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