reactos/lib/mesa32/src/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 (ctx->DrawBuffer->_NumColorDrawBuffers[0] != 1) {
  92       /* more than one color buffer designated for writing (or zero buffers) */
  93       rasterMask |= MULTI_DRAW_BIT;
  94    }
  95    else if (ctx->Visual.rgbMode && *((GLuint *) ctx->Color.ColorMask) == 0) {
  96       rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
  97    }
  98    else if (!ctx->Visual.rgbMode && ctx->Color.IndexMask==0) {
  99       rasterMask |= MULTI_DRAW_BIT; /* all color index bits disabled */
 100    }
 101
 102    if (ctx->FragmentProgram._Active) {
 103       rasterMask |= FRAGPROG_BIT;
 104    }
 105
 106    if (ctx->ATIFragmentShader._Enabled) {
 107       rasterMask |= ATIFRAGSHADER_BIT;
 108    }
 109
 110    SWRAST_CONTEXT(ctx)->_RasterMask = rasterMask;
 111 }
 112
 113
 114 /**
 115  * Examine polycon culls tate to compute the _BackfaceSign field.
 116  * _BackfaceSign will be 0 if no culling, -1 if culling back-faces,
 117  * and 1 if culling front-faces.  The Polygon FrontFace state also
 118  * factors in.
 119  */
 120 static void
 121 _swrast_update_polygon( GLcontext *ctx )
 122 {
 123    GLfloat backface_sign = 1;
 124
 125    if (ctx->Polygon.CullFlag) {
 126       backface_sign = 1;
 127       switch(ctx->Polygon.CullFaceMode) {
 128       case GL_BACK:
 129          if(ctx->Polygon.FrontFace==GL_CCW)
 130             backface_sign = -1;
 131          break;
 132       case GL_FRONT:
 133          if(ctx->Polygon.FrontFace!=GL_CCW)
 134             backface_sign = -1;
 135          break;
 136       default:
 137       case GL_FRONT_AND_BACK:
 138          backface_sign = 0;
 139          break;
 140       }
 141    }
 142    else {
 143       backface_sign = 0;
 144    }
 145
 146    SWRAST_CONTEXT(ctx)->_BackfaceSign = backface_sign;
 147 }
 148
 149
 150 /**
 151  * Update the _PreferPixelFog field to indicate if we need to compute
 152  * fog factors per-fragment.
 153  */
 154 static void
 155 _swrast_update_fog_hint( GLcontext *ctx )
 156 {
 157    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 158    swrast->_PreferPixelFog = (!swrast->AllowVertexFog ||
 159                               ctx->FragmentProgram._Enabled || /* not _Active! */
 160                               (ctx->Hint.Fog == GL_NICEST &&
 161                                swrast->AllowPixelFog));
 162 }
 163
 164
 165
 166 /**
 167  * Update the swrast->_AnyTextureCombine flag.
 168  */
 169 static void
 170 _swrast_update_texture_env( GLcontext *ctx )
 171 {
 172    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 173    GLuint i;
 174    swrast->_AnyTextureCombine = GL_FALSE;
 175    for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
 176       if (ctx->Texture.Unit[i].EnvMode == GL_COMBINE_EXT ||
 177           ctx->Texture.Unit[i].EnvMode == GL_COMBINE4_NV) {
 178          swrast->_AnyTextureCombine = GL_TRUE;
 179          return;
 180       }
 181    }
 182 }
 183
 184
 185 /**
 186  * Update swrast->_FogColor and swrast->_FogEnable values.
 187  */
 188 static void
 189 _swrast_update_fog_state( GLcontext *ctx )
 190 {
 191    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 192
 193    /* convert fog color to GLchan values */
 194    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[RCOMP], ctx->Fog.Color[RCOMP]);
 195    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[GCOMP], ctx->Fog.Color[GCOMP]);
 196    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[BCOMP], ctx->Fog.Color[BCOMP]);
 197
 198    /* determine if fog is needed, and if so, which fog mode */
 199    swrast->_FogEnabled = GL_FALSE;
 200    if (ctx->FragmentProgram._Active) {
 201       if (ctx->FragmentProgram._Current->Base.Target==GL_FRAGMENT_PROGRAM_ARB) {
 202          const struct fragment_program *p
 203             = (struct fragment_program *) ctx->FragmentProgram._Current;
 204          if (p->FogOption != GL_NONE) {
 205             swrast->_FogEnabled = GL_TRUE;
 206             swrast->_FogMode = p->FogOption;
 207          }
 208       }
 209    }
 210    else if (ctx->Fog.Enabled) {
 211       swrast->_FogEnabled = GL_TRUE;
 212       swrast->_FogMode = ctx->Fog.Mode;
 213    }
 214 }
 215
 216
 217 /**
 218  * Update state for running fragment programs.  Basically, load the
 219  * program parameters with current state values.
 220  */
 221 static void
 222 _swrast_update_fragment_program( GLcontext *ctx )
 223 {
 224    if (ctx->FragmentProgram._Active) {
 225       struct fragment_program *program = ctx->FragmentProgram._Current;
 226       _mesa_load_state_parameters(ctx, program->Parameters);
 227    }
 228 }
 229
 230
 231
 232 #define _SWRAST_NEW_DERIVED (_SWRAST_NEW_RASTERMASK |   \
 233                              _NEW_TEXTURE |             \
 234                              _NEW_HINT |                \
 235                              _NEW_POLYGON )
 236
 237 /* State referenced by _swrast_choose_triangle, _swrast_choose_line.
 238  */
 239 #define _SWRAST_NEW_TRIANGLE (_SWRAST_NEW_DERIVED |             \
 240                               _NEW_RENDERMODE|                  \
 241                               _NEW_POLYGON|                     \
 242                               _NEW_DEPTH|                       \
 243                               _NEW_STENCIL|                     \
 244                               _NEW_COLOR|                       \
 245                               _NEW_TEXTURE|                     \
 246                               _SWRAST_NEW_RASTERMASK|           \
 247                               _NEW_LIGHT|                       \
 248                               _NEW_FOG |                        \
 249                               _DD_NEW_SEPARATE_SPECULAR)
 250
 251 #define _SWRAST_NEW_LINE (_SWRAST_NEW_DERIVED |         \
 252                           _NEW_RENDERMODE|              \
 253                           _NEW_LINE|                    \
 254                           _NEW_TEXTURE|                 \
 255                           _NEW_LIGHT|                   \
 256                           _NEW_FOG|                     \
 257                           _NEW_DEPTH |                  \
 258                           _DD_NEW_SEPARATE_SPECULAR)
 259
 260 #define _SWRAST_NEW_POINT (_SWRAST_NEW_DERIVED |        \
 261                            _NEW_RENDERMODE |            \
 262                            _NEW_POINT |                 \
 263                            _NEW_TEXTURE |               \
 264                            _NEW_LIGHT |                 \
 265                            _NEW_FOG |                   \
 266                            _DD_NEW_SEPARATE_SPECULAR)
 267
 268 #define _SWRAST_NEW_TEXTURE_SAMPLE_FUNC _NEW_TEXTURE
 269
 270 #define _SWRAST_NEW_TEXTURE_ENV_MODE _NEW_TEXTURE
 271
 272 #define _SWRAST_NEW_BLEND_FUNC _NEW_COLOR
 273
 274
 275
 276 /**
 277  * Stub for swrast->Triangle to select a true triangle function
 278  * after a state change.
 279  */
 280 static void
 281 _swrast_validate_triangle( GLcontext *ctx,
 282                            const SWvertex *v0,
 283                            const SWvertex *v1,
 284                            const SWvertex *v2 )
 285 {
 286    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 287
 288    _swrast_validate_derived( ctx );
 289    swrast->choose_triangle( ctx );
 290
 291    if (ctx->Texture._EnabledUnits == 0
 292        && NEED_SECONDARY_COLOR(ctx)
 293        && !ctx->FragmentProgram._Active) {
 294       /* separate specular color, but no texture */
 295       swrast->SpecTriangle = swrast->Triangle;
 296       swrast->Triangle = _swrast_add_spec_terms_triangle;
 297    }
 298
 299    swrast->Triangle( ctx, v0, v1, v2 );
 300 }
 301
 302 /**
 303  * Called via swrast->Line.  Examine current GL state and choose a software
 304  * line routine.  Then call it.
 305  */
 306 static void
 307 _swrast_validate_line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 308 {
 309    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 310
 311    _swrast_validate_derived( ctx );
 312    swrast->choose_line( ctx );
 313
 314    if (ctx->Texture._EnabledUnits == 0
 315        && NEED_SECONDARY_COLOR(ctx)
 316        && !ctx->FragmentProgram._Active) {
 317       swrast->SpecLine = swrast->Line;
 318       swrast->Line = _swrast_add_spec_terms_line;
 319    }
 320
 321
 322    swrast->Line( ctx, v0, v1 );
 323 }
 324
 325 /**
 326  * Called via swrast->Point.  Examine current GL state and choose a software
 327  * point routine.  Then call it.
 328  */
 329 static void
 330 _swrast_validate_point( GLcontext *ctx, const SWvertex *v0 )
 331 {
 332    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 333
 334    _swrast_validate_derived( ctx );
 335    swrast->choose_point( ctx );
 336
 337    if (ctx->Texture._EnabledUnits == 0
 338        && NEED_SECONDARY_COLOR(ctx)
 339        && !ctx->FragmentProgram._Active) {
 340       swrast->SpecPoint = swrast->Point;
 341       swrast->Point = _swrast_add_spec_terms_point;
 342    }
 343
 344    swrast->Point( ctx, v0 );
 345 }
 346
 347
 348 /**
 349  * Called via swrast->BlendFunc.  Examine GL state to choose a blending
 350  * function, then call it.
 351  */
 352 static void _ASMAPI
 353 _swrast_validate_blend_func( GLcontext *ctx, GLuint n,
 354                              const GLubyte mask[],
 355                              GLchan src[][4],
 356                              CONST GLchan dst[][4] )
 357 {
 358    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 359
 360    _swrast_validate_derived( ctx );
 361    _swrast_choose_blend_func( ctx );
 362
 363    swrast->BlendFunc( ctx, n, mask, src, dst );
 364 }
 365
 366
 367 /**
 368  * Called via the swrast->TextureSample[i] function pointer.
 369  * Basically, given a texture object, an array of texture coords
 370  * and an array of level-of-detail values, return an array of colors.
 371  * In this case, determine the correct texture sampling routine
 372  * (depending on filter mode, texture dimensions, etc) then call the
 373  * sampler routine.
 374  */
 375 static void
 376 _swrast_validate_texture_sample( GLcontext *ctx, GLuint texUnit,
 377                                  const struct gl_texture_object *tObj,
 378                                  GLuint n, const GLfloat texcoords[][4],
 379                                  const GLfloat lambda[], GLchan rgba[][4] )
 380 {
 381    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 382
 383    _swrast_validate_derived( ctx );
 384
 385    /* Compute min/mag filter threshold */
 386    if (tObj && tObj->MinFilter != tObj->MagFilter) {
 387       if (tObj->MagFilter == GL_LINEAR
 388           && (tObj->MinFilter == GL_NEAREST_MIPMAP_NEAREST ||
 389               tObj->MinFilter == GL_NEAREST_MIPMAP_LINEAR)) {
 390          swrast->_MinMagThresh[texUnit] = 0.5F;
 391       }
 392       else {
 393          swrast->_MinMagThresh[texUnit] = 0.0F;
 394       }
 395    }
 396
 397    swrast->TextureSample[texUnit] =
 398       _swrast_choose_texture_sample_func( ctx, tObj );
 399
 400    swrast->TextureSample[texUnit]( ctx, texUnit, tObj, n, texcoords,
 401                                    lambda, rgba );
 402 }
 403
 404
 405 static void
 406 _swrast_sleep( GLcontext *ctx, GLuint new_state )
 407 {
 408    (void) ctx; (void) new_state;
 409 }
 410
 411
 412 static void
 413 _swrast_invalidate_state( GLcontext *ctx, GLuint new_state )
 414 {
 415    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 416    GLuint i;
 417
 418    swrast->NewState |= new_state;
 419
 420    /* After 10 statechanges without any swrast functions being called,
 421     * put the module to sleep.
 422     */
 423    if (++swrast->StateChanges > 10) {
 424       swrast->InvalidateState = _swrast_sleep;
 425       swrast->NewState = ~0;
 426       new_state = ~0;
 427    }
 428
 429    if (new_state & swrast->invalidate_triangle)
 430       swrast->Triangle = _swrast_validate_triangle;
 431
 432    if (new_state & swrast->invalidate_line)
 433       swrast->Line = _swrast_validate_line;
 434
 435    if (new_state & swrast->invalidate_point)
 436       swrast->Point = _swrast_validate_point;
 437
 438    if (new_state & _SWRAST_NEW_BLEND_FUNC)
 439       swrast->BlendFunc = _swrast_validate_blend_func;
 440
 441    if (new_state & _SWRAST_NEW_TEXTURE_SAMPLE_FUNC)
 442       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 443          swrast->TextureSample[i] = _swrast_validate_texture_sample;
 444 }
 445
 446
 447 void
 448 _swrast_validate_derived( GLcontext *ctx )
 449 {
 450    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 451
 452    if (swrast->NewState) {
 453       if (swrast->NewState & _SWRAST_NEW_RASTERMASK)
 454          _swrast_update_rasterflags( ctx );
 455
 456       if (swrast->NewState & _NEW_POLYGON)
 457          _swrast_update_polygon( ctx );
 458
 459       if (swrast->NewState & (_NEW_HINT | _NEW_PROGRAM))
 460          _swrast_update_fog_hint( ctx );
 461
 462       if (swrast->NewState & _SWRAST_NEW_TEXTURE_ENV_MODE)
 463          _swrast_update_texture_env( ctx );
 464
 465       if (swrast->NewState & (_NEW_FOG | _NEW_PROGRAM))
 466          _swrast_update_fog_state( ctx );
 467
 468       if (swrast->NewState & _NEW_PROGRAM)
 469          _swrast_update_fragment_program( ctx );
 470
 471       swrast->NewState = 0;
 472       swrast->StateChanges = 0;
 473       swrast->InvalidateState = _swrast_invalidate_state;
 474    }
 475 }
 476
 477 #define SWRAST_DEBUG 0
 478
 479 /* Public entrypoints:  See also s_accum.c, s_bitmap.c, etc.
 480  */
 481 void
 482 _swrast_Quad( GLcontext *ctx,
 483               const SWvertex *v0, const SWvertex *v1,
 484               const SWvertex *v2, const SWvertex *v3 )
 485 {
 486    if (SWRAST_DEBUG) {
 487       _mesa_debug(ctx, "_swrast_Quad\n");
 488       _swrast_print_vertex( ctx, v0 );
 489       _swrast_print_vertex( ctx, v1 );
 490       _swrast_print_vertex( ctx, v2 );
 491       _swrast_print_vertex( ctx, v3 );
 492    }
 493    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v3 );
 494    SWRAST_CONTEXT(ctx)->Triangle( ctx, v1, v2, v3 );
 495 }
 496
 497 void
 498 _swrast_Triangle( GLcontext *ctx, const SWvertex *v0,
 499                   const SWvertex *v1, const SWvertex *v2 )
 500 {
 501    if (SWRAST_DEBUG) {
 502       _mesa_debug(ctx, "_swrast_Triangle\n");
 503       _swrast_print_vertex( ctx, v0 );
 504       _swrast_print_vertex( ctx, v1 );
 505       _swrast_print_vertex( ctx, v2 );
 506    }
 507    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v2 );
 508 }
 509
 510 void
 511 _swrast_Line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 512 {
 513    if (SWRAST_DEBUG) {
 514       _mesa_debug(ctx, "_swrast_Line\n");
 515       _swrast_print_vertex( ctx, v0 );
 516       _swrast_print_vertex( ctx, v1 );
 517    }
 518    SWRAST_CONTEXT(ctx)->Line( ctx, v0, v1 );
 519 }
 520
 521 void
 522 _swrast_Point( GLcontext *ctx, const SWvertex *v0 )
 523 {
 524    if (SWRAST_DEBUG) {
 525       _mesa_debug(ctx, "_swrast_Point\n");
 526       _swrast_print_vertex( ctx, v0 );
 527    }
 528    SWRAST_CONTEXT(ctx)->Point( ctx, v0 );
 529 }
 530
 531 void
 532 _swrast_InvalidateState( GLcontext *ctx, GLuint new_state )
 533 {
 534    if (SWRAST_DEBUG) {
 535       _mesa_debug(ctx, "_swrast_InvalidateState\n");
 536    }
 537    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, new_state );
 538 }
 539
 540 void
 541 _swrast_ResetLineStipple( GLcontext *ctx )
 542 {
 543    if (SWRAST_DEBUG) {
 544       _mesa_debug(ctx, "_swrast_ResetLineStipple\n");
 545    }
 546    SWRAST_CONTEXT(ctx)->StippleCounter = 0;
 547 }
 548
 549 void
 550 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 551 {
 552    if (SWRAST_DEBUG) {
 553       _mesa_debug(ctx, "_swrast_allow_vertex_fog %d\n", value);
 554    }
 555    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 556    SWRAST_CONTEXT(ctx)->AllowVertexFog = value;
 557 }
 558
 559 void
 560 _swrast_allow_pixel_fog( GLcontext *ctx, GLboolean value )
 561 {
 562    if (SWRAST_DEBUG) {
 563       _mesa_debug(ctx, "_swrast_allow_pixel_fog %d\n", value);
 564    }
 565    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 566    SWRAST_CONTEXT(ctx)->AllowPixelFog = value;
 567 }
 568
 569
 570 GLboolean
 571 _swrast_CreateContext( GLcontext *ctx )
 572 {
 573    GLuint i;
 574    SWcontext *swrast = (SWcontext *)CALLOC(sizeof(SWcontext));
 575
 576    if (SWRAST_DEBUG) {
 577       _mesa_debug(ctx, "_swrast_CreateContext\n");
 578    }
 579
 580    if (!swrast)
 581       return GL_FALSE;
 582
 583    swrast->NewState = ~0;
 584
 585    swrast->choose_point = _swrast_choose_point;
 586    swrast->choose_line = _swrast_choose_line;
 587    swrast->choose_triangle = _swrast_choose_triangle;
 588
 589    swrast->invalidate_point = _SWRAST_NEW_POINT;
 590    swrast->invalidate_line = _SWRAST_NEW_LINE;
 591    swrast->invalidate_triangle = _SWRAST_NEW_TRIANGLE;
 592
 593    swrast->Point = _swrast_validate_point;
 594    swrast->Line = _swrast_validate_line;
 595    swrast->Triangle = _swrast_validate_triangle;
 596    swrast->InvalidateState = _swrast_sleep;
 597    swrast->BlendFunc = _swrast_validate_blend_func;
 598
 599    swrast->AllowVertexFog = GL_TRUE;
 600    swrast->AllowPixelFog = GL_TRUE;
 601
 602    if (ctx->Visual.doubleBufferMode)
 603       swrast->CurrentBufferBit = BUFFER_BIT_BACK_LEFT;
 604    else
 605       swrast->CurrentBufferBit = BUFFER_FRONT_LEFT;
 606
 607    /* Optimized Accum buffer */
 608    swrast->_IntegerAccumMode = GL_FALSE;
 609    swrast->_IntegerAccumScaler = 0.0;
 610
 611    for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 612       swrast->TextureSample[i] = _swrast_validate_texture_sample;
 613
 614    swrast->SpanArrays = MALLOC_STRUCT(span_arrays);
 615    if (!swrast->SpanArrays) {
 616       FREE(swrast);
 617       return GL_FALSE;
 618    }
 619
 620    /* init point span buffer */
 621    swrast->PointSpan.primitive = GL_POINT;
 622    swrast->PointSpan.start = 0;
 623    swrast->PointSpan.end = 0;
 624    swrast->PointSpan.facing = 0;
 625    swrast->PointSpan.array = swrast->SpanArrays;
 626
 627    assert(ctx->Const.MaxTextureUnits > 0);
 628    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_UNITS);
 629
 630    swrast->TexelBuffer = (GLchan *) MALLOC(ctx->Const.MaxTextureUnits *
 631                                            MAX_WIDTH * 4 * sizeof(GLchan));
 632    if (!swrast->TexelBuffer) {
 633       FREE(swrast->SpanArrays);
 634       FREE(swrast);
 635       return GL_FALSE;
 636    }
 637
 638    ctx->swrast_context = swrast;
 639
 640    return GL_TRUE;
 641 }
 642
 643 void
 644 _swrast_DestroyContext( GLcontext *ctx )
 645 {
 646    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 647
 648    if (SWRAST_DEBUG) {
 649       _mesa_debug(ctx, "_swrast_DestroyContext\n");
 650    }
 651
 652    FREE( swrast->SpanArrays );
 653    FREE( swrast->TexelBuffer );
 654    FREE( swrast );
 655
 656    ctx->swrast_context = 0;
 657 }
 658
 659
 660 struct swrast_device_driver *
 661 _swrast_GetDeviceDriverReference( GLcontext *ctx )
 662 {
 663    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 664    return &swrast->Driver;
 665 }
 666
 667 void
 668 _swrast_flush( GLcontext *ctx )
 669 {
 670    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 671    /* flush any pending fragments from rendering points */
 672    if (swrast->PointSpan.end > 0) {
 673       if (ctx->Visual.rgbMode) {
 674          _swrast_write_rgba_span(ctx, &(swrast->PointSpan));
 675       }
 676       else {
 677          _swrast_write_index_span(ctx, &(swrast->PointSpan));
 678       }
 679       swrast->PointSpan.end = 0;
 680    }
 681 }
 682
 683 void
 684 _swrast_render_primitive( GLcontext *ctx, GLenum prim )
 685 {
 686    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 687    if (swrast->Primitive == GL_POINTS && prim != GL_POINTS) {
 688       _swrast_flush(ctx);
 689    }
 690    swrast->Primitive = prim;
 691 }
 692
 693
 694 void
 695 _swrast_render_start( GLcontext *ctx )
 696 {
 697    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 698    if (swrast->Driver.SpanRenderStart)
 699       swrast->Driver.SpanRenderStart( ctx );
 700    swrast->PointSpan.end = 0;
 701 }
 702
 703 void
 704 _swrast_render_finish( GLcontext *ctx )
 705 {
 706    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 707    if (swrast->Driver.SpanRenderFinish)
 708       swrast->Driver.SpanRenderFinish( ctx );
 709
 710    _swrast_flush(ctx);
 711 }
 712
 713
 714 #define SWRAST_DEBUG_VERTICES 0
 715
 716 void
 717 _swrast_print_vertex( GLcontext *ctx, const SWvertex *v )
 718 {
 719    GLuint i;
 720
 721    if (SWRAST_DEBUG_VERTICES) {
 722       _mesa_debug(ctx, "win %f %f %f %f\n",
 723                   v->win[0], v->win[1], v->win[2], v->win[3]);
 724
 725       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 726          if (ctx->Texture.Unit[i]._ReallyEnabled)
 727             _mesa_debug(ctx, "texcoord[%d] %f %f %f %f\n", i,
 728                         v->texcoord[i][0], v->texcoord[i][1],
 729                         v->texcoord[i][2], v->texcoord[i][3]);
 730
 731 #if CHAN_TYPE == GL_FLOAT
 732       _mesa_debug(ctx, "color %f %f %f %f\n",
 733                   v->color[0], v->color[1], v->color[2], v->color[3]);
 734       _mesa_debug(ctx, "spec %f %f %f %f\n",
 735                   v->specular[0], v->specular[1],
 736                   v->specular[2], v->specular[3]);
 737 #else
 738       _mesa_debug(ctx, "color %d %d %d %d\n",
 739                   v->color[0], v->color[1], v->color[2], v->color[3]);
 740       _mesa_debug(ctx, "spec %d %d %d %d\n",
 741                   v->specular[0], v->specular[1],
 742                   v->specular[2], v->specular[3]);
 743 #endif
 744       _mesa_debug(ctx, "fog %f\n", v->fog);
 745       _mesa_debug(ctx, "index %d\n", v->index);
 746       _mesa_debug(ctx, "pointsize %f\n", v->pointSize);
 747       _mesa_debug(ctx, "\n");
 748    }
 749 }