
 308  * Called via swrast->Line.  Examine current GL state and choose a software
 309  * line routine.  Then call it.
 310  */
 311 static void
 312 _swrast_validate_line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 313 {
 314    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 315
 316    _swrast_validate_derived( ctx );
 317    swrast->choose_line( ctx );
 318
 319    if (ctx->Texture._EnabledUnits == 0
 320        && NEED_SECONDARY_COLOR(ctx)
 321        && !ctx->FragmentProgram._Active) {
 322       swrast->SpecLine = swrast->Line;
 323       swrast->Line = _swrast_add_spec_terms_line;
 324    }
 325
 326
 327    swrast->Line( ctx, v0, v1 );
 328 }
 329
 330 /**
 331  * Called via swrast->Point.  Examine current GL state and choose a software
 332  * point routine.  Then call it.
 333  */
 334 static void
 335 _swrast_validate_point( GLcontext *ctx, const SWvertex *v0 )
 336 {
 337    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 338
 339    _swrast_validate_derived( ctx );
 340    swrast->choose_point( ctx );
 341
 342    if (ctx->Texture._EnabledUnits == 0
 343        && NEED_SECONDARY_COLOR(ctx)
 344        && !ctx->FragmentProgram._Active) {
 345       swrast->SpecPoint = swrast->Point;
 346       swrast->Point = _swrast_add_spec_terms_point;
 347    }
 348
 349    swrast->Point( ctx, v0 );
 350 }
 351
 352
 353 /**
 354  * Called via swrast->BlendFunc.  Examine GL state to choose a blending
 355  * function, then call it.
 356  */
 357 static void _ASMAPI
 358 _swrast_validate_blend_func( GLcontext *ctx, GLuint n,
 359                              const GLubyte mask[],
 360                              GLchan src[][4],
 361                              CONST GLchan dst[][4] )
 362 {
 363    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 364
 365    _swrast_validate_derived( ctx );
 366    _swrast_choose_blend_func( ctx );
 367
 368    swrast->BlendFunc( ctx, n, mask, src, dst );
 369 }
 370
 371
 372 /**
 373  * Called via the swrast->TextureSample[i] function pointer.
 374  * Basically, given a texture object, an array of texture coords
 375  * and an array of level-of-detail values, return an array of colors.
 376  * In this case, determine the correct texture sampling routine
 377  * (depending on filter mode, texture dimensions, etc) then call the
 378  * sampler routine.
 379  */
 380 static void
 381 _swrast_validate_texture_sample( GLcontext *ctx, GLuint texUnit,
 382                                  const struct gl_texture_object *tObj,
 383                                  GLuint n, const GLfloat texcoords[][4],
 384                                  const GLfloat lambda[], GLchan rgba[][4] )
 385 {
 386    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 387
 388    _swrast_validate_derived( ctx );
 389
 390    /* Compute min/mag filter threshold */
 391    if (tObj && tObj->MinFilter != tObj->MagFilter) {
 392       if (tObj->MagFilter == GL_LINEAR
 393           && (tObj->MinFilter == GL_NEAREST_MIPMAP_NEAREST ||
 394               tObj->MinFilter == GL_NEAREST_MIPMAP_LINEAR)) {
 395          swrast->_MinMagThresh[texUnit] = 0.5F;
 396       }
 397       else {
 398          swrast->_MinMagThresh[texUnit] = 0.0F;
 399       }
 400    }
 401
 402    swrast->TextureSample[texUnit] =
 403       _swrast_choose_texture_sample_func( ctx, tObj );
 404
 405    swrast->TextureSample[texUnit]( ctx, texUnit, tObj, n, texcoords,
 406                                    lambda, rgba );
 407 }
 408
 409
 410 static void
 411 _swrast_sleep( GLcontext *ctx, GLuint new_state )
 412 {
 413    (void) ctx; (void) new_state;
 414 }
 415
 416
 417 static void
 418 _swrast_invalidate_state( GLcontext *ctx, GLuint new_state )
 419 {
 420    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 421    GLuint i;
 422
 423    swrast->NewState |= new_state;
 424
 425    /* After 10 statechanges without any swrast functions being called,
 426     * put the module to sleep.
 427     */
 428    if (++swrast->StateChanges > 10) {
 429       swrast->InvalidateState = _swrast_sleep;
 430       swrast->NewState = ~0;
 431       new_state = ~0;
 432    }
 433
 434    if (new_state & swrast->invalidate_triangle)
 435       swrast->Triangle = _swrast_validate_triangle;
 436
 437    if (new_state & swrast->invalidate_line)
 438       swrast->Line = _swrast_validate_line;
 439
 440    if (new_state & swrast->invalidate_point)
 441       swrast->Point = _swrast_validate_point;
 442
 443    if (new_state & _SWRAST_NEW_BLEND_FUNC)
 444       swrast->BlendFunc = _swrast_validate_blend_func;
 445
 446    if (new_state & _SWRAST_NEW_TEXTURE_SAMPLE_FUNC)
 447       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 448          swrast->TextureSample[i] = _swrast_validate_texture_sample;
 449
 450    /* Debug checks */
 451    if (ctx->Visual.rgbMode) {
 452       ASSERT(swrast->Driver.WriteRGBASpan);
 453       ASSERT(swrast->Driver.WriteRGBSpan);
 454       ASSERT(swrast->Driver.WriteMonoRGBASpan);
 455       ASSERT(swrast->Driver.WriteRGBAPixels);
 456       ASSERT(swrast->Driver.WriteMonoRGBAPixels);
 457       ASSERT(swrast->Driver.ReadRGBASpan);
 458       ASSERT(swrast->Driver.ReadRGBAPixels);
 459    }
 460    else {
 461       ASSERT(swrast->Driver.WriteCI32Span);
 462       ASSERT(swrast->Driver.WriteCI8Span);
 463       ASSERT(swrast->Driver.WriteMonoCISpan);
 464       ASSERT(swrast->Driver.WriteCI32Pixels);
 465       ASSERT(swrast->Driver.WriteMonoCIPixels);
 466       ASSERT(swrast->Driver.ReadCI32Span);
 467       ASSERT(swrast->Driver.ReadCI32Pixels);
 468    }
 469 }
 470
 471
 472 void
 473 _swrast_validate_derived( GLcontext *ctx )
 474 {
 475    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 476
 477    if (swrast->NewState) {
 478       if (swrast->NewState & _SWRAST_NEW_RASTERMASK)
 479          _swrast_update_rasterflags( ctx );
 480
 481       if (swrast->NewState & _NEW_POLYGON)
 482          _swrast_update_polygon( ctx );
 483
 484       if (swrast->NewState & (_NEW_HINT | _NEW_PROGRAM))
 485          _swrast_update_fog_hint( ctx );
 486
 487       if (swrast->NewState & _SWRAST_NEW_TEXTURE_ENV_MODE)
 488          _swrast_update_texture_env( ctx );
 489
 490       if (swrast->NewState & (_NEW_FOG | _NEW_PROGRAM))
 491          _swrast_update_fog_state( ctx );
 492
 493       if (swrast->NewState & _NEW_PROGRAM)
 494          _swrast_update_fragment_program( ctx );
 495
 496       swrast->NewState = 0;
 497       swrast->StateChanges = 0;
 498       swrast->InvalidateState = _swrast_invalidate_state;
 499    }
 500 }
 501
 502 #define SWRAST_DEBUG 0
 503
 504 /* Public entrypoints:  See also s_accum.c, s_bitmap.c, etc.
 505  */
 506 void
 507 _swrast_Quad( GLcontext *ctx,
 508               const SWvertex *v0, const SWvertex *v1,
 509               const SWvertex *v2, const SWvertex *v3 )
 510 {
 511    if (SWRAST_DEBUG) {
 512       _mesa_debug(ctx, "_swrast_Quad\n");
 513       _swrast_print_vertex( ctx, v0 );
 514       _swrast_print_vertex( ctx, v1 );
 515       _swrast_print_vertex( ctx, v2 );
 516       _swrast_print_vertex( ctx, v3 );
 517    }
 518    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v3 );
 519    SWRAST_CONTEXT(ctx)->Triangle( ctx, v1, v2, v3 );
 520 }
 521
 522 void
 523 _swrast_Triangle( GLcontext *ctx, const SWvertex *v0,
 524                   const SWvertex *v1, const SWvertex *v2 )
 525 {
 526    if (SWRAST_DEBUG) {
 527       _mesa_debug(ctx, "_swrast_Triangle\n");
 528       _swrast_print_vertex( ctx, v0 );
 529       _swrast_print_vertex( ctx, v1 );
 530       _swrast_print_vertex( ctx, v2 );
 531    }
 532    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v2 );
 533 }
 534
 535 void
 536 _swrast_Line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 537 {
 538    if (SWRAST_DEBUG) {
 539       _mesa_debug(ctx, "_swrast_Line\n");
 540       _swrast_print_vertex( ctx, v0 );
 541       _swrast_print_vertex( ctx, v1 );
 542    }
 543    SWRAST_CONTEXT(ctx)->Line( ctx, v0, v1 );
 544 }
 545
 546 void
 547 _swrast_Point( GLcontext *ctx, const SWvertex *v0 )
 548 {
 549    if (SWRAST_DEBUG) {
 550       _mesa_debug(ctx, "_swrast_Point\n");
 551       _swrast_print_vertex( ctx, v0 );
 552    }
 553    SWRAST_CONTEXT(ctx)->Point( ctx, v0 );
 554 }
 555
 556 void
 557 _swrast_InvalidateState( GLcontext *ctx, GLuint new_state )
 558 {
 559    if (SWRAST_DEBUG) {
 560       _mesa_debug(ctx, "_swrast_InvalidateState\n");
 561    }
 562    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, new_state );
 563 }
 564
 565 void
 566 _swrast_ResetLineStipple( GLcontext *ctx )
 567 {
 568    if (SWRAST_DEBUG) {
 569       _mesa_debug(ctx, "_swrast_ResetLineStipple\n");
 570    }
 571    SWRAST_CONTEXT(ctx)->StippleCounter = 0;
 572 }
 573
 574 void
 575 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 576 {
 577    if (SWRAST_DEBUG) {
 578       _mesa_debug(ctx, "_swrast_allow_vertex_fog %d\n", value);
 579    }
 580    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 581    SWRAST_CONTEXT(ctx)->AllowVertexFog = value;
 582 }
 583
 584 void
 585 _swrast_allow_pixel_fog( GLcontext *ctx, GLboolean value )
 586 {
 587    if (SWRAST_DEBUG) {
 588       _mesa_debug(ctx, "_swrast_allow_pixel_fog %d\n", value);
 589    }
 590    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 591    SWRAST_CONTEXT(ctx)->AllowPixelFog = value;
 592 }
 593
 594
 595 GLboolean
 596 _swrast_CreateContext( GLcontext *ctx )
 597 {
 598    GLuint i;
 599    SWcontext *swrast = (SWcontext *)CALLOC(sizeof(SWcontext));
 600
 601    if (SWRAST_DEBUG) {
 602       _mesa_debug(ctx, "_swrast_CreateContext\n");
 603    }
 604
 605    if (!swrast)
 606       return GL_FALSE;
 607
 608    swrast->NewState = ~0;
 609
 610    swrast->choose_point = _swrast_choose_point;
 611    swrast->choose_line = _swrast_choose_line;
 612    swrast->choose_triangle = _swrast_choose_triangle;
 613
 614    swrast->invalidate_point = _SWRAST_NEW_POINT;
 615    swrast->invalidate_line = _SWRAST_NEW_LINE;
 616    swrast->invalidate_triangle = _SWRAST_NEW_TRIANGLE;
 617
 618    swrast->Point = _swrast_validate_point;
 619    swrast->Line = _swrast_validate_line;
 620    swrast->Triangle = _swrast_validate_triangle;
 621    swrast->InvalidateState = _swrast_sleep;
 622    swrast->BlendFunc = _swrast_validate_blend_func;
 623
 624    swrast->AllowVertexFog = GL_TRUE;
 625    swrast->AllowPixelFog = GL_TRUE;
 626
 627    if (ctx->Visual.doubleBufferMode)
 628       swrast->CurrentBufferBit = DD_BACK_LEFT_BIT;
 629    else
 630       swrast->CurrentBufferBit = DD_FRONT_LEFT_BIT;
 631
 632    /* Optimized Accum buffer */
 633    swrast->_IntegerAccumMode = GL_TRUE;
 634    swrast->_IntegerAccumScaler = 0.0;
 635
 636    for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 637       swrast->TextureSample[i] = _swrast_validate_texture_sample;
 638
 639    swrast->SpanArrays = MALLOC_STRUCT(span_arrays);
 640    if (!swrast->SpanArrays) {
 641       FREE(swrast);
 642       return GL_FALSE;
 643    }
 644
 645    /* init point span buffer */
 646    swrast->PointSpan.primitive = GL_POINT;
 647    swrast->PointSpan.start = 0;
 648    swrast->PointSpan.end = 0;
 649    swrast->PointSpan.facing = 0;
 650    swrast->PointSpan.array = swrast->SpanArrays;
 651
 652    assert(ctx->Const.MaxTextureUnits > 0);
 653    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_UNITS);
 654
 655    swrast->TexelBuffer = (GLchan *) MALLOC(ctx->Const.MaxTextureUnits *
 656                                            MAX_WIDTH * 4 * sizeof(GLchan));
 657    if (!swrast->TexelBuffer) {
 658       FREE(swrast->SpanArrays);
 659       FREE(swrast);
 660       return GL_FALSE;
 661    }
 662
 663    ctx->swrast_context = swrast;
 664
 665    return GL_TRUE;
 666 }
 667
 668 void
 669 _swrast_DestroyContext( GLcontext *ctx )
 670 {
 671    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 672
 673    if (SWRAST_DEBUG) {
 674       _mesa_debug(ctx, "_swrast_DestroyContext\n");
 675    }
 676
 677    FREE( swrast->SpanArrays );
 678    FREE( swrast->TexelBuffer );
 679    FREE( swrast );
 680
 681    ctx->swrast_context = 0;
 682 }
 683
 684
 685 struct swrast_device_driver *
 686 _swrast_GetDeviceDriverReference( GLcontext *ctx )
 687 {
 688    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 689    return &swrast->Driver;
 690 }
 691
 692 void
 693 _swrast_flush( GLcontext *ctx )
 694 {
 695    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 696    /* flush any pending fragments from rendering points */
 697    if (swrast->PointSpan.end > 0) {
 698       if (ctx->Visual.rgbMode) {
 699          _swrast_write_rgba_span(ctx, &(swrast->PointSpan));
 700       }
 701       else {
 702          _swrast_write_index_span(ctx, &(swrast->PointSpan));
 703       }
 704       swrast->PointSpan.end = 0;
 705    }
 706 }
 707
 708 void
 709 _swrast_render_primitive( GLcontext *ctx, GLenum prim )
 710 {
 711    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 712    if (swrast->Primitive == GL_POINTS && prim != GL_POINTS) {
 713       _swrast_flush(ctx);
 714    }
 715    swrast->Primitive = prim;
 716 }
 717
 718
 719 void
 720 _swrast_render_start( GLcontext *ctx )
 721 {
 722    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 723    if (swrast->Driver.SpanRenderStart)
 724       swrast->Driver.SpanRenderStart( ctx );
 725    swrast->PointSpan.end = 0;
 726 }
 727
 728 void
 729 _swrast_render_finish( GLcontext *ctx )
 730 {
 731    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 732    if (swrast->Driver.SpanRenderFinish)
 733       swrast->Driver.SpanRenderFinish( ctx );
 734
 735    _swrast_flush(ctx);
 736 }
 737
 738
 739 #define SWRAST_DEBUG_VERTICES 0
 740
 741 void
 742 _swrast_print_vertex( GLcontext *ctx, const SWvertex *v )
 743 {
 744    GLuint i;
 745
 746    if (SWRAST_DEBUG_VERTICES) {
 747       _mesa_debug(ctx, "win %f %f %f %f\n",
 748                   v->win[0], v->win[1], v->win[2], v->win[3]);
 749
 750       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 751          if (ctx->Texture.Unit[i]._ReallyEnabled)
 752             _mesa_debug(ctx, "texcoord[%d] %f %f %f %f\n", i,
 753                         v->texcoord[i][0], v->texcoord[i][1],
 754                         v->texcoord[i][2], v->texcoord[i][3]);
 755
 756 #if CHAN_TYPE == GL_FLOAT
 757       _mesa_debug(ctx, "color %f %f %f %f\n",
 758                   v->color[0], v->color[1], v->color[2], v->color[3]);
 759       _mesa_debug(ctx, "spec %f %f %f %f\n",
 760                   v->specular[0], v->specular[1],
 761                   v->specular[2], v->specular[3]);
 762 #else
 763       _mesa_debug(ctx, "color %d %d %d %d\n",
 764                   v->color[0], v->color[1], v->color[2], v->color[3]);
 765       _mesa_debug(ctx, "spec %d %d %d %d\n",
 766                   v->specular[0], v->specular[1],
 767                   v->specular[2], v->specular[3]);
 768 #endif
 769       _mesa_debug(ctx, "fog %f\n", v->fog);
 770       _mesa_debug(ctx, "index %d\n", v->index);
 771       _mesa_debug(ctx, "pointsize %f\n", v->pointSize);
 772       _mesa_debug(ctx, "\n");
 773    }
 774 }