src/mesa/swrast/s_context.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  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 "swrast.h"
  36 #include "s_blend.h"
  37 #include "s_context.h"
  38 #include "s_lines.h"
  39 #include "s_points.h"
  40 #include "s_span.h"
  41 #include "s_triangle.h"
  42 #include "s_texfilter.h"
  43
  44
  45 /**
  46  * Recompute the value of swrast->_RasterMask, etc. according to
  47  * the current context.  The _RasterMask field can be easily tested by
  48  * drivers to determine certain basic GL state (does the primitive need
  49  * stenciling, logic-op, fog, etc?).
  50  */
  51 static void
  52 _swrast_update_rasterflags( GLcontext *ctx )
  53 {
  54    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  55    GLbitfield rasterMask = 0;
  56
  57    if (ctx->Color.AlphaEnabled)           rasterMask |= ALPHATEST_BIT;
  58    if (ctx->Color.BlendEnabled)           rasterMask |= BLEND_BIT;
  59    if (ctx->Depth.Test)                   rasterMask |= DEPTH_BIT;
  60    if (swrast->_FogEnabled)               rasterMask |= FOG_BIT;
  61    if (ctx->Scissor.Enabled)              rasterMask |= CLIP_BIT;
  62    if (ctx->Stencil.Enabled)              rasterMask |= STENCIL_BIT;
  63    if (ctx->Visual.rgbMode) {
  64       const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
  65       if (colorMask != 0xffffffff)        rasterMask |= MASKING_BIT;
  66       if (ctx->Color._LogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  67       if (ctx->Texture._EnabledUnits)     rasterMask |= TEXTURE_BIT;
  68    }
  69    else {
  70       if (ctx->Color.IndexMask != 0xffffffff) rasterMask |= MASKING_BIT;
  71       if (ctx->Color.IndexLogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  72    }
  73
  74    if (   ctx->Viewport.X < 0
  75        || ctx->Viewport.X + ctx->Viewport.Width > (GLint) ctx->DrawBuffer->Width
  76        || ctx->Viewport.Y < 0
  77        || ctx->Viewport.Y + ctx->Viewport.Height > (GLint) ctx->DrawBuffer->Height) {
  78       rasterMask |= CLIP_BIT;
  79    }
  80
  81    if (ctx->Query.CurrentOcclusionObject)
  82       rasterMask |= OCCLUSION_BIT;
  83
  84
  85    /* If we're not drawing to exactly one color buffer set the
  86     * MULTI_DRAW_BIT flag.  Also set it if we're drawing to no
  87     * buffers or the RGBA or CI mask disables all writes.
  88     */
  89    if (ctx->DrawBuffer->_NumColorDrawBuffers[0] != 1) {
  90       /* more than one color buffer designated for writing (or zero buffers) */
  91       rasterMask |= MULTI_DRAW_BIT;
  92    }
  93    else if (ctx->Visual.rgbMode && *((GLuint *) ctx->Color.ColorMask) == 0) {
  94       rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
  95    }
  96    else if (!ctx->Visual.rgbMode && ctx->Color.IndexMask==0) {
  97       rasterMask |= MULTI_DRAW_BIT; /* all color index bits disabled */
  98    }
  99
 100    if (ctx->FragmentProgram._Active) {
 101       rasterMask |= FRAGPROG_BIT;
 102    }
 103
 104    if (ctx->ShaderObjects._FragmentShaderPresent) {
 105       rasterMask |= FRAGPROG_BIT;
 106    }
 107
 108    if (ctx->ATIFragmentShader._Enabled) {
 109       rasterMask |= ATIFRAGSHADER_BIT;
 110    }
 111
 112 #if CHAN_TYPE == GL_FLOAT
 113    if (ctx->Color.ClampFragmentColor == GL_TRUE) {
 114       rasterMask |= CLAMPING_BIT;
 115    }
 116 #endif
 117
 118    SWRAST_CONTEXT(ctx)->_RasterMask = rasterMask;
 119 }
 120
 121
 122 /**
 123  * Examine polycon culls tate to compute the _BackfaceSign field.
 124  * _BackfaceSign will be 0 if no culling, -1 if culling back-faces,
 125  * and 1 if culling front-faces.  The Polygon FrontFace state also
 126  * factors in.
 127  */
 128 static void
 129 _swrast_update_polygon( GLcontext *ctx )
 130 {
 131    GLfloat backface_sign = 1;
 132
 133    if (ctx->Polygon.CullFlag) {
 134       backface_sign = 1;
 135       switch(ctx->Polygon.CullFaceMode) {
 136       case GL_BACK:
 137          if(ctx->Polygon.FrontFace==GL_CCW)
 138             backface_sign = -1;
 139          break;
 140       case GL_FRONT:
 141          if(ctx->Polygon.FrontFace!=GL_CCW)
 142             backface_sign = -1;
 143          break;
 144       default:
 145       case GL_FRONT_AND_BACK:
 146          backface_sign = 0;
 147          break;
 148       }
 149    }
 150    else {
 151       backface_sign = 0;
 152    }
 153
 154    SWRAST_CONTEXT(ctx)->_BackfaceSign = backface_sign;
 155 }
 156
 157
 158 /**
 159  * Update the _PreferPixelFog field to indicate if we need to compute
 160  * fog factors per-fragment.
 161  */
 162 static void
 163 _swrast_update_fog_hint( GLcontext *ctx )
 164 {
 165    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 166    swrast->_PreferPixelFog = (!swrast->AllowVertexFog ||
 167                               ctx->FragmentProgram._Enabled || /* not _Active! */
 168                               (ctx->Hint.Fog == GL_NICEST &&
 169                                swrast->AllowPixelFog));
 170 }
 171
 172
 173
 174 /**
 175  * Update the swrast->_AnyTextureCombine flag.
 176  */
 177 static void
 178 _swrast_update_texture_env( GLcontext *ctx )
 179 {
 180    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 181    GLuint i;
 182    swrast->_AnyTextureCombine = GL_FALSE;
 183    for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
 184       if (ctx->Texture.Unit[i].EnvMode == GL_COMBINE_EXT ||
 185           ctx->Texture.Unit[i].EnvMode == GL_COMBINE4_NV) {
 186          swrast->_AnyTextureCombine = GL_TRUE;
 187          return;
 188       }
 189    }
 190 }
 191
 192
 193 /**
 194  * Update swrast->_FogColor and swrast->_FogEnable values.
 195  */
 196 static void
 197 _swrast_update_fog_state( GLcontext *ctx )
 198 {
 199    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 200
 201    /* convert fog color to GLchan values */
 202    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[RCOMP], ctx->Fog.Color[RCOMP]);
 203    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[GCOMP], ctx->Fog.Color[GCOMP]);
 204    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[BCOMP], ctx->Fog.Color[BCOMP]);
 205
 206    /* determine if fog is needed, and if so, which fog mode */
 207    swrast->_FogEnabled = GL_FALSE;
 208    if (ctx->FragmentProgram._Active) {
 209       if (ctx->FragmentProgram._Current->Base.Target==GL_FRAGMENT_PROGRAM_ARB) {
 210          const struct fragment_program *p
 211             = (struct fragment_program *) ctx->FragmentProgram._Current;
 212          if (p->FogOption != GL_NONE) {
 213             swrast->_FogEnabled = GL_TRUE;
 214             swrast->_FogMode = p->FogOption;
 215          }
 216       }
 217    }
 218    else if (ctx->Fog.Enabled) {
 219       swrast->_FogEnabled = GL_TRUE;
 220       swrast->_FogMode = ctx->Fog.Mode;
 221    }
 222 }
 223
 224
 225 /**
 226  * Update state for running fragment programs.  Basically, load the
 227  * program parameters with current state values.
 228  */
 229 static void
 230 _swrast_update_fragment_program( GLcontext *ctx )
 231 {
 232    if (ctx->FragmentProgram._Active) {
 233       struct fragment_program *program = ctx->FragmentProgram._Current;
 234       _mesa_load_state_parameters(ctx, program->Base.Parameters);
 235    }
 236 }
 237
 238
 239
 240 #define _SWRAST_NEW_DERIVED (_SWRAST_NEW_RASTERMASK |   \
 241                              _NEW_TEXTURE |             \
 242                              _NEW_HINT |                \
 243                              _NEW_POLYGON )
 244
 245 /* State referenced by _swrast_choose_triangle, _swrast_choose_line.
 246  */
 247 #define _SWRAST_NEW_TRIANGLE (_SWRAST_NEW_DERIVED |             \
 248                               _NEW_RENDERMODE|                  \
 249                               _NEW_POLYGON|                     \
 250                               _NEW_DEPTH|                       \
 251                               _NEW_STENCIL|                     \
 252                               _NEW_COLOR|                       \
 253                               _NEW_TEXTURE|                     \
 254                               _SWRAST_NEW_RASTERMASK|           \
 255                               _NEW_LIGHT|                       \
 256                               _NEW_FOG |                        \
 257                               _DD_NEW_SEPARATE_SPECULAR)
 258
 259 #define _SWRAST_NEW_LINE (_SWRAST_NEW_DERIVED |         \
 260                           _NEW_RENDERMODE|              \
 261                           _NEW_LINE|                    \
 262                           _NEW_TEXTURE|                 \
 263                           _NEW_LIGHT|                   \
 264                           _NEW_FOG|                     \
 265                           _NEW_DEPTH |                  \
 266                           _DD_NEW_SEPARATE_SPECULAR)
 267
 268 #define _SWRAST_NEW_POINT (_SWRAST_NEW_DERIVED |        \
 269                            _NEW_RENDERMODE |            \
 270                            _NEW_POINT |                 \
 271                            _NEW_TEXTURE |               \
 272                            _NEW_LIGHT |                 \
 273                            _NEW_FOG |                   \
 274                            _DD_NEW_SEPARATE_SPECULAR)
 275
 276 #define _SWRAST_NEW_TEXTURE_SAMPLE_FUNC _NEW_TEXTURE
 277
 278 #define _SWRAST_NEW_TEXTURE_ENV_MODE _NEW_TEXTURE
 279
 280 #define _SWRAST_NEW_BLEND_FUNC _NEW_COLOR
 281
 282
 283
 284 /**
 285  * Stub for swrast->Triangle to select a true triangle function
 286  * after a state change.
 287  */
 288 static void
 289 _swrast_validate_triangle( GLcontext *ctx,
 290                            const SWvertex *v0,
 291                            const SWvertex *v1,
 292                            const SWvertex *v2 )
 293 {
 294    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 295
 296    _swrast_validate_derived( ctx );
 297    swrast->choose_triangle( ctx );
 298
 299    if (ctx->Texture._EnabledUnits == 0
 300        && NEED_SECONDARY_COLOR(ctx)
 301        && !ctx->FragmentProgram._Active) {
 302       /* separate specular color, but no texture */
 303       swrast->SpecTriangle = swrast->Triangle;
 304       swrast->Triangle = _swrast_add_spec_terms_triangle;
 305    }
 306
 307    swrast->Triangle( ctx, v0, v1, v2 );
 308 }
 309
 310 /**
 311  * Called via swrast->Line.  Examine current GL state and choose a software
 312  * line routine.  Then call it.
 313  */
 314 static void
 315 _swrast_validate_line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 316 {
 317    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 318
 319    _swrast_validate_derived( ctx );
 320    swrast->choose_line( ctx );
 321
 322    if (ctx->Texture._EnabledUnits == 0
 323        && NEED_SECONDARY_COLOR(ctx)
 324        && !ctx->FragmentProgram._Active) {
 325       swrast->SpecLine = swrast->Line;
 326       swrast->Line = _swrast_add_spec_terms_line;
 327    }
 328
 329
 330    swrast->Line( ctx, v0, v1 );
 331 }
 332
 333 /**
 334  * Called via swrast->Point.  Examine current GL state and choose a software
 335  * point routine.  Then call it.
 336  */
 337 static void
 338 _swrast_validate_point( GLcontext *ctx, const SWvertex *v0 )
 339 {
 340    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 341
 342    _swrast_validate_derived( ctx );
 343    swrast->choose_point( ctx );
 344
 345    if (ctx->Texture._EnabledUnits == 0
 346        && NEED_SECONDARY_COLOR(ctx)
 347        && !ctx->FragmentProgram._Active) {
 348       swrast->SpecPoint = swrast->Point;
 349       swrast->Point = _swrast_add_spec_terms_point;
 350    }
 351
 352    swrast->Point( ctx, v0 );
 353 }
 354
 355
 356 /**
 357  * Called via swrast->BlendFunc.  Examine GL state to choose a blending
 358  * function, then call it.
 359  */
 360 static void _ASMAPI
 361 _swrast_validate_blend_func( GLcontext *ctx, GLuint n,
 362                              const GLubyte mask[],
 363                              GLchan src[][4],
 364                              CONST GLchan dst[][4] )
 365 {
 366    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 367
 368    _swrast_validate_derived( ctx );
 369    _swrast_choose_blend_func( ctx );
 370
 371    swrast->BlendFunc( ctx, n, mask, src, dst );
 372 }
 373
 374
 375 static void
 376 _swrast_sleep( GLcontext *ctx, GLbitfield new_state )
 377 {
 378    (void) ctx; (void) new_state;
 379 }
 380
 381
 382 static void
 383 _swrast_invalidate_state( GLcontext *ctx, GLbitfield new_state )
 384 {
 385    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 386    GLuint i;
 387
 388    swrast->NewState |= new_state;
 389
 390    /* After 10 statechanges without any swrast functions being called,
 391     * put the module to sleep.
 392     */
 393    if (++swrast->StateChanges > 10) {
 394       swrast->InvalidateState = _swrast_sleep;
 395       swrast->NewState = ~0;
 396       new_state = ~0;
 397    }
 398
 399    if (new_state & swrast->InvalidateTriangleMask)
 400       swrast->Triangle = _swrast_validate_triangle;
 401
 402    if (new_state & swrast->InvalidateLineMask)
 403       swrast->Line = _swrast_validate_line;
 404
 405    if (new_state & swrast->InvalidatePointMask)
 406       swrast->Point = _swrast_validate_point;
 407
 408    if (new_state & _SWRAST_NEW_BLEND_FUNC)
 409       swrast->BlendFunc = _swrast_validate_blend_func;
 410
 411    if (new_state & _SWRAST_NEW_TEXTURE_SAMPLE_FUNC)
 412       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 413          swrast->TextureSample[i] = NULL;
 414 }
 415
 416
 417 static void
 418 _swrast_update_texture_samplers(GLcontext *ctx)
 419 {
 420    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 421    GLuint u;
 422
 423    for (u = 0; u < ctx->Const.MaxTextureImageUnits; u++) {
 424       const struct gl_texture_object *tObj = ctx->Texture.Unit[u]._Current;
 425       if (tObj)
 426          swrast->TextureSample[u] =
 427             _swrast_choose_texture_sample_func(ctx, tObj);
 428    }
 429 }
 430
 431
 432 void
 433 _swrast_validate_derived( GLcontext *ctx )
 434 {
 435    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 436
 437    if (swrast->NewState) {
 438       if (swrast->NewState & _SWRAST_NEW_RASTERMASK)
 439          _swrast_update_rasterflags( ctx );
 440
 441       if (swrast->NewState & _NEW_POLYGON)
 442          _swrast_update_polygon( ctx );
 443
 444       if (swrast->NewState & (_NEW_HINT | _NEW_PROGRAM))
 445          _swrast_update_fog_hint( ctx );
 446
 447       if (swrast->NewState & _SWRAST_NEW_TEXTURE_ENV_MODE)
 448          _swrast_update_texture_env( ctx );
 449
 450       if (swrast->NewState & (_NEW_FOG | _NEW_PROGRAM))
 451          _swrast_update_fog_state( ctx );
 452
 453       if (swrast->NewState & _NEW_PROGRAM)
 454          _swrast_update_fragment_program( ctx );
 455
 456       if (swrast->NewState & _NEW_TEXTURE)
 457          _swrast_update_texture_samplers( ctx );
 458
 459       swrast->NewState = 0;
 460       swrast->StateChanges = 0;
 461       swrast->InvalidateState = _swrast_invalidate_state;
 462    }
 463 }
 464
 465 #define SWRAST_DEBUG 0
 466
 467 /* Public entrypoints:  See also s_accum.c, s_bitmap.c, etc.
 468  */
 469 void
 470 _swrast_Quad( GLcontext *ctx,
 471               const SWvertex *v0, const SWvertex *v1,
 472               const SWvertex *v2, const SWvertex *v3 )
 473 {
 474    if (SWRAST_DEBUG) {
 475       _mesa_debug(ctx, "_swrast_Quad\n");
 476       _swrast_print_vertex( ctx, v0 );
 477       _swrast_print_vertex( ctx, v1 );
 478       _swrast_print_vertex( ctx, v2 );
 479       _swrast_print_vertex( ctx, v3 );
 480    }
 481    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v3 );
 482    SWRAST_CONTEXT(ctx)->Triangle( ctx, v1, v2, v3 );
 483 }
 484
 485 void
 486 _swrast_Triangle( GLcontext *ctx, const SWvertex *v0,
 487                   const SWvertex *v1, const SWvertex *v2 )
 488 {
 489    if (SWRAST_DEBUG) {
 490       _mesa_debug(ctx, "_swrast_Triangle\n");
 491       _swrast_print_vertex( ctx, v0 );
 492       _swrast_print_vertex( ctx, v1 );
 493       _swrast_print_vertex( ctx, v2 );
 494    }
 495    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v2 );
 496 }
 497
 498 void
 499 _swrast_Line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 500 {
 501    if (SWRAST_DEBUG) {
 502       _mesa_debug(ctx, "_swrast_Line\n");
 503       _swrast_print_vertex( ctx, v0 );
 504       _swrast_print_vertex( ctx, v1 );
 505    }
 506    SWRAST_CONTEXT(ctx)->Line( ctx, v0, v1 );
 507 }
 508
 509 void
 510 _swrast_Point( GLcontext *ctx, const SWvertex *v0 )
 511 {
 512    if (SWRAST_DEBUG) {
 513       _mesa_debug(ctx, "_swrast_Point\n");
 514       _swrast_print_vertex( ctx, v0 );
 515    }
 516    SWRAST_CONTEXT(ctx)->Point( ctx, v0 );
 517 }
 518
 519 void
 520 _swrast_InvalidateState( GLcontext *ctx, GLbitfield new_state )
 521 {
 522    if (SWRAST_DEBUG) {
 523       _mesa_debug(ctx, "_swrast_InvalidateState\n");
 524    }
 525    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, new_state );
 526 }
 527
 528 void
 529 _swrast_ResetLineStipple( GLcontext *ctx )
 530 {
 531    if (SWRAST_DEBUG) {
 532       _mesa_debug(ctx, "_swrast_ResetLineStipple\n");
 533    }
 534    SWRAST_CONTEXT(ctx)->StippleCounter = 0;
 535 }
 536
 537 void
 538 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 539 {
 540    if (SWRAST_DEBUG) {
 541       _mesa_debug(ctx, "_swrast_allow_vertex_fog %d\n", value);
 542    }
 543    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 544    SWRAST_CONTEXT(ctx)->AllowVertexFog = value;
 545 }
 546
 547 void
 548 _swrast_allow_pixel_fog( GLcontext *ctx, GLboolean value )
 549 {
 550    if (SWRAST_DEBUG) {
 551       _mesa_debug(ctx, "_swrast_allow_pixel_fog %d\n", value);
 552    }
 553    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 554    SWRAST_CONTEXT(ctx)->AllowPixelFog = value;
 555 }
 556
 557
 558 GLboolean
 559 _swrast_CreateContext( GLcontext *ctx )
 560 {
 561    GLuint i;
 562    SWcontext *swrast = (SWcontext *)CALLOC(sizeof(SWcontext));
 563
 564    if (SWRAST_DEBUG) {
 565       _mesa_debug(ctx, "_swrast_CreateContext\n");
 566    }
 567
 568    if (!swrast)
 569       return GL_FALSE;
 570
 571    swrast->NewState = ~0;
 572
 573    swrast->choose_point = _swrast_choose_point;
 574    swrast->choose_line = _swrast_choose_line;
 575    swrast->choose_triangle = _swrast_choose_triangle;
 576
 577    swrast->InvalidatePointMask = _SWRAST_NEW_POINT;
 578    swrast->InvalidateLineMask = _SWRAST_NEW_LINE;
 579    swrast->InvalidateTriangleMask = _SWRAST_NEW_TRIANGLE;
 580
 581    swrast->Point = _swrast_validate_point;
 582    swrast->Line = _swrast_validate_line;
 583    swrast->Triangle = _swrast_validate_triangle;
 584    swrast->InvalidateState = _swrast_sleep;
 585    swrast->BlendFunc = _swrast_validate_blend_func;
 586
 587    swrast->AllowVertexFog = GL_TRUE;
 588    swrast->AllowPixelFog = GL_TRUE;
 589
 590    /* Optimized Accum buffer */
 591    swrast->_IntegerAccumMode = GL_FALSE;
 592    swrast->_IntegerAccumScaler = 0.0;
 593
 594    for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 595       swrast->TextureSample[i] = NULL;
 596
 597    swrast->SpanArrays = MALLOC_STRUCT(span_arrays);
 598    if (!swrast->SpanArrays) {
 599       FREE(swrast);
 600       return GL_FALSE;
 601    }
 602
 603    /* init point span buffer */
 604    swrast->PointSpan.primitive = GL_POINT;
 605    swrast->PointSpan.start = 0;
 606    swrast->PointSpan.end = 0;
 607    swrast->PointSpan.facing = 0;
 608    swrast->PointSpan.array = swrast->SpanArrays;
 609
 610    assert(ctx->Const.MaxTextureUnits > 0);
 611    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_UNITS);
 612
 613    swrast->TexelBuffer = (GLchan *) MALLOC(ctx->Const.MaxTextureUnits *
 614                                            MAX_WIDTH * 4 * sizeof(GLchan));
 615    if (!swrast->TexelBuffer) {
 616       FREE(swrast->SpanArrays);
 617       FREE(swrast);
 618       return GL_FALSE;
 619    }
 620
 621    ctx->swrast_context = swrast;
 622
 623    return GL_TRUE;
 624 }
 625
 626 void
 627 _swrast_DestroyContext( GLcontext *ctx )
 628 {
 629    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 630
 631    if (SWRAST_DEBUG) {
 632       _mesa_debug(ctx, "_swrast_DestroyContext\n");
 633    }
 634
 635    FREE( swrast->SpanArrays );
 636    FREE( swrast->TexelBuffer );
 637    FREE( swrast );
 638
 639    ctx->swrast_context = 0;
 640 }
 641
 642
 643 struct swrast_device_driver *
 644 _swrast_GetDeviceDriverReference( GLcontext *ctx )
 645 {
 646    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 647    return &swrast->Driver;
 648 }
 649
 650 void
 651 _swrast_flush( GLcontext *ctx )
 652 {
 653    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 654    /* flush any pending fragments from rendering points */
 655    if (swrast->PointSpan.end > 0) {
 656       if (ctx->Visual.rgbMode) {
 657          _swrast_write_rgba_span(ctx, &(swrast->PointSpan));
 658       }
 659       else {
 660          _swrast_write_index_span(ctx, &(swrast->PointSpan));
 661       }
 662       swrast->PointSpan.end = 0;
 663    }
 664 }
 665
 666 void
 667 _swrast_render_primitive( GLcontext *ctx, GLenum prim )
 668 {
 669    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 670    if (swrast->Primitive == GL_POINTS && prim != GL_POINTS) {
 671       _swrast_flush(ctx);
 672    }
 673    swrast->Primitive = prim;
 674 }
 675
 676
 677 void
 678 _swrast_render_start( GLcontext *ctx )
 679 {
 680    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 681    if (swrast->Driver.SpanRenderStart)
 682       swrast->Driver.SpanRenderStart( ctx );
 683    swrast->PointSpan.end = 0;
 684 }
 685
 686 void
 687 _swrast_render_finish( GLcontext *ctx )
 688 {
 689    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 690    if (swrast->Driver.SpanRenderFinish)
 691       swrast->Driver.SpanRenderFinish( ctx );
 692
 693    _swrast_flush(ctx);
 694 }
 695
 696
 697 #define SWRAST_DEBUG_VERTICES 0
 698
 699 void
 700 _swrast_print_vertex( GLcontext *ctx, const SWvertex *v )
 701 {
 702    GLuint i;
 703
 704    if (SWRAST_DEBUG_VERTICES) {
 705       _mesa_debug(ctx, "win %f %f %f %f\n",
 706                   v->win[0], v->win[1], v->win[2], v->win[3]);
 707
 708       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 709          if (ctx->Texture.Unit[i]._ReallyEnabled)
 710             _mesa_debug(ctx, "texcoord[%d] %f %f %f %f\n", i,
 711                         v->texcoord[i][0], v->texcoord[i][1],
 712                         v->texcoord[i][2], v->texcoord[i][3]);
 713
 714 #if CHAN_TYPE == GL_FLOAT
 715       _mesa_debug(ctx, "color %f %f %f %f\n",
 716                   v->color[0], v->color[1], v->color[2], v->color[3]);
 717       _mesa_debug(ctx, "spec %f %f %f %f\n",
 718                   v->specular[0], v->specular[1],
 719                   v->specular[2], v->specular[3]);
 720 #else
 721       _mesa_debug(ctx, "color %d %d %d %d\n",
 722                   v->color[0], v->color[1], v->color[2], v->color[3]);
 723       _mesa_debug(ctx, "spec %d %d %d %d\n",
 724                   v->specular[0], v->specular[1],
 725                   v->specular[2], v->specular[3]);
 726 #endif
 727       _mesa_debug(ctx, "fog %f\n", v->fog);
 728       _mesa_debug(ctx, "index %d\n", v->index);
 729       _mesa_debug(ctx, "pointsize %f\n", v->pointSize);
 730       _mesa_debug(ctx, "\n");
 731    }
 732 }