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, _NEW_COLOR);
 263
 264    for (buf = 0; buf < numBuffers; buf++) {
 265       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 266       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 267       ctx->Color.Blend[buf].SrcA = sfactorA;
 268       ctx->Color.Blend[buf].DstA = dfactorA;
 269    }
 270
 271    update_uses_dual_src(ctx, 0);
 272    for (buf = 1; buf < numBuffers; buf++) {
 273       ctx->Color.Blend[buf]._UsesDualSrc = ctx->Color.Blend[0]._UsesDualSrc;
 274    }
 275
 276    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
 277
 278    if (ctx->Driver.BlendFuncSeparate) {
 279       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
 280                                     sfactorA, dfactorA);
 281    }
 282 }
 283
 284
 285 void GLAPIENTRY
 286 _mesa_BlendFunciARB_no_error(GLuint buf, GLenum sfactor, GLenum dfactor)
 287 {
 288    _mesa_BlendFuncSeparateiARB_no_error(buf, sfactor, dfactor, sfactor,
 289                                         dfactor);
 290 }
 291
 292
 293 /**
 294  * Set blend source/dest factors for one color buffer/target.
 295  */
 296 void GLAPIENTRY
 297 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
 298 {
 299    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
 300 }
 301
 302
 303 static ALWAYS_INLINE void
 304 blend_func_separatei(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 305                      GLenum sfactorA, GLenum dfactorA, bool no_error)
 306 {
 307    GET_CURRENT_CONTEXT(ctx);
 308
 309    if (!no_error) {
 310       if (!ctx->Extensions.ARB_draw_buffers_blend) {
 311          _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 312          return;
 313       }
 314
 315       if (buf >= ctx->Const.MaxDrawBuffers) {
 316          _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 317                      buf);
 318          return;
 319       }
 320    }
 321
 322    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 323        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 324        ctx->Color.Blend[buf].SrcA == sfactorA &&
 325        ctx->Color.Blend[buf].DstA == dfactorA)
 326       return; /* no change */
 327
 328    if (!no_error && !validate_blend_factors(ctx, "glBlendFuncSeparatei",
 329                                             sfactorRGB, dfactorRGB,
 330                                             sfactorA, dfactorA)) {
 331       return;
 332    }
 333
 334    FLUSH_VERTICES(ctx, _NEW_COLOR);
 335
 336    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 337    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 338    ctx->Color.Blend[buf].SrcA = sfactorA;
 339    ctx->Color.Blend[buf].DstA = dfactorA;
 340    update_uses_dual_src(ctx, buf);
 341    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 342 }
 343
 344
 345 void GLAPIENTRY
 346 _mesa_BlendFuncSeparateiARB_no_error(GLuint buf, GLenum sfactorRGB,
 347                                      GLenum dfactorRGB, GLenum sfactorA,
 348                                      GLenum dfactorA)
 349 {
 350    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 351                         true);
 352 }
 353
 354
 355 /**
 356  * Set separate blend source/dest factors for one color buffer/target.
 357  */
 358 void GLAPIENTRY
 359 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 360                             GLenum sfactorA, GLenum dfactorA)
 361 {
 362    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 363                         false);
 364 }
 365
 366
 367 /**
 368  * Return true if \p mode is a legal blending equation, excluding
 369  * GL_KHR_blend_equation_advanced modes.
 370  */
 371 static bool
 372 legal_simple_blend_equation(const struct gl_context *ctx, GLenum mode)
 373 {
 374    switch (mode) {
 375    case GL_FUNC_ADD:
 376    case GL_FUNC_SUBTRACT:
 377    case GL_FUNC_REVERSE_SUBTRACT:
 378       return GL_TRUE;
 379    case GL_MIN:
 380    case GL_MAX:
 381       return ctx->Extensions.EXT_blend_minmax;
 382    default:
 383       return GL_FALSE;
 384    }
 385 }
 386
 387 static enum gl_advanced_blend_mode
 388 advanced_blend_mode_from_gl_enum(GLenum mode)
 389 {
 390    switch (mode) {
 391    case GL_MULTIPLY_KHR:
 392       return BLEND_MULTIPLY;
 393    case GL_SCREEN_KHR:
 394       return BLEND_SCREEN;
 395    case GL_OVERLAY_KHR:
 396       return BLEND_OVERLAY;
 397    case GL_DARKEN_KHR:
 398       return BLEND_DARKEN;
 399    case GL_LIGHTEN_KHR:
 400       return BLEND_LIGHTEN;
 401    case GL_COLORDODGE_KHR:
 402       return BLEND_COLORDODGE;
 403    case GL_COLORBURN_KHR:
 404       return BLEND_COLORBURN;
 405    case GL_HARDLIGHT_KHR:
 406       return BLEND_HARDLIGHT;
 407    case GL_SOFTLIGHT_KHR:
 408       return BLEND_SOFTLIGHT;
 409    case GL_DIFFERENCE_KHR:
 410       return BLEND_DIFFERENCE;
 411    case GL_EXCLUSION_KHR:
 412       return BLEND_EXCLUSION;
 413    case GL_HSL_HUE_KHR:
 414       return BLEND_HSL_HUE;
 415    case GL_HSL_SATURATION_KHR:
 416       return BLEND_HSL_SATURATION;
 417    case GL_HSL_COLOR_KHR:
 418       return BLEND_HSL_COLOR;
 419    case GL_HSL_LUMINOSITY_KHR:
 420       return BLEND_HSL_LUMINOSITY;
 421    default:
 422       return BLEND_NONE;
 423    }
 424 }
 425
 426 /**
 427  * If \p mode is one of the advanced blending equations defined by
 428  * GL_KHR_blend_equation_advanced (and the extension is supported),
 429  * return the corresponding BLEND_* enum.  Otherwise, return BLEND_NONE
 430  * (which can also be treated as false).
 431  */
 432 static enum gl_advanced_blend_mode
 433 advanced_blend_mode(const struct gl_context *ctx, GLenum mode)
 434 {
 435    return _mesa_has_KHR_blend_equation_advanced(ctx) ?
 436           advanced_blend_mode_from_gl_enum(mode) : BLEND_NONE;
 437 }
 438
 439 /* This is really an extension function! */
 440 void GLAPIENTRY
 441 _mesa_BlendEquation( GLenum mode )
 442 {
 443    GET_CURRENT_CONTEXT(ctx);
 444    const unsigned numBuffers = num_buffers(ctx);
 445    unsigned buf;
 446    bool changed = false;
 447    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 448
 449    if (MESA_VERBOSE & VERBOSE_API)
 450       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 451                   _mesa_enum_to_string(mode));
 452
 453    if (ctx->Color._BlendEquationPerBuffer) {
 454       /* Check all per-buffer states */
 455       for (buf = 0; buf < numBuffers; buf++) {
 456          if (ctx->Color.Blend[buf].EquationRGB != mode ||
 457              ctx->Color.Blend[buf].EquationA != mode) {
 458             changed = true;
 459             break;
 460          }
 461       }
 462    }
 463    else {
 464       /* only need to check 0th per-buffer state */
 465       if (ctx->Color.Blend[0].EquationRGB != mode ||
 466           ctx->Color.Blend[0].EquationA != mode) {
 467          changed = true;
 468       }
 469    }
 470
 471    if (!changed)
 472       return;
 473
 474
 475    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 476       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 477       return;
 478    }
 479
 480    FLUSH_VERTICES(ctx, _NEW_COLOR);
 481
 482    for (buf = 0; buf < numBuffers; buf++) {
 483       ctx->Color.Blend[buf].EquationRGB = mode;
 484       ctx->Color.Blend[buf].EquationA = mode;
 485    }
 486    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 487    ctx->Color._AdvancedBlendMode = advanced_mode;
 488
 489    if (ctx->Driver.BlendEquationSeparate)
 490       ctx->Driver.BlendEquationSeparate(ctx, mode, mode);
 491 }
 492
 493
 494 /**
 495  * Set blend equation for one color buffer/target.
 496  */
 497 void GLAPIENTRY
 498 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
 499 {
 500    GET_CURRENT_CONTEXT(ctx);
 501    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 502
 503    if (MESA_VERBOSE & VERBOSE_API)
 504       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 505                   buf, _mesa_enum_to_string(mode));
 506
 507    if (buf >= ctx->Const.MaxDrawBuffers) {
 508       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationi(buffer=%u)",
 509                   buf);
 510       return;
 511    }
 512
 513    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 514       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 515       return;
 516    }
 517
 518    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 519        ctx->Color.Blend[buf].EquationA == mode)
 520       return;  /* no change */
 521
 522    FLUSH_VERTICES(ctx, _NEW_COLOR);
 523    ctx->Color.Blend[buf].EquationRGB = mode;
 524    ctx->Color.Blend[buf].EquationA = mode;
 525    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 526
 527    if (buf == 0)
 528       ctx->Color._AdvancedBlendMode = advanced_mode;
 529 }
 530
 531
 532 void GLAPIENTRY
 533 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
 534 {
 535    GET_CURRENT_CONTEXT(ctx);
 536    const unsigned numBuffers = num_buffers(ctx);
 537    unsigned buf;
 538    bool changed = false;
 539
 540    if (MESA_VERBOSE & VERBOSE_API)
 541       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 542                   _mesa_enum_to_string(modeRGB),
 543                   _mesa_enum_to_string(modeA));
 544
 545    if (ctx->Color._BlendEquationPerBuffer) {
 546       /* Check all per-buffer states */
 547       for (buf = 0; buf < numBuffers; buf++) {
 548          if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 549              ctx->Color.Blend[buf].EquationA != modeA) {
 550             changed = true;
 551             break;
 552          }
 553       }
 554    }
 555    else {
 556       /* only need to check 0th per-buffer state */
 557       if (ctx->Color.Blend[0].EquationRGB != modeRGB ||
 558           ctx->Color.Blend[0].EquationA != modeA) {
 559          changed = true;
 560       }
 561    }
 562
 563    if (!changed)
 564       return;
 565
 566    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 567       _mesa_error(ctx, GL_INVALID_OPERATION,
 568                   "glBlendEquationSeparateEXT not supported by driver");
 569       return;
 570    }
 571
 572    /* Only allow simple blending equations.
 573     * The GL_KHR_blend_equation_advanced spec says:
 574     *
 575     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 576     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 577     */
 578    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 579       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 580       return;
 581    }
 582
 583    if (!legal_simple_blend_equation(ctx, modeA)) {
 584       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 585       return;
 586    }
 587
 588    FLUSH_VERTICES(ctx, _NEW_COLOR);
 589
 590    for (buf = 0; buf < numBuffers; buf++) {
 591       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 592       ctx->Color.Blend[buf].EquationA = modeA;
 593    }
 594    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 595    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 596
 597    if (ctx->Driver.BlendEquationSeparate)
 598       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 599 }
 600
 601
 602 static void
 603 blend_equation_separatei(struct gl_context *ctx, GLuint buf, GLenum modeRGB,
 604                          GLenum modeA)
 605 {
 606    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 607        ctx->Color.Blend[buf].EquationA == modeA)
 608       return;  /* no change */
 609
 610    FLUSH_VERTICES(ctx, _NEW_COLOR);
 611    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 612    ctx->Color.Blend[buf].EquationA = modeA;
 613    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 614    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 615 }
 616
 617
 618 void GLAPIENTRY
 619 _mesa_BlendEquationSeparateiARB_no_error(GLuint buf, GLenum modeRGB,
 620                                          GLenum modeA)
 621 {
 622    GET_CURRENT_CONTEXT(ctx);
 623    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 624 }
 625
 626
 627 /**
 628  * Set separate blend equations for one color buffer/target.
 629  */
 630 void GLAPIENTRY
 631 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 632 {
 633    GET_CURRENT_CONTEXT(ctx);
 634
 635    if (MESA_VERBOSE & VERBOSE_API)
 636       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 637                   _mesa_enum_to_string(modeRGB),
 638                   _mesa_enum_to_string(modeA));
 639
 640    if (buf >= ctx->Const.MaxDrawBuffers) {
 641       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 642                   buf);
 643       return;
 644    }
 645
 646    /* Only allow simple blending equations.
 647     * The GL_KHR_blend_equation_advanced spec says:
 648     *
 649     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 650     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 651     */
 652    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 653       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 654       return;
 655    }
 656
 657    if (!legal_simple_blend_equation(ctx, modeA)) {
 658       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 659       return;
 660    }
 661
 662    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 663 }
 664
 665
 666 /**
 667  * Set the blending color.
 668  *
 669  * \param red red color component.
 670  * \param green green color component.
 671  * \param blue blue color component.
 672  * \param alpha alpha color component.
 673  *
 674  * \sa glBlendColor().
 675  *
 676  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 677  * change, flushes the vertices and notifies the driver via
 678  * dd_function_table::BlendColor callback.
 679  */
 680 void GLAPIENTRY
 681 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 682 {
 683    GLfloat tmp[4];
 684    GET_CURRENT_CONTEXT(ctx);
 685
 686    tmp[0] = red;
 687    tmp[1] = green;
 688    tmp[2] = blue;
 689    tmp[3] = alpha;
 690
 691    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 692       return;
 693
 694    FLUSH_VERTICES(ctx, _NEW_COLOR);
 695    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 696
 697    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 698    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 699    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 700    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 701
 702    if (ctx->Driver.BlendColor)
 703       ctx->Driver.BlendColor(ctx, ctx->Color.BlendColor);
 704 }
 705
 706
 707 /**
 708  * Specify the alpha test function.
 709  *
 710  * \param func alpha comparison function.
 711  * \param ref reference value.
 712  *
 713  * Verifies the parameters and updates gl_colorbuffer_attrib.
 714  * On a change, flushes the vertices and notifies the driver via
 715  * dd_function_table::AlphaFunc callback.
 716  */
 717 void GLAPIENTRY
 718 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 719 {
 720    GET_CURRENT_CONTEXT(ctx);
 721
 722    if (MESA_VERBOSE & VERBOSE_API)
 723       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 724                   _mesa_enum_to_string(func), ref);
 725
 726    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 727       return; /* no change */
 728
 729    switch (func) {
 730    case GL_NEVER:
 731    case GL_LESS:
 732    case GL_EQUAL:
 733    case GL_LEQUAL:
 734    case GL_GREATER:
 735    case GL_NOTEQUAL:
 736    case GL_GEQUAL:
 737    case GL_ALWAYS:
 738       FLUSH_VERTICES(ctx, _NEW_COLOR);
 739       ctx->Color.AlphaFunc = func;
 740       ctx->Color.AlphaRefUnclamped = ref;
 741       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 742
 743       if (ctx->Driver.AlphaFunc)
 744          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 745       return;
 746
 747    default:
 748       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 749       return;
 750    }
 751 }
 752
 753
 754 /**
 755  * Specify a logic pixel operation for color index rendering.
 756  *
 757  * \param opcode operation.
 758  *
 759  * Verifies that \p opcode is a valid enum and updates
 760  * gl_colorbuffer_attrib::LogicOp.
 761  * On a change, flushes the vertices and notifies the driver via the
 762  * dd_function_table::LogicOpcode callback.
 763  */
 764 void GLAPIENTRY
 765 _mesa_LogicOp( GLenum opcode )
 766 {
 767    GET_CURRENT_CONTEXT(ctx);
 768
 769    if (MESA_VERBOSE & VERBOSE_API)
 770       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
 771
 772    switch (opcode) {
 773       case GL_CLEAR:
 774       case GL_SET:
 775       case GL_COPY:
 776       case GL_COPY_INVERTED:
 777       case GL_NOOP:
 778       case GL_INVERT:
 779       case GL_AND:
 780       case GL_NAND:
 781       case GL_OR:
 782       case GL_NOR:
 783       case GL_XOR:
 784       case GL_EQUIV:
 785       case GL_AND_REVERSE:
 786       case GL_AND_INVERTED:
 787       case GL_OR_REVERSE:
 788       case GL_OR_INVERTED:
 789          break;
 790       default:
 791          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 792          return;
 793    }
 794
 795    if (ctx->Color.LogicOp == opcode)
 796       return;
 797
 798    FLUSH_VERTICES(ctx, _NEW_COLOR);
 799    ctx->Color.LogicOp = opcode;
 800
 801    if (ctx->Driver.LogicOpcode)
 802       ctx->Driver.LogicOpcode( ctx, opcode );
 803 }
 804
 805
 806 void GLAPIENTRY
 807 _mesa_IndexMask( GLuint mask )
 808 {
 809    GET_CURRENT_CONTEXT(ctx);
 810
 811    if (ctx->Color.IndexMask == mask)
 812       return;
 813
 814    FLUSH_VERTICES(ctx, _NEW_COLOR);
 815    ctx->Color.IndexMask = mask;
 816 }
 817
 818
 819 /**
 820  * Enable or disable writing of frame buffer color components.
 821  *
 822  * \param red whether to mask writing of the red color component.
 823  * \param green whether to mask writing of the green color component.
 824  * \param blue whether to mask writing of the blue color component.
 825  * \param alpha whether to mask writing of the alpha color component.
 826  *
 827  * \sa glColorMask().
 828  *
 829  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 830  * change, flushes the vertices and notifies the driver via the
 831  * dd_function_table::ColorMask callback.
 832  */
 833 void GLAPIENTRY
 834 _mesa_ColorMask( GLboolean red, GLboolean green,
 835                  GLboolean blue, GLboolean alpha )
 836 {
 837    GET_CURRENT_CONTEXT(ctx);
 838    GLubyte tmp[4];
 839    GLuint i;
 840    GLboolean flushed;
 841
 842    if (MESA_VERBOSE & VERBOSE_API)
 843       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 844                   red, green, blue, alpha);
 845
 846    /* Shouldn't have any information about channel depth in core mesa
 847     * -- should probably store these as the native booleans:
 848     */
 849    tmp[RCOMP] = red    ? 0xff : 0x0;
 850    tmp[GCOMP] = green  ? 0xff : 0x0;
 851    tmp[BCOMP] = blue   ? 0xff : 0x0;
 852    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 853
 854    flushed = GL_FALSE;
 855    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 856       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 857          if (!flushed) {
 858             FLUSH_VERTICES(ctx, _NEW_COLOR);
 859          }
 860          flushed = GL_TRUE;
 861          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 862       }
 863    }
 864
 865    if (ctx->Driver.ColorMask)
 866       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 867 }
 868
 869
 870 /**
 871  * For GL_EXT_draw_buffers2 and GL3
 872  */
 873 void GLAPIENTRY
 874 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 875                         GLboolean blue, GLboolean alpha )
 876 {
 877    GLubyte tmp[4];
 878    GET_CURRENT_CONTEXT(ctx);
 879
 880    if (MESA_VERBOSE & VERBOSE_API)
 881       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 882                   buf, red, green, blue, alpha);
 883
 884    if (buf >= ctx->Const.MaxDrawBuffers) {
 885       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 886       return;
 887    }
 888
 889    /* Shouldn't have any information about channel depth in core mesa
 890     * -- should probably store these as the native booleans:
 891     */
 892    tmp[RCOMP] = red    ? 0xff : 0x0;
 893    tmp[GCOMP] = green  ? 0xff : 0x0;
 894    tmp[BCOMP] = blue   ? 0xff : 0x0;
 895    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 896
 897    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 898       return;
 899
 900    FLUSH_VERTICES(ctx, _NEW_COLOR);
 901    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 902 }
 903
 904
 905 void GLAPIENTRY
 906 _mesa_ClampColor(GLenum target, GLenum clamp)
 907 {
 908    GET_CURRENT_CONTEXT(ctx);
 909
 910    /* Check for both the extension and the GL version, since the Intel driver
 911     * does not advertise the extension in core profiles.
 912     */
 913    if (ctx->Version <= 30 && !ctx->Extensions.ARB_color_buffer_float) {
 914       _mesa_error(ctx, GL_INVALID_OPERATION, "glClampColor()");
 915       return;
 916    }
 917
 918    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 919       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 920       return;
 921    }
 922
 923    switch (target) {
 924    case GL_CLAMP_VERTEX_COLOR_ARB:
 925       if (ctx->API == API_OPENGL_CORE)
 926          goto invalid_enum;
 927       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 928       ctx->Light.ClampVertexColor = clamp;
 929       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
 930       break;
 931    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 932       if (ctx->API == API_OPENGL_CORE)
 933          goto invalid_enum;
 934       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 935       ctx->Color.ClampFragmentColor = clamp;
 936       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
 937       break;
 938    case GL_CLAMP_READ_COLOR_ARB:
 939       ctx->Color.ClampReadColor = clamp;
 940       break;
 941    default:
 942       goto invalid_enum;
 943    }
 944    return;
 945
 946 invalid_enum:
 947    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
 948                _mesa_enum_to_string(target));
 949 }
 950
 951 static GLboolean
 952 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
 953 {
 954    if (clamp == GL_TRUE || clamp == GL_FALSE)
 955       return clamp;
 956
 957    assert(clamp == GL_FIXED_ONLY);
 958    if (!fb)
 959       return GL_TRUE;
 960
 961    return fb->_AllColorBuffersFixedPoint;
 962 }
 963
 964 GLboolean
 965 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
 966                                const struct gl_framebuffer *drawFb)
 967 {
 968    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
 969 }
 970
 971 GLboolean
 972 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
 973                              const struct gl_framebuffer *drawFb)
 974 {
 975    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
 976 }
 977
 978 GLboolean
 979 _mesa_get_clamp_read_color(const struct gl_context *ctx,
 980                            const struct gl_framebuffer *readFb)
 981 {
 982    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
 983 }
 984
 985 /**
 986  * Update the ctx->Color._ClampFragmentColor field
 987  */
 988 void
 989 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
 990                                   const struct gl_framebuffer *drawFb)
 991 {
 992    /* Don't clamp if:
 993     * - there is no colorbuffer
 994     * - all colorbuffers are unsigned normalized, so clamping has no effect
 995     * - there is an integer colorbuffer
 996     */
 997    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
 998        drawFb->_IntegerBuffers)
 999       ctx->Color._ClampFragmentColor = GL_FALSE;
1000    else
1001       ctx->Color._ClampFragmentColor =
1002          _mesa_get_clamp_fragment_color(ctx, drawFb);
1003 }
1004
1005 /**
1006  * Update the ctx->Color._ClampVertexColor field
1007  */
1008 void
1009 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
1010                                 const struct gl_framebuffer *drawFb)
1011 {
1012    ctx->Light._ClampVertexColor =
1013          _mesa_get_clamp_vertex_color(ctx, drawFb);
1014 }
1015
1016 /**
1017  * Returns an appropriate mesa_format for color rendering based on the
1018  * GL_FRAMEBUFFER_SRGB state.
1019  *
1020  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
1021  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
1022  * overriding the format of the surface.  This is a helper for doing the
1023  * surface format override variant.
1024  */
1025 mesa_format
1026 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
1027 {
1028    if (ctx->Color.sRGBEnabled)
1029       return format;
1030    else
1031       return _mesa_get_srgb_format_linear(format);
1032 }
1033
1034 /**********************************************************************/
1035 /** \name Initialization */
1036 /*@{*/
1037
1038 /**
1039  * Initialization of the context's Color attribute group.
1040  *
1041  * \param ctx GL context.
1042  *
1043  * Initializes the related fields in the context color attribute group,
1044  * __struct gl_contextRec::Color.
1045  */
1046 void _mesa_init_color( struct gl_context * ctx )
1047 {
1048    GLuint i;
1049
1050    /* Color buffer group */
1051    ctx->Color.IndexMask = ~0u;
1052    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
1053    ctx->Color.ClearIndex = 0;
1054    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
1055    ctx->Color.AlphaEnabled = GL_FALSE;
1056    ctx->Color.AlphaFunc = GL_ALWAYS;
1057    ctx->Color.AlphaRef = 0;
1058    ctx->Color.BlendEnabled = 0x0;
1059    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
1060       ctx->Color.Blend[i].SrcRGB = GL_ONE;
1061       ctx->Color.Blend[i].DstRGB = GL_ZERO;
1062       ctx->Color.Blend[i].SrcA = GL_ONE;
1063       ctx->Color.Blend[i].DstA = GL_ZERO;
1064       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
1065       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
1066    }
1067    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
1068    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
1069    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
1070    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
1071    ctx->Color.LogicOp = GL_COPY;
1072    ctx->Color.DitherFlag = GL_TRUE;
1073
1074    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
1075     * the front or the back buffer depending on the config */
1076    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
1077       ctx->Color.DrawBuffer[0] = GL_BACK;
1078    }
1079    else {
1080       ctx->Color.DrawBuffer[0] = GL_FRONT;
1081    }
1082
1083    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
1084                                    GL_FIXED_ONLY_ARB : GL_FALSE;
1085    ctx->Color._ClampFragmentColor = GL_FALSE;
1086    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
1087
1088    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
1089     * if EGL_KHR_gl_colorspace has been used to request sRGB.
1090     */
1091    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
1092
1093    ctx->Color.BlendCoherent = true;
1094 }
1095
1096 /*@}*/