src/mesa/main/blend.c

   1 /**
   2  * \file blend.c
   3  * Blending operations.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  6.5.1
   9  *
  10  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31
  32 #include "glheader.h"
  33 #include "blend.h"
  34 #include "context.h"
  35 #include "enums.h"
  36 #include "macros.h"
  37 #include "mtypes.h"
  38
  39
  40
  41 /**
  42  * Check if given blend source factor is legal.
  43  * \return GL_TRUE if legal, GL_FALSE otherwise.
  44  */
  45 static GLboolean
  46 legal_src_factor(const struct gl_context *ctx, GLenum factor)
  47 {
  48    switch (factor) {
  49    case GL_SRC_COLOR:
  50    case GL_ONE_MINUS_SRC_COLOR:
  51       return ctx->Extensions.NV_blend_square;
  52    case GL_ZERO:
  53    case GL_ONE:
  54    case GL_DST_COLOR:
  55    case GL_ONE_MINUS_DST_COLOR:
  56    case GL_SRC_ALPHA:
  57    case GL_ONE_MINUS_SRC_ALPHA:
  58    case GL_DST_ALPHA:
  59    case GL_ONE_MINUS_DST_ALPHA:
  60    case GL_SRC_ALPHA_SATURATE:
  61    case GL_CONSTANT_COLOR:
  62    case GL_ONE_MINUS_CONSTANT_COLOR:
  63    case GL_CONSTANT_ALPHA:
  64    case GL_ONE_MINUS_CONSTANT_ALPHA:
  65       return GL_TRUE;
  66    case GL_SRC1_COLOR:
  67    case GL_SRC1_ALPHA:
  68    case GL_ONE_MINUS_SRC1_COLOR:
  69    case GL_ONE_MINUS_SRC1_ALPHA:
  70       return ctx->Extensions.ARB_blend_func_extended;
  71    default:
  72       return GL_FALSE;
  73    }
  74 }
  75
  76
  77 /**
  78  * Check if given blend destination factor is legal.
  79  * \return GL_TRUE if legal, GL_FALSE otherwise.
  80  */
  81 static GLboolean
  82 legal_dst_factor(const struct gl_context *ctx, GLenum factor)
  83 {
  84    switch (factor) {
  85    case GL_DST_COLOR:
  86    case GL_ONE_MINUS_DST_COLOR:
  87       return ctx->Extensions.NV_blend_square;
  88    case GL_ZERO:
  89    case GL_ONE:
  90    case GL_SRC_COLOR:
  91    case GL_ONE_MINUS_SRC_COLOR:
  92    case GL_SRC_ALPHA:
  93    case GL_ONE_MINUS_SRC_ALPHA:
  94    case GL_DST_ALPHA:
  95    case GL_ONE_MINUS_DST_ALPHA:
  96    case GL_CONSTANT_COLOR:
  97    case GL_ONE_MINUS_CONSTANT_COLOR:
  98    case GL_CONSTANT_ALPHA:
  99    case GL_ONE_MINUS_CONSTANT_ALPHA:
 100       return GL_TRUE;
 101    case GL_SRC_ALPHA_SATURATE:
 102    case GL_SRC1_COLOR:
 103    case GL_SRC1_ALPHA:
 104    case GL_ONE_MINUS_SRC1_COLOR:
 105    case GL_ONE_MINUS_SRC1_ALPHA:
 106       return ctx->Extensions.ARB_blend_func_extended;
 107    default:
 108       return GL_FALSE;
 109    }
 110 }
 111
 112
 113 /**
 114  * Check if src/dest RGB/A blend factors are legal.  If not generate
 115  * a GL error.
 116  * \return GL_TRUE if factors are legal, GL_FALSE otherwise.
 117  */
 118 static GLboolean
 119 validate_blend_factors(struct gl_context *ctx, const char *func,
 120                        GLenum sfactorRGB, GLenum dfactorRGB,
 121                        GLenum sfactorA, GLenum dfactorA)
 122 {
 123    if (!legal_src_factor(ctx, sfactorRGB)) {
 124       _mesa_error(ctx, GL_INVALID_ENUM,
 125                   "%s(sfactorRGB = %s)", func,
 126                   _mesa_lookup_enum_by_nr(sfactorRGB));
 127       return GL_FALSE;
 128    }
 129
 130    if (!legal_dst_factor(ctx, dfactorRGB)) {
 131       _mesa_error(ctx, GL_INVALID_ENUM,
 132                   "%s(dfactorRGB = %s)", func,
 133                   _mesa_lookup_enum_by_nr(dfactorRGB));
 134       return GL_FALSE;
 135    }
 136
 137    if (sfactorA != sfactorRGB && !legal_src_factor(ctx, sfactorA)) {
 138       _mesa_error(ctx, GL_INVALID_ENUM,
 139                   "%s(sfactorA = %s)", func,
 140                   _mesa_lookup_enum_by_nr(sfactorA));
 141       return GL_FALSE;
 142    }
 143
 144    if (dfactorA != dfactorRGB && !legal_dst_factor(ctx, dfactorA)) {
 145       _mesa_error(ctx, GL_INVALID_ENUM,
 146                   "%s(dfactorA = %s)", func,
 147                   _mesa_lookup_enum_by_nr(dfactorA));
 148       return GL_FALSE;
 149    }
 150
 151    return GL_TRUE;
 152 }
 153
 154
 155 /**
 156  * Specify the blending operation.
 157  *
 158  * \param sfactor source factor operator.
 159  * \param dfactor destination factor operator.
 160  *
 161  * \sa glBlendFunc, glBlendFuncSeparateEXT
 162  */
 163 void GLAPIENTRY
 164 _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
 165 {
 166    _mesa_BlendFuncSeparateEXT(sfactor, dfactor, sfactor, dfactor);
 167 }
 168
 169 static GLboolean
 170 blend_factor_is_dual_src(GLenum factor)
 171 {
 172    return (factor == GL_SRC1_COLOR ||
 173            factor == GL_SRC1_ALPHA ||
 174            factor == GL_ONE_MINUS_SRC1_COLOR ||
 175            factor == GL_ONE_MINUS_SRC1_ALPHA);
 176 }
 177
 178 static void
 179 update_uses_dual_src(struct gl_context *ctx, int buf)
 180 {
 181    ctx->Color.Blend[buf]._UsesDualSrc =
 182       (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
 183        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
 184        blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
 185        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
 186 }
 187
 188 /**
 189  * Set the separate blend source/dest factors for all draw buffers.
 190  *
 191  * \param sfactorRGB RGB source factor operator.
 192  * \param dfactorRGB RGB destination factor operator.
 193  * \param sfactorA alpha source factor operator.
 194  * \param dfactorA alpha destination factor operator.
 195  */
 196 void GLAPIENTRY
 197 _mesa_BlendFuncSeparateEXT( GLenum sfactorRGB, GLenum dfactorRGB,
 198                             GLenum sfactorA, GLenum dfactorA )
 199 {
 200    GLuint buf, numBuffers;
 201    GLboolean changed;
 202    GET_CURRENT_CONTEXT(ctx);
 203    ASSERT_OUTSIDE_BEGIN_END(ctx);
 204
 205    if (MESA_VERBOSE & VERBOSE_API)
 206       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
 207                   _mesa_lookup_enum_by_nr(sfactorRGB),
 208                   _mesa_lookup_enum_by_nr(dfactorRGB),
 209                   _mesa_lookup_enum_by_nr(sfactorA),
 210                   _mesa_lookup_enum_by_nr(dfactorA));
 211
 212    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
 213                                sfactorRGB, dfactorRGB,
 214                                sfactorA, dfactorA)) {
 215       return;
 216    }
 217
 218    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 219       ? ctx->Const.MaxDrawBuffers : 1;
 220
 221    changed = GL_FALSE;
 222    for (buf = 0; buf < numBuffers; buf++) {
 223       if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
 224           ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
 225           ctx->Color.Blend[buf].SrcA != sfactorA ||
 226           ctx->Color.Blend[buf].DstA != dfactorA) {
 227          changed = GL_TRUE;
 228          break;
 229       }
 230    }
 231    if (!changed)
 232       return;
 233
 234    FLUSH_VERTICES(ctx, _NEW_COLOR);
 235
 236    for (buf = 0; buf < numBuffers; buf++) {
 237       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 238       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 239       ctx->Color.Blend[buf].SrcA = sfactorA;
 240       ctx->Color.Blend[buf].DstA = dfactorA;
 241       update_uses_dual_src(ctx, buf);
 242    }
 243    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
 244
 245    if (ctx->Driver.BlendFuncSeparate) {
 246       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
 247                                     sfactorA, dfactorA);
 248    }
 249 }
 250
 251
 252 #if _HAVE_FULL_GL
 253
 254
 255 /**
 256  * Set blend source/dest factors for one color buffer/target.
 257  */
 258 void GLAPIENTRY
 259 _mesa_BlendFunci(GLuint buf, GLenum sfactor, GLenum dfactor)
 260 {
 261    _mesa_BlendFuncSeparatei(buf, sfactor, dfactor, sfactor, dfactor);
 262 }
 263
 264
 265 /**
 266  * Set separate blend source/dest factors for one color buffer/target.
 267  */
 268 void GLAPIENTRY
 269 _mesa_BlendFuncSeparatei(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 270                          GLenum sfactorA, GLenum dfactorA)
 271 {
 272    GET_CURRENT_CONTEXT(ctx);
 273    ASSERT_OUTSIDE_BEGIN_END(ctx);
 274
 275    if (!ctx->Extensions.ARB_draw_buffers_blend) {
 276       _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 277       return;
 278    }
 279
 280    if (buf >= ctx->Const.MaxDrawBuffers) {
 281       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 282                   buf);
 283       return;
 284    }
 285
 286    if (!validate_blend_factors(ctx, "glBlendFuncSeparatei",
 287                                sfactorRGB, dfactorRGB,
 288                                sfactorA, dfactorA)) {
 289       return;
 290    }
 291
 292    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 293        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 294        ctx->Color.Blend[buf].SrcA == sfactorA &&
 295        ctx->Color.Blend[buf].DstA == dfactorA)
 296       return; /* no change */
 297
 298    FLUSH_VERTICES(ctx, _NEW_COLOR);
 299
 300    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 301    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 302    ctx->Color.Blend[buf].SrcA = sfactorA;
 303    ctx->Color.Blend[buf].DstA = dfactorA;
 304    update_uses_dual_src(ctx, buf);
 305    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 306
 307    if (ctx->Driver.BlendFuncSeparatei) {
 308       ctx->Driver.BlendFuncSeparatei(ctx, buf, sfactorRGB, dfactorRGB,
 309                                      sfactorA, dfactorA);
 310    }
 311 }
 312
 313
 314 /**
 315  * Check if given blend equation is legal.
 316  * \return GL_TRUE if legal, GL_FALSE otherwise.
 317  */
 318 static GLboolean
 319 legal_blend_equation(const struct gl_context *ctx, GLenum mode)
 320 {
 321    switch (mode) {
 322    case GL_FUNC_ADD:
 323    case GL_FUNC_SUBTRACT:
 324    case GL_FUNC_REVERSE_SUBTRACT:
 325       return GL_TRUE;
 326    case GL_MIN:
 327    case GL_MAX:
 328       return ctx->Extensions.EXT_blend_minmax;
 329    default:
 330       return GL_FALSE;
 331    }
 332 }
 333
 334
 335 /* This is really an extension function! */
 336 void GLAPIENTRY
 337 _mesa_BlendEquation( GLenum mode )
 338 {
 339    GLuint buf, numBuffers;
 340    GLboolean changed;
 341    GET_CURRENT_CONTEXT(ctx);
 342    ASSERT_OUTSIDE_BEGIN_END(ctx);
 343
 344    if (MESA_VERBOSE & VERBOSE_API)
 345       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 346                   _mesa_lookup_enum_by_nr(mode));
 347
 348    if (!legal_blend_equation(ctx, mode)) {
 349       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 350       return;
 351    }
 352
 353    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 354       ? ctx->Const.MaxDrawBuffers : 1;
 355
 356    changed = GL_FALSE;
 357    for (buf = 0; buf < numBuffers; buf++) {
 358       if (ctx->Color.Blend[buf].EquationRGB != mode ||
 359           ctx->Color.Blend[buf].EquationA != mode) {
 360          changed = GL_TRUE;
 361          break;
 362       }
 363    }
 364    if (!changed)
 365       return;
 366
 367    FLUSH_VERTICES(ctx, _NEW_COLOR);
 368    for (buf = 0; buf < numBuffers; buf++) {
 369       ctx->Color.Blend[buf].EquationRGB = mode;
 370       ctx->Color.Blend[buf].EquationA = mode;
 371    }
 372    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 373
 374    if (ctx->Driver.BlendEquationSeparate)
 375       (*ctx->Driver.BlendEquationSeparate)( ctx, mode, mode );
 376 }
 377
 378
 379 /**
 380  * Set blend equation for one color buffer/target.
 381  */
 382 void GLAPIENTRY
 383 _mesa_BlendEquationi(GLuint buf, GLenum mode)
 384 {
 385    GET_CURRENT_CONTEXT(ctx);
 386    ASSERT_OUTSIDE_BEGIN_END(ctx);
 387
 388    if (MESA_VERBOSE & VERBOSE_API)
 389       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 390                   buf, _mesa_lookup_enum_by_nr(mode));
 391
 392    if (buf >= ctx->Const.MaxDrawBuffers) {
 393       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 394                   buf);
 395       return;
 396    }
 397
 398    if (!legal_blend_equation(ctx, mode)) {
 399       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 400       return;
 401    }
 402
 403    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 404        ctx->Color.Blend[buf].EquationA == mode)
 405       return;  /* no change */
 406
 407    FLUSH_VERTICES(ctx, _NEW_COLOR);
 408    ctx->Color.Blend[buf].EquationRGB = mode;
 409    ctx->Color.Blend[buf].EquationA = mode;
 410    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 411
 412    if (ctx->Driver.BlendEquationSeparatei)
 413       ctx->Driver.BlendEquationSeparatei(ctx, buf, mode, mode);
 414 }
 415
 416
 417 void GLAPIENTRY
 418 _mesa_BlendEquationSeparateEXT( GLenum modeRGB, GLenum modeA )
 419 {
 420    GLuint buf, numBuffers;
 421    GLboolean changed;
 422    GET_CURRENT_CONTEXT(ctx);
 423    ASSERT_OUTSIDE_BEGIN_END(ctx);
 424
 425    if (MESA_VERBOSE & VERBOSE_API)
 426       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 427                   _mesa_lookup_enum_by_nr(modeRGB),
 428                   _mesa_lookup_enum_by_nr(modeA));
 429
 430    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 431       _mesa_error(ctx, GL_INVALID_OPERATION,
 432                   "glBlendEquationSeparateEXT not supported by driver");
 433       return;
 434    }
 435
 436    if (!legal_blend_equation(ctx, modeRGB)) {
 437       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 438       return;
 439    }
 440
 441    if (!legal_blend_equation(ctx, modeA)) {
 442       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 443       return;
 444    }
 445
 446    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 447       ? ctx->Const.MaxDrawBuffers : 1;
 448
 449    changed = GL_FALSE;
 450    for (buf = 0; buf < numBuffers; buf++) {
 451       if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 452           ctx->Color.Blend[buf].EquationA != modeA) {
 453          changed = GL_TRUE;
 454          break;
 455       }
 456    }
 457    if (!changed)
 458       return;
 459
 460    FLUSH_VERTICES(ctx, _NEW_COLOR);
 461    for (buf = 0; buf < numBuffers; buf++) {
 462       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 463       ctx->Color.Blend[buf].EquationA = modeA;
 464    }
 465    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 466
 467    if (ctx->Driver.BlendEquationSeparate)
 468       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 469 }
 470
 471
 472 /**
 473  * Set separate blend equations for one color buffer/target.
 474  */
 475 void GLAPIENTRY
 476 _mesa_BlendEquationSeparatei(GLuint buf, GLenum modeRGB, GLenum modeA)
 477 {
 478    GET_CURRENT_CONTEXT(ctx);
 479    ASSERT_OUTSIDE_BEGIN_END(ctx);
 480
 481    if (MESA_VERBOSE & VERBOSE_API)
 482       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 483                   _mesa_lookup_enum_by_nr(modeRGB),
 484                   _mesa_lookup_enum_by_nr(modeA));
 485
 486    if (buf >= ctx->Const.MaxDrawBuffers) {
 487       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 488                   buf);
 489       return;
 490    }
 491
 492    if (!legal_blend_equation(ctx, modeRGB)) {
 493       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 494       return;
 495    }
 496
 497    if (!legal_blend_equation(ctx, modeA)) {
 498       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 499       return;
 500    }
 501
 502    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 503        ctx->Color.Blend[buf].EquationA == modeA)
 504       return;  /* no change */
 505
 506    FLUSH_VERTICES(ctx, _NEW_COLOR);
 507    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 508    ctx->Color.Blend[buf].EquationA = modeA;
 509    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 510
 511    if (ctx->Driver.BlendEquationSeparatei)
 512       ctx->Driver.BlendEquationSeparatei(ctx, buf, modeRGB, modeA);
 513 }
 514
 515
 516
 517 #endif /* _HAVE_FULL_GL */
 518
 519
 520 /**
 521  * Set the blending color.
 522  *
 523  * \param red red color component.
 524  * \param green green color component.
 525  * \param blue blue color component.
 526  * \param alpha alpha color component.
 527  *
 528  * \sa glBlendColor().
 529  *
 530  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 531  * change, flushes the vertices and notifies the driver via
 532  * dd_function_table::BlendColor callback.
 533  */
 534 void GLAPIENTRY
 535 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 536 {
 537    GLfloat tmp[4];
 538    GET_CURRENT_CONTEXT(ctx);
 539    ASSERT_OUTSIDE_BEGIN_END(ctx);
 540
 541    tmp[0] = red;
 542    tmp[1] = green;
 543    tmp[2] = blue;
 544    tmp[3] = alpha;
 545
 546    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 547       return;
 548
 549    FLUSH_VERTICES(ctx, _NEW_COLOR);
 550    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 551
 552    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 553    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 554    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 555    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 556
 557    if (ctx->Driver.BlendColor)
 558       (*ctx->Driver.BlendColor)(ctx, ctx->Color.BlendColor);
 559 }
 560
 561
 562 /**
 563  * Specify the alpha test function.
 564  *
 565  * \param func alpha comparison function.
 566  * \param ref reference value.
 567  *
 568  * Verifies the parameters and updates gl_colorbuffer_attrib.
 569  * On a change, flushes the vertices and notifies the driver via
 570  * dd_function_table::AlphaFunc callback.
 571  */
 572 void GLAPIENTRY
 573 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 574 {
 575    GET_CURRENT_CONTEXT(ctx);
 576    ASSERT_OUTSIDE_BEGIN_END(ctx);
 577
 578    if (MESA_VERBOSE & VERBOSE_API)
 579       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 580                   _mesa_lookup_enum_by_nr(func), ref);
 581
 582    switch (func) {
 583    case GL_NEVER:
 584    case GL_LESS:
 585    case GL_EQUAL:
 586    case GL_LEQUAL:
 587    case GL_GREATER:
 588    case GL_NOTEQUAL:
 589    case GL_GEQUAL:
 590    case GL_ALWAYS:
 591       if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 592          return; /* no change */
 593
 594       FLUSH_VERTICES(ctx, _NEW_COLOR);
 595       ctx->Color.AlphaFunc = func;
 596       ctx->Color.AlphaRefUnclamped = ref;
 597       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 598
 599       if (ctx->Driver.AlphaFunc)
 600          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 601       return;
 602
 603    default:
 604       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 605       return;
 606    }
 607 }
 608
 609
 610 /**
 611  * Specify a logic pixel operation for color index rendering.
 612  *
 613  * \param opcode operation.
 614  *
 615  * Verifies that \p opcode is a valid enum and updates
 616 gl_colorbuffer_attrib::LogicOp.
 617  * On a change, flushes the vertices and notifies the driver via the
 618  * dd_function_table::LogicOpcode callback.
 619  */
 620 void GLAPIENTRY
 621 _mesa_LogicOp( GLenum opcode )
 622 {
 623    GET_CURRENT_CONTEXT(ctx);
 624    ASSERT_OUTSIDE_BEGIN_END(ctx);
 625
 626    if (MESA_VERBOSE & VERBOSE_API)
 627       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_lookup_enum_by_nr(opcode));
 628
 629    switch (opcode) {
 630       case GL_CLEAR:
 631       case GL_SET:
 632       case GL_COPY:
 633       case GL_COPY_INVERTED:
 634       case GL_NOOP:
 635       case GL_INVERT:
 636       case GL_AND:
 637       case GL_NAND:
 638       case GL_OR:
 639       case GL_NOR:
 640       case GL_XOR:
 641       case GL_EQUIV:
 642       case GL_AND_REVERSE:
 643       case GL_AND_INVERTED:
 644       case GL_OR_REVERSE:
 645       case GL_OR_INVERTED:
 646          break;
 647       default:
 648          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 649          return;
 650    }
 651
 652    if (ctx->Color.LogicOp == opcode)
 653       return;
 654
 655    FLUSH_VERTICES(ctx, _NEW_COLOR);
 656    ctx->Color.LogicOp = opcode;
 657
 658    if (ctx->Driver.LogicOpcode)
 659       ctx->Driver.LogicOpcode( ctx, opcode );
 660 }
 661
 662 #if _HAVE_FULL_GL
 663 void GLAPIENTRY
 664 _mesa_IndexMask( GLuint mask )
 665 {
 666    GET_CURRENT_CONTEXT(ctx);
 667    ASSERT_OUTSIDE_BEGIN_END(ctx);
 668
 669    if (ctx->Color.IndexMask == mask)
 670       return;
 671
 672    FLUSH_VERTICES(ctx, _NEW_COLOR);
 673    ctx->Color.IndexMask = mask;
 674 }
 675 #endif
 676
 677
 678 /**
 679  * Enable or disable writing of frame buffer color components.
 680  *
 681  * \param red whether to mask writing of the red color component.
 682  * \param green whether to mask writing of the green color component.
 683  * \param blue whether to mask writing of the blue color component.
 684  * \param alpha whether to mask writing of the alpha color component.
 685  *
 686  * \sa glColorMask().
 687  *
 688  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 689  * change, flushes the vertices and notifies the driver via the
 690  * dd_function_table::ColorMask callback.
 691  */
 692 void GLAPIENTRY
 693 _mesa_ColorMask( GLboolean red, GLboolean green,
 694                  GLboolean blue, GLboolean alpha )
 695 {
 696    GET_CURRENT_CONTEXT(ctx);
 697    GLubyte tmp[4];
 698    GLuint i;
 699    GLboolean flushed;
 700    ASSERT_OUTSIDE_BEGIN_END(ctx);
 701
 702    if (MESA_VERBOSE & VERBOSE_API)
 703       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 704                   red, green, blue, alpha);
 705
 706    /* Shouldn't have any information about channel depth in core mesa
 707     * -- should probably store these as the native booleans:
 708     */
 709    tmp[RCOMP] = red    ? 0xff : 0x0;
 710    tmp[GCOMP] = green  ? 0xff : 0x0;
 711    tmp[BCOMP] = blue   ? 0xff : 0x0;
 712    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 713
 714    flushed = GL_FALSE;
 715    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 716       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 717          if (!flushed) {
 718             FLUSH_VERTICES(ctx, _NEW_COLOR);
 719          }
 720          flushed = GL_TRUE;
 721          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 722       }
 723    }
 724
 725    if (ctx->Driver.ColorMask)
 726       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 727 }
 728
 729
 730 /**
 731  * For GL_EXT_draw_buffers2 and GL3
 732  */
 733 void GLAPIENTRY
 734 _mesa_ColorMaskIndexed( GLuint buf, GLboolean red, GLboolean green,
 735                         GLboolean blue, GLboolean alpha )
 736 {
 737    GLubyte tmp[4];
 738    GET_CURRENT_CONTEXT(ctx);
 739    ASSERT_OUTSIDE_BEGIN_END(ctx);
 740
 741    if (MESA_VERBOSE & VERBOSE_API)
 742       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 743                   buf, red, green, blue, alpha);
 744
 745    if (buf >= ctx->Const.MaxDrawBuffers) {
 746       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 747       return;
 748    }
 749
 750    /* Shouldn't have any information about channel depth in core mesa
 751     * -- should probably store these as the native booleans:
 752     */
 753    tmp[RCOMP] = red    ? 0xff : 0x0;
 754    tmp[GCOMP] = green  ? 0xff : 0x0;
 755    tmp[BCOMP] = blue   ? 0xff : 0x0;
 756    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 757
 758    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 759       return;
 760
 761    FLUSH_VERTICES(ctx, _NEW_COLOR);
 762    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 763
 764    if (ctx->Driver.ColorMaskIndexed)
 765       ctx->Driver.ColorMaskIndexed(ctx, buf, red, green, blue, alpha);
 766 }
 767
 768
 769 void GLAPIENTRY
 770 _mesa_ClampColorARB(GLenum target, GLenum clamp)
 771 {
 772    GET_CURRENT_CONTEXT(ctx);
 773
 774    ASSERT_OUTSIDE_BEGIN_END(ctx);
 775
 776    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 777       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 778       return;
 779    }
 780
 781    switch (target) {
 782    case GL_CLAMP_VERTEX_COLOR_ARB:
 783       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 784       ctx->Light.ClampVertexColor = clamp;
 785       break;
 786    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 787       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 788       ctx->Color.ClampFragmentColor = clamp;
 789       break;
 790    case GL_CLAMP_READ_COLOR_ARB:
 791       FLUSH_VERTICES(ctx, _NEW_COLOR);
 792       ctx->Color.ClampReadColor = clamp;
 793       break;
 794    default:
 795       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(target)");
 796       return;
 797    }
 798 }
 799
 800
 801
 802
 803 /**********************************************************************/
 804 /** \name Initialization */
 805 /*@{*/
 806
 807 /**
 808  * Initialization of the context's Color attribute group.
 809  *
 810  * \param ctx GL context.
 811  *
 812  * Initializes the related fields in the context color attribute group,
 813  * __struct gl_contextRec::Color.
 814  */
 815 void _mesa_init_color( struct gl_context * ctx )
 816 {
 817    GLuint i;
 818
 819    /* Color buffer group */
 820    ctx->Color.IndexMask = ~0u;
 821    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
 822    ctx->Color.ClearIndex = 0;
 823    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
 824    ctx->Color.AlphaEnabled = GL_FALSE;
 825    ctx->Color.AlphaFunc = GL_ALWAYS;
 826    ctx->Color.AlphaRef = 0;
 827    ctx->Color.BlendEnabled = 0x0;
 828    for (i = 0; i < Elements(ctx->Color.Blend); i++) {
 829       ctx->Color.Blend[i].SrcRGB = GL_ONE;
 830       ctx->Color.Blend[i].DstRGB = GL_ZERO;
 831       ctx->Color.Blend[i].SrcA = GL_ONE;
 832       ctx->Color.Blend[i].DstA = GL_ZERO;
 833       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
 834       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
 835    }
 836    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
 837    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
 838    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
 839    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
 840    ctx->Color.LogicOp = GL_COPY;
 841    ctx->Color.DitherFlag = GL_TRUE;
 842
 843    if (ctx->Visual.doubleBufferMode) {
 844       ctx->Color.DrawBuffer[0] = GL_BACK;
 845    }
 846    else {
 847       ctx->Color.DrawBuffer[0] = GL_FRONT;
 848    }
 849
 850    ctx->Color.ClampFragmentColor = GL_FIXED_ONLY_ARB;
 851    ctx->Color._ClampFragmentColor = GL_TRUE;
 852    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
 853    ctx->Color._ClampReadColor = GL_TRUE;
 854 }
 855
 856 /*@}*/