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 /**
 603  * Set separate blend equations for one color buffer/target.
 604  */
 605 void GLAPIENTRY
 606 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 607 {
 608    GET_CURRENT_CONTEXT(ctx);
 609
 610    if (MESA_VERBOSE & VERBOSE_API)
 611       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 612                   _mesa_enum_to_string(modeRGB),
 613                   _mesa_enum_to_string(modeA));
 614
 615    if (buf >= ctx->Const.MaxDrawBuffers) {
 616       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 617                   buf);
 618       return;
 619    }
 620
 621    /* Only allow simple blending equations.
 622     * The GL_KHR_blend_equation_advanced spec says:
 623     *
 624     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 625     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 626     */
 627    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 628       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 629       return;
 630    }
 631
 632    if (!legal_simple_blend_equation(ctx, modeA)) {
 633       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 634       return;
 635    }
 636
 637    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 638        ctx->Color.Blend[buf].EquationA == modeA)
 639       return;  /* no change */
 640
 641    FLUSH_VERTICES(ctx, _NEW_COLOR);
 642    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 643    ctx->Color.Blend[buf].EquationA = modeA;
 644    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 645    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 646 }
 647
 648
 649 /**
 650  * Set the blending color.
 651  *
 652  * \param red red color component.
 653  * \param green green color component.
 654  * \param blue blue color component.
 655  * \param alpha alpha color component.
 656  *
 657  * \sa glBlendColor().
 658  *
 659  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 660  * change, flushes the vertices and notifies the driver via
 661  * dd_function_table::BlendColor callback.
 662  */
 663 void GLAPIENTRY
 664 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 665 {
 666    GLfloat tmp[4];
 667    GET_CURRENT_CONTEXT(ctx);
 668
 669    tmp[0] = red;
 670    tmp[1] = green;
 671    tmp[2] = blue;
 672    tmp[3] = alpha;
 673
 674    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 675       return;
 676
 677    FLUSH_VERTICES(ctx, _NEW_COLOR);
 678    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 679
 680    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 681    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 682    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 683    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 684
 685    if (ctx->Driver.BlendColor)
 686       ctx->Driver.BlendColor(ctx, ctx->Color.BlendColor);
 687 }
 688
 689
 690 /**
 691  * Specify the alpha test function.
 692  *
 693  * \param func alpha comparison function.
 694  * \param ref reference value.
 695  *
 696  * Verifies the parameters and updates gl_colorbuffer_attrib.
 697  * On a change, flushes the vertices and notifies the driver via
 698  * dd_function_table::AlphaFunc callback.
 699  */
 700 void GLAPIENTRY
 701 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 702 {
 703    GET_CURRENT_CONTEXT(ctx);
 704
 705    if (MESA_VERBOSE & VERBOSE_API)
 706       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 707                   _mesa_enum_to_string(func), ref);
 708
 709    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 710       return; /* no change */
 711
 712    switch (func) {
 713    case GL_NEVER:
 714    case GL_LESS:
 715    case GL_EQUAL:
 716    case GL_LEQUAL:
 717    case GL_GREATER:
 718    case GL_NOTEQUAL:
 719    case GL_GEQUAL:
 720    case GL_ALWAYS:
 721       FLUSH_VERTICES(ctx, _NEW_COLOR);
 722       ctx->Color.AlphaFunc = func;
 723       ctx->Color.AlphaRefUnclamped = ref;
 724       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 725
 726       if (ctx->Driver.AlphaFunc)
 727          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 728       return;
 729
 730    default:
 731       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 732       return;
 733    }
 734 }
 735
 736
 737 /**
 738  * Specify a logic pixel operation for color index rendering.
 739  *
 740  * \param opcode operation.
 741  *
 742  * Verifies that \p opcode is a valid enum and updates
 743  * gl_colorbuffer_attrib::LogicOp.
 744  * On a change, flushes the vertices and notifies the driver via the
 745  * dd_function_table::LogicOpcode callback.
 746  */
 747 void GLAPIENTRY
 748 _mesa_LogicOp( GLenum opcode )
 749 {
 750    GET_CURRENT_CONTEXT(ctx);
 751
 752    if (MESA_VERBOSE & VERBOSE_API)
 753       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
 754
 755    switch (opcode) {
 756       case GL_CLEAR:
 757       case GL_SET:
 758       case GL_COPY:
 759       case GL_COPY_INVERTED:
 760       case GL_NOOP:
 761       case GL_INVERT:
 762       case GL_AND:
 763       case GL_NAND:
 764       case GL_OR:
 765       case GL_NOR:
 766       case GL_XOR:
 767       case GL_EQUIV:
 768       case GL_AND_REVERSE:
 769       case GL_AND_INVERTED:
 770       case GL_OR_REVERSE:
 771       case GL_OR_INVERTED:
 772          break;
 773       default:
 774          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 775          return;
 776    }
 777
 778    if (ctx->Color.LogicOp == opcode)
 779       return;
 780
 781    FLUSH_VERTICES(ctx, _NEW_COLOR);
 782    ctx->Color.LogicOp = opcode;
 783
 784    if (ctx->Driver.LogicOpcode)
 785       ctx->Driver.LogicOpcode( ctx, opcode );
 786 }
 787
 788
 789 void GLAPIENTRY
 790 _mesa_IndexMask( GLuint mask )
 791 {
 792    GET_CURRENT_CONTEXT(ctx);
 793
 794    if (ctx->Color.IndexMask == mask)
 795       return;
 796
 797    FLUSH_VERTICES(ctx, _NEW_COLOR);
 798    ctx->Color.IndexMask = mask;
 799 }
 800
 801
 802 /**
 803  * Enable or disable writing of frame buffer color components.
 804  *
 805  * \param red whether to mask writing of the red color component.
 806  * \param green whether to mask writing of the green color component.
 807  * \param blue whether to mask writing of the blue color component.
 808  * \param alpha whether to mask writing of the alpha color component.
 809  *
 810  * \sa glColorMask().
 811  *
 812  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 813  * change, flushes the vertices and notifies the driver via the
 814  * dd_function_table::ColorMask callback.
 815  */
 816 void GLAPIENTRY
 817 _mesa_ColorMask( GLboolean red, GLboolean green,
 818                  GLboolean blue, GLboolean alpha )
 819 {
 820    GET_CURRENT_CONTEXT(ctx);
 821    GLubyte tmp[4];
 822    GLuint i;
 823    GLboolean flushed;
 824
 825    if (MESA_VERBOSE & VERBOSE_API)
 826       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 827                   red, green, blue, alpha);
 828
 829    /* Shouldn't have any information about channel depth in core mesa
 830     * -- should probably store these as the native booleans:
 831     */
 832    tmp[RCOMP] = red    ? 0xff : 0x0;
 833    tmp[GCOMP] = green  ? 0xff : 0x0;
 834    tmp[BCOMP] = blue   ? 0xff : 0x0;
 835    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 836
 837    flushed = GL_FALSE;
 838    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 839       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 840          if (!flushed) {
 841             FLUSH_VERTICES(ctx, _NEW_COLOR);
 842          }
 843          flushed = GL_TRUE;
 844          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 845       }
 846    }
 847
 848    if (ctx->Driver.ColorMask)
 849       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 850 }
 851
 852
 853 /**
 854  * For GL_EXT_draw_buffers2 and GL3
 855  */
 856 void GLAPIENTRY
 857 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 858                         GLboolean blue, GLboolean alpha )
 859 {
 860    GLubyte tmp[4];
 861    GET_CURRENT_CONTEXT(ctx);
 862
 863    if (MESA_VERBOSE & VERBOSE_API)
 864       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 865                   buf, red, green, blue, alpha);
 866
 867    if (buf >= ctx->Const.MaxDrawBuffers) {
 868       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 869       return;
 870    }
 871
 872    /* Shouldn't have any information about channel depth in core mesa
 873     * -- should probably store these as the native booleans:
 874     */
 875    tmp[RCOMP] = red    ? 0xff : 0x0;
 876    tmp[GCOMP] = green  ? 0xff : 0x0;
 877    tmp[BCOMP] = blue   ? 0xff : 0x0;
 878    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 879
 880    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 881       return;
 882
 883    FLUSH_VERTICES(ctx, _NEW_COLOR);
 884    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 885 }
 886
 887
 888 void GLAPIENTRY
 889 _mesa_ClampColor(GLenum target, GLenum clamp)
 890 {
 891    GET_CURRENT_CONTEXT(ctx);
 892
 893    /* Check for both the extension and the GL version, since the Intel driver
 894     * does not advertise the extension in core profiles.
 895     */
 896    if (ctx->Version <= 30 && !ctx->Extensions.ARB_color_buffer_float) {
 897       _mesa_error(ctx, GL_INVALID_OPERATION, "glClampColor()");
 898       return;
 899    }
 900
 901    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 902       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 903       return;
 904    }
 905
 906    switch (target) {
 907    case GL_CLAMP_VERTEX_COLOR_ARB:
 908       if (ctx->API == API_OPENGL_CORE)
 909          goto invalid_enum;
 910       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 911       ctx->Light.ClampVertexColor = clamp;
 912       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
 913       break;
 914    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 915       if (ctx->API == API_OPENGL_CORE)
 916          goto invalid_enum;
 917       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 918       ctx->Color.ClampFragmentColor = clamp;
 919       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
 920       break;
 921    case GL_CLAMP_READ_COLOR_ARB:
 922       ctx->Color.ClampReadColor = clamp;
 923       break;
 924    default:
 925       goto invalid_enum;
 926    }
 927    return;
 928
 929 invalid_enum:
 930    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
 931                _mesa_enum_to_string(target));
 932 }
 933
 934 static GLboolean
 935 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
 936 {
 937    if (clamp == GL_TRUE || clamp == GL_FALSE)
 938       return clamp;
 939
 940    assert(clamp == GL_FIXED_ONLY);
 941    if (!fb)
 942       return GL_TRUE;
 943
 944    return fb->_AllColorBuffersFixedPoint;
 945 }
 946
 947 GLboolean
 948 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
 949                                const struct gl_framebuffer *drawFb)
 950 {
 951    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
 952 }
 953
 954 GLboolean
 955 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
 956                              const struct gl_framebuffer *drawFb)
 957 {
 958    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
 959 }
 960
 961 GLboolean
 962 _mesa_get_clamp_read_color(const struct gl_context *ctx,
 963                            const struct gl_framebuffer *readFb)
 964 {
 965    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
 966 }
 967
 968 /**
 969  * Update the ctx->Color._ClampFragmentColor field
 970  */
 971 void
 972 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
 973                                   const struct gl_framebuffer *drawFb)
 974 {
 975    /* Don't clamp if:
 976     * - there is no colorbuffer
 977     * - all colorbuffers are unsigned normalized, so clamping has no effect
 978     * - there is an integer colorbuffer
 979     */
 980    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
 981        drawFb->_IntegerBuffers)
 982       ctx->Color._ClampFragmentColor = GL_FALSE;
 983    else
 984       ctx->Color._ClampFragmentColor =
 985          _mesa_get_clamp_fragment_color(ctx, drawFb);
 986 }
 987
 988 /**
 989  * Update the ctx->Color._ClampVertexColor field
 990  */
 991 void
 992 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
 993                                 const struct gl_framebuffer *drawFb)
 994 {
 995    ctx->Light._ClampVertexColor =
 996          _mesa_get_clamp_vertex_color(ctx, drawFb);
 997 }
 998
 999 /**
1000  * Returns an appropriate mesa_format for color rendering based on the
1001  * GL_FRAMEBUFFER_SRGB state.
1002  *
1003  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
1004  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
1005  * overriding the format of the surface.  This is a helper for doing the
1006  * surface format override variant.
1007  */
1008 mesa_format
1009 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
1010 {
1011    if (ctx->Color.sRGBEnabled)
1012       return format;
1013    else
1014       return _mesa_get_srgb_format_linear(format);
1015 }
1016
1017 /**********************************************************************/
1018 /** \name Initialization */
1019 /*@{*/
1020
1021 /**
1022  * Initialization of the context's Color attribute group.
1023  *
1024  * \param ctx GL context.
1025  *
1026  * Initializes the related fields in the context color attribute group,
1027  * __struct gl_contextRec::Color.
1028  */
1029 void _mesa_init_color( struct gl_context * ctx )
1030 {
1031    GLuint i;
1032
1033    /* Color buffer group */
1034    ctx->Color.IndexMask = ~0u;
1035    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
1036    ctx->Color.ClearIndex = 0;
1037    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
1038    ctx->Color.AlphaEnabled = GL_FALSE;
1039    ctx->Color.AlphaFunc = GL_ALWAYS;
1040    ctx->Color.AlphaRef = 0;
1041    ctx->Color.BlendEnabled = 0x0;
1042    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
1043       ctx->Color.Blend[i].SrcRGB = GL_ONE;
1044       ctx->Color.Blend[i].DstRGB = GL_ZERO;
1045       ctx->Color.Blend[i].SrcA = GL_ONE;
1046       ctx->Color.Blend[i].DstA = GL_ZERO;
1047       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
1048       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
1049    }
1050    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
1051    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
1052    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
1053    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
1054    ctx->Color.LogicOp = GL_COPY;
1055    ctx->Color.DitherFlag = GL_TRUE;
1056
1057    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
1058     * the front or the back buffer depending on the config */
1059    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
1060       ctx->Color.DrawBuffer[0] = GL_BACK;
1061    }
1062    else {
1063       ctx->Color.DrawBuffer[0] = GL_FRONT;
1064    }
1065
1066    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
1067                                    GL_FIXED_ONLY_ARB : GL_FALSE;
1068    ctx->Color._ClampFragmentColor = GL_FALSE;
1069    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
1070
1071    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
1072     * if EGL_KHR_gl_colorspace has been used to request sRGB.
1073     */
1074    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
1075
1076    ctx->Color.BlendCoherent = true;
1077 }
1078
1079 /*@}*/