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 _mesa_is_desktop_gl(ctx)
  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 (_mesa_is_desktop_gl(ctx)
 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 _mesa_is_desktop_gl(ctx)
 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  * Set the separate blend source/dest factors for all draw buffers.
 195  *
 196  * \param sfactorRGB RGB source factor operator.
 197  * \param dfactorRGB RGB destination factor operator.
 198  * \param sfactorA alpha source factor operator.
 199  * \param dfactorA alpha destination factor operator.
 200  */
 201 void GLAPIENTRY
 202 _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB,
 203                             GLenum sfactorA, GLenum dfactorA )
 204 {
 205    GLuint buf, numBuffers;
 206    GLboolean changed;
 207    GET_CURRENT_CONTEXT(ctx);
 208
 209    if (MESA_VERBOSE & VERBOSE_API)
 210       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
 211                   _mesa_enum_to_string(sfactorRGB),
 212                   _mesa_enum_to_string(dfactorRGB),
 213                   _mesa_enum_to_string(sfactorA),
 214                   _mesa_enum_to_string(dfactorA));
 215
 216    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
 217                                sfactorRGB, dfactorRGB,
 218                                sfactorA, dfactorA)) {
 219       return;
 220    }
 221
 222    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 223       ? ctx->Const.MaxDrawBuffers : 1;
 224
 225    changed = GL_FALSE;
 226    for (buf = 0; buf < numBuffers; buf++) {
 227       if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
 228           ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
 229           ctx->Color.Blend[buf].SrcA != sfactorA ||
 230           ctx->Color.Blend[buf].DstA != dfactorA) {
 231          changed = GL_TRUE;
 232          break;
 233       }
 234    }
 235    if (!changed)
 236       return;
 237
 238    FLUSH_VERTICES(ctx, _NEW_COLOR);
 239
 240    for (buf = 0; buf < numBuffers; buf++) {
 241       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 242       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 243       ctx->Color.Blend[buf].SrcA = sfactorA;
 244       ctx->Color.Blend[buf].DstA = dfactorA;
 245       update_uses_dual_src(ctx, buf);
 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  * Set blend source/dest factors for one color buffer/target.
 258  */
 259 void GLAPIENTRY
 260 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
 261 {
 262    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
 263 }
 264
 265
 266 /**
 267  * Set separate blend source/dest factors for one color buffer/target.
 268  */
 269 void GLAPIENTRY
 270 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
 271                          GLenum sfactorA, GLenum dfactorA)
 272 {
 273    GET_CURRENT_CONTEXT(ctx);
 274
 275    if (!ctx->Extensions.ARB_draw_buffers_blend) {
 276       _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
 277       return;
 278    }
 279
 280    if (buf >= ctx->Const.MaxDrawBuffers) {
 281       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 282                   buf);
 283       return;
 284    }
 285
 286    if (!validate_blend_factors(ctx, "glBlendFuncSeparatei",
 287                                sfactorRGB, dfactorRGB,
 288                                sfactorA, dfactorA)) {
 289       return;
 290    }
 291
 292    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
 293        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
 294        ctx->Color.Blend[buf].SrcA == sfactorA &&
 295        ctx->Color.Blend[buf].DstA == dfactorA)
 296       return; /* no change */
 297
 298    FLUSH_VERTICES(ctx, _NEW_COLOR);
 299
 300    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
 301    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
 302    ctx->Color.Blend[buf].SrcA = sfactorA;
 303    ctx->Color.Blend[buf].DstA = dfactorA;
 304    update_uses_dual_src(ctx, buf);
 305    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
 306 }
 307
 308
 309 /**
 310  * Check if given blend equation is legal.
 311  * \return GL_TRUE if legal, GL_FALSE otherwise.
 312  */
 313 static GLboolean
 314 legal_blend_equation(const struct gl_context *ctx, GLenum mode)
 315 {
 316    switch (mode) {
 317    case GL_FUNC_ADD:
 318    case GL_FUNC_SUBTRACT:
 319    case GL_FUNC_REVERSE_SUBTRACT:
 320       return GL_TRUE;
 321    case GL_MIN:
 322    case GL_MAX:
 323       return ctx->Extensions.EXT_blend_minmax;
 324    default:
 325       return GL_FALSE;
 326    }
 327 }
 328
 329
 330 /* This is really an extension function! */
 331 void GLAPIENTRY
 332 _mesa_BlendEquation( GLenum mode )
 333 {
 334    GLuint buf, numBuffers;
 335    GLboolean changed;
 336    GET_CURRENT_CONTEXT(ctx);
 337
 338    if (MESA_VERBOSE & VERBOSE_API)
 339       _mesa_debug(ctx, "glBlendEquation(%s)\n",
 340                   _mesa_enum_to_string(mode));
 341
 342    if (!legal_blend_equation(ctx, mode)) {
 343       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
 344       return;
 345    }
 346
 347    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 348       ? ctx->Const.MaxDrawBuffers : 1;
 349
 350    changed = GL_FALSE;
 351    for (buf = 0; buf < numBuffers; buf++) {
 352       if (ctx->Color.Blend[buf].EquationRGB != mode ||
 353           ctx->Color.Blend[buf].EquationA != mode) {
 354          changed = GL_TRUE;
 355          break;
 356       }
 357    }
 358    if (!changed)
 359       return;
 360
 361    FLUSH_VERTICES(ctx, _NEW_COLOR);
 362    for (buf = 0; buf < numBuffers; buf++) {
 363       ctx->Color.Blend[buf].EquationRGB = mode;
 364       ctx->Color.Blend[buf].EquationA = mode;
 365    }
 366    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 367
 368    if (ctx->Driver.BlendEquationSeparate)
 369       (*ctx->Driver.BlendEquationSeparate)( ctx, mode, mode );
 370 }
 371
 372
 373 /**
 374  * Set blend equation for one color buffer/target.
 375  */
 376 void GLAPIENTRY
 377 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
 378 {
 379    GET_CURRENT_CONTEXT(ctx);
 380
 381    if (MESA_VERBOSE & VERBOSE_API)
 382       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
 383                   buf, _mesa_enum_to_string(mode));
 384
 385    if (buf >= ctx->Const.MaxDrawBuffers) {
 386       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
 387                   buf);
 388       return;
 389    }
 390
 391    if (!legal_blend_equation(ctx, mode)) {
 392       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
 393       return;
 394    }
 395
 396    if (ctx->Color.Blend[buf].EquationRGB == mode &&
 397        ctx->Color.Blend[buf].EquationA == mode)
 398       return;  /* no change */
 399
 400    FLUSH_VERTICES(ctx, _NEW_COLOR);
 401    ctx->Color.Blend[buf].EquationRGB = mode;
 402    ctx->Color.Blend[buf].EquationA = mode;
 403    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 404 }
 405
 406
 407 void GLAPIENTRY
 408 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
 409 {
 410    GLuint buf, numBuffers;
 411    GLboolean changed;
 412    GET_CURRENT_CONTEXT(ctx);
 413
 414    if (MESA_VERBOSE & VERBOSE_API)
 415       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
 416                   _mesa_enum_to_string(modeRGB),
 417                   _mesa_enum_to_string(modeA));
 418
 419    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
 420       _mesa_error(ctx, GL_INVALID_OPERATION,
 421                   "glBlendEquationSeparateEXT not supported by driver");
 422       return;
 423    }
 424
 425    if (!legal_blend_equation(ctx, modeRGB)) {
 426       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
 427       return;
 428    }
 429
 430    if (!legal_blend_equation(ctx, modeA)) {
 431       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
 432       return;
 433    }
 434
 435    numBuffers = ctx->Extensions.ARB_draw_buffers_blend
 436       ? ctx->Const.MaxDrawBuffers : 1;
 437
 438    changed = GL_FALSE;
 439    for (buf = 0; buf < numBuffers; buf++) {
 440       if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
 441           ctx->Color.Blend[buf].EquationA != modeA) {
 442          changed = GL_TRUE;
 443          break;
 444       }
 445    }
 446    if (!changed)
 447       return;
 448
 449    FLUSH_VERTICES(ctx, _NEW_COLOR);
 450    for (buf = 0; buf < numBuffers; buf++) {
 451       ctx->Color.Blend[buf].EquationRGB = modeRGB;
 452       ctx->Color.Blend[buf].EquationA = modeA;
 453    }
 454    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
 455
 456    if (ctx->Driver.BlendEquationSeparate)
 457       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
 458 }
 459
 460
 461 /**
 462  * Set separate blend equations for one color buffer/target.
 463  */
 464 void GLAPIENTRY
 465 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
 466 {
 467    GET_CURRENT_CONTEXT(ctx);
 468
 469    if (MESA_VERBOSE & VERBOSE_API)
 470       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
 471                   _mesa_enum_to_string(modeRGB),
 472                   _mesa_enum_to_string(modeA));
 473
 474    if (buf >= ctx->Const.MaxDrawBuffers) {
 475       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
 476                   buf);
 477       return;
 478    }
 479
 480    if (!legal_blend_equation(ctx, modeRGB)) {
 481       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
 482       return;
 483    }
 484
 485    if (!legal_blend_equation(ctx, modeA)) {
 486       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
 487       return;
 488    }
 489
 490    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
 491        ctx->Color.Blend[buf].EquationA == modeA)
 492       return;  /* no change */
 493
 494    FLUSH_VERTICES(ctx, _NEW_COLOR);
 495    ctx->Color.Blend[buf].EquationRGB = modeRGB;
 496    ctx->Color.Blend[buf].EquationA = modeA;
 497    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
 498 }
 499
 500
 501 /**
 502  * Set the blending color.
 503  *
 504  * \param red red color component.
 505  * \param green green color component.
 506  * \param blue blue color component.
 507  * \param alpha alpha color component.
 508  *
 509  * \sa glBlendColor().
 510  *
 511  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
 512  * change, flushes the vertices and notifies the driver via
 513  * dd_function_table::BlendColor callback.
 514  */
 515 void GLAPIENTRY
 516 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
 517 {
 518    GLfloat tmp[4];
 519    GET_CURRENT_CONTEXT(ctx);
 520
 521    tmp[0] = red;
 522    tmp[1] = green;
 523    tmp[2] = blue;
 524    tmp[3] = alpha;
 525
 526    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
 527       return;
 528
 529    FLUSH_VERTICES(ctx, _NEW_COLOR);
 530    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
 531
 532    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
 533    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
 534    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
 535    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 536
 537    if (ctx->Driver.BlendColor)
 538       (*ctx->Driver.BlendColor)(ctx, ctx->Color.BlendColor);
 539 }
 540
 541
 542 /**
 543  * Specify the alpha test function.
 544  *
 545  * \param func alpha comparison function.
 546  * \param ref reference value.
 547  *
 548  * Verifies the parameters and updates gl_colorbuffer_attrib.
 549  * On a change, flushes the vertices and notifies the driver via
 550  * dd_function_table::AlphaFunc callback.
 551  */
 552 void GLAPIENTRY
 553 _mesa_AlphaFunc( GLenum func, GLclampf ref )
 554 {
 555    GET_CURRENT_CONTEXT(ctx);
 556
 557    if (MESA_VERBOSE & VERBOSE_API)
 558       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
 559                   _mesa_enum_to_string(func), ref);
 560
 561    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
 562       return; /* no change */
 563
 564    switch (func) {
 565    case GL_NEVER:
 566    case GL_LESS:
 567    case GL_EQUAL:
 568    case GL_LEQUAL:
 569    case GL_GREATER:
 570    case GL_NOTEQUAL:
 571    case GL_GEQUAL:
 572    case GL_ALWAYS:
 573       FLUSH_VERTICES(ctx, _NEW_COLOR);
 574       ctx->Color.AlphaFunc = func;
 575       ctx->Color.AlphaRefUnclamped = ref;
 576       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 577
 578       if (ctx->Driver.AlphaFunc)
 579          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
 580       return;
 581
 582    default:
 583       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
 584       return;
 585    }
 586 }
 587
 588
 589 /**
 590  * Specify a logic pixel operation for color index rendering.
 591  *
 592  * \param opcode operation.
 593  *
 594  * Verifies that \p opcode is a valid enum and updates
 595 gl_colorbuffer_attrib::LogicOp.
 596  * On a change, flushes the vertices and notifies the driver via the
 597  * dd_function_table::LogicOpcode callback.
 598  */
 599 void GLAPIENTRY
 600 _mesa_LogicOp( GLenum opcode )
 601 {
 602    GET_CURRENT_CONTEXT(ctx);
 603
 604    if (MESA_VERBOSE & VERBOSE_API)
 605       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
 606
 607    switch (opcode) {
 608       case GL_CLEAR:
 609       case GL_SET:
 610       case GL_COPY:
 611       case GL_COPY_INVERTED:
 612       case GL_NOOP:
 613       case GL_INVERT:
 614       case GL_AND:
 615       case GL_NAND:
 616       case GL_OR:
 617       case GL_NOR:
 618       case GL_XOR:
 619       case GL_EQUIV:
 620       case GL_AND_REVERSE:
 621       case GL_AND_INVERTED:
 622       case GL_OR_REVERSE:
 623       case GL_OR_INVERTED:
 624          break;
 625       default:
 626          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
 627          return;
 628    }
 629
 630    if (ctx->Color.LogicOp == opcode)
 631       return;
 632
 633    FLUSH_VERTICES(ctx, _NEW_COLOR);
 634    ctx->Color.LogicOp = opcode;
 635
 636    if (ctx->Driver.LogicOpcode)
 637       ctx->Driver.LogicOpcode( ctx, opcode );
 638 }
 639
 640
 641 void GLAPIENTRY
 642 _mesa_IndexMask( GLuint mask )
 643 {
 644    GET_CURRENT_CONTEXT(ctx);
 645
 646    if (ctx->Color.IndexMask == mask)
 647       return;
 648
 649    FLUSH_VERTICES(ctx, _NEW_COLOR);
 650    ctx->Color.IndexMask = mask;
 651 }
 652
 653
 654 /**
 655  * Enable or disable writing of frame buffer color components.
 656  *
 657  * \param red whether to mask writing of the red color component.
 658  * \param green whether to mask writing of the green color component.
 659  * \param blue whether to mask writing of the blue color component.
 660  * \param alpha whether to mask writing of the alpha color component.
 661  *
 662  * \sa glColorMask().
 663  *
 664  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
 665  * change, flushes the vertices and notifies the driver via the
 666  * dd_function_table::ColorMask callback.
 667  */
 668 void GLAPIENTRY
 669 _mesa_ColorMask( GLboolean red, GLboolean green,
 670                  GLboolean blue, GLboolean alpha )
 671 {
 672    GET_CURRENT_CONTEXT(ctx);
 673    GLubyte tmp[4];
 674    GLuint i;
 675    GLboolean flushed;
 676
 677    if (MESA_VERBOSE & VERBOSE_API)
 678       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
 679                   red, green, blue, alpha);
 680
 681    /* Shouldn't have any information about channel depth in core mesa
 682     * -- should probably store these as the native booleans:
 683     */
 684    tmp[RCOMP] = red    ? 0xff : 0x0;
 685    tmp[GCOMP] = green  ? 0xff : 0x0;
 686    tmp[BCOMP] = blue   ? 0xff : 0x0;
 687    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 688
 689    flushed = GL_FALSE;
 690    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
 691       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
 692          if (!flushed) {
 693             FLUSH_VERTICES(ctx, _NEW_COLOR);
 694          }
 695          flushed = GL_TRUE;
 696          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
 697       }
 698    }
 699
 700    if (ctx->Driver.ColorMask)
 701       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
 702 }
 703
 704
 705 /**
 706  * For GL_EXT_draw_buffers2 and GL3
 707  */
 708 void GLAPIENTRY
 709 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 710                         GLboolean blue, GLboolean alpha )
 711 {
 712    GLubyte tmp[4];
 713    GET_CURRENT_CONTEXT(ctx);
 714
 715    if (MESA_VERBOSE & VERBOSE_API)
 716       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
 717                   buf, red, green, blue, alpha);
 718
 719    if (buf >= ctx->Const.MaxDrawBuffers) {
 720       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
 721       return;
 722    }
 723
 724    /* Shouldn't have any information about channel depth in core mesa
 725     * -- should probably store these as the native booleans:
 726     */
 727    tmp[RCOMP] = red    ? 0xff : 0x0;
 728    tmp[GCOMP] = green  ? 0xff : 0x0;
 729    tmp[BCOMP] = blue   ? 0xff : 0x0;
 730    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 731
 732    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
 733       return;
 734
 735    FLUSH_VERTICES(ctx, _NEW_COLOR);
 736    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 737 }
 738
 739
 740 void GLAPIENTRY
 741 _mesa_ClampColor(GLenum target, GLenum clamp)
 742 {
 743    GET_CURRENT_CONTEXT(ctx);
 744
 745    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
 746       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
 747       return;
 748    }
 749
 750    switch (target) {
 751    case GL_CLAMP_VERTEX_COLOR_ARB:
 752       if (ctx->API == API_OPENGL_CORE &&
 753           !ctx->Extensions.ARB_color_buffer_float) {
 754          goto invalid_enum;
 755       }
 756       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 757       ctx->Light.ClampVertexColor = clamp;
 758       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
 759       break;
 760    case GL_CLAMP_FRAGMENT_COLOR_ARB:
 761       if (ctx->API == API_OPENGL_CORE &&
 762           !ctx->Extensions.ARB_color_buffer_float) {
 763          goto invalid_enum;
 764       }
 765       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
 766       ctx->Color.ClampFragmentColor = clamp;
 767       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
 768       break;
 769    case GL_CLAMP_READ_COLOR_ARB:
 770       ctx->Color.ClampReadColor = clamp;
 771       break;
 772    default:
 773       goto invalid_enum;
 774    }
 775    return;
 776
 777 invalid_enum:
 778    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
 779                _mesa_enum_to_string(target));
 780 }
 781
 782 static GLboolean
 783 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
 784 {
 785    if (clamp == GL_TRUE || clamp == GL_FALSE)
 786       return clamp;
 787
 788    assert(clamp == GL_FIXED_ONLY);
 789    if (!fb)
 790       return GL_TRUE;
 791
 792    return fb->_AllColorBuffersFixedPoint;
 793 }
 794
 795 GLboolean
 796 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
 797                                const struct gl_framebuffer *drawFb)
 798 {
 799    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
 800 }
 801
 802 GLboolean
 803 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
 804                              const struct gl_framebuffer *drawFb)
 805 {
 806    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
 807 }
 808
 809 GLboolean
 810 _mesa_get_clamp_read_color(const struct gl_context *ctx,
 811                            const struct gl_framebuffer *readFb)
 812 {
 813    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
 814 }
 815
 816 /**
 817  * Update the ctx->Color._ClampFragmentColor field
 818  */
 819 void
 820 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
 821                                   const struct gl_framebuffer *drawFb)
 822 {
 823    /* Don't clamp if:
 824     * - there is no colorbuffer
 825     * - all colorbuffers are unsigned normalized, so clamping has no effect
 826     * - there is an integer colorbuffer
 827     */
 828    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
 829        drawFb->_IntegerColor)
 830       ctx->Color._ClampFragmentColor = GL_FALSE;
 831    else
 832       ctx->Color._ClampFragmentColor =
 833          _mesa_get_clamp_fragment_color(ctx, drawFb);
 834 }
 835
 836 /**
 837  * Update the ctx->Color._ClampVertexColor field
 838  */
 839 void
 840 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
 841                                 const struct gl_framebuffer *drawFb)
 842 {
 843    ctx->Light._ClampVertexColor =
 844          _mesa_get_clamp_vertex_color(ctx, drawFb);
 845 }
 846
 847 /**
 848  * Returns an appropriate mesa_format for color rendering based on the
 849  * GL_FRAMEBUFFER_SRGB state.
 850  *
 851  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
 852  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
 853  * overriding the format of the surface.  This is a helper for doing the
 854  * surface format override variant.
 855  */
 856 mesa_format
 857 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
 858 {
 859    if (ctx->Color.sRGBEnabled)
 860       return format;
 861    else
 862       return _mesa_get_srgb_format_linear(format);
 863 }
 864
 865 /**********************************************************************/
 866 /** \name Initialization */
 867 /*@{*/
 868
 869 /**
 870  * Initialization of the context's Color attribute group.
 871  *
 872  * \param ctx GL context.
 873  *
 874  * Initializes the related fields in the context color attribute group,
 875  * __struct gl_contextRec::Color.
 876  */
 877 void _mesa_init_color( struct gl_context * ctx )
 878 {
 879    GLuint i;
 880
 881    /* Color buffer group */
 882    ctx->Color.IndexMask = ~0u;
 883    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
 884    ctx->Color.ClearIndex = 0;
 885    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
 886    ctx->Color.AlphaEnabled = GL_FALSE;
 887    ctx->Color.AlphaFunc = GL_ALWAYS;
 888    ctx->Color.AlphaRef = 0;
 889    ctx->Color.BlendEnabled = 0x0;
 890    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
 891       ctx->Color.Blend[i].SrcRGB = GL_ONE;
 892       ctx->Color.Blend[i].DstRGB = GL_ZERO;
 893       ctx->Color.Blend[i].SrcA = GL_ONE;
 894       ctx->Color.Blend[i].DstA = GL_ZERO;
 895       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
 896       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
 897    }
 898    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
 899    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
 900    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
 901    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
 902    ctx->Color.LogicOp = GL_COPY;
 903    ctx->Color.DitherFlag = GL_TRUE;
 904
 905    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
 906     * the front or the back buffer depending on the config */
 907    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
 908       ctx->Color.DrawBuffer[0] = GL_BACK;
 909    }
 910    else {
 911       ctx->Color.DrawBuffer[0] = GL_FRONT;
 912    }
 913
 914    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
 915                                    GL_FIXED_ONLY_ARB : GL_FALSE;
 916    ctx->Color._ClampFragmentColor = GL_FALSE;
 917    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
 918
 919    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
 920     * if EGL_KHR_gl_colorspace has been used to request sRGB.
 921     */
 922    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
 923 }
 924
 925 /*@}*/