src/mesa/main/blend.c

   1 /**
   2  * \file blend.c
   3  * Blending operations.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  6.5.1
   9  *
  10  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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       return ctx->Extensions.NV_blend_square;
  52    case GL_ZERO:
  53    case GL_ONE:
  54    case GL_DST_COLOR:
  55    case GL_ONE_MINUS_DST_COLOR:
  56    case GL_SRC_ALPHA:
  57    case GL_ONE_MINUS_SRC_ALPHA:
  58    case GL_DST_ALPHA:
  59    case GL_ONE_MINUS_DST_ALPHA:
  60    case GL_SRC_ALPHA_SATURATE:
  61       return GL_TRUE;
  62    case GL_CONSTANT_COLOR:
  63    case GL_ONE_MINUS_CONSTANT_COLOR:
  64    case GL_CONSTANT_ALPHA:
  65    case GL_ONE_MINUS_CONSTANT_ALPHA:
  66       return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
  67    case GL_SRC1_COLOR:
  68    case GL_SRC1_ALPHA:
  69    case GL_ONE_MINUS_SRC1_COLOR:
  70    case GL_ONE_MINUS_SRC1_ALPHA:
  71       return _mesa_is_desktop_gl(ctx)
  72          && ctx->Extensions.ARB_blend_func_extended;
  73    default:
  74       return GL_FALSE;
  75    }
  76 }
  77
  78
  79 /**
  80  * Check if given blend destination factor is legal.
  81  * \return GL_TRUE if legal, GL_FALSE otherwise.
  82  */
  83 static GLboolean
  84 legal_dst_factor(const struct gl_context *ctx, GLenum factor)
  85 {
  86    switch (factor) {
  87    case GL_DST_COLOR:
  88    case GL_ONE_MINUS_DST_COLOR:
  89       return ctx->Extensions.NV_blend_square;
  90    case GL_ZERO:
  91    case GL_ONE:
  92    case GL_SRC_COLOR:
  93    case GL_ONE_MINUS_SRC_COLOR:
  94    case GL_SRC_ALPHA:
  95    case GL_ONE_MINUS_SRC_ALPHA:
  96    case GL_DST_ALPHA:
  97    case GL_ONE_MINUS_DST_ALPHA:
  98       return GL_TRUE;
  99    case GL_CONSTANT_COLOR:
 100    case GL_ONE_MINUS_CONSTANT_COLOR:
 101    case GL_CONSTANT_ALPHA:
 102    case GL_ONE_MINUS_CONSTANT_ALPHA:
 103       return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
 104    case GL_SRC_ALPHA_SATURATE:
 105       return (_mesa_is_desktop_gl(ctx)
 106               && ctx->Extensions.ARB_blend_func_extended)
 107          || _mesa_is_gles3(ctx);
 108    case GL_SRC1_COLOR:
 109    case GL_SRC1_ALPHA:
 110    case GL_ONE_MINUS_SRC1_COLOR:
 111    case GL_ONE_MINUS_SRC1_ALPHA:
 112       return _mesa_is_desktop_gl(ctx)
 113          && ctx->Extensions.ARB_blend_func_extended;
 114    default:
 115       return GL_FALSE;
 116    }
 117 }
 118
 119
 120 /**
 121  * Check if src/dest RGB/A blend factors are legal.  If not generate
 122  * a GL error.
 123  * \return GL_TRUE if factors are legal, GL_FALSE otherwise.
 124  */
 125 static GLboolean
 126 validate_blend_factors(struct gl_context *ctx, const char *func,
 127                        GLenum sfactorRGB, GLenum dfactorRGB,
 128                        GLenum sfactorA, GLenum dfactorA)
 129 {
 130    if (!legal_src_factor(ctx, sfactorRGB)) {
 131       _mesa_error(ctx, GL_INVALID_ENUM,
 132                   "%s(sfactorRGB = %s)", func,
 133                   _mesa_lookup_enum_by_nr(sfactorRGB));
 134       return GL_FALSE;
 135    }
 136
 137    if (!legal_dst_factor(ctx, dfactorRGB)) {
 138       _mesa_error(ctx, GL_INVALID_ENUM,
 139                   "%s(dfactorRGB = %s)", func,
 140                   _mesa_lookup_enum_by_nr(dfactorRGB));
 141       return GL_FALSE;
 142    }
 143
 144    if (sfactorA != sfactorRGB && !legal_src_factor(ctx, sfactorA)) {
 145       _mesa_error(ctx, GL_INVALID_ENUM,
 146                   "%s(sfactorA = %s)", func,
 147                   _mesa_lookup_enum_by_nr(sfactorA));
 148       return GL_FALSE;
 149    }
 150
 151    if (dfactorA != dfactorRGB && !legal_dst_factor(ctx, dfactorA)) {
 152       _mesa_error(ctx, GL_INVALID_ENUM,
 153                   "%s(dfactorA = %s)", func,
 154                   _mesa_lookup_enum_by_nr(dfactorA));
 155       return GL_FALSE;
 156    }
 157
 158    return GL_TRUE;
 159 }
 160
 161
 162 /**
 163  * Specify the blending operation.
 164  *
 165  * \param sfactor source factor operator.
 166  * \param dfactor destination factor operator.
 167  *
 168  * \sa glBlendFunc, glBlendFuncSeparateEXT
 169  */
 170 void GLAPIENTRY
 171 _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
 172 {
 173    _mesa_BlendFuncSeparate(sfactor, dfactor, sfactor, dfactor);
 174 }
 175
 176 static GLboolean
 177 blend_factor_is_dual_src(GLenum factor)
 178 {
 179    return (factor == GL_SRC1_COLOR ||
 180            factor == GL_SRC1_ALPHA ||
 181            factor == GL_ONE_MINUS_SRC1_COLOR ||
 182            factor == GL_ONE_MINUS_SRC1_ALPHA);
 183 }
 184
 185 static void
 186 update_uses_dual_src(struct gl_context *ctx, int buf)
 187 {
 188    ctx->Color.Blend[buf]._UsesDualSrc =
 189       (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
 190        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
 191        blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
 192        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
 193 }
 194
 195 /**
 196  * Set the separate blend source/dest factors for all draw buffers.
 197  *
 198  * \param sfactorRGB RGB source factor operator.
 199  * \param dfactorRGB RGB destination factor operator.
 200  * \param sfactorA alpha source factor operator.
 201  * \param dfactorA alpha destination factor operator.
 202  */
 203 void GLAPIENTRY
 204 _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB,
 205                             GLenum sfactorA, GLenum dfactorA )
 206 {
 207    GLuint buf, numBuffers;
 208    GLboolean changed;
 209    GET_CURRENT_CONTEXT(ctx);
 210
 211    if (MESA_VERBOSE & VERBOSE_API)
 212       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
 213                   _mesa_lookup_enum_by_nr(sfactorRGB),
 214                   _mesa_lookup_enum_by_nr(dfactorRGB),
 215                   _mesa_lookup_enum_by_nr(sfactorA),
 216                   _mesa_lookup_enum_by_nr(dfactorA));
 217
 218    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
 219                                sfactorRGB, dfactorRGB,
 220                                sfactorA, dfactorA)) {
 221       return;
 222    }
 223
 224    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 225       ? ctx->Const.MaxDrawBuffers : 1;
 226
 227    changed = GL_FALSE;
 228    for (buf = 0; buf < numBuffers; buf++) {
 229       if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
 230           ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
 231           ctx->Color.Blend[buf].SrcA != sfactorA ||
 232           ctx->Color.Blend[buf].DstA != dfactorA) {
 233          changed = GL_TRUE;
 234          break;
 235       }
 236    }
 237    if (!changed)
 238       return;
 239
 240    FLUSH_VERTICES(ctx, _NEW_COLOR);
 241
 242    for (buf = 0; buf < numBuffers; buf++) {
 243       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 244       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 245       ctx->Color.Blend[buf].SrcA = sfactorA;
 246       ctx->Color.Blend[buf].DstA = dfactorA;
 247       update_uses_dual_src(ctx, buf);
 248    }
 249    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
 250
 251    if (ctx->Driver.BlendFuncSeparate) {
 252       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
 253                                     sfactorA, dfactorA);
 254    }
 255 }
 256
 257
 258 /**
 259  * Set blend source/dest factors for one color buffer/target.
 260  */
 261 void GLAPIENTRY
 262 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
 263 {
 264    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
 265 }
 266
 267
 268 /**
 269  * Set separate blend source/dest factors for one color buffer/target.
 270  */
 271 void GLAPIENTRY
 272 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 273                          GLenum sfactorA, GLenum dfactorA)
 274 {
 275    GET_CURRENT_CONTEXT(ctx);
 276
 277    if (!ctx->Extensions.ARB_draw_buffers_blend) {
 278       _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 279       return;
 280    }
 281
 282    if (buf >= ctx->Const.MaxDrawBuffers) {
 283       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 284                   buf);
 285       return;
 286    }
 287
 288    if (!validate_blend_factors(ctx, "glBlendFuncSeparatei",
 289                                sfactorRGB, dfactorRGB,
 290                                sfactorA, dfactorA)) {
 291       return;
 292    }
 293
 294    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 295        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 296        ctx->Color.Blend[buf].SrcA == sfactorA &&
 297        ctx->Color.Blend[buf].DstA == dfactorA)
 298       return; /* no change */
 299
 300    FLUSH_VERTICES(ctx, _NEW_COLOR);
 301
 302    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 303    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 304    ctx->Color.Blend[buf].SrcA = sfactorA;
 305    ctx->Color.Blend[buf].DstA = dfactorA;
 306    update_uses_dual_src(ctx, buf);
 307    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 308
 309    if (ctx->Driver.BlendFuncSeparatei) {
 310       ctx->Driver.BlendFuncSeparatei(ctx, buf, sfactorRGB, dfactorRGB,
 311                                      sfactorA, dfactorA);
 312    }
 313 }
 314
 315
 316 /**
 317  * Check if given blend equation is legal.
 318  * \return GL_TRUE if legal, GL_FALSE otherwise.
 319  */
 320 static GLboolean
 321 legal_blend_equation(const struct gl_context *ctx, GLenum mode)
 322 {
 323    switch (mode) {
 324    case GL_FUNC_ADD:
 325    case GL_FUNC_SUBTRACT:
 326    case GL_FUNC_REVERSE_SUBTRACT:
 327       return GL_TRUE;
 328    case GL_MIN:
 329    case GL_MAX:
 330       return ctx->Extensions.EXT_blend_minmax;
 331    default:
 332       return GL_FALSE;
 333    }
 334 }
 335
 336
 337 /* This is really an extension function! */
 338 void GLAPIENTRY
 339 _mesa_BlendEquation( GLenum mode )
 340 {
 341    GLuint buf, numBuffers;
 342    GLboolean changed;
 343    GET_CURRENT_CONTEXT(ctx);
 344
 345    if (MESA_VERBOSE & VERBOSE_API)
 346       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 347                   _mesa_lookup_enum_by_nr(mode));
 348
 349    if (!legal_blend_equation(ctx, mode)) {
 350       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 351       return;
 352    }
 353
 354    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 355       ? ctx->Const.MaxDrawBuffers : 1;
 356
 357    changed = GL_FALSE;
 358    for (buf = 0; buf < numBuffers; buf++) {
 359       if (ctx->Color.Blend[buf].EquationRGB != mode ||
 360           ctx->Color.Blend[buf].EquationA != mode) {
 361          changed = GL_TRUE;
 362          break;
 363       }
 364    }
 365    if (!changed)
 366       return;
 367
 368    FLUSH_VERTICES(ctx, _NEW_COLOR);
 369    for (buf = 0; buf < numBuffers; buf++) {
 370       ctx->Color.Blend[buf].EquationRGB = mode;
 371       ctx->Color.Blend[buf].EquationA = mode;
 372    }
 373    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 374
 375    if (ctx->Driver.BlendEquationSeparate)
 376       (*ctx->Driver.BlendEquationSeparate)( ctx, mode, mode );
 377 }
 378
 379
 380 /**
 381  * Set blend equation for one color buffer/target.
 382  */
 383 void GLAPIENTRY
 384 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
 385 {
 386    GET_CURRENT_CONTEXT(ctx);
 387
 388    if (MESA_VERBOSE & VERBOSE_API)
 389       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 390                   buf, _mesa_lookup_enum_by_nr(mode));
 391
 392    if (buf >= ctx->Const.MaxDrawBuffers) {
 393       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 394                   buf);
 395       return;
 396    }
 397
 398    if (!legal_blend_equation(ctx, mode)) {
 399       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 400       return;
 401    }
 402
 403    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 404        ctx->Color.Blend[buf].EquationA == mode)
 405       return;  /* no change */
 406
 407    FLUSH_VERTICES(ctx, _NEW_COLOR);
 408    ctx->Color.Blend[buf].EquationRGB = mode;
 409    ctx->Color.Blend[buf].EquationA = mode;
 410    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 411
 412    if (ctx->Driver.BlendEquationSeparatei)
 413       ctx->Driver.BlendEquationSeparatei(ctx, buf, mode, mode);
 414 }
 415
 416
 417 void GLAPIENTRY
 418 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
 419 {
 420    GLuint buf, numBuffers;
 421    GLboolean changed;
 422    GET_CURRENT_CONTEXT(ctx);
 423
 424    if (MESA_VERBOSE & VERBOSE_API)
 425       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 426                   _mesa_lookup_enum_by_nr(modeRGB),
 427                   _mesa_lookup_enum_by_nr(modeA));
 428
 429    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 430       _mesa_error(ctx, GL_INVALID_OPERATION,
 431                   "glBlendEquationSeparateEXT not supported by driver");
 432       return;
 433    }
 434
 435    if (!legal_blend_equation(ctx, modeRGB)) {
 436       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 437       return;
 438    }
 439
 440    if (!legal_blend_equation(ctx, modeA)) {
 441       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 442       return;
 443    }
 444
 445    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 446       ? ctx->Const.MaxDrawBuffers : 1;
 447
 448    changed = GL_FALSE;
 449    for (buf = 0; buf < numBuffers; buf++) {
 450       if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 451           ctx->Color.Blend[buf].EquationA != modeA) {
 452          changed = GL_TRUE;
 453          break;
 454       }
 455    }
 456    if (!changed)
 457       return;
 458
 459    FLUSH_VERTICES(ctx, _NEW_COLOR);
 460    for (buf = 0; buf < numBuffers; buf++) {
 461       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 462       ctx->Color.Blend[buf].EquationA = modeA;
 463    }
 464    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 465
 466    if (ctx->Driver.BlendEquationSeparate)
 467       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 468 }
 469
 470
 471 /**
 472  * Set separate blend equations for one color buffer/target.
 473  */
 474 void GLAPIENTRY
 475 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 476 {
 477    GET_CURRENT_CONTEXT(ctx);
 478
 479    if (MESA_VERBOSE & VERBOSE_API)
 480       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 481                   _mesa_lookup_enum_by_nr(modeRGB),
 482                   _mesa_lookup_enum_by_nr(modeA));
 483
 484    if (buf >= ctx->Const.MaxDrawBuffers) {
 485       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 486                   buf);
 487       return;
 488    }
 489
 490    if (!legal_blend_equation(ctx, modeRGB)) {
 491       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 492       return;
 493    }
 494
 495    if (!legal_blend_equation(ctx, modeA)) {
 496       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 497       return;
 498    }
 499
 500    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 501        ctx->Color.Blend[buf].EquationA == modeA)
 502       return;  /* no change */
 503
 504    FLUSH_VERTICES(ctx, _NEW_COLOR);
 505    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 506    ctx->Color.Blend[buf].EquationA = modeA;
 507    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 508
 509    if (ctx->Driver.BlendEquationSeparatei)
 510       ctx->Driver.BlendEquationSeparatei(ctx, buf, modeRGB, modeA);
 511 }
 512
 513
 514 /**
 515  * Set the blending color.
 516  *
 517  * \param red red color component.
 518  * \param green green color component.
 519  * \param blue blue color component.
 520  * \param alpha alpha color component.
 521  *
 522  * \sa glBlendColor().
 523  *
 524  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 525  * change, flushes the vertices and notifies the driver via
 526  * dd_function_table::BlendColor callback.
 527  */
 528 void GLAPIENTRY
 529 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 530 {
 531    GLfloat tmp[4];
 532    GET_CURRENT_CONTEXT(ctx);
 533
 534    tmp[0] = red;
 535    tmp[1] = green;
 536    tmp[2] = blue;
 537    tmp[3] = alpha;
 538
 539    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 540       return;
 541
 542    FLUSH_VERTICES(ctx, _NEW_COLOR);
 543    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 544
 545    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 546    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 547    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 548    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 549
 550    if (ctx->Driver.BlendColor)
 551       (*ctx->Driver.BlendColor)(ctx, ctx->Color.BlendColor);
 552 }
 553
 554
 555 /**
 556  * Specify the alpha test function.
 557  *
 558  * \param func alpha comparison function.
 559  * \param ref reference value.
 560  *
 561  * Verifies the parameters and updates gl_colorbuffer_attrib.
 562  * On a change, flushes the vertices and notifies the driver via
 563  * dd_function_table::AlphaFunc callback.
 564  */
 565 void GLAPIENTRY
 566 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 567 {
 568    GET_CURRENT_CONTEXT(ctx);
 569
 570    if (MESA_VERBOSE & VERBOSE_API)
 571       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 572                   _mesa_lookup_enum_by_nr(func), ref);
 573
 574    switch (func) {
 575    case GL_NEVER:
 576    case GL_LESS:
 577    case GL_EQUAL:
 578    case GL_LEQUAL:
 579    case GL_GREATER:
 580    case GL_NOTEQUAL:
 581    case GL_GEQUAL:
 582    case GL_ALWAYS:
 583       if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 584          return; /* no change */
 585
 586       FLUSH_VERTICES(ctx, _NEW_COLOR);
 587       ctx->Color.AlphaFunc = func;
 588       ctx->Color.AlphaRefUnclamped = ref;
 589       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 590
 591       if (ctx->Driver.AlphaFunc)
 592          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 593       return;
 594
 595    default:
 596       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 597       return;
 598    }
 599 }
 600
 601
 602 /**
 603  * Specify a logic pixel operation for color index rendering.
 604  *
 605  * \param opcode operation.
 606  *
 607  * Verifies that \p opcode is a valid enum and updates
 608 gl_colorbuffer_attrib::LogicOp.
 609  * On a change, flushes the vertices and notifies the driver via the
 610  * dd_function_table::LogicOpcode callback.
 611  */
 612 void GLAPIENTRY
 613 _mesa_LogicOp( GLenum opcode )
 614 {
 615    GET_CURRENT_CONTEXT(ctx);
 616
 617    if (MESA_VERBOSE & VERBOSE_API)
 618       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_lookup_enum_by_nr(opcode));
 619
 620    switch (opcode) {
 621       case GL_CLEAR:
 622       case GL_SET:
 623       case GL_COPY:
 624       case GL_COPY_INVERTED:
 625       case GL_NOOP:
 626       case GL_INVERT:
 627       case GL_AND:
 628       case GL_NAND:
 629       case GL_OR:
 630       case GL_NOR:
 631       case GL_XOR:
 632       case GL_EQUIV:
 633       case GL_AND_REVERSE:
 634       case GL_AND_INVERTED:
 635       case GL_OR_REVERSE:
 636       case GL_OR_INVERTED:
 637          break;
 638       default:
 639          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 640          return;
 641    }
 642
 643    if (ctx->Color.LogicOp == opcode)
 644       return;
 645
 646    FLUSH_VERTICES(ctx, _NEW_COLOR);
 647    ctx->Color.LogicOp = opcode;
 648
 649    if (ctx->Driver.LogicOpcode)
 650       ctx->Driver.LogicOpcode( ctx, opcode );
 651 }
 652
 653
 654 void GLAPIENTRY
 655 _mesa_IndexMask( GLuint mask )
 656 {
 657    GET_CURRENT_CONTEXT(ctx);
 658
 659    if (ctx->Color.IndexMask == mask)
 660       return;
 661
 662    FLUSH_VERTICES(ctx, _NEW_COLOR);
 663    ctx->Color.IndexMask = mask;
 664 }
 665
 666
 667 /**
 668  * Enable or disable writing of frame buffer color components.
 669  *
 670  * \param red whether to mask writing of the red color component.
 671  * \param green whether to mask writing of the green color component.
 672  * \param blue whether to mask writing of the blue color component.
 673  * \param alpha whether to mask writing of the alpha color component.
 674  *
 675  * \sa glColorMask().
 676  *
 677  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 678  * change, flushes the vertices and notifies the driver via the
 679  * dd_function_table::ColorMask callback.
 680  */
 681 void GLAPIENTRY
 682 _mesa_ColorMask( GLboolean red, GLboolean green,
 683                  GLboolean blue, GLboolean alpha )
 684 {
 685    GET_CURRENT_CONTEXT(ctx);
 686    GLubyte tmp[4];
 687    GLuint i;
 688    GLboolean flushed;
 689
 690    if (MESA_VERBOSE & VERBOSE_API)
 691       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 692                   red, green, blue, alpha);
 693
 694    /* Shouldn't have any information about channel depth in core mesa
 695     * -- should probably store these as the native booleans:
 696     */
 697    tmp[RCOMP] = red    ? 0xff : 0x0;
 698    tmp[GCOMP] = green  ? 0xff : 0x0;
 699    tmp[BCOMP] = blue   ? 0xff : 0x0;
 700    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 701
 702    flushed = GL_FALSE;
 703    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 704       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 705          if (!flushed) {
 706             FLUSH_VERTICES(ctx, _NEW_COLOR);
 707          }
 708          flushed = GL_TRUE;
 709          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 710       }
 711    }
 712
 713    if (ctx->Driver.ColorMask)
 714       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 715 }
 716
 717
 718 /**
 719  * For GL_EXT_draw_buffers2 and GL3
 720  */
 721 void GLAPIENTRY
 722 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 723                         GLboolean blue, GLboolean alpha )
 724 {
 725    GLubyte tmp[4];
 726    GET_CURRENT_CONTEXT(ctx);
 727
 728    if (MESA_VERBOSE & VERBOSE_API)
 729       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 730                   buf, red, green, blue, alpha);
 731
 732    if (buf >= ctx->Const.MaxDrawBuffers) {
 733       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 734       return;
 735    }
 736
 737    /* Shouldn't have any information about channel depth in core mesa
 738     * -- should probably store these as the native booleans:
 739     */
 740    tmp[RCOMP] = red    ? 0xff : 0x0;
 741    tmp[GCOMP] = green  ? 0xff : 0x0;
 742    tmp[BCOMP] = blue   ? 0xff : 0x0;
 743    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 744
 745    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 746       return;
 747
 748    FLUSH_VERTICES(ctx, _NEW_COLOR);
 749    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 750
 751    if (ctx->Driver.ColorMaskIndexed)
 752       ctx->Driver.ColorMaskIndexed(ctx, buf, red, green, blue, alpha);
 753 }
 754
 755
 756 void GLAPIENTRY
 757 _mesa_ClampColor(GLenum target, GLenum clamp)
 758 {
 759    GET_CURRENT_CONTEXT(ctx);
 760
 761    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 762       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 763       return;
 764    }
 765
 766    switch (target) {
 767    case GL_CLAMP_VERTEX_COLOR_ARB:
 768       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 769       ctx->Light.ClampVertexColor = clamp;
 770       break;
 771    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 772       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 773       ctx->Color.ClampFragmentColor = clamp;
 774       break;
 775    case GL_CLAMP_READ_COLOR_ARB:
 776       FLUSH_VERTICES(ctx, _NEW_COLOR);
 777       ctx->Color.ClampReadColor = clamp;
 778       break;
 779    default:
 780       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(target)");
 781       return;
 782    }
 783 }
 784
 785 static GLboolean
 786 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
 787 {
 788    if (clamp == GL_TRUE || clamp == GL_FALSE)
 789       return clamp;
 790
 791    ASSERT(clamp == GL_FIXED_ONLY);
 792    if (!fb)
 793       return GL_TRUE;
 794
 795    return fb->_AllColorBuffersFixedPoint;
 796 }
 797
 798 GLboolean
 799 _mesa_get_clamp_fragment_color(const struct gl_context *ctx)
 800 {
 801    return get_clamp_color(ctx->DrawBuffer,
 802                                 ctx->Color.ClampFragmentColor);
 803 }
 804
 805 GLboolean
 806 _mesa_get_clamp_vertex_color(const struct gl_context *ctx)
 807 {
 808    return get_clamp_color(ctx->DrawBuffer, ctx->Light.ClampVertexColor);
 809 }
 810
 811 GLboolean
 812 _mesa_get_clamp_read_color(const struct gl_context *ctx)
 813 {
 814    return get_clamp_color(ctx->ReadBuffer, ctx->Color.ClampReadColor);
 815 }
 816
 817
 818 /**********************************************************************/
 819 /** \name Initialization */
 820 /*@{*/
 821
 822 /**
 823  * Initialization of the context's Color attribute group.
 824  *
 825  * \param ctx GL context.
 826  *
 827  * Initializes the related fields in the context color attribute group,
 828  * __struct gl_contextRec::Color.
 829  */
 830 void _mesa_init_color( struct gl_context * ctx )
 831 {
 832    GLuint i;
 833
 834    /* Color buffer group */
 835    ctx->Color.IndexMask = ~0u;
 836    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
 837    ctx->Color.ClearIndex = 0;
 838    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
 839    ctx->Color.AlphaEnabled = GL_FALSE;
 840    ctx->Color.AlphaFunc = GL_ALWAYS;
 841    ctx->Color.AlphaRef = 0;
 842    ctx->Color.BlendEnabled = 0x0;
 843    for (i = 0; i < Elements(ctx->Color.Blend); i++) {
 844       ctx->Color.Blend[i].SrcRGB = GL_ONE;
 845       ctx->Color.Blend[i].DstRGB = GL_ZERO;
 846       ctx->Color.Blend[i].SrcA = GL_ONE;
 847       ctx->Color.Blend[i].DstA = GL_ZERO;
 848       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
 849       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
 850    }
 851    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
 852    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
 853    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
 854    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
 855    ctx->Color.LogicOp = GL_COPY;
 856    ctx->Color.DitherFlag = GL_TRUE;
 857
 858    if (ctx->Visual.doubleBufferMode) {
 859       ctx->Color.DrawBuffer[0] = GL_BACK;
 860    }
 861    else {
 862       ctx->Color.DrawBuffer[0] = GL_FRONT;
 863    }
 864
 865    ctx->Color.ClampFragmentColor = GL_FIXED_ONLY_ARB;
 866    ctx->Color._ClampFragmentColor = GL_FALSE;
 867    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
 868
 869    if (ctx->API == API_OPENGLES2) {
 870       /* GLES 3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled. */
 871       ctx->Color.sRGBEnabled = GL_TRUE;
 872    } else {
 873       ctx->Color.sRGBEnabled = GL_FALSE;
 874    }
 875 }
 876
 877 /*@}*/