src/mesa/swrast/s_context.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Keith Whitwell <keith@tungstengraphics.com>
  26  *    Brian Paul
  27  */
  28
  29 #include "imports.h"
  30 #include "bufferobj.h"
  31 #include "context.h"
  32 #include "colormac.h"
  33 #include "mtypes.h"
  34 #include "program.h"
  35 #include "texobj.h"
  36 #include "nvfragprog.h"
  37
  38 #include "swrast.h"
  39 #include "s_blend.h"
  40 #include "s_context.h"
  41 #include "s_lines.h"
  42 #include "s_points.h"
  43 #include "s_span.h"
  44 #include "s_triangle.h"
  45 #include "s_texture.h"
  46
  47
  48 /**
  49  * Recompute the value of swrast->_RasterMask, etc. according to
  50  * the current context.  The _RasterMask field can be easily tested by
  51  * drivers to determine certain basic GL state (does the primitive need
  52  * stenciling, logic-op, fog, etc?).
  53  */
  54 static void
  55 _swrast_update_rasterflags( GLcontext *ctx )
  56 {
  57    GLuint rasterMask = 0;
  58
  59    if (ctx->Color.AlphaEnabled)           rasterMask |= ALPHATEST_BIT;
  60    if (ctx->Color.BlendEnabled)           rasterMask |= BLEND_BIT;
  61    if (ctx->Depth.Test)                   rasterMask |= DEPTH_BIT;
  62    if (ctx->Fog.Enabled)                  rasterMask |= FOG_BIT;
  63    if (ctx->Scissor.Enabled)              rasterMask |= CLIP_BIT;
  64    if (ctx->Stencil.Enabled)              rasterMask |= STENCIL_BIT;
  65    if (ctx->Visual.rgbMode) {
  66       const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
  67       if (colorMask != 0xffffffff)        rasterMask |= MASKING_BIT;
  68       if (ctx->Color._LogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  69       if (ctx->Texture._EnabledUnits)     rasterMask |= TEXTURE_BIT;
  70    }
  71    else {
  72       if (ctx->Color.IndexMask != 0xffffffff) rasterMask |= MASKING_BIT;
  73       if (ctx->Color.IndexLogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
  74    }
  75
  76    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers
  77        && ctx->Color.ColorMask[ACOMP]
  78        && ctx->Color.DrawBuffer != GL_NONE)
  79       rasterMask |= ALPHABUF_BIT;
  80
  81    if (   ctx->Viewport.X < 0
  82        || ctx->Viewport.X + ctx->Viewport.Width > (GLint) ctx->DrawBuffer->Width
  83        || ctx->Viewport.Y < 0
  84        || ctx->Viewport.Y + ctx->Viewport.Height > (GLint) ctx->DrawBuffer->Height) {
  85       rasterMask |= CLIP_BIT;
  86    }
  87
  88    if (ctx->Depth.OcclusionTest || ctx->Occlusion.Active)
  89       rasterMask |= OCCLUSION_BIT;
  90
  91
  92    /* If we're not drawing to exactly one color buffer set the
  93     * MULTI_DRAW_BIT flag.  Also set it if we're drawing to no
  94     * buffers or the RGBA or CI mask disables all writes.
  95     */
  96    if (_mesa_bitcount(ctx->Color._DrawDestMask[0]) != 1) {
  97       /* more than one color buffer designated for writing (or zero buffers) */
  98       rasterMask |= MULTI_DRAW_BIT;
  99    }
 100    else if (ctx->Visual.rgbMode && *((GLuint *) ctx->Color.ColorMask) == 0) {
 101       rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
 102    }
 103    else if (!ctx->Visual.rgbMode && ctx->Color.IndexMask==0) {
 104       rasterMask |= MULTI_DRAW_BIT; /* all color index bits disabled */
 105    }
 106
 107    if (ctx->FragmentProgram._Enabled) {
 108       rasterMask |= FRAGPROG_BIT;
 109    }
 110
 111    SWRAST_CONTEXT(ctx)->_RasterMask = rasterMask;
 112 }
 113
 114
 115 /**
 116  * Examine polycon culls tate to compute the _BackfaceSign field.
 117  * _BackfaceSign will be 0 if no culling, -1 if culling back-faces,
 118  * and 1 if culling front-faces.  The Polygon FrontFace state also
 119  * factors in.
 120  */
 121 static void
 122 _swrast_update_polygon( GLcontext *ctx )
 123 {
 124    GLfloat backface_sign = 1;
 125
 126    if (ctx->Polygon.CullFlag) {
 127       backface_sign = 1;
 128       switch(ctx->Polygon.CullFaceMode) {
 129       case GL_BACK:
 130          if(ctx->Polygon.FrontFace==GL_CCW)
 131             backface_sign = -1;
 132          break;
 133       case GL_FRONT:
 134          if(ctx->Polygon.FrontFace!=GL_CCW)
 135             backface_sign = -1;
 136          break;
 137       default:
 138       case GL_FRONT_AND_BACK:
 139          backface_sign = 0;
 140          break;
 141       }
 142    }
 143    else {
 144       backface_sign = 0;
 145    }
 146
 147    SWRAST_CONTEXT(ctx)->_BackfaceSign = backface_sign;
 148 }
 149
 150
 151 /**
 152  * Update the _PreferPixelFog field to indicate if we need to compute
 153  * fog factors per-fragment.
 154  */
 155 static void
 156 _swrast_update_fog_hint( GLcontext *ctx )
 157 {
 158    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 159    swrast->_PreferPixelFog = (!swrast->AllowVertexFog ||
 160                               ctx->FragmentProgram._Enabled ||
 161                               (ctx->Hint.Fog == GL_NICEST &&
 162                                swrast->AllowPixelFog));
 163 }
 164
 165
 166
 167 /**
 168  * Update the swrast->_AnyTextureCombine flag.
 169  */
 170 static void
 171 _swrast_update_texture_env( GLcontext *ctx )
 172 {
 173    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 174    GLuint i;
 175    swrast->_AnyTextureCombine = GL_FALSE;
 176    for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
 177       if (ctx->Texture.Unit[i].EnvMode == GL_COMBINE_EXT ||
 178           ctx->Texture.Unit[i].EnvMode == GL_COMBINE4_NV) {
 179          swrast->_AnyTextureCombine = GL_TRUE;
 180          return;
 181       }
 182    }
 183 }
 184
 185
 186 /**
 187  * Update swrast->_FogColor and swrast->_FogEnable values.
 188  */
 189 static void
 190 _swrast_update_fog_state( GLcontext *ctx )
 191 {
 192    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 193
 194    /* convert fog color to GLchan values */
 195    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[RCOMP], ctx->Fog.Color[RCOMP]);
 196    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[GCOMP], ctx->Fog.Color[GCOMP]);
 197    CLAMPED_FLOAT_TO_CHAN(swrast->_FogColor[BCOMP], ctx->Fog.Color[BCOMP]);
 198
 199    /* determine if fog is needed */
 200    swrast->_FogEnabled = GL_FALSE;
 201    if (ctx->Fog.Enabled) {
 202       swrast->_FogEnabled = GL_TRUE;
 203    }
 204    else if (ctx->FragmentProgram._Enabled &&
 205         ctx->FragmentProgram.Current->Base.Target == GL_FRAGMENT_PROGRAM_ARB) {
 206       const struct fragment_program *p;
 207       p = (struct fragment_program *) ctx->FragmentProgram.Current;
 208       if (p->FogOption != GL_NONE) {
 209          swrast->_FogEnabled = GL_TRUE;
 210       }
 211    }
 212 }
 213
 214
 215 /**
 216  * Update state for running fragment programs.  Basically, load the
 217  * program parameters with current state values.
 218  */
 219 static void
 220 _swrast_update_fragment_program( GLcontext *ctx )
 221 {
 222    if (ctx->FragmentProgram._Enabled) {
 223       struct fragment_program *program = ctx->FragmentProgram.Current;
 224       _mesa_load_state_parameters(ctx, program->Parameters);
 225    }
 226 }
 227
 228
 229
 230 #define _SWRAST_NEW_DERIVED (_SWRAST_NEW_RASTERMASK |   \
 231                              _NEW_TEXTURE |             \
 232                              _NEW_HINT |                \
 233                              _NEW_POLYGON )
 234
 235 /* State referenced by _swrast_choose_triangle, _swrast_choose_line.
 236  */
 237 #define _SWRAST_NEW_TRIANGLE (_SWRAST_NEW_DERIVED |             \
 238                               _NEW_RENDERMODE|                  \
 239                               _NEW_POLYGON|                     \
 240                               _NEW_DEPTH|                       \
 241                               _NEW_STENCIL|                     \
 242                               _NEW_COLOR|                       \
 243                               _NEW_TEXTURE|                     \
 244                               _SWRAST_NEW_RASTERMASK|           \
 245                               _NEW_LIGHT|                       \
 246                               _NEW_FOG |                        \
 247                               _DD_NEW_SEPARATE_SPECULAR)
 248
 249 #define _SWRAST_NEW_LINE (_SWRAST_NEW_DERIVED |         \
 250                           _NEW_RENDERMODE|              \
 251                           _NEW_LINE|                    \
 252                           _NEW_TEXTURE|                 \
 253                           _NEW_LIGHT|                   \
 254                           _NEW_FOG|                     \
 255                           _NEW_DEPTH |                  \
 256                           _DD_NEW_SEPARATE_SPECULAR)
 257
 258 #define _SWRAST_NEW_POINT (_SWRAST_NEW_DERIVED |        \
 259                            _NEW_RENDERMODE |            \
 260                            _NEW_POINT |                 \
 261                            _NEW_TEXTURE |               \
 262                            _NEW_LIGHT |                 \
 263                            _NEW_FOG |                   \
 264                            _DD_NEW_SEPARATE_SPECULAR)
 265
 266 #define _SWRAST_NEW_TEXTURE_SAMPLE_FUNC _NEW_TEXTURE
 267
 268 #define _SWRAST_NEW_TEXTURE_ENV_MODE _NEW_TEXTURE
 269
 270 #define _SWRAST_NEW_BLEND_FUNC _NEW_COLOR
 271
 272
 273
 274 /**
 275  * Stub for swrast->Triangle to select a true triangle function
 276  * after a state change.
 277  */
 278 static void
 279 _swrast_validate_triangle( GLcontext *ctx,
 280                            const SWvertex *v0,
 281                            const SWvertex *v1,
 282                            const SWvertex *v2 )
 283 {
 284    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 285
 286    _swrast_validate_derived( ctx );
 287    swrast->choose_triangle( ctx );
 288
 289    if (ctx->Texture._EnabledUnits == 0
 290        && NEED_SECONDARY_COLOR(ctx)
 291        && !ctx->FragmentProgram._Enabled) {
 292       /* separate specular color, but no texture */
 293       swrast->SpecTriangle = swrast->Triangle;
 294       swrast->Triangle = _swrast_add_spec_terms_triangle;
 295    }
 296
 297    swrast->Triangle( ctx, v0, v1, v2 );
 298 }
 299
 300 /**
 301  * Called via swrast->Line.  Examine current GL state and choose a software
 302  * line routine.  Then call it.
 303  */
 304 static void
 305 _swrast_validate_line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 306 {
 307    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 308
 309    _swrast_validate_derived( ctx );
 310    swrast->choose_line( ctx );
 311
 312    if (ctx->Texture._EnabledUnits == 0
 313        && NEED_SECONDARY_COLOR(ctx)
 314        && !ctx->FragmentProgram._Enabled) {
 315       swrast->SpecLine = swrast->Line;
 316       swrast->Line = _swrast_add_spec_terms_line;
 317    }
 318
 319
 320    swrast->Line( ctx, v0, v1 );
 321 }
 322
 323 /**
 324  * Called via swrast->Point.  Examine current GL state and choose a software
 325  * point routine.  Then call it.
 326  */
 327 static void
 328 _swrast_validate_point( GLcontext *ctx, const SWvertex *v0 )
 329 {
 330    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 331
 332    _swrast_validate_derived( ctx );
 333    swrast->choose_point( ctx );
 334
 335    if (ctx->Texture._EnabledUnits == 0
 336        && NEED_SECONDARY_COLOR(ctx)
 337        && !ctx->FragmentProgram._Enabled) {
 338       swrast->SpecPoint = swrast->Point;
 339       swrast->Point = _swrast_add_spec_terms_point;
 340    }
 341
 342    swrast->Point( ctx, v0 );
 343 }
 344
 345
 346 /**
 347  * Called via swrast->BlendFunc.  Examine GL state to choose a blending
 348  * function, then call it.
 349  */
 350 static void _ASMAPI
 351 _swrast_validate_blend_func( GLcontext *ctx, GLuint n,
 352                              const GLubyte mask[],
 353                              GLchan src[][4],
 354                              CONST GLchan dst[][4] )
 355 {
 356    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 357
 358    _swrast_validate_derived( ctx );
 359    _swrast_choose_blend_func( ctx );
 360
 361    swrast->BlendFunc( ctx, n, mask, src, dst );
 362 }
 363
 364
 365 /**
 366  * Called via the swrast->TextureSample[i] function pointer.
 367  * Basically, given a texture object, an array of texture coords
 368  * and an array of level-of-detail values, return an array of colors.
 369  * In this case, determine the correct texture sampling routine
 370  * (depending on filter mode, texture dimensions, etc) then call the
 371  * sampler routine.
 372  */
 373 static void
 374 _swrast_validate_texture_sample( GLcontext *ctx, GLuint texUnit,
 375                                  const struct gl_texture_object *tObj,
 376                                  GLuint n, const GLfloat texcoords[][4],
 377                                  const GLfloat lambda[], GLchan rgba[][4] )
 378 {
 379    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 380
 381    _swrast_validate_derived( ctx );
 382
 383    /* Compute min/mag filter threshold */
 384    if (tObj && tObj->MinFilter != tObj->MagFilter) {
 385       if (tObj->MagFilter == GL_LINEAR
 386           && (tObj->MinFilter == GL_NEAREST_MIPMAP_NEAREST ||
 387               tObj->MinFilter == GL_NEAREST_MIPMAP_LINEAR)) {
 388          swrast->_MinMagThresh[texUnit] = 0.5F;
 389       }
 390       else {
 391          swrast->_MinMagThresh[texUnit] = 0.0F;
 392       }
 393    }
 394
 395    swrast->TextureSample[texUnit] =
 396       _swrast_choose_texture_sample_func( ctx, tObj );
 397
 398    swrast->TextureSample[texUnit]( ctx, texUnit, tObj, n, texcoords,
 399                                    lambda, rgba );
 400 }
 401
 402
 403 static void
 404 _swrast_sleep( GLcontext *ctx, GLuint new_state )
 405 {
 406    (void) ctx; (void) new_state;
 407 }
 408
 409
 410 static void
 411 _swrast_invalidate_state( GLcontext *ctx, GLuint new_state )
 412 {
 413    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 414    GLuint i;
 415
 416    swrast->NewState |= new_state;
 417
 418    /* After 10 statechanges without any swrast functions being called,
 419     * put the module to sleep.
 420     */
 421    if (++swrast->StateChanges > 10) {
 422       swrast->InvalidateState = _swrast_sleep;
 423       swrast->NewState = ~0;
 424       new_state = ~0;
 425    }
 426
 427    if (new_state & swrast->invalidate_triangle)
 428       swrast->Triangle = _swrast_validate_triangle;
 429
 430    if (new_state & swrast->invalidate_line)
 431       swrast->Line = _swrast_validate_line;
 432
 433    if (new_state & swrast->invalidate_point)
 434       swrast->Point = _swrast_validate_point;
 435
 436    if (new_state & _SWRAST_NEW_BLEND_FUNC)
 437       swrast->BlendFunc = _swrast_validate_blend_func;
 438
 439    if (new_state & _SWRAST_NEW_TEXTURE_SAMPLE_FUNC)
 440       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 441          swrast->TextureSample[i] = _swrast_validate_texture_sample;
 442
 443    /* Debug checks */
 444    if (ctx->Visual.rgbMode) {
 445       ASSERT(swrast->Driver.WriteRGBASpan);
 446       ASSERT(swrast->Driver.WriteRGBSpan);
 447       ASSERT(swrast->Driver.WriteMonoRGBASpan);
 448       ASSERT(swrast->Driver.WriteRGBAPixels);
 449       ASSERT(swrast->Driver.WriteMonoRGBAPixels);
 450       ASSERT(swrast->Driver.ReadRGBASpan);
 451       ASSERT(swrast->Driver.ReadRGBAPixels);
 452    }
 453    else {
 454       ASSERT(swrast->Driver.WriteCI32Span);
 455       ASSERT(swrast->Driver.WriteCI8Span);
 456       ASSERT(swrast->Driver.WriteMonoCISpan);
 457       ASSERT(swrast->Driver.WriteCI32Pixels);
 458       ASSERT(swrast->Driver.WriteMonoCIPixels);
 459       ASSERT(swrast->Driver.ReadCI32Span);
 460       ASSERT(swrast->Driver.ReadCI32Pixels);
 461    }
 462 }
 463
 464
 465 void
 466 _swrast_validate_derived( GLcontext *ctx )
 467 {
 468    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 469
 470    if (swrast->NewState) {
 471       if (swrast->NewState & _SWRAST_NEW_RASTERMASK)
 472          _swrast_update_rasterflags( ctx );
 473
 474       if (swrast->NewState & _NEW_POLYGON)
 475          _swrast_update_polygon( ctx );
 476
 477       if (swrast->NewState & (_NEW_HINT | _NEW_PROGRAM))
 478          _swrast_update_fog_hint( ctx );
 479
 480       if (swrast->NewState & _SWRAST_NEW_TEXTURE_ENV_MODE)
 481          _swrast_update_texture_env( ctx );
 482
 483       if (swrast->NewState & _NEW_FOG)
 484          _swrast_update_fog_state( ctx );
 485
 486       if (swrast->NewState & _NEW_PROGRAM)
 487          _swrast_update_fragment_program( ctx );
 488
 489       swrast->NewState = 0;
 490       swrast->StateChanges = 0;
 491       swrast->InvalidateState = _swrast_invalidate_state;
 492    }
 493 }
 494
 495 #define SWRAST_DEBUG 0
 496
 497 /* Public entrypoints:  See also s_accum.c, s_bitmap.c, etc.
 498  */
 499 void
 500 _swrast_Quad( GLcontext *ctx,
 501               const SWvertex *v0, const SWvertex *v1,
 502               const SWvertex *v2, const SWvertex *v3 )
 503 {
 504    if (SWRAST_DEBUG) {
 505       _mesa_debug(ctx, "_swrast_Quad\n");
 506       _swrast_print_vertex( ctx, v0 );
 507       _swrast_print_vertex( ctx, v1 );
 508       _swrast_print_vertex( ctx, v2 );
 509       _swrast_print_vertex( ctx, v3 );
 510    }
 511    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v3 );
 512    SWRAST_CONTEXT(ctx)->Triangle( ctx, v1, v2, v3 );
 513 }
 514
 515 void
 516 _swrast_Triangle( GLcontext *ctx, const SWvertex *v0,
 517                   const SWvertex *v1, const SWvertex *v2 )
 518 {
 519    if (SWRAST_DEBUG) {
 520       _mesa_debug(ctx, "_swrast_Triangle\n");
 521       _swrast_print_vertex( ctx, v0 );
 522       _swrast_print_vertex( ctx, v1 );
 523       _swrast_print_vertex( ctx, v2 );
 524    }
 525    SWRAST_CONTEXT(ctx)->Triangle( ctx, v0, v1, v2 );
 526 }
 527
 528 void
 529 _swrast_Line( GLcontext *ctx, const SWvertex *v0, const SWvertex *v1 )
 530 {
 531    if (SWRAST_DEBUG) {
 532       _mesa_debug(ctx, "_swrast_Line\n");
 533       _swrast_print_vertex( ctx, v0 );
 534       _swrast_print_vertex( ctx, v1 );
 535    }
 536    SWRAST_CONTEXT(ctx)->Line( ctx, v0, v1 );
 537 }
 538
 539 void
 540 _swrast_Point( GLcontext *ctx, const SWvertex *v0 )
 541 {
 542    if (SWRAST_DEBUG) {
 543       _mesa_debug(ctx, "_swrast_Point\n");
 544       _swrast_print_vertex( ctx, v0 );
 545    }
 546    SWRAST_CONTEXT(ctx)->Point( ctx, v0 );
 547 }
 548
 549 void
 550 _swrast_InvalidateState( GLcontext *ctx, GLuint new_state )
 551 {
 552    if (SWRAST_DEBUG) {
 553       _mesa_debug(ctx, "_swrast_InvalidateState\n");
 554    }
 555    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, new_state );
 556 }
 557
 558 void
 559 _swrast_ResetLineStipple( GLcontext *ctx )
 560 {
 561    if (SWRAST_DEBUG) {
 562       _mesa_debug(ctx, "_swrast_ResetLineStipple\n");
 563    }
 564    SWRAST_CONTEXT(ctx)->StippleCounter = 0;
 565 }
 566
 567 void
 568 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 569 {
 570    if (SWRAST_DEBUG) {
 571       _mesa_debug(ctx, "_swrast_allow_vertex_fog %d\n", value);
 572    }
 573    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 574    SWRAST_CONTEXT(ctx)->AllowVertexFog = value;
 575 }
 576
 577 void
 578 _swrast_allow_pixel_fog( GLcontext *ctx, GLboolean value )
 579 {
 580    if (SWRAST_DEBUG) {
 581       _mesa_debug(ctx, "_swrast_allow_pixel_fog %d\n", value);
 582    }
 583    SWRAST_CONTEXT(ctx)->InvalidateState( ctx, _NEW_HINT );
 584    SWRAST_CONTEXT(ctx)->AllowPixelFog = value;
 585 }
 586
 587
 588 GLboolean
 589 _swrast_CreateContext( GLcontext *ctx )
 590 {
 591    GLuint i;
 592    SWcontext *swrast = (SWcontext *)CALLOC(sizeof(SWcontext));
 593
 594    if (SWRAST_DEBUG) {
 595       _mesa_debug(ctx, "_swrast_CreateContext\n");
 596    }
 597
 598    if (!swrast)
 599       return GL_FALSE;
 600
 601    swrast->NewState = ~0;
 602
 603    swrast->choose_point = _swrast_choose_point;
 604    swrast->choose_line = _swrast_choose_line;
 605    swrast->choose_triangle = _swrast_choose_triangle;
 606
 607    swrast->invalidate_point = _SWRAST_NEW_POINT;
 608    swrast->invalidate_line = _SWRAST_NEW_LINE;
 609    swrast->invalidate_triangle = _SWRAST_NEW_TRIANGLE;
 610
 611    swrast->Point = _swrast_validate_point;
 612    swrast->Line = _swrast_validate_line;
 613    swrast->Triangle = _swrast_validate_triangle;
 614    swrast->InvalidateState = _swrast_sleep;
 615    swrast->BlendFunc = _swrast_validate_blend_func;
 616
 617    swrast->AllowVertexFog = GL_TRUE;
 618    swrast->AllowPixelFog = GL_TRUE;
 619
 620    if (ctx->Visual.doubleBufferMode)
 621       swrast->CurrentBufferBit = DD_BACK_LEFT_BIT;
 622    else
 623       swrast->CurrentBufferBit = DD_FRONT_LEFT_BIT;
 624
 625    /* Optimized Accum buffer */
 626    swrast->_IntegerAccumMode = GL_TRUE;
 627    swrast->_IntegerAccumScaler = 0.0;
 628
 629    for (i = 0; i < MAX_TEXTURE_IMAGE_UNITS; i++)
 630       swrast->TextureSample[i] = _swrast_validate_texture_sample;
 631
 632    swrast->SpanArrays = MALLOC_STRUCT(span_arrays);
 633    if (!swrast->SpanArrays) {
 634       FREE(swrast);
 635       return GL_FALSE;
 636    }
 637
 638    /* init point span buffer */
 639    swrast->PointSpan.primitive = GL_POINT;
 640    swrast->PointSpan.start = 0;
 641    swrast->PointSpan.end = 0;
 642    swrast->PointSpan.facing = 0;
 643    swrast->PointSpan.array = swrast->SpanArrays;
 644
 645    assert(ctx->Const.MaxTextureUnits > 0);
 646    assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_UNITS);
 647
 648    swrast->TexelBuffer = (GLchan *) MALLOC(ctx->Const.MaxTextureUnits *
 649                                            MAX_WIDTH * 4 * sizeof(GLchan));
 650    if (!swrast->TexelBuffer) {
 651       FREE(swrast->SpanArrays);
 652       FREE(swrast);
 653       return GL_FALSE;
 654    }
 655
 656    ctx->swrast_context = swrast;
 657
 658    return GL_TRUE;
 659 }
 660
 661 void
 662 _swrast_DestroyContext( GLcontext *ctx )
 663 {
 664    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 665
 666    if (SWRAST_DEBUG) {
 667       _mesa_debug(ctx, "_swrast_DestroyContext\n");
 668    }
 669
 670    FREE( swrast->SpanArrays );
 671    FREE( swrast->TexelBuffer );
 672    FREE( swrast );
 673
 674    ctx->swrast_context = 0;
 675 }
 676
 677
 678 struct swrast_device_driver *
 679 _swrast_GetDeviceDriverReference( GLcontext *ctx )
 680 {
 681    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 682    return &swrast->Driver;
 683 }
 684
 685 void
 686 _swrast_flush( GLcontext *ctx )
 687 {
 688    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 689    /* flush any pending fragments from rendering points */
 690    if (swrast->PointSpan.end > 0) {
 691       if (ctx->Visual.rgbMode) {
 692          if (ctx->Texture._EnabledCoordUnits)
 693             _swrast_write_texture_span(ctx, &(swrast->PointSpan));
 694          else
 695             _swrast_write_rgba_span(ctx, &(swrast->PointSpan));
 696       }
 697       else {
 698          _swrast_write_index_span(ctx, &(swrast->PointSpan));
 699       }
 700       swrast->PointSpan.end = 0;
 701    }
 702 }
 703
 704 void
 705 _swrast_render_primitive( GLcontext *ctx, GLenum prim )
 706 {
 707    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 708    if (swrast->Primitive == GL_POINTS && prim != GL_POINTS) {
 709       _swrast_flush(ctx);
 710    }
 711    swrast->Primitive = prim;
 712 }
 713
 714
 715 void
 716 _swrast_render_start( GLcontext *ctx )
 717 {
 718    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 719    if (swrast->Driver.SpanRenderStart)
 720       swrast->Driver.SpanRenderStart( ctx );
 721    swrast->PointSpan.end = 0;
 722 }
 723
 724 void
 725 _swrast_render_finish( GLcontext *ctx )
 726 {
 727    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 728    if (swrast->Driver.SpanRenderFinish)
 729       swrast->Driver.SpanRenderFinish( ctx );
 730
 731    _swrast_flush(ctx);
 732 }
 733
 734
 735 #define SWRAST_DEBUG_VERTICES 0
 736
 737 void
 738 _swrast_print_vertex( GLcontext *ctx, const SWvertex *v )
 739 {
 740    GLuint i;
 741
 742    if (SWRAST_DEBUG_VERTICES) {
 743       _mesa_debug(ctx, "win %f %f %f %f\n",
 744                   v->win[0], v->win[1], v->win[2], v->win[3]);
 745
 746       for (i = 0 ; i < ctx->Const.MaxTextureUnits ; i++)
 747          if (ctx->Texture.Unit[i]._ReallyEnabled)
 748             _mesa_debug(ctx, "texcoord[%d] %f %f %f %f\n", i,
 749                         v->texcoord[i][0], v->texcoord[i][1],
 750                         v->texcoord[i][2], v->texcoord[i][3]);
 751
 752 #if CHAN_TYPE == GL_FLOAT
 753       _mesa_debug(ctx, "color %f %f %f %f\n",
 754                   v->color[0], v->color[1], v->color[2], v->color[3]);
 755       _mesa_debug(ctx, "spec %f %f %f %f\n",
 756                   v->specular[0], v->specular[1],
 757                   v->specular[2], v->specular[3]);
 758 #else
 759       _mesa_debug(ctx, "color %d %d %d %d\n",
 760                   v->color[0], v->color[1], v->color[2], v->color[3]);
 761       _mesa_debug(ctx, "spec %d %d %d %d\n",
 762                   v->specular[0], v->specular[1],
 763                   v->specular[2], v->specular[3]);
 764 #endif
 765       _mesa_debug(ctx, "fog %f\n", v->fog);
 766       _mesa_debug(ctx, "index %d\n", v->index);
 767       _mesa_debug(ctx, "pointsize %f\n", v->pointSize);
 768       _mesa_debug(ctx, "\n");
 769    }
 770 }
 771
 772
 773 /**
 774  * Validate access to a PBO to be sure we're not going to read/write
 775  * out of buffer bounds.
 776  */
 777 GLvoid *
 778 _swrast_validate_pbo_access(const struct gl_pixelstore_attrib *pack,
 779                             GLsizei width, GLsizei height, GLsizei depth,
 780                             GLenum format, GLenum type, GLvoid *ptr)
 781 {
 782    if (pack->BufferObj->Name == 0) {
 783       /* no PBO */
 784       return ptr;
 785    }
 786    else if (_mesa_validate_pbo_access(pack, width, height, depth, format,
 787                                       type, ptr)) {
 788       return ADD_POINTERS(pack->BufferObj->Data, ptr);
 789    }
 790    /* bad access! */
 791    return NULL;
 792 }