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