src/mesa/swrast/s_context.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  5.1
   4  *
   5  * Copyright (C) 1999-2003  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 "context.h"
  31 #include "mtypes.h"
  32 #include "texobj.h"
  33
  34 #include "swrast.h"
  35 #include "s_blend.h"
  36 #include "s_context.h"
  37 #include "s_lines.h"
  38 #include "s_points.h"
  39 #include "s_span.h"
  40 #include "s_triangle.h"
  41 #include "s_texture.h"
  42
  43
  44 /*
  45  * Recompute the value of swrast->_RasterMask, etc. according to
  46  * the current context.
  47  */
  48 static void
  49 _swrast_update_rasterflags( GLcontext *ctx )
  50 {
  51    GLuint RasterMask = 0;
  52
  53    if (ctx->Color.AlphaEnabled)           RasterMask |= ALPHATEST_BIT;
  54    if (ctx->Color.BlendEnabled)           RasterMask |= BLEND_BIT;
  55    if (ctx->Depth.Test)                   RasterMask |= DEPTH_BIT;
  56    if (ctx->Fog.Enabled)                  RasterMask |= FOG_BIT;
  57    if (ctx->Scissor.Enabled)              RasterMask |= CLIP_BIT;
  58    if (ctx->Stencil.Enabled)              RasterMask |= STENCIL_BIT;
  59    if (ctx->Visual.rgbMode) {
  60       const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
  61       if (colorMask != 0xffffffff)        RasterMask |= MASKING_BIT;
  62       if (ctx->Color.ColorLogicOpEnabled) RasterMask |= LOGIC_OP_BIT;
  63       if (ctx->Texture._EnabledUnits)     RasterMask |= TEXTURE_BIT;
  64    }
  65    else {
  66       if (ctx->Color.IndexMask != 0xffffffff) RasterMask |= MASKING_BIT;
  67       if (ctx->Color.IndexLogicOpEnabled)     RasterMask |= LOGIC_OP_BIT;
  68    }
  69
  70    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers
  71        && ctx->Color.ColorMask[ACOMP]
  72        && ctx->Color.DrawBuffer != GL_NONE)
  73       RasterMask |= ALPHABUF_BIT;
  74
  75    if (   ctx->Viewport.X < 0
  76        || ctx->Viewport.X + ctx->Viewport.Width > (GLint) ctx->DrawBuffer->Width
  77        || ctx->Viewport.Y < 0
  78        || ctx->Viewport.Y + ctx->Viewport.Height > (GLint) ctx->DrawBuffer->Height) {
  79       RasterMask |= CLIP_BIT;
  80    }
  81
  82    if (ctx->Depth.OcclusionTest)
  83       RasterMask |= OCCLUSION_BIT;
  84
  85
  86    /* If we're not drawing to exactly one color buffer set the
  87     * MULTI_DRAW_BIT flag.  Also set it if we're drawing to no
  88     * buffers or the RGBA or CI mask disables all writes.
  89     */
  90    if (ctx->Color._DrawDestMask != FRONT_LEFT_BIT &&
  91        ctx->Color._DrawDestMask != BACK_LEFT_BIT &&
  92        ctx->Color._DrawDestMask != FRONT_RIGHT_BIT &&
  93        ctx->Color._DrawDestMask != BACK_RIGHT_BIT) {
  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.Enabled) {
 105       RasterMask |= FRAGPROG_BIT;
 106    }
 107
 108    SWRAST_CONTEXT(ctx)->_RasterMask = RasterMask;
 109 }
 110
 111
 112 static void
 113 _swrast_update_polygon( GLcontext *ctx )
 114 {
 115    GLfloat backface_sign = 1;
 116
 117    if (ctx->Polygon.CullFlag) {
 118       backface_sign = 1;
 119       switch(ctx->Polygon.CullFaceMode) {
 120       case GL_BACK:
 121          if(ctx->Polygon.FrontFace==GL_CCW)
 122             backface_sign = -1;
 123          break;
 124       case GL_FRONT:
 125          if(ctx->Polygon.FrontFace!=GL_CCW)
 126             backface_sign = -1;
 127          break;
 128       default:
 129       case GL_FRONT_AND_BACK:
 130          backface_sign = 0;
 131          break;
 132       }
 133    }
 134    else {
 135       backface_sign = 0;
 136    }
 137
 138    SWRAST_CONTEXT(ctx)->_backface_sign = backface_sign;
 139 }
 140
 141
 142 static void
 143 _swrast_update_hint( GLcontext *ctx )
 144 {
 145    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 146    swrast->_PreferPixelFog = (!swrast->AllowVertexFog ||
 147                               (ctx->Hint.Fog == GL_NICEST &&
 148                                swrast->AllowPixelFog));
 149 }
 150
 151
 152 /*
 153  * Update the swrast->_AnyTextureCombine flag.
 154  */
 155 static void
 156 _swrast_update_texture_env( GLcontext *ctx )
 157 {
 158    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 159    GLuint i;
 160    swrast->_AnyTextureCombine = GL_FALSE;
 161    for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
 162       if (ctx->Texture.Unit[i].EnvMode == GL_COMBINE_EXT ||
 163           ctx->Texture.Unit[i].EnvMode == GL_COMBINE4_NV) {
 164          swrast->_AnyTextureCombine = GL_TRUE;
 165          return;
 166       }
 167    }
 168 }
 169
 170
 171 #define _SWRAST_NEW_DERIVED (_SWRAST_NEW_RASTERMASK |   \
 172                              _NEW_TEXTURE |             \
 173                              _NEW_HINT |                \
 174                              _NEW_POLYGON )
 175
 176 /* State referenced by _swrast_choose_triangle, _swrast_choose_line.
 177  */
 178 #define _SWRAST_NEW_TRIANGLE (_SWRAST_NEW_DERIVED |             \
 179                               _NEW_RENDERMODE|                  \
 180                               _NEW_POLYGON|                     \
 181                               _NEW_DEPTH|                       \
 182                               _NEW_STENCIL|                     \
 183                               _NEW_COLOR|                       \
 184                               _NEW_TEXTURE|                     \
 185                               _SWRAST_NEW_RASTERMASK|           \
 186                               _NEW_LIGHT|                       \
 187                               _NEW_FOG |                        \
 188                               _DD_NEW_SEPARATE_SPECULAR)
 189
 190 #define _SWRAST_NEW_LINE (_SWRAST_NEW_DERIVED |         \
 191                           _NEW_RENDERMODE|              \
 192                           _NEW_LINE|                    \
 193                           _NEW_TEXTURE|                 \
 194                           _NEW_LIGHT|                   \
 195                           _NEW_FOG|                     \
 196                           _NEW_DEPTH |                  \
 197                           _DD_NEW_SEPARATE_SPECULAR)
 198
 199 #define _SWRAST_NEW_POINT (_SWRAST_NEW_DERIVED |        \
 200                            _NEW_RENDERMODE |            \
 201                            _NEW_POINT |                 \
 202                            _NEW_TEXTURE |               \
 203                            _NEW_LIGHT |                 \
 204                            _NEW_FOG |                   \
 205                            _DD_NEW_SEPARATE_SPECULAR)
 206
 207 #define _SWRAST_NEW_TEXTURE_SAMPLE_FUNC _NEW_TEXTURE
 208
 209 #define _SWRAST_NEW_TEXTURE_ENV_MODE _NEW_TEXTURE
 210
 211 #define _SWRAST_NEW_BLEND_FUNC _NEW_COLOR
 212
 213
 214
 215 /* Stub for swrast->Triangle to select a true triangle function
 216  * after a state change.
 217  */
 218 static void
 219 _swrast_validate_triangle( GLcontext *ctx,
 220                            const SWvertex *v0,
 221                            const SWvertex *v1,
 222                            const SWvertex *v2 )
 223 {
 224    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 225
 226    _swrast_validate_derived( ctx );
 227    swrast->choose_triangle( ctx );
 228
 229    if ((ctx->_TriangleCaps & DD_SEPARATE_SPECULAR) &&
 230        ctx->Texture._EnabledUnits == 0) {
 231       swrast->SpecTriangle = swrast->Triangle;
 232       swrast->Triangle = _swrast_add_spec_terms_triangle;
 233    }
 234
 235    swrast->Triangle( ctx, v0, v1, v2 );
 236 }
 237
 238 static void
 239 _swrast_validate_line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 240 {
 241    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 242
 243    _swrast_validate_derived( ctx );
 244    swrast->choose_line( ctx );
 245
 246    if ((ctx->_TriangleCaps & DD_SEPARATE_SPECULAR) &&
 247        ctx->Texture._EnabledUnits == 0) {
 248       swrast->SpecLine = swrast->Line;
 249       swrast->Line = _swrast_add_spec_terms_line;
 250    }
 251
 252
 253    swrast->Line( ctx, v0, v1 );
 254 }
 255
 256 static void
 257 _swrast_validate_point( GLcontext *ctx, const SWvertex *v0 )
 258 {
 259    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 260
 261    _swrast_validate_derived( ctx );
 262    swrast->choose_point( ctx );
 263
 264    if ((ctx->_TriangleCaps & DD_SEPARATE_SPECULAR) &&
 265        ctx->Texture._EnabledUnits == 0) {
 266       swrast->SpecPoint = swrast->Point;
 267       swrast->Point = _swrast_add_spec_terms_point;
 268    }
 269
 270    swrast->Point( ctx, v0 );
 271 }
 272
 273
 274 static void
 275 _swrast_validate_blend_func( GLcontext *ctx, GLuint n,
 276                              const GLubyte mask[],
 277                              GLchan src[][4],
 278                              CONST GLchan dst[][4] )
 279 {
 280    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 281
 282    _swrast_validate_derived( ctx );
 283    _swrast_choose_blend_func( ctx );
 284
 285    swrast->BlendFunc( ctx, n, mask, src, dst );
 286 }
 287
 288
 289 static void
 290 _swrast_validate_texture_sample( GLcontext *ctx, GLuint texUnit,
 291                                  const struct gl_texture_object *tObj,
 292                                  GLuint n, const GLfloat texcoords[][4],
 293                                  const GLfloat lambda[], GLchan rgba[][4] )
 294 {
 295    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 296
 297    _swrast_validate_derived( ctx );
 298
 299    /* Compute min/mag filter threshold */
 300    if (tObj->MinFilter != tObj->MagFilter) {
 301       if (tObj->MagFilter == GL_LINEAR
 302           && (tObj->MinFilter == GL_NEAREST_MIPMAP_NEAREST ||
 303               tObj->MinFilter == GL_NEAREST_MIPMAP_LINEAR)) {
 304          swrast->_MinMagThresh[texUnit] = 0.5F;
 305       }
 306       else {
 307          swrast->_MinMagThresh[texUnit] = 0.0F;
 308       }
 309    }
 310
 311    swrast->TextureSample[texUnit] =
 312       _swrast_choose_texture_sample_func( ctx, tObj );
 313
 314    swrast->TextureSample[texUnit]( ctx, texUnit, tObj, n, texcoords,
 315                                    lambda, rgba );
 316
 317    /* GL_SGI_texture_color_table */
 318    if (ctx->Texture.Unit[texUnit].ColorTableEnabled) {
 319       _swrast_texture_table_lookup(&ctx->Texture.Unit[texUnit].ColorTable, n, rgba);
 320    }
 321 }
 322
 323
 324 static void
 325 _swrast_sleep( GLcontext *ctx, GLuint new_state )
 326 {
 327 }
 328
 329
 330 static void
 331 _swrast_invalidate_state( GLcontext *ctx, GLuint new_state )
 332 {
 333    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 334    GLuint i;
 335
 336    swrast->NewState |= new_state;
 337
 338    /* After 10 statechanges without any swrast functions being called,
 339     * put the module to sleep.
 340     */
 341    if (++swrast->StateChanges > 10) {
 342       swrast->InvalidateState = _swrast_sleep;
 343       swrast->NewState = ~0;
 344       new_state = ~0;
 345    }
 346
 347    if (new_state & swrast->invalidate_triangle)
 348       swrast->Triangle = _swrast_validate_triangle;
 349
 350    if (new_state & swrast->invalidate_line)
 351       swrast->Line = _swrast_validate_line;
 352
 353    if (new_state & swrast->invalidate_point)
 354       swrast->Point = _swrast_validate_point;
 355
 356    if (new_state & _SWRAST_NEW_BLEND_FUNC)
 357       swrast->BlendFunc = _swrast_validate_blend_func;
 358
 359    if (new_state & _SWRAST_NEW_TEXTURE_SAMPLE_FUNC)
 360       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 361          swrast->TextureSample[i] = _swrast_validate_texture_sample;
 362
 363    if (ctx->Visual.rgbMode) {
 364       ASSERT(swrast->Driver.WriteRGBASpan);
 365       ASSERT(swrast->Driver.WriteRGBSpan);
 366       ASSERT(swrast->Driver.WriteMonoRGBASpan);
 367       ASSERT(swrast->Driver.WriteRGBAPixels);
 368       ASSERT(swrast->Driver.WriteMonoRGBAPixels);
 369       ASSERT(swrast->Driver.ReadRGBASpan);
 370       ASSERT(swrast->Driver.ReadRGBAPixels);
 371    }
 372    else {
 373       ASSERT(swrast->Driver.WriteCI32Span);
 374       ASSERT(swrast->Driver.WriteCI8Span);
 375       ASSERT(swrast->Driver.WriteMonoCISpan);
 376       ASSERT(swrast->Driver.WriteCI32Pixels);
 377       ASSERT(swrast->Driver.WriteMonoCIPixels);
 378       ASSERT(swrast->Driver.ReadCI32Span);
 379       ASSERT(swrast->Driver.ReadCI32Pixels);
 380    }
 381 }
 382
 383
 384 void
 385 _swrast_validate_derived( GLcontext *ctx )
 386 {
 387    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 388
 389    if (swrast->NewState) {
 390       if (swrast->NewState & _SWRAST_NEW_RASTERMASK)
 391          _swrast_update_rasterflags( ctx );
 392
 393       if (swrast->NewState & _NEW_POLYGON)
 394          _swrast_update_polygon( ctx );
 395
 396       if (swrast->NewState & _NEW_HINT)
 397          _swrast_update_hint( ctx );
 398
 399       if (swrast->NewState & _SWRAST_NEW_TEXTURE_ENV_MODE)
 400          _swrast_update_texture_env( ctx );
 401
 402       swrast->NewState = 0;
 403       swrast->StateChanges = 0;
 404       swrast->InvalidateState = _swrast_invalidate_state;
 405    }
 406 }
 407
 408 #define SWRAST_DEBUG 0
 409
 410 /* Public entrypoints:  See also s_accum.c, s_bitmap.c, etc.
 411  */
 412 void
 413 _swrast_Quad( GLcontext *ctx,
 414               const SWvertex *v0, const SWvertex *v1,
 415               const SWvertex *v2, const SWvertex *v3 )
 416 {
 417    if (SWRAST_DEBUG) {
 418       _mesa_debug(ctx, "_swrast_Quad\n");
 419       _swrast_print_vertex( ctx, v0 );
 420       _swrast_print_vertex( ctx, v1 );
 421       _swrast_print_vertex( ctx, v2 );
 422       _swrast_print_vertex( ctx, v3 );
 423    }
 424    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v3 );
 425    SWRAST_CONTEXT(ctx)->Triangle( ctx, v1, v2, v3 );
 426 }
 427
 428 void
 429 _swrast_Triangle( GLcontext *ctx, const SWvertex *v0,
 430                   const SWvertex *v1, const SWvertex *v2 )
 431 {
 432    if (SWRAST_DEBUG) {
 433       _mesa_debug(ctx, "_swrast_Triangle\n");
 434       _swrast_print_vertex( ctx, v0 );
 435       _swrast_print_vertex( ctx, v1 );
 436       _swrast_print_vertex( ctx, v2 );
 437    }
 438    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v2 );
 439 }
 440
 441 void
 442 _swrast_Line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 443 {
 444    if (SWRAST_DEBUG) {
 445       _mesa_debug(ctx, "_swrast_Line\n");
 446       _swrast_print_vertex( ctx, v0 );
 447       _swrast_print_vertex( ctx, v1 );
 448    }
 449    SWRAST_CONTEXT(ctx)->Line( ctx, v0, v1 );
 450 }
 451
 452 void
 453 _swrast_Point( GLcontext *ctx, const SWvertex *v0 )
 454 {
 455    if (SWRAST_DEBUG) {
 456       _mesa_debug(ctx, "_swrast_Point\n");
 457       _swrast_print_vertex( ctx, v0 );
 458    }
 459    SWRAST_CONTEXT(ctx)->Point( ctx, v0 );
 460 }
 461
 462 void
 463 _swrast_InvalidateState( GLcontext *ctx, GLuint new_state )
 464 {
 465    if (SWRAST_DEBUG) {
 466       _mesa_debug(ctx, "_swrast_InvalidateState\n");
 467    }
 468    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, new_state );
 469 }
 470
 471 void
 472 _swrast_ResetLineStipple( GLcontext *ctx )
 473 {
 474    if (SWRAST_DEBUG) {
 475       _mesa_debug(ctx, "_swrast_ResetLineStipple\n");
 476    }
 477    SWRAST_CONTEXT(ctx)->StippleCounter = 0;
 478 }
 479
 480 void
 481 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 482 {
 483    if (SWRAST_DEBUG) {
 484       _mesa_debug(ctx, "_swrast_allow_vertex_fog %d\n", value);
 485    }
 486    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 487    SWRAST_CONTEXT(ctx)->AllowVertexFog = value;
 488 }
 489
 490 void
 491 _swrast_allow_pixel_fog( GLcontext *ctx, GLboolean value )
 492 {
 493    if (SWRAST_DEBUG) {
 494       _mesa_debug(ctx, "_swrast_allow_pixel_fog %d\n", value);
 495    }
 496    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 497    SWRAST_CONTEXT(ctx)->AllowPixelFog = value;
 498 }
 499
 500
 501 GLboolean
 502 _swrast_CreateContext( GLcontext *ctx )
 503 {
 504    GLuint i;
 505    SWcontext *swrast = (SWcontext *)CALLOC(sizeof(SWcontext));
 506
 507    if (SWRAST_DEBUG) {
 508       _mesa_debug(ctx, "_swrast_CreateContext\n");
 509    }
 510
 511    if (!swrast)
 512       return GL_FALSE;
 513
 514    swrast->NewState = ~0;
 515
 516    swrast->choose_point = _swrast_choose_point;
 517    swrast->choose_line = _swrast_choose_line;
 518    swrast->choose_triangle = _swrast_choose_triangle;
 519
 520    swrast->invalidate_point = _SWRAST_NEW_POINT;
 521    swrast->invalidate_line = _SWRAST_NEW_LINE;
 522    swrast->invalidate_triangle = _SWRAST_NEW_TRIANGLE;
 523
 524    swrast->Point = _swrast_validate_point;
 525    swrast->Line = _swrast_validate_line;
 526    swrast->Triangle = _swrast_validate_triangle;
 527    swrast->InvalidateState = _swrast_sleep;
 528    swrast->BlendFunc = _swrast_validate_blend_func;
 529
 530    swrast->AllowVertexFog = GL_TRUE;
 531    swrast->AllowPixelFog = GL_TRUE;
 532
 533    if (ctx->Visual.doubleBufferMode)
 534       swrast->CurrentBuffer = BACK_LEFT_BIT;
 535    else
 536       swrast->CurrentBuffer = FRONT_LEFT_BIT;
 537
 538    /* Optimized Accum buffer */
 539    swrast->_IntegerAccumMode = GL_TRUE;
 540    swrast->_IntegerAccumScaler = 0.0;
 541
 542    for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 543       swrast->TextureSample[i] = _swrast_validate_texture_sample;
 544
 545    swrast->SpanArrays = MALLOC_STRUCT(span_arrays);
 546    if (!swrast->SpanArrays) {
 547       FREE(swrast);
 548       return GL_FALSE;
 549    }
 550
 551    /* init point span buffer */
 552    swrast->PointSpan.primitive = GL_POINT;
 553    swrast->PointSpan.start = 0;
 554    swrast->PointSpan.end = 0;
 555    swrast->PointSpan.facing = 0;
 556    swrast->PointSpan.array = swrast->SpanArrays;
 557
 558    assert(ctx->Const.MaxTextureUnits > 0);
 559    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_UNITS);
 560
 561    swrast->TexelBuffer = (GLchan *) MALLOC(ctx->Const.MaxTextureUnits *
 562                                            MAX_WIDTH * 4 * sizeof(GLchan));
 563    if (!swrast->TexelBuffer) {
 564       FREE(swrast->SpanArrays);
 565       FREE(swrast);
 566       return GL_FALSE;
 567    }
 568
 569    ctx->swrast_context = swrast;
 570
 571    return GL_TRUE;
 572 }
 573
 574 void
 575 _swrast_DestroyContext( GLcontext *ctx )
 576 {
 577    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 578
 579    if (SWRAST_DEBUG) {
 580       _mesa_debug(ctx, "_swrast_DestroyContext\n");
 581    }
 582
 583    FREE( swrast->SpanArrays );
 584    FREE( swrast->TexelBuffer );
 585    FREE( swrast );
 586
 587    ctx->swrast_context = 0;
 588 }
 589
 590
 591 struct swrast_device_driver *
 592 _swrast_GetDeviceDriverReference( GLcontext *ctx )
 593 {
 594    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 595    return &swrast->Driver;
 596 }
 597
 598 void
 599 _swrast_flush( GLcontext *ctx )
 600 {
 601    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 602    /* flush any pending fragments from rendering points */
 603    if (swrast->PointSpan.end > 0) {
 604       if (ctx->Visual.rgbMode) {
 605          if (ctx->Texture._EnabledCoordUnits)
 606             _swrast_write_texture_span(ctx, &(swrast->PointSpan));
 607          else
 608             _swrast_write_rgba_span(ctx, &(swrast->PointSpan));
 609       }
 610       else {
 611          _swrast_write_index_span(ctx, &(swrast->PointSpan));
 612       }
 613       swrast->PointSpan.end = 0;
 614    }
 615 }
 616
 617 void
 618 _swrast_render_primitive( GLcontext *ctx, GLenum prim )
 619 {
 620    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 621    if (swrast->Primitive == GL_POINTS && prim != GL_POINTS) {
 622       _swrast_flush(ctx);
 623    }
 624    swrast->Primitive = prim;
 625 }
 626
 627
 628 void
 629 _swrast_render_start( GLcontext *ctx )
 630 {
 631    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 632    if (swrast->Driver.SpanRenderStart)
 633       swrast->Driver.SpanRenderStart( ctx );
 634    swrast->PointSpan.end = 0;
 635 }
 636
 637 void
 638 _swrast_render_finish( GLcontext *ctx )
 639 {
 640    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 641    if (swrast->Driver.SpanRenderFinish)
 642       swrast->Driver.SpanRenderFinish( ctx );
 643
 644    _swrast_flush(ctx);
 645 }
 646
 647
 648 #define SWRAST_DEBUG_VERTICES 0
 649
 650 void
 651 _swrast_print_vertex( GLcontext *ctx, const SWvertex *v )
 652 {
 653    GLuint i;
 654
 655    if (SWRAST_DEBUG_VERTICES) {
 656       _mesa_debug(ctx, "win %f %f %f %f\n",
 657                   v->win[0], v->win[1], v->win[2], v->win[3]);
 658
 659       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 660          if (ctx->Texture.Unit[i]._ReallyEnabled)
 661             _mesa_debug(ctx, "texcoord[%d] %f %f %f %f\n", i,
 662                         v->texcoord[i][0], v->texcoord[i][1],
 663                         v->texcoord[i][2], v->texcoord[i][3]);
 664
 665 #if CHAN_TYPE == GL_FLOAT
 666       _mesa_debug(ctx, "color %f %f %f %f\n",
 667                   v->color[0], v->color[1], v->color[2], v->color[3]);
 668       _mesa_debug(ctx, "spec %f %f %f %f\n",
 669                   v->specular[0], v->specular[1],
 670                   v->specular[2], v->specular[3]);
 671 #else
 672       _mesa_debug(ctx, "color %d %d %d %d\n",
 673                   v->color[0], v->color[1], v->color[2], v->color[3]);
 674       _mesa_debug(ctx, "spec %d %d %d %d\n",
 675                   v->specular[0], v->specular[1],
 676                   v->specular[2], v->specular[3]);
 677 #endif
 678       _mesa_debug(ctx, "fog %f\n", v->fog);
 679       _mesa_debug(ctx, "index %d\n", v->index);
 680       _mesa_debug(ctx, "pointsize %f\n", v->pointSize);
 681       _mesa_debug(ctx, "\n");
 682    }
 683 }