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 static GLboolean
 161 blend_factor_is_dual_src(GLenum factor)
 162 {
 163    return (factor == GL_SRC1_COLOR ||
 164            factor == GL_SRC1_ALPHA ||
 165            factor == GL_ONE_MINUS_SRC1_COLOR ||
 166            factor == GL_ONE_MINUS_SRC1_ALPHA);
 167 }
 168
 169 static void
 170 update_uses_dual_src(struct gl_context *ctx, int buf)
 171 {
 172    ctx->Color.Blend[buf]._UsesDualSrc =
 173       (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
 174        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
 175        blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
 176        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
 177 }
 178
 179
 180 /**
 181  * Return the number of per-buffer blend states to update in
 182  * glBlendFunc, glBlendFuncSeparate, glBlendEquation, etc.
 183  */
 184 static inline unsigned
 185 num_buffers(const struct gl_context *ctx)
 186 {
 187    return ctx->Extensions.ARB_draw_buffers_blend
 188       ? ctx->Const.MaxDrawBuffers : 1;
 189 }
 190
 191
 192 /* Returns true if there was no change */
 193 static bool
 194 skip_blend_state_update(const struct gl_context *ctx,
 195                         GLenum sfactorRGB, GLenum dfactorRGB,
 196                         GLenum sfactorA, GLenum dfactorA)
 197 {
 198    /* Check if we're really changing any state.  If not, return early. */
 199    if (ctx->Color._BlendFuncPerBuffer) {
 200       const unsigned numBuffers = num_buffers(ctx);
 201
 202       /* Check all per-buffer states */
 203       for (unsigned buf = 0; buf < numBuffers; buf++) {
 204          if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
 205              ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
 206              ctx->Color.Blend[buf].SrcA != sfactorA ||
 207              ctx->Color.Blend[buf].DstA != dfactorA) {
 208             return false;
 209          }
 210       }
 211    }
 212    else {
 213       /* only need to check 0th per-buffer state */
 214       if (ctx->Color.Blend[0].SrcRGB != sfactorRGB ||
 215           ctx->Color.Blend[0].DstRGB != dfactorRGB ||
 216           ctx->Color.Blend[0].SrcA != sfactorA ||
 217           ctx->Color.Blend[0].DstA != dfactorA) {
 218          return false;
 219       }
 220    }
 221
 222    return true;
 223 }
 224
 225
 226 static void
 227 blend_func_separate(struct gl_context *ctx,
 228                     GLenum sfactorRGB, GLenum dfactorRGB,
 229                     GLenum sfactorA, GLenum dfactorA)
 230 {
 231    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlend ? 0 : _NEW_COLOR);
 232    ctx->NewDriverState |= ctx->DriverFlags.NewBlend;
 233
 234    const unsigned numBuffers = num_buffers(ctx);
 235    for (unsigned buf = 0; buf < numBuffers; buf++) {
 236       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 237       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 238       ctx->Color.Blend[buf].SrcA = sfactorA;
 239       ctx->Color.Blend[buf].DstA = dfactorA;
 240    }
 241
 242    update_uses_dual_src(ctx, 0);
 243    for (unsigned buf = 1; buf < numBuffers; buf++) {
 244       ctx->Color.Blend[buf]._UsesDualSrc = ctx->Color.Blend[0]._UsesDualSrc;
 245    }
 246
 247    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
 248
 249    if (ctx->Driver.BlendFuncSeparate) {
 250       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
 251                                     sfactorA, dfactorA);
 252    }
 253 }
 254
 255
 256 /**
 257  * Specify the blending operation.
 258  *
 259  * \param sfactor source factor operator.
 260  * \param dfactor destination factor operator.
 261  *
 262  * \sa glBlendFunc, glBlendFuncSeparateEXT
 263  */
 264 void GLAPIENTRY
 265 _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
 266 {
 267    GET_CURRENT_CONTEXT(ctx);
 268
 269    if (skip_blend_state_update(ctx, sfactor, dfactor, sfactor, dfactor))
 270       return;
 271
 272    if (!validate_blend_factors(ctx, "glBlendFunc",
 273                                sfactor, dfactor, sfactor, dfactor)) {
 274       return;
 275    }
 276
 277    blend_func_separate(ctx, sfactor, dfactor, sfactor, dfactor);
 278 }
 279
 280
 281 void GLAPIENTRY
 282 _mesa_BlendFunc_no_error(GLenum sfactor, GLenum dfactor)
 283 {
 284    GET_CURRENT_CONTEXT(ctx);
 285
 286    if (skip_blend_state_update(ctx, sfactor, dfactor, sfactor, dfactor))
 287       return;
 288
 289    blend_func_separate(ctx, sfactor, dfactor, sfactor, dfactor);
 290 }
 291
 292
 293 /**
 294  * Set the separate blend source/dest factors for all draw buffers.
 295  *
 296  * \param sfactorRGB RGB source factor operator.
 297  * \param dfactorRGB RGB destination factor operator.
 298  * \param sfactorA alpha source factor operator.
 299  * \param dfactorA alpha destination factor operator.
 300  */
 301 void GLAPIENTRY
 302 _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB,
 303                             GLenum sfactorA, GLenum dfactorA )
 304 {
 305    GET_CURRENT_CONTEXT(ctx);
 306
 307    if (MESA_VERBOSE & VERBOSE_API)
 308       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
 309                   _mesa_enum_to_string(sfactorRGB),
 310                   _mesa_enum_to_string(dfactorRGB),
 311                   _mesa_enum_to_string(sfactorA),
 312                   _mesa_enum_to_string(dfactorA));
 313
 314
 315
 316    if (skip_blend_state_update(ctx, sfactorRGB, dfactorRGB, sfactorA, dfactorA))
 317       return;
 318
 319    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
 320                                sfactorRGB, dfactorRGB,
 321                                sfactorA, dfactorA)) {
 322       return;
 323    }
 324
 325    blend_func_separate(ctx, sfactorRGB, dfactorRGB, sfactorA, dfactorA);
 326 }
 327
 328
 329 void GLAPIENTRY
 330 _mesa_BlendFuncSeparate_no_error(GLenum sfactorRGB, GLenum dfactorRGB,
 331                                  GLenum sfactorA, GLenum dfactorA)
 332 {
 333    GET_CURRENT_CONTEXT(ctx);
 334
 335    if (skip_blend_state_update(ctx, sfactorRGB, dfactorRGB, sfactorA, dfactorA))
 336       return;
 337
 338    blend_func_separate(ctx, sfactorRGB, dfactorRGB, sfactorA, dfactorA);
 339 }
 340
 341
 342 void GLAPIENTRY
 343 _mesa_BlendFunciARB_no_error(GLuint buf, GLenum sfactor, GLenum dfactor)
 344 {
 345    _mesa_BlendFuncSeparateiARB_no_error(buf, sfactor, dfactor, sfactor,
 346                                         dfactor);
 347 }
 348
 349
 350 /**
 351  * Set blend source/dest factors for one color buffer/target.
 352  */
 353 void GLAPIENTRY
 354 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
 355 {
 356    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
 357 }
 358
 359
 360 static ALWAYS_INLINE void
 361 blend_func_separatei(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 362                      GLenum sfactorA, GLenum dfactorA, bool no_error)
 363 {
 364    GET_CURRENT_CONTEXT(ctx);
 365
 366    if (!no_error) {
 367       if (!ctx->Extensions.ARB_draw_buffers_blend) {
 368          _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 369          return;
 370       }
 371
 372       if (buf >= ctx->Const.MaxDrawBuffers) {
 373          _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 374                      buf);
 375          return;
 376       }
 377    }
 378
 379    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 380        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 381        ctx->Color.Blend[buf].SrcA == sfactorA &&
 382        ctx->Color.Blend[buf].DstA == dfactorA)
 383       return; /* no change */
 384
 385    if (!no_error && !validate_blend_factors(ctx, "glBlendFuncSeparatei",
 386                                             sfactorRGB, dfactorRGB,
 387                                             sfactorA, dfactorA)) {
 388       return;
 389    }
 390
 391    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlend ? 0 : _NEW_COLOR);
 392    ctx->NewDriverState |= ctx->DriverFlags.NewBlend;
 393
 394    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 395    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 396    ctx->Color.Blend[buf].SrcA = sfactorA;
 397    ctx->Color.Blend[buf].DstA = dfactorA;
 398    update_uses_dual_src(ctx, buf);
 399    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 400 }
 401
 402
 403 void GLAPIENTRY
 404 _mesa_BlendFuncSeparateiARB_no_error(GLuint buf, GLenum sfactorRGB,
 405                                      GLenum dfactorRGB, GLenum sfactorA,
 406                                      GLenum dfactorA)
 407 {
 408    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 409                         true);
 410 }
 411
 412
 413 /**
 414  * Set separate blend source/dest factors for one color buffer/target.
 415  */
 416 void GLAPIENTRY
 417 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 418                             GLenum sfactorA, GLenum dfactorA)
 419 {
 420    blend_func_separatei(buf, sfactorRGB, dfactorRGB, sfactorA, dfactorA,
 421                         false);
 422 }
 423
 424
 425 /**
 426  * Return true if \p mode is a legal blending equation, excluding
 427  * GL_KHR_blend_equation_advanced modes.
 428  */
 429 static bool
 430 legal_simple_blend_equation(const struct gl_context *ctx, GLenum mode)
 431 {
 432    switch (mode) {
 433    case GL_FUNC_ADD:
 434    case GL_FUNC_SUBTRACT:
 435    case GL_FUNC_REVERSE_SUBTRACT:
 436       return GL_TRUE;
 437    case GL_MIN:
 438    case GL_MAX:
 439       return ctx->Extensions.EXT_blend_minmax;
 440    default:
 441       return GL_FALSE;
 442    }
 443 }
 444
 445 static enum gl_advanced_blend_mode
 446 advanced_blend_mode_from_gl_enum(GLenum mode)
 447 {
 448    switch (mode) {
 449    case GL_MULTIPLY_KHR:
 450       return BLEND_MULTIPLY;
 451    case GL_SCREEN_KHR:
 452       return BLEND_SCREEN;
 453    case GL_OVERLAY_KHR:
 454       return BLEND_OVERLAY;
 455    case GL_DARKEN_KHR:
 456       return BLEND_DARKEN;
 457    case GL_LIGHTEN_KHR:
 458       return BLEND_LIGHTEN;
 459    case GL_COLORDODGE_KHR:
 460       return BLEND_COLORDODGE;
 461    case GL_COLORBURN_KHR:
 462       return BLEND_COLORBURN;
 463    case GL_HARDLIGHT_KHR:
 464       return BLEND_HARDLIGHT;
 465    case GL_SOFTLIGHT_KHR:
 466       return BLEND_SOFTLIGHT;
 467    case GL_DIFFERENCE_KHR:
 468       return BLEND_DIFFERENCE;
 469    case GL_EXCLUSION_KHR:
 470       return BLEND_EXCLUSION;
 471    case GL_HSL_HUE_KHR:
 472       return BLEND_HSL_HUE;
 473    case GL_HSL_SATURATION_KHR:
 474       return BLEND_HSL_SATURATION;
 475    case GL_HSL_COLOR_KHR:
 476       return BLEND_HSL_COLOR;
 477    case GL_HSL_LUMINOSITY_KHR:
 478       return BLEND_HSL_LUMINOSITY;
 479    default:
 480       return BLEND_NONE;
 481    }
 482 }
 483
 484 /**
 485  * If \p mode is one of the advanced blending equations defined by
 486  * GL_KHR_blend_equation_advanced (and the extension is supported),
 487  * return the corresponding BLEND_* enum.  Otherwise, return BLEND_NONE
 488  * (which can also be treated as false).
 489  */
 490 static enum gl_advanced_blend_mode
 491 advanced_blend_mode(const struct gl_context *ctx, GLenum mode)
 492 {
 493    return _mesa_has_KHR_blend_equation_advanced(ctx) ?
 494           advanced_blend_mode_from_gl_enum(mode) : BLEND_NONE;
 495 }
 496
 497 /* This is really an extension function! */
 498 void GLAPIENTRY
 499 _mesa_BlendEquation( GLenum mode )
 500 {
 501    GET_CURRENT_CONTEXT(ctx);
 502    const unsigned numBuffers = num_buffers(ctx);
 503    unsigned buf;
 504    bool changed = false;
 505    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 506
 507    if (MESA_VERBOSE & VERBOSE_API)
 508       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 509                   _mesa_enum_to_string(mode));
 510
 511    if (ctx->Color._BlendEquationPerBuffer) {
 512       /* Check all per-buffer states */
 513       for (buf = 0; buf < numBuffers; buf++) {
 514          if (ctx->Color.Blend[buf].EquationRGB != mode ||
 515              ctx->Color.Blend[buf].EquationA != mode) {
 516             changed = true;
 517             break;
 518          }
 519       }
 520    }
 521    else {
 522       /* only need to check 0th per-buffer state */
 523       if (ctx->Color.Blend[0].EquationRGB != mode ||
 524           ctx->Color.Blend[0].EquationA != mode) {
 525          changed = true;
 526       }
 527    }
 528
 529    if (!changed)
 530       return;
 531
 532
 533    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 534       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 535       return;
 536    }
 537
 538    _mesa_flush_vertices_for_blend_state(ctx);
 539
 540    for (buf = 0; buf < numBuffers; buf++) {
 541       ctx->Color.Blend[buf].EquationRGB = mode;
 542       ctx->Color.Blend[buf].EquationA = mode;
 543    }
 544    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 545    ctx->Color._AdvancedBlendMode = advanced_mode;
 546
 547    if (ctx->Driver.BlendEquationSeparate)
 548       ctx->Driver.BlendEquationSeparate(ctx, mode, mode);
 549 }
 550
 551
 552 /**
 553  * Set blend equation for one color buffer/target.
 554  */
 555 void GLAPIENTRY
 556 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
 557 {
 558    GET_CURRENT_CONTEXT(ctx);
 559    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
 560
 561    if (MESA_VERBOSE & VERBOSE_API)
 562       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 563                   buf, _mesa_enum_to_string(mode));
 564
 565    if (buf >= ctx->Const.MaxDrawBuffers) {
 566       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationi(buffer=%u)",
 567                   buf);
 568       return;
 569    }
 570
 571    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
 572       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 573       return;
 574    }
 575
 576    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 577        ctx->Color.Blend[buf].EquationA == mode)
 578       return;  /* no change */
 579
 580    _mesa_flush_vertices_for_blend_state(ctx);
 581    ctx->Color.Blend[buf].EquationRGB = mode;
 582    ctx->Color.Blend[buf].EquationA = mode;
 583    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 584
 585    if (buf == 0)
 586       ctx->Color._AdvancedBlendMode = advanced_mode;
 587 }
 588
 589
 590 void GLAPIENTRY
 591 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
 592 {
 593    GET_CURRENT_CONTEXT(ctx);
 594    const unsigned numBuffers = num_buffers(ctx);
 595    unsigned buf;
 596    bool changed = false;
 597
 598    if (MESA_VERBOSE & VERBOSE_API)
 599       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 600                   _mesa_enum_to_string(modeRGB),
 601                   _mesa_enum_to_string(modeA));
 602
 603    if (ctx->Color._BlendEquationPerBuffer) {
 604       /* Check all per-buffer states */
 605       for (buf = 0; buf < numBuffers; buf++) {
 606          if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 607              ctx->Color.Blend[buf].EquationA != modeA) {
 608             changed = true;
 609             break;
 610          }
 611       }
 612    }
 613    else {
 614       /* only need to check 0th per-buffer state */
 615       if (ctx->Color.Blend[0].EquationRGB != modeRGB ||
 616           ctx->Color.Blend[0].EquationA != modeA) {
 617          changed = true;
 618       }
 619    }
 620
 621    if (!changed)
 622       return;
 623
 624    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 625       _mesa_error(ctx, GL_INVALID_OPERATION,
 626                   "glBlendEquationSeparateEXT not supported by driver");
 627       return;
 628    }
 629
 630    /* Only allow simple blending equations.
 631     * The GL_KHR_blend_equation_advanced spec says:
 632     *
 633     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 634     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 635     */
 636    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 637       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 638       return;
 639    }
 640
 641    if (!legal_simple_blend_equation(ctx, modeA)) {
 642       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 643       return;
 644    }
 645
 646    _mesa_flush_vertices_for_blend_state(ctx);
 647
 648    for (buf = 0; buf < numBuffers; buf++) {
 649       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 650       ctx->Color.Blend[buf].EquationA = modeA;
 651    }
 652    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 653    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 654
 655    if (ctx->Driver.BlendEquationSeparate)
 656       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 657 }
 658
 659
 660 static void
 661 blend_equation_separatei(struct gl_context *ctx, GLuint buf, GLenum modeRGB,
 662                          GLenum modeA)
 663 {
 664    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 665        ctx->Color.Blend[buf].EquationA == modeA)
 666       return;  /* no change */
 667
 668    _mesa_flush_vertices_for_blend_state(ctx);
 669    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 670    ctx->Color.Blend[buf].EquationA = modeA;
 671    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 672    ctx->Color._AdvancedBlendMode = BLEND_NONE;
 673 }
 674
 675
 676 void GLAPIENTRY
 677 _mesa_BlendEquationSeparateiARB_no_error(GLuint buf, GLenum modeRGB,
 678                                          GLenum modeA)
 679 {
 680    GET_CURRENT_CONTEXT(ctx);
 681    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 682 }
 683
 684
 685 /**
 686  * Set separate blend equations for one color buffer/target.
 687  */
 688 void GLAPIENTRY
 689 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 690 {
 691    GET_CURRENT_CONTEXT(ctx);
 692
 693    if (MESA_VERBOSE & VERBOSE_API)
 694       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 695                   _mesa_enum_to_string(modeRGB),
 696                   _mesa_enum_to_string(modeA));
 697
 698    if (buf >= ctx->Const.MaxDrawBuffers) {
 699       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 700                   buf);
 701       return;
 702    }
 703
 704    /* Only allow simple blending equations.
 705     * The GL_KHR_blend_equation_advanced spec says:
 706     *
 707     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
 708     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
 709     */
 710    if (!legal_simple_blend_equation(ctx, modeRGB)) {
 711       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 712       return;
 713    }
 714
 715    if (!legal_simple_blend_equation(ctx, modeA)) {
 716       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 717       return;
 718    }
 719
 720    blend_equation_separatei(ctx, buf, modeRGB, modeA);
 721 }
 722
 723
 724 /**
 725  * Set the blending color.
 726  *
 727  * \param red red color component.
 728  * \param green green color component.
 729  * \param blue blue color component.
 730  * \param alpha alpha color component.
 731  *
 732  * \sa glBlendColor().
 733  *
 734  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 735  * change, flushes the vertices and notifies the driver via
 736  * dd_function_table::BlendColor callback.
 737  */
 738 void GLAPIENTRY
 739 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 740 {
 741    GLfloat tmp[4];
 742    GET_CURRENT_CONTEXT(ctx);
 743
 744    tmp[0] = red;
 745    tmp[1] = green;
 746    tmp[2] = blue;
 747    tmp[3] = alpha;
 748
 749    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 750       return;
 751
 752    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewBlendColor ? 0 : _NEW_COLOR);
 753    ctx->NewDriverState |= ctx->DriverFlags.NewBlendColor;
 754    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 755
 756    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 757    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 758    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 759    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 760
 761    if (ctx->Driver.BlendColor)
 762       ctx->Driver.BlendColor(ctx, ctx->Color.BlendColor);
 763 }
 764
 765
 766 /**
 767  * Specify the alpha test function.
 768  *
 769  * \param func alpha comparison function.
 770  * \param ref reference value.
 771  *
 772  * Verifies the parameters and updates gl_colorbuffer_attrib.
 773  * On a change, flushes the vertices and notifies the driver via
 774  * dd_function_table::AlphaFunc callback.
 775  */
 776 void GLAPIENTRY
 777 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 778 {
 779    GET_CURRENT_CONTEXT(ctx);
 780
 781    if (MESA_VERBOSE & VERBOSE_API)
 782       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 783                   _mesa_enum_to_string(func), ref);
 784
 785    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 786       return; /* no change */
 787
 788    switch (func) {
 789    case GL_NEVER:
 790    case GL_LESS:
 791    case GL_EQUAL:
 792    case GL_LEQUAL:
 793    case GL_GREATER:
 794    case GL_NOTEQUAL:
 795    case GL_GEQUAL:
 796    case GL_ALWAYS:
 797       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewAlphaTest ? 0 : _NEW_COLOR);
 798       ctx->NewDriverState |= ctx->DriverFlags.NewAlphaTest;
 799       ctx->Color.AlphaFunc = func;
 800       ctx->Color.AlphaRefUnclamped = ref;
 801       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 802
 803       if (ctx->Driver.AlphaFunc)
 804          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 805       return;
 806
 807    default:
 808       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 809       return;
 810    }
 811 }
 812
 813
 814 static void
 815 logic_op(struct gl_context *ctx, GLenum opcode)
 816 {
 817    if (ctx->Color.LogicOp == opcode)
 818       return;
 819
 820    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewLogicOp ? 0 : _NEW_COLOR);
 821    ctx->NewDriverState |= ctx->DriverFlags.NewLogicOp;
 822    ctx->Color.LogicOp = opcode;
 823
 824    if (ctx->Driver.LogicOpcode)
 825       ctx->Driver.LogicOpcode(ctx, opcode);
 826 }
 827
 828
 829 /**
 830  * Specify a logic pixel operation for color index rendering.
 831  *
 832  * \param opcode operation.
 833  *
 834  * Verifies that \p opcode is a valid enum and updates
 835  * gl_colorbuffer_attrib::LogicOp.
 836  * On a change, flushes the vertices and notifies the driver via the
 837  * dd_function_table::LogicOpcode callback.
 838  */
 839 void GLAPIENTRY
 840 _mesa_LogicOp( GLenum opcode )
 841 {
 842    GET_CURRENT_CONTEXT(ctx);
 843
 844    if (MESA_VERBOSE & VERBOSE_API)
 845       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
 846
 847    switch (opcode) {
 848       case GL_CLEAR:
 849       case GL_SET:
 850       case GL_COPY:
 851       case GL_COPY_INVERTED:
 852       case GL_NOOP:
 853       case GL_INVERT:
 854       case GL_AND:
 855       case GL_NAND:
 856       case GL_OR:
 857       case GL_NOR:
 858       case GL_XOR:
 859       case GL_EQUIV:
 860       case GL_AND_REVERSE:
 861       case GL_AND_INVERTED:
 862       case GL_OR_REVERSE:
 863       case GL_OR_INVERTED:
 864          break;
 865       default:
 866          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 867          return;
 868    }
 869
 870    logic_op(ctx, opcode);
 871 }
 872
 873
 874 void GLAPIENTRY
 875 _mesa_LogicOp_no_error(GLenum opcode)
 876 {
 877    GET_CURRENT_CONTEXT(ctx);
 878    logic_op(ctx, opcode);
 879 }
 880
 881
 882 void GLAPIENTRY
 883 _mesa_IndexMask( GLuint mask )
 884 {
 885    GET_CURRENT_CONTEXT(ctx);
 886
 887    if (ctx->Color.IndexMask == mask)
 888       return;
 889
 890    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 891    ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 892    ctx->Color.IndexMask = mask;
 893 }
 894
 895
 896 /**
 897  * Enable or disable writing of frame buffer color components.
 898  *
 899  * \param red whether to mask writing of the red color component.
 900  * \param green whether to mask writing of the green color component.
 901  * \param blue whether to mask writing of the blue color component.
 902  * \param alpha whether to mask writing of the alpha color component.
 903  *
 904  * \sa glColorMask().
 905  *
 906  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 907  * change, flushes the vertices and notifies the driver via the
 908  * dd_function_table::ColorMask callback.
 909  */
 910 void GLAPIENTRY
 911 _mesa_ColorMask( GLboolean red, GLboolean green,
 912                  GLboolean blue, GLboolean alpha )
 913 {
 914    GET_CURRENT_CONTEXT(ctx);
 915    GLubyte tmp[4];
 916    GLuint i;
 917    GLboolean flushed;
 918
 919    if (MESA_VERBOSE & VERBOSE_API)
 920       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 921                   red, green, blue, alpha);
 922
 923    /* Shouldn't have any information about channel depth in core mesa
 924     * -- should probably store these as the native booleans:
 925     */
 926    tmp[RCOMP] = red    ? 0xff : 0x0;
 927    tmp[GCOMP] = green  ? 0xff : 0x0;
 928    tmp[BCOMP] = blue   ? 0xff : 0x0;
 929    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 930
 931    flushed = GL_FALSE;
 932    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 933       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 934          if (!flushed) {
 935             FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 936             ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 937          }
 938          flushed = GL_TRUE;
 939          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 940       }
 941    }
 942
 943    if (ctx->Driver.ColorMask)
 944       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 945 }
 946
 947
 948 /**
 949  * For GL_EXT_draw_buffers2 and GL3
 950  */
 951 void GLAPIENTRY
 952 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 953                         GLboolean blue, GLboolean alpha )
 954 {
 955    GLubyte tmp[4];
 956    GET_CURRENT_CONTEXT(ctx);
 957
 958    if (MESA_VERBOSE & VERBOSE_API)
 959       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 960                   buf, red, green, blue, alpha);
 961
 962    if (buf >= ctx->Const.MaxDrawBuffers) {
 963       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 964       return;
 965    }
 966
 967    /* Shouldn't have any information about channel depth in core mesa
 968     * -- should probably store these as the native booleans:
 969     */
 970    tmp[RCOMP] = red    ? 0xff : 0x0;
 971    tmp[GCOMP] = green  ? 0xff : 0x0;
 972    tmp[BCOMP] = blue   ? 0xff : 0x0;
 973    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 974
 975    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 976       return;
 977
 978    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewColorMask ? 0 : _NEW_COLOR);
 979    ctx->NewDriverState |= ctx->DriverFlags.NewColorMask;
 980    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 981 }
 982
 983
 984 void GLAPIENTRY
 985 _mesa_ClampColor(GLenum target, GLenum clamp)
 986 {
 987    GET_CURRENT_CONTEXT(ctx);
 988
 989    /* Check for both the extension and the GL version, since the Intel driver
 990     * does not advertise the extension in core profiles.
 991     */
 992    if (ctx->Version <= 30 && !ctx->Extensions.ARB_color_buffer_float) {
 993       _mesa_error(ctx, GL_INVALID_OPERATION, "glClampColor()");
 994       return;
 995    }
 996
 997    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 998       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 999       return;
1000    }
1001
1002    switch (target) {
1003    case GL_CLAMP_VERTEX_COLOR_ARB:
1004       if (ctx->API == API_OPENGL_CORE)
1005          goto invalid_enum;
1006       FLUSH_VERTICES(ctx, _NEW_LIGHT);
1007       ctx->Light.ClampVertexColor = clamp;
1008       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
1009       break;
1010    case GL_CLAMP_FRAGMENT_COLOR_ARB:
1011       if (ctx->API == API_OPENGL_CORE)
1012          goto invalid_enum;
1013       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
1014       ctx->Color.ClampFragmentColor = clamp;
1015       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
1016       break;
1017    case GL_CLAMP_READ_COLOR_ARB:
1018       ctx->Color.ClampReadColor = clamp;
1019       break;
1020    default:
1021       goto invalid_enum;
1022    }
1023    return;
1024
1025 invalid_enum:
1026    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
1027                _mesa_enum_to_string(target));
1028 }
1029
1030 static GLboolean
1031 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
1032 {
1033    if (clamp == GL_TRUE || clamp == GL_FALSE)
1034       return clamp;
1035
1036    assert(clamp == GL_FIXED_ONLY);
1037    if (!fb)
1038       return GL_TRUE;
1039
1040    return fb->_AllColorBuffersFixedPoint;
1041 }
1042
1043 GLboolean
1044 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
1045                                const struct gl_framebuffer *drawFb)
1046 {
1047    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
1048 }
1049
1050 GLboolean
1051 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
1052                              const struct gl_framebuffer *drawFb)
1053 {
1054    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
1055 }
1056
1057 GLboolean
1058 _mesa_get_clamp_read_color(const struct gl_context *ctx,
1059                            const struct gl_framebuffer *readFb)
1060 {
1061    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
1062 }
1063
1064 /**
1065  * Update the ctx->Color._ClampFragmentColor field
1066  */
1067 void
1068 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
1069                                   const struct gl_framebuffer *drawFb)
1070 {
1071    /* Don't clamp if:
1072     * - there is no colorbuffer
1073     * - all colorbuffers are unsigned normalized, so clamping has no effect
1074     * - there is an integer colorbuffer
1075     */
1076    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
1077        drawFb->_IntegerBuffers)
1078       ctx->Color._ClampFragmentColor = GL_FALSE;
1079    else
1080       ctx->Color._ClampFragmentColor =
1081          _mesa_get_clamp_fragment_color(ctx, drawFb);
1082 }
1083
1084 /**
1085  * Update the ctx->Color._ClampVertexColor field
1086  */
1087 void
1088 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
1089                                 const struct gl_framebuffer *drawFb)
1090 {
1091    ctx->Light._ClampVertexColor =
1092          _mesa_get_clamp_vertex_color(ctx, drawFb);
1093 }
1094
1095 /**
1096  * Returns an appropriate mesa_format for color rendering based on the
1097  * GL_FRAMEBUFFER_SRGB state.
1098  *
1099  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
1100  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
1101  * overriding the format of the surface.  This is a helper for doing the
1102  * surface format override variant.
1103  */
1104 mesa_format
1105 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
1106 {
1107    if (ctx->Color.sRGBEnabled)
1108       return format;
1109    else
1110       return _mesa_get_srgb_format_linear(format);
1111 }
1112
1113 /**********************************************************************/
1114 /** \name Initialization */
1115 /*@{*/
1116
1117 /**
1118  * Initialization of the context's Color attribute group.
1119  *
1120  * \param ctx GL context.
1121  *
1122  * Initializes the related fields in the context color attribute group,
1123  * __struct gl_contextRec::Color.
1124  */
1125 void _mesa_init_color( struct gl_context * ctx )
1126 {
1127    GLuint i;
1128
1129    /* Color buffer group */
1130    ctx->Color.IndexMask = ~0u;
1131    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
1132    ctx->Color.ClearIndex = 0;
1133    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
1134    ctx->Color.AlphaEnabled = GL_FALSE;
1135    ctx->Color.AlphaFunc = GL_ALWAYS;
1136    ctx->Color.AlphaRef = 0;
1137    ctx->Color.BlendEnabled = 0x0;
1138    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
1139       ctx->Color.Blend[i].SrcRGB = GL_ONE;
1140       ctx->Color.Blend[i].DstRGB = GL_ZERO;
1141       ctx->Color.Blend[i].SrcA = GL_ONE;
1142       ctx->Color.Blend[i].DstA = GL_ZERO;
1143       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
1144       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
1145    }
1146    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
1147    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
1148    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
1149    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
1150    ctx->Color.LogicOp = GL_COPY;
1151    ctx->Color.DitherFlag = GL_TRUE;
1152
1153    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
1154     * the front or the back buffer depending on the config */
1155    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
1156       ctx->Color.DrawBuffer[0] = GL_BACK;
1157    }
1158    else {
1159       ctx->Color.DrawBuffer[0] = GL_FRONT;
1160    }
1161
1162    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
1163                                    GL_FIXED_ONLY_ARB : GL_FALSE;
1164    ctx->Color._ClampFragmentColor = GL_FALSE;
1165    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
1166
1167    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
1168     * if EGL_KHR_gl_colorspace has been used to request sRGB.
1169     */
1170    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
1171
1172    ctx->Color.BlendCoherent = true;
1173 }
1174
1175 /*@}*/