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