src/mesa/main/blend.c

   1 /**
   2  * \file blend.c
   3  * Blending operations.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  *
   9  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a
  12  * copy of this software and associated documentation files (the "Software"),
  13  * to deal in the Software without restriction, including without limitation
  14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  15  * and/or sell copies of the Software, and to permit persons to whom the
  16  * Software is furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included
  19  * in all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  22  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  27  * 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    case GL_ZERO:
  52    case GL_ONE:
  53    case GL_DST_COLOR:
  54    case GL_ONE_MINUS_DST_COLOR:
  55    case GL_SRC_ALPHA:
  56    case GL_ONE_MINUS_SRC_ALPHA:
  57    case GL_DST_ALPHA:
  58    case GL_ONE_MINUS_DST_ALPHA:
  59    case GL_SRC_ALPHA_SATURATE:
  60       return GL_TRUE;
  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 _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
  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->API != API_OPENGLES
  71          && ctx->Extensions.ARB_blend_func_extended;
  72    default:
  73       return GL_FALSE;
  74    }
  75 }
  76
  77
  78 /**
  79  * Check if given blend destination factor is legal.
  80  * \return GL_TRUE if legal, GL_FALSE otherwise.
  81  */
  82 static GLboolean
  83 legal_dst_factor(const struct gl_context *ctx, GLenum factor)
  84 {
  85    switch (factor) {
  86    case GL_DST_COLOR:
  87    case GL_ONE_MINUS_DST_COLOR:
  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       return GL_TRUE;
  97    case GL_CONSTANT_COLOR:
  98    case GL_ONE_MINUS_CONSTANT_COLOR:
  99    case GL_CONSTANT_ALPHA:
 100    case GL_ONE_MINUS_CONSTANT_ALPHA:
 101       return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
 102    case GL_SRC_ALPHA_SATURATE:
 103       return (ctx->API != API_OPENGLES
 104               && ctx->Extensions.ARB_blend_func_extended)
 105          || _mesa_is_gles3(ctx);
 106    case GL_SRC1_COLOR:
 107    case GL_SRC1_ALPHA:
 108    case GL_ONE_MINUS_SRC1_COLOR:
 109    case GL_ONE_MINUS_SRC1_ALPHA:
 110       return ctx->API != API_OPENGLES
 111          && ctx->Extensions.ARB_blend_func_extended;
 112    default:
 113       return GL_FALSE;
 114    }
 115 }
 116
 117
 118 /**
 119  * Check if src/dest RGB/A blend factors are legal.  If not generate
 120  * a GL error.
 121  * \return GL_TRUE if factors are legal, GL_FALSE otherwise.
 122  */
 123 static GLboolean
 124 validate_blend_factors(struct gl_context *ctx, const char *func,
 125                        GLenum sfactorRGB, GLenum dfactorRGB,
 126                        GLenum sfactorA, GLenum dfactorA)
 127 {
 128    if (!legal_src_factor(ctx, sfactorRGB)) {
 129       _mesa_error(ctx, GL_INVALID_ENUM,
 130                   "%s(sfactorRGB = %s)", func,
 131                   _mesa_enum_to_string(sfactorRGB));
 132       return GL_FALSE;
 133    }
 134
 135    if (!legal_dst_factor(ctx, dfactorRGB)) {
 136       _mesa_error(ctx, GL_INVALID_ENUM,
 137                   "%s(dfactorRGB = %s)", func,
 138                   _mesa_enum_to_string(dfactorRGB));
 139       return GL_FALSE;
 140    }
 141
 142    if (sfactorA != sfactorRGB && !legal_src_factor(ctx, sfactorA)) {
 143       _mesa_error(ctx, GL_INVALID_ENUM,
 144                   "%s(sfactorA = %s)", func,
 145                   _mesa_enum_to_string(sfactorA));
 146       return GL_FALSE;
 147    }
 148
 149    if (dfactorA != dfactorRGB && !legal_dst_factor(ctx, dfactorA)) {
 150       _mesa_error(ctx, GL_INVALID_ENUM,
 151                   "%s(dfactorA = %s)", func,
 152                   _mesa_enum_to_string(dfactorA));
 153       return GL_FALSE;
 154    }
 155
 156    return GL_TRUE;
 157 }
 158
 159
 160 /**
 161  * Specify the blending operation.
 162  *
 163  * \param sfactor source factor operator.
 164  * \param dfactor destination factor operator.
 165  *
 166  * \sa glBlendFunc, glBlendFuncSeparateEXT
 167  */
 168 void GLAPIENTRY
 169 _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
 170 {
 171    _mesa_BlendFuncSeparate(sfactor, dfactor, sfactor, dfactor);
 172 }
 173
 174 static GLboolean
 175 blend_factor_is_dual_src(GLenum factor)
 176 {
 177    return (factor == GL_SRC1_COLOR ||
 178            factor == GL_SRC1_ALPHA ||
 179            factor == GL_ONE_MINUS_SRC1_COLOR ||
 180            factor == GL_ONE_MINUS_SRC1_ALPHA);
 181 }
 182
 183 static void
 184 update_uses_dual_src(struct gl_context *ctx, int buf)
 185 {
 186    ctx->Color.Blend[buf]._UsesDualSrc =
 187       (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
 188        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
 189        blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
 190        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
 191 }
 192
 193
 194 /**
 195  * Return the number of per-buffer blend states to update in
 196  * glBlendFunc, glBlendFuncSeparate, glBlendEquation, etc.
 197  */
 198 static inline unsigned
 199 num_buffers(const struct gl_context *ctx)
 200 {
 201    return ctx->Extensions.ARB_draw_buffers_blend
 202       ? ctx->Const.MaxDrawBuffers : 1;
 203 }
 204
 205
 206 /**
 207  * Set the separate blend source/dest factors for all draw buffers.
 208  *
 209  * \param sfactorRGB RGB source factor operator.
 210  * \param dfactorRGB RGB destination factor operator.
 211  * \param sfactorA alpha source factor operator.
 212  * \param dfactorA alpha destination factor operator.
 213  */
 214 void GLAPIENTRY
 215 _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB,
 216                             GLenum sfactorA, GLenum dfactorA )
 217 {
 218    GET_CURRENT_CONTEXT(ctx);
 219    const unsigned numBuffers = num_buffers(ctx);
 220    unsigned buf;
 221    bool changed = false;
 222
 223    if (MESA_VERBOSE & VERBOSE_API)
 224       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
 225                   _mesa_enum_to_string(sfactorRGB),
 226                   _mesa_enum_to_string(dfactorRGB),
 227                   _mesa_enum_to_string(sfactorA),
 228                   _mesa_enum_to_string(dfactorA));
 229
 230    /* Check if we're really changing any state.  If not, return early. */
 231    if (ctx->Color._BlendFuncPerBuffer) {
 232       /* Check all per-buffer states */
 233       for (buf = 0; buf < numBuffers; buf++) {
 234          if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
 235              ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
 236              ctx->Color.Blend[buf].SrcA != sfactorA ||
 237              ctx->Color.Blend[buf].DstA != dfactorA) {
 238             changed = true;
 239             break;
 240          }
 241       }
 242    }
 243    else {
 244       /* only need to check 0th per-buffer state */
 245       if (ctx->Color.Blend[0].SrcRGB != sfactorRGB ||
 246           ctx->Color.Blend[0].DstRGB != dfactorRGB ||
 247           ctx->Color.Blend[0].SrcA != sfactorA ||
 248           ctx->Color.Blend[0].DstA != dfactorA) {
 249          changed = true;
 250       }
 251    }
 252
 253    if (!changed)
 254       return;
 255
 256    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
 257                                sfactorRGB, dfactorRGB,
 258                                sfactorA, dfactorA)) {
 259       return;
 260    }
 261
 262    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlend ? 0 : _NEW_COLOR);
 263    ctx->NewDriverState |= ctx->DriverFlags.NewBlend;
 264
 265    for (buf = 0; buf < numBuffers; buf++) {
 266       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 267       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 268       ctx->Color.Blend[buf].SrcA = sfactorA;
 269       ctx->Color.Blend[buf].DstA = dfactorA;
 270    }
 271
 272    update_uses_dual_src(ctx, 0);
 273    for (buf = 1; buf < numBuffers; buf++) {
 274       ctx->Color.Blend[buf]._UsesDualSrc = ctx->Color.Blend[0]._UsesDualSrc;
 275    }
 276
 277    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
 278
 279    if (ctx->Driver.BlendFuncSeparate) {
 280       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
 281                                     sfactorA, dfactorA);
 282    }
 283 }
 284
 285
 286 void GLAPIENTRY
 287 _mesa_BlendFunciARB_no_error(GLuint buf, GLenum sfactor, GLenum dfactor)
 288 {
 289    _mesa_BlendFuncSeparateiARB_no_error(buf, sfactor, dfactor, sfactor,
 290                                         dfactor);
 291 }
 292
 293
 294 /**
 295  * Set blend source/dest factors for one color buffer/target.
 296  */
 297 void GLAPIENTRY
 298 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
 299 {
 300    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
 301 }
 302
 303
 304 static ALWAYS_INLINE void
 305 blend_func_separatei(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 306                      GLenum sfactorA, GLenum dfactorA, bool no_error)
 307 {
 308    GET_CURRENT_CONTEXT(ctx);
 309
 310    if (!no_error) {
 311       if (!ctx->Extensions.ARB_draw_buffers_blend) {
 312          _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 313          return;
 314       }
 315
 316       if (buf >= ctx->Const.MaxDrawBuffers) {
 317          _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 318                      buf);
 319          return;
 320       }
 321    }
 322
 323    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 324        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 325        ctx->Color.Blend[buf].SrcA == sfactorA &&
 326        ctx->Color.Blend[buf].DstA == dfactorA)
 327       return; /* no change */
 328
 329    if (!no_error && !validate_blend_factors(ctx, "glBlendFuncSeparatei",
 330                                             sfactorRGB, dfactorRGB,
 331                                             sfactorA, dfactorA)) {
 332       return;
 333    }
 334
 335    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlend ? 0 : _NEW_COLOR);
 336    ctx->NewDriverState |= ctx->DriverFlags.NewBlend;
 337
 338    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 339    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 340    ctx->Color.Blend[buf].SrcA = sfactorA;
 341    ctx->Color.Blend[buf].DstA = dfactorA;
 342    update_uses_dual_src(ctx, buf);
 343    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 344 }
 345
 346
 347 void GLAPIENTRY
 348 _mesa_BlendFuncSeparateiARB_no_error(GLuint buf, GLenum sfactorRGB,
 349                                      GLenum dfactorRGB, GLenum sfactorA,
 350                                      GLenum dfactorA)
 351 {
 352    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 353                         true);
 354 }
 355
 356
 357 /**
 358  * Set separate blend source/dest factors for one color buffer/target.
 359  */
 360 void GLAPIENTRY
 361 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 362                             GLenum sfactorA, GLenum dfactorA)
 363 {
 364    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 365                         false);
 366 }
 367
 368
 369 /**
 370  * Return true if \p mode is a legal blending equation, excluding
 371  * GL_KHR_blend_equation_advanced modes.
 372  */
 373 static bool
 374 legal_simple_blend_equation(const struct gl_context *ctx, GLenum mode)
 375 {
 376    switch (mode) {
 377    case GL_FUNC_ADD:
 378    case GL_FUNC_SUBTRACT:
 379    case GL_FUNC_REVERSE_SUBTRACT:
 380       return GL_TRUE;
 381    case GL_MIN:
 382    case GL_MAX:
 383       return ctx->Extensions.EXT_blend_minmax;
 384    default:
 385       return GL_FALSE;
 386    }
 387 }
 388
 389 static enum gl_advanced_blend_mode
 390 advanced_blend_mode_from_gl_enum(GLenum mode)
 391 {
 392    switch (mode) {
 393    case GL_MULTIPLY_KHR:
 394       return BLEND_MULTIPLY;
 395    case GL_SCREEN_KHR:
 396       return BLEND_SCREEN;
 397    case GL_OVERLAY_KHR:
 398       return BLEND_OVERLAY;
 399    case GL_DARKEN_KHR:
 400       return BLEND_DARKEN;
 401    case GL_LIGHTEN_KHR:
 402       return BLEND_LIGHTEN;
 403    case GL_COLORDODGE_KHR:
 404       return BLEND_COLORDODGE;
 405    case GL_COLORBURN_KHR:
 406       return BLEND_COLORBURN;
 407    case GL_HARDLIGHT_KHR:
 408       return BLEND_HARDLIGHT;
 409    case GL_SOFTLIGHT_KHR:
 410       return BLEND_SOFTLIGHT;
 411    case GL_DIFFERENCE_KHR:
 412       return BLEND_DIFFERENCE;
 413    case GL_EXCLUSION_KHR:
 414       return BLEND_EXCLUSION;
 415    case GL_HSL_HUE_KHR:
 416       return BLEND_HSL_HUE;
 417    case GL_HSL_SATURATION_KHR:
 418       return BLEND_HSL_SATURATION;
 419    case GL_HSL_COLOR_KHR:
 420       return BLEND_HSL_COLOR;
 421    case GL_HSL_LUMINOSITY_KHR:
 422       return BLEND_HSL_LUMINOSITY;
 423    default:
 424       return BLEND_NONE;
 425    }
 426 }
 427
 428 /**
 429  * If \p mode is one of the advanced blending equations defined by
 430  * GL_KHR_blend_equation_advanced (and the extension is supported),
 431  * return the corresponding BLEND_* enum.  Otherwise, return BLEND_NONE
 432  * (which can also be treated as false).
 433  */
 434 static enum gl_advanced_blend_mode
 435 advanced_blend_mode(const struct gl_context *ctx, GLenum mode)
 436 {
 437    return _mesa_has_KHR_blend_equation_advanced(ctx) ?
 438           advanced_blend_mode_from_gl_enum(mode) : BLEND_NONE;
 439 }
 440
 441 /* This is really an extension function! */
 442 void GLAPIENTRY
 443 _mesa_BlendEquation( GLenum mode )
 444 {
 445    GET_CURRENT_CONTEXT(ctx);
 446    const unsigned numBuffers = num_buffers(ctx);
 447    unsigned buf;
 448    bool changed = false;
 449    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 450
 451    if (MESA_VERBOSE & VERBOSE_API)
 452       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 453                   _mesa_enum_to_string(mode));
 454
 455    if (ctx->Color._BlendEquationPerBuffer) {
 456       /* Check all per-buffer states */
 457       for (buf = 0; buf < numBuffers; buf++) {
 458          if (ctx->Color.Blend[buf].EquationRGB != mode ||
 459              ctx->Color.Blend[buf].EquationA != mode) {
 460             changed = true;
 461             break;
 462          }
 463       }
 464    }
 465    else {
 466       /* only need to check 0th per-buffer state */
 467       if (ctx->Color.Blend[0].EquationRGB != mode ||
 468           ctx->Color.Blend[0].EquationA != mode) {
 469          changed = true;
 470       }
 471    }
 472
 473    if (!changed)
 474       return;
 475
 476
 477    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 478       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 479       return;
 480    }
 481
 482    _mesa_flush_vertices_for_blend_state(ctx);
 483
 484    for (buf = 0; buf < numBuffers; buf++) {
 485       ctx->Color.Blend[buf].EquationRGB = mode;
 486       ctx->Color.Blend[buf].EquationA = mode;
 487    }
 488    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 489    ctx->Color._AdvancedBlendMode = advanced_mode;
 490
 491    if (ctx->Driver.BlendEquationSeparate)
 492       ctx->Driver.BlendEquationSeparate(ctx, mode, mode);
 493 }
 494
 495
 496 /**
 497  * Set blend equation for one color buffer/target.
 498  */
 499 void GLAPIENTRY
 500 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
 501 {
 502    GET_CURRENT_CONTEXT(ctx);
 503    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 504
 505    if (MESA_VERBOSE & VERBOSE_API)
 506       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 507                   buf, _mesa_enum_to_string(mode));
 508
 509    if (buf >= ctx->Const.MaxDrawBuffers) {
 510       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationi(buffer=%u)",
 511                   buf);
 512       return;
 513    }
 514
 515    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 516       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 517       return;
 518    }
 519
 520    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 521        ctx->Color.Blend[buf].EquationA == mode)
 522       return;  /* no change */
 523
 524    _mesa_flush_vertices_for_blend_state(ctx);
 525    ctx->Color.Blend[buf].EquationRGB = mode;
 526    ctx->Color.Blend[buf].EquationA = mode;
 527    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 528
 529    if (buf == 0)
 530       ctx->Color._AdvancedBlendMode = advanced_mode;
 531 }
 532
 533
 534 void GLAPIENTRY
 535 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
 536 {
 537    GET_CURRENT_CONTEXT(ctx);
 538    const unsigned numBuffers = num_buffers(ctx);
 539    unsigned buf;
 540    bool changed = false;
 541
 542    if (MESA_VERBOSE & VERBOSE_API)
 543       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 544                   _mesa_enum_to_string(modeRGB),
 545                   _mesa_enum_to_string(modeA));
 546
 547    if (ctx->Color._BlendEquationPerBuffer) {
 548       /* Check all per-buffer states */
 549       for (buf = 0; buf < numBuffers; buf++) {
 550          if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 551              ctx->Color.Blend[buf].EquationA != modeA) {
 552             changed = true;
 553             break;
 554          }
 555       }
 556    }
 557    else {
 558       /* only need to check 0th per-buffer state */
 559       if (ctx->Color.Blend[0].EquationRGB != modeRGB ||
 560           ctx->Color.Blend[0].EquationA != modeA) {
 561          changed = true;
 562       }
 563    }
 564
 565    if (!changed)
 566       return;
 567
 568    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 569       _mesa_error(ctx, GL_INVALID_OPERATION,
 570                   "glBlendEquationSeparateEXT not supported by driver");
 571       return;
 572    }
 573
 574    /* Only allow simple blending equations.
 575     * The GL_KHR_blend_equation_advanced spec says:
 576     *
 577     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 578     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 579     */
 580    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 581       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 582       return;
 583    }
 584
 585    if (!legal_simple_blend_equation(ctx, modeA)) {
 586       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 587       return;
 588    }
 589
 590    _mesa_flush_vertices_for_blend_state(ctx);
 591
 592    for (buf = 0; buf < numBuffers; buf++) {
 593       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 594       ctx->Color.Blend[buf].EquationA = modeA;
 595    }
 596    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 597    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 598
 599    if (ctx->Driver.BlendEquationSeparate)
 600       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 601 }
 602
 603
 604 static void
 605 blend_equation_separatei(struct gl_context *ctx, GLuint buf, GLenum modeRGB,
 606                          GLenum modeA)
 607 {
 608    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 609        ctx->Color.Blend[buf].EquationA == modeA)
 610       return;  /* no change */
 611
 612    _mesa_flush_vertices_for_blend_state(ctx);
 613    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 614    ctx->Color.Blend[buf].EquationA = modeA;
 615    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 616    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 617 }
 618
 619
 620 void GLAPIENTRY
 621 _mesa_BlendEquationSeparateiARB_no_error(GLuint buf, GLenum modeRGB,
 622                                          GLenum modeA)
 623 {
 624    GET_CURRENT_CONTEXT(ctx);
 625    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 626 }
 627
 628
 629 /**
 630  * Set separate blend equations for one color buffer/target.
 631  */
 632 void GLAPIENTRY
 633 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 634 {
 635    GET_CURRENT_CONTEXT(ctx);
 636
 637    if (MESA_VERBOSE & VERBOSE_API)
 638       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 639                   _mesa_enum_to_string(modeRGB),
 640                   _mesa_enum_to_string(modeA));
 641
 642    if (buf >= ctx->Const.MaxDrawBuffers) {
 643       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 644                   buf);
 645       return;
 646    }
 647
 648    /* Only allow simple blending equations.
 649     * The GL_KHR_blend_equation_advanced spec says:
 650     *
 651     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 652     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 653     */
 654    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 655       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 656       return;
 657    }
 658
 659    if (!legal_simple_blend_equation(ctx, modeA)) {
 660       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 661       return;
 662    }
 663
 664    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 665 }
 666
 667
 668 /**
 669  * Set the blending color.
 670  *
 671  * \param red red color component.
 672  * \param green green color component.
 673  * \param blue blue color component.
 674  * \param alpha alpha color component.
 675  *
 676  * \sa glBlendColor().
 677  *
 678  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 679  * change, flushes the vertices and notifies the driver via
 680  * dd_function_table::BlendColor callback.
 681  */
 682 void GLAPIENTRY
 683 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 684 {
 685    GLfloat tmp[4];
 686    GET_CURRENT_CONTEXT(ctx);
 687
 688    tmp[0] = red;
 689    tmp[1] = green;
 690    tmp[2] = blue;
 691    tmp[3] = alpha;
 692
 693    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 694       return;
 695
 696    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlendColor ? 0 : _NEW_COLOR);
 697    ctx->NewDriverState |= ctx->DriverFlags.NewBlendColor;
 698    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 699
 700    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 701    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 702    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 703    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 704
 705    if (ctx->Driver.BlendColor)
 706       ctx->Driver.BlendColor(ctx, ctx->Color.BlendColor);
 707 }
 708
 709
 710 /**
 711  * Specify the alpha test function.
 712  *
 713  * \param func alpha comparison function.
 714  * \param ref reference value.
 715  *
 716  * Verifies the parameters and updates gl_colorbuffer_attrib.
 717  * On a change, flushes the vertices and notifies the driver via
 718  * dd_function_table::AlphaFunc callback.
 719  */
 720 void GLAPIENTRY
 721 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 722 {
 723    GET_CURRENT_CONTEXT(ctx);
 724
 725    if (MESA_VERBOSE & VERBOSE_API)
 726       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 727                   _mesa_enum_to_string(func), ref);
 728
 729    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 730       return; /* no change */
 731
 732    switch (func) {
 733    case GL_NEVER:
 734    case GL_LESS:
 735    case GL_EQUAL:
 736    case GL_LEQUAL:
 737    case GL_GREATER:
 738    case GL_NOTEQUAL:
 739    case GL_GEQUAL:
 740    case GL_ALWAYS:
 741       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewAlphaTest ? 0 : _NEW_COLOR);
 742       ctx->NewDriverState |= ctx->DriverFlags.NewAlphaTest;
 743       ctx->Color.AlphaFunc = func;
 744       ctx->Color.AlphaRefUnclamped = ref;
 745       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 746
 747       if (ctx->Driver.AlphaFunc)
 748          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 749       return;
 750
 751    default:
 752       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 753       return;
 754    }
 755 }
 756
 757
 758 /**
 759  * Specify a logic pixel operation for color index rendering.
 760  *
 761  * \param opcode operation.
 762  *
 763  * Verifies that \p opcode is a valid enum and updates
 764  * gl_colorbuffer_attrib::LogicOp.
 765  * On a change, flushes the vertices and notifies the driver via the
 766  * dd_function_table::LogicOpcode callback.
 767  */
 768 void GLAPIENTRY
 769 _mesa_LogicOp( GLenum opcode )
 770 {
 771    GET_CURRENT_CONTEXT(ctx);
 772
 773    if (MESA_VERBOSE & VERBOSE_API)
 774       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
 775
 776    switch (opcode) {
 777       case GL_CLEAR:
 778       case GL_SET:
 779       case GL_COPY:
 780       case GL_COPY_INVERTED:
 781       case GL_NOOP:
 782       case GL_INVERT:
 783       case GL_AND:
 784       case GL_NAND:
 785       case GL_OR:
 786       case GL_NOR:
 787       case GL_XOR:
 788       case GL_EQUIV:
 789       case GL_AND_REVERSE:
 790       case GL_AND_INVERTED:
 791       case GL_OR_REVERSE:
 792       case GL_OR_INVERTED:
 793          break;
 794       default:
 795          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 796          return;
 797    }
 798
 799    if (ctx->Color.LogicOp == opcode)
 800       return;
 801
 802    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewLogicOp ? 0 : _NEW_COLOR);
 803    ctx->NewDriverState |= ctx->DriverFlags.NewLogicOp;
 804    ctx->Color.LogicOp = opcode;
 805
 806    if (ctx->Driver.LogicOpcode)
 807       ctx->Driver.LogicOpcode( ctx, opcode );
 808 }
 809
 810
 811 void GLAPIENTRY
 812 _mesa_IndexMask( GLuint mask )
 813 {
 814    GET_CURRENT_CONTEXT(ctx);
 815
 816    if (ctx->Color.IndexMask == mask)
 817       return;
 818
 819    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 820    ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 821    ctx->Color.IndexMask = mask;
 822 }
 823
 824
 825 /**
 826  * Enable or disable writing of frame buffer color components.
 827  *
 828  * \param red whether to mask writing of the red color component.
 829  * \param green whether to mask writing of the green color component.
 830  * \param blue whether to mask writing of the blue color component.
 831  * \param alpha whether to mask writing of the alpha color component.
 832  *
 833  * \sa glColorMask().
 834  *
 835  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 836  * change, flushes the vertices and notifies the driver via the
 837  * dd_function_table::ColorMask callback.
 838  */
 839 void GLAPIENTRY
 840 _mesa_ColorMask( GLboolean red, GLboolean green,
 841                  GLboolean blue, GLboolean alpha )
 842 {
 843    GET_CURRENT_CONTEXT(ctx);
 844    GLubyte tmp[4];
 845    GLuint i;
 846    GLboolean flushed;
 847
 848    if (MESA_VERBOSE & VERBOSE_API)
 849       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 850                   red, green, blue, alpha);
 851
 852    /* Shouldn't have any information about channel depth in core mesa
 853     * -- should probably store these as the native booleans:
 854     */
 855    tmp[RCOMP] = red    ? 0xff : 0x0;
 856    tmp[GCOMP] = green  ? 0xff : 0x0;
 857    tmp[BCOMP] = blue   ? 0xff : 0x0;
 858    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 859
 860    flushed = GL_FALSE;
 861    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 862       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 863          if (!flushed) {
 864             FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 865             ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 866          }
 867          flushed = GL_TRUE;
 868          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 869       }
 870    }
 871
 872    if (ctx->Driver.ColorMask)
 873       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 874 }
 875
 876
 877 /**
 878  * For GL_EXT_draw_buffers2 and GL3
 879  */
 880 void GLAPIENTRY
 881 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 882                         GLboolean blue, GLboolean alpha )
 883 {
 884    GLubyte tmp[4];
 885    GET_CURRENT_CONTEXT(ctx);
 886
 887    if (MESA_VERBOSE & VERBOSE_API)
 888       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 889                   buf, red, green, blue, alpha);
 890
 891    if (buf >= ctx->Const.MaxDrawBuffers) {
 892       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 893       return;
 894    }
 895
 896    /* Shouldn't have any information about channel depth in core mesa
 897     * -- should probably store these as the native booleans:
 898     */
 899    tmp[RCOMP] = red    ? 0xff : 0x0;
 900    tmp[GCOMP] = green  ? 0xff : 0x0;
 901    tmp[BCOMP] = blue   ? 0xff : 0x0;
 902    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 903
 904    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 905       return;
 906
 907    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 908    ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 909    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 910 }
 911
 912
 913 void GLAPIENTRY
 914 _mesa_ClampColor(GLenum target, GLenum clamp)
 915 {
 916    GET_CURRENT_CONTEXT(ctx);
 917
 918    /* Check for both the extension and the GL version, since the Intel driver
 919     * does not advertise the extension in core profiles.
 920     */
 921    if (ctx->Version <= 30 && !ctx->Extensions.ARB_color_buffer_float) {
 922       _mesa_error(ctx, GL_INVALID_OPERATION, "glClampColor()");
 923       return;
 924    }
 925
 926    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 927       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 928       return;
 929    }
 930
 931    switch (target) {
 932    case GL_CLAMP_VERTEX_COLOR_ARB:
 933       if (ctx->API == API_OPENGL_CORE)
 934          goto invalid_enum;
 935       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 936       ctx->Light.ClampVertexColor = clamp;
 937       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
 938       break;
 939    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 940       if (ctx->API == API_OPENGL_CORE)
 941          goto invalid_enum;
 942       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 943       ctx->Color.ClampFragmentColor = clamp;
 944       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
 945       break;
 946    case GL_CLAMP_READ_COLOR_ARB:
 947       ctx->Color.ClampReadColor = clamp;
 948       break;
 949    default:
 950       goto invalid_enum;
 951    }
 952    return;
 953
 954 invalid_enum:
 955    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
 956                _mesa_enum_to_string(target));
 957 }
 958
 959 static GLboolean
 960 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
 961 {
 962    if (clamp == GL_TRUE || clamp == GL_FALSE)
 963       return clamp;
 964
 965    assert(clamp == GL_FIXED_ONLY);
 966    if (!fb)
 967       return GL_TRUE;
 968
 969    return fb->_AllColorBuffersFixedPoint;
 970 }
 971
 972 GLboolean
 973 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
 974                                const struct gl_framebuffer *drawFb)
 975 {
 976    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
 977 }
 978
 979 GLboolean
 980 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
 981                              const struct gl_framebuffer *drawFb)
 982 {
 983    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
 984 }
 985
 986 GLboolean
 987 _mesa_get_clamp_read_color(const struct gl_context *ctx,
 988                            const struct gl_framebuffer *readFb)
 989 {
 990    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
 991 }
 992
 993 /**
 994  * Update the ctx->Color._ClampFragmentColor field
 995  */
 996 void
 997 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
 998                                   const struct gl_framebuffer *drawFb)
 999 {
1000    /* Don't clamp if:
1001     * - there is no colorbuffer
1002     * - all colorbuffers are unsigned normalized, so clamping has no effect
1003     * - there is an integer colorbuffer
1004     */
1005    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
1006        drawFb->_IntegerBuffers)
1007       ctx->Color._ClampFragmentColor = GL_FALSE;
1008    else
1009       ctx->Color._ClampFragmentColor =
1010          _mesa_get_clamp_fragment_color(ctx, drawFb);
1011 }
1012
1013 /**
1014  * Update the ctx->Color._ClampVertexColor field
1015  */
1016 void
1017 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
1018                                 const struct gl_framebuffer *drawFb)
1019 {
1020    ctx->Light._ClampVertexColor =
1021          _mesa_get_clamp_vertex_color(ctx, drawFb);
1022 }
1023
1024 /**
1025  * Returns an appropriate mesa_format for color rendering based on the
1026  * GL_FRAMEBUFFER_SRGB state.
1027  *
1028  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
1029  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
1030  * overriding the format of the surface.  This is a helper for doing the
1031  * surface format override variant.
1032  */
1033 mesa_format
1034 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
1035 {
1036    if (ctx->Color.sRGBEnabled)
1037       return format;
1038    else
1039       return _mesa_get_srgb_format_linear(format);
1040 }
1041
1042 /**********************************************************************/
1043 /** \name Initialization */
1044 /*@{*/
1045
1046 /**
1047  * Initialization of the context's Color attribute group.
1048  *
1049  * \param ctx GL context.
1050  *
1051  * Initializes the related fields in the context color attribute group,
1052  * __struct gl_contextRec::Color.
1053  */
1054 void _mesa_init_color( struct gl_context * ctx )
1055 {
1056    GLuint i;
1057
1058    /* Color buffer group */
1059    ctx->Color.IndexMask = ~0u;
1060    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
1061    ctx->Color.ClearIndex = 0;
1062    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
1063    ctx->Color.AlphaEnabled = GL_FALSE;
1064    ctx->Color.AlphaFunc = GL_ALWAYS;
1065    ctx->Color.AlphaRef = 0;
1066    ctx->Color.BlendEnabled = 0x0;
1067    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
1068       ctx->Color.Blend[i].SrcRGB = GL_ONE;
1069       ctx->Color.Blend[i].DstRGB = GL_ZERO;
1070       ctx->Color.Blend[i].SrcA = GL_ONE;
1071       ctx->Color.Blend[i].DstA = GL_ZERO;
1072       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
1073       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
1074    }
1075    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
1076    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
1077    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
1078    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
1079    ctx->Color.LogicOp = GL_COPY;
1080    ctx->Color.DitherFlag = GL_TRUE;
1081
1082    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
1083     * the front or the back buffer depending on the config */
1084    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
1085       ctx->Color.DrawBuffer[0] = GL_BACK;
1086    }
1087    else {
1088       ctx->Color.DrawBuffer[0] = GL_FRONT;
1089    }
1090
1091    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
1092                                    GL_FIXED_ONLY_ARB : GL_FALSE;
1093    ctx->Color._ClampFragmentColor = GL_FALSE;
1094    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
1095
1096    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
1097     * if EGL_KHR_gl_colorspace has been used to request sRGB.
1098     */
1099    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
1100
1101    ctx->Color.BlendCoherent = true;
1102 }
1103
1104 /*@}*/