src/mesa/main/stencil.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file stencil.c
  28  * Stencil operations.
  29  *
  30  * Note: There's some conflict between GL_EXT_stencil_two_side and
  31  * OpenGL 2.0's two-sided stencil feature.
  32  *
  33  * With GL_EXT_stencil_two_side, calling glStencilOp/Func/Mask() only the
  34  * front OR back face state (as set by glActiveStencilFaceEXT) is set.
  35  *
  36  * But with OpenGL 2.0, calling glStencilOp/Func/Mask() sets BOTH the
  37  * front AND back state.
  38  *
  39  * Also, note that GL_ATI_separate_stencil is different as well:
  40  * glStencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, ...)  vs.
  41  * glStencilFuncSeparate(GLenum face, GLenum func, ...).
  42  *
  43  * This problem is solved by keeping three sets of stencil state:
  44  *  state[0] = GL_FRONT state.
  45  *  state[1] = OpenGL 2.0 / GL_ATI_separate_stencil GL_BACK state.
  46  *  state[2] = GL_EXT_stencil_two_side GL_BACK state.
  47  */
  48
  49
  50 #include "glheader.h"
  51 #include "util/imports.h"
  52 #include "context.h"
  53 #include "macros.h"
  54 #include "stencil.h"
  55 #include "mtypes.h"
  56
  57
  58 static GLboolean
  59 validate_stencil_op(struct gl_context *ctx, GLenum op)
  60 {
  61    switch (op) {
  62    case GL_KEEP:
  63    case GL_ZERO:
  64    case GL_REPLACE:
  65    case GL_INCR:
  66    case GL_DECR:
  67    case GL_INVERT:
  68    case GL_INCR_WRAP:
  69    case GL_DECR_WRAP:
  70       return GL_TRUE;
  71    default:
  72       return GL_FALSE;
  73    }
  74 }
  75
  76
  77 static GLboolean
  78 validate_stencil_func(struct gl_context *ctx, GLenum func)
  79 {
  80    switch (func) {
  81    case GL_NEVER:
  82    case GL_LESS:
  83    case GL_LEQUAL:
  84    case GL_GREATER:
  85    case GL_GEQUAL:
  86    case GL_EQUAL:
  87    case GL_NOTEQUAL:
  88    case GL_ALWAYS:
  89       return GL_TRUE;
  90    default:
  91       return GL_FALSE;
  92    }
  93 }
  94
  95
  96 /**
  97  * Set the clear value for the stencil buffer.
  98  *
  99  * \param s clear value.
 100  *
 101  * \sa glClearStencil().
 102  *
 103  * Updates gl_stencil_attrib::Clear. On change
 104  * flushes the vertices and notifies the driver via
 105  * the dd_function_table::ClearStencil callback.
 106  */
 107 void GLAPIENTRY
 108 _mesa_ClearStencil( GLint s )
 109 {
 110    GET_CURRENT_CONTEXT(ctx);
 111
 112    if (MESA_VERBOSE & VERBOSE_API)
 113       _mesa_debug(ctx, "glClearStencil(%d)\n", s);
 114
 115    ctx->Stencil.Clear = (GLuint) s;
 116 }
 117
 118
 119 /**
 120  * Set the function and reference value for stencil testing.
 121  *
 122  * \param frontfunc front test function.
 123  * \param backfunc back test function.
 124  * \param ref front and back reference value.
 125  * \param mask front and back bitmask.
 126  *
 127  * \sa glStencilFunc().
 128  *
 129  * Verifies the parameters and updates the respective values in
 130  * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies
 131  * the driver via the dd_function_table::StencilFunc callback.
 132  */
 133 void GLAPIENTRY
 134 _mesa_StencilFuncSeparateATI( GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask )
 135 {
 136    GET_CURRENT_CONTEXT(ctx);
 137
 138    if (MESA_VERBOSE & VERBOSE_API)
 139       _mesa_debug(ctx, "glStencilFuncSeparateATI()\n");
 140
 141    if (!validate_stencil_func(ctx, frontfunc)) {
 142       _mesa_error(ctx, GL_INVALID_ENUM,
 143                   "glStencilFuncSeparateATI(frontfunc)");
 144       return;
 145    }
 146    if (!validate_stencil_func(ctx, backfunc)) {
 147       _mesa_error(ctx, GL_INVALID_ENUM,
 148                   "glStencilFuncSeparateATI(backfunc)");
 149       return;
 150    }
 151
 152    /* set both front and back state */
 153    if (ctx->Stencil.Function[0] == frontfunc &&
 154        ctx->Stencil.Function[1] == backfunc &&
 155        ctx->Stencil.ValueMask[0] == mask &&
 156        ctx->Stencil.ValueMask[1] == mask &&
 157        ctx->Stencil.Ref[0] == ref &&
 158        ctx->Stencil.Ref[1] == ref)
 159       return;
 160    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 161    ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 162    ctx->Stencil.Function[0]  = frontfunc;
 163    ctx->Stencil.Function[1]  = backfunc;
 164    ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
 165    ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
 166    if (ctx->Driver.StencilFuncSeparate) {
 167       ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT,
 168                                       frontfunc, ref, mask);
 169       ctx->Driver.StencilFuncSeparate(ctx, GL_BACK,
 170                                       backfunc, ref, mask);
 171    }
 172 }
 173
 174
 175 /**
 176  * Set the function and reference value for stencil testing.
 177  *
 178  * \param func test function.
 179  * \param ref reference value.
 180  * \param mask bitmask.
 181  *
 182  * \sa glStencilFunc().
 183  *
 184  * Verifies the parameters and updates the respective values in
 185  * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies
 186  * the driver via the dd_function_table::StencilFunc callback.
 187  */
 188 static void
 189 stencil_func(struct gl_context *ctx, GLenum func, GLint ref, GLuint mask)
 190 {
 191    const GLint face = ctx->Stencil.ActiveFace;
 192
 193    if (face != 0) {
 194       if (ctx->Stencil.Function[face] == func &&
 195           ctx->Stencil.ValueMask[face] == mask &&
 196           ctx->Stencil.Ref[face] == ref)
 197          return;
 198       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 199       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 200       ctx->Stencil.Function[face] = func;
 201       ctx->Stencil.Ref[face] = ref;
 202       ctx->Stencil.ValueMask[face] = mask;
 203
 204       /* Only propagate the change to the driver if EXT_stencil_two_side
 205        * is enabled.
 206        */
 207       if (ctx->Driver.StencilFuncSeparate && ctx->Stencil.TestTwoSide) {
 208          ctx->Driver.StencilFuncSeparate(ctx, GL_BACK, func, ref, mask);
 209       }
 210    }
 211    else {
 212       /* set both front and back state */
 213       if (ctx->Stencil.Function[0] == func &&
 214           ctx->Stencil.Function[1] == func &&
 215           ctx->Stencil.ValueMask[0] == mask &&
 216           ctx->Stencil.ValueMask[1] == mask &&
 217           ctx->Stencil.Ref[0] == ref &&
 218           ctx->Stencil.Ref[1] == ref)
 219          return;
 220       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 221       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 222       ctx->Stencil.Function[0]  = ctx->Stencil.Function[1]  = func;
 223       ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
 224       ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
 225       if (ctx->Driver.StencilFuncSeparate) {
 226          ctx->Driver.StencilFuncSeparate(ctx,
 227                                          ((ctx->Stencil.TestTwoSide)
 228                                           ? GL_FRONT : GL_FRONT_AND_BACK),
 229                                          func, ref, mask);
 230       }
 231    }
 232 }
 233
 234
 235 void GLAPIENTRY
 236 _mesa_StencilFunc_no_error(GLenum func, GLint ref, GLuint mask)
 237 {
 238    GET_CURRENT_CONTEXT(ctx);
 239    stencil_func(ctx, func, ref, mask);
 240 }
 241
 242
 243 void GLAPIENTRY
 244 _mesa_StencilFunc(GLenum func, GLint ref, GLuint mask)
 245 {
 246    GET_CURRENT_CONTEXT(ctx);
 247
 248    if (MESA_VERBOSE & VERBOSE_API)
 249       _mesa_debug(ctx, "glStencilFunc()\n");
 250
 251    if (!validate_stencil_func(ctx, func)) {
 252       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFunc(func)");
 253       return;
 254    }
 255
 256    stencil_func(ctx, func, ref, mask);
 257 }
 258
 259
 260 /**
 261  * Set the stencil writing mask.
 262  *
 263  * \param mask bit-mask to enable/disable writing of individual bits in the
 264  * stencil planes.
 265  *
 266  * \sa glStencilMask().
 267  *
 268  * Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
 269  * notifies the driver via the dd_function_table::StencilMask callback.
 270  */
 271 void GLAPIENTRY
 272 _mesa_StencilMask( GLuint mask )
 273 {
 274    GET_CURRENT_CONTEXT(ctx);
 275    const GLint face = ctx->Stencil.ActiveFace;
 276
 277    if (MESA_VERBOSE & VERBOSE_API)
 278       _mesa_debug(ctx, "glStencilMask()\n");
 279
 280    if (face != 0) {
 281       /* Only modify the EXT_stencil_two_side back-face state.
 282        */
 283       if (ctx->Stencil.WriteMask[face] == mask)
 284          return;
 285       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 286       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 287       ctx->Stencil.WriteMask[face] = mask;
 288
 289       /* Only propagate the change to the driver if EXT_stencil_two_side
 290        * is enabled.
 291        */
 292       if (ctx->Driver.StencilMaskSeparate && ctx->Stencil.TestTwoSide) {
 293          ctx->Driver.StencilMaskSeparate(ctx, GL_BACK, mask);
 294       }
 295    }
 296    else {
 297       /* set both front and back state */
 298       if (ctx->Stencil.WriteMask[0] == mask &&
 299           ctx->Stencil.WriteMask[1] == mask)
 300          return;
 301       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 302       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 303       ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
 304       if (ctx->Driver.StencilMaskSeparate) {
 305          ctx->Driver.StencilMaskSeparate(ctx,
 306                                          ((ctx->Stencil.TestTwoSide)
 307                                           ? GL_FRONT : GL_FRONT_AND_BACK),
 308                                           mask);
 309       }
 310    }
 311 }
 312
 313
 314 /**
 315  * Set the stencil test actions.
 316  *
 317  * \param fail action to take when stencil test fails.
 318  * \param zfail action to take when stencil test passes, but depth test fails.
 319  * \param zpass action to take when stencil test passes and the depth test
 320  * passes (or depth testing is not enabled).
 321  *
 322  * \sa glStencilOp().
 323  *
 324  * Verifies the parameters and updates the respective fields in
 325  * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies
 326  * the driver via the dd_function_table::StencilOp callback.
 327  */
 328 static void
 329 stencil_op(struct gl_context *ctx, GLenum fail, GLenum zfail, GLenum zpass)
 330 {
 331    const GLint face = ctx->Stencil.ActiveFace;
 332
 333    if (face != 0) {
 334       /* only set active face state */
 335       if (ctx->Stencil.ZFailFunc[face] == zfail &&
 336           ctx->Stencil.ZPassFunc[face] == zpass &&
 337           ctx->Stencil.FailFunc[face] == fail)
 338          return;
 339       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 340       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 341       ctx->Stencil.ZFailFunc[face] = zfail;
 342       ctx->Stencil.ZPassFunc[face] = zpass;
 343       ctx->Stencil.FailFunc[face] = fail;
 344
 345       /* Only propagate the change to the driver if EXT_stencil_two_side
 346        * is enabled.
 347        */
 348       if (ctx->Driver.StencilOpSeparate && ctx->Stencil.TestTwoSide) {
 349          ctx->Driver.StencilOpSeparate(ctx, GL_BACK, fail, zfail, zpass);
 350       }
 351    }
 352    else {
 353       /* set both front and back state */
 354       if (ctx->Stencil.ZFailFunc[0] == zfail &&
 355           ctx->Stencil.ZFailFunc[1] == zfail &&
 356           ctx->Stencil.ZPassFunc[0] == zpass &&
 357           ctx->Stencil.ZPassFunc[1] == zpass &&
 358           ctx->Stencil.FailFunc[0] == fail &&
 359           ctx->Stencil.FailFunc[1] == fail)
 360          return;
 361       FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 362       ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 363       ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
 364       ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
 365       ctx->Stencil.FailFunc[0]  = ctx->Stencil.FailFunc[1]  = fail;
 366       if (ctx->Driver.StencilOpSeparate) {
 367          ctx->Driver.StencilOpSeparate(ctx,
 368                                        ((ctx->Stencil.TestTwoSide)
 369                                         ? GL_FRONT : GL_FRONT_AND_BACK),
 370                                        fail, zfail, zpass);
 371       }
 372    }
 373 }
 374
 375
 376 void GLAPIENTRY
 377 _mesa_StencilOp_no_error(GLenum fail, GLenum zfail, GLenum zpass)
 378 {
 379    GET_CURRENT_CONTEXT(ctx);
 380    stencil_op(ctx, fail, zfail, zpass);
 381 }
 382
 383
 384 void GLAPIENTRY
 385 _mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
 386 {
 387    GET_CURRENT_CONTEXT(ctx);
 388
 389    if (MESA_VERBOSE & VERBOSE_API)
 390       _mesa_debug(ctx, "glStencilOp()\n");
 391
 392    if (!validate_stencil_op(ctx, fail)) {
 393       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(sfail)");
 394       return;
 395    }
 396
 397    if (!validate_stencil_op(ctx, zfail)) {
 398       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zfail)");
 399       return;
 400    }
 401
 402    if (!validate_stencil_op(ctx, zpass)) {
 403       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zpass)");
 404       return;
 405    }
 406
 407    stencil_op(ctx, fail, zfail, zpass);
 408 }
 409
 410
 411 /* GL_EXT_stencil_two_side */
 412 void GLAPIENTRY
 413 _mesa_ActiveStencilFaceEXT(GLenum face)
 414 {
 415    GET_CURRENT_CONTEXT(ctx);
 416
 417    if (MESA_VERBOSE & VERBOSE_API)
 418       _mesa_debug(ctx, "glActiveStencilFaceEXT()\n");
 419
 420    if (!ctx->Extensions.EXT_stencil_two_side) {
 421       _mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
 422       return;
 423    }
 424
 425    if (face == GL_FRONT || face == GL_BACK) {
 426       ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 2;
 427    }
 428    else {
 429       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
 430    }
 431 }
 432
 433
 434 static void
 435 stencil_op_separate(struct gl_context *ctx, GLenum face, GLenum sfail,
 436                     GLenum zfail, GLenum zpass)
 437 {
 438    GLboolean set = GL_FALSE;
 439
 440    if (face != GL_BACK) {
 441       /* set front */
 442       if (ctx->Stencil.ZFailFunc[0] != zfail ||
 443           ctx->Stencil.ZPassFunc[0] != zpass ||
 444           ctx->Stencil.FailFunc[0] != sfail){
 445          FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 446          ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 447          ctx->Stencil.ZFailFunc[0] = zfail;
 448          ctx->Stencil.ZPassFunc[0] = zpass;
 449          ctx->Stencil.FailFunc[0] = sfail;
 450          set = GL_TRUE;
 451       }
 452    }
 453
 454    if (face != GL_FRONT) {
 455       /* set back */
 456       if (ctx->Stencil.ZFailFunc[1] != zfail ||
 457           ctx->Stencil.ZPassFunc[1] != zpass ||
 458           ctx->Stencil.FailFunc[1] != sfail) {
 459          FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 460          ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 461          ctx->Stencil.ZFailFunc[1] = zfail;
 462          ctx->Stencil.ZPassFunc[1] = zpass;
 463          ctx->Stencil.FailFunc[1] = sfail;
 464          set = GL_TRUE;
 465       }
 466    }
 467
 468    if (set && ctx->Driver.StencilOpSeparate) {
 469       ctx->Driver.StencilOpSeparate(ctx, face, sfail, zfail, zpass);
 470    }
 471 }
 472
 473
 474 void GLAPIENTRY
 475 _mesa_StencilOpSeparate_no_error(GLenum face, GLenum sfail, GLenum zfail,
 476                                  GLenum zpass)
 477 {
 478    GET_CURRENT_CONTEXT(ctx);
 479    stencil_op_separate(ctx, face, sfail, zfail, zpass);
 480 }
 481
 482
 483 void GLAPIENTRY
 484 _mesa_StencilOpSeparate(GLenum face, GLenum sfail, GLenum zfail, GLenum zpass)
 485 {
 486    GET_CURRENT_CONTEXT(ctx);
 487
 488    if (MESA_VERBOSE & VERBOSE_API)
 489       _mesa_debug(ctx, "glStencilOpSeparate()\n");
 490
 491    if (!validate_stencil_op(ctx, sfail)) {
 492       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(sfail)");
 493       return;
 494    }
 495
 496    if (!validate_stencil_op(ctx, zfail)) {
 497       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
 498       return;
 499    }
 500
 501    if (!validate_stencil_op(ctx, zpass)) {
 502       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
 503       return;
 504    }
 505
 506    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 507       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
 508       return;
 509    }
 510
 511    stencil_op_separate(ctx, face, sfail, zfail, zpass);
 512 }
 513
 514
 515 static void
 516 stencil_func_separate(struct gl_context *ctx, GLenum face, GLenum func,
 517                       GLint ref, GLuint mask)
 518 {
 519    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 520    ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 521
 522    if (face != GL_BACK) {
 523       /* set front */
 524       ctx->Stencil.Function[0] = func;
 525       ctx->Stencil.Ref[0] = ref;
 526       ctx->Stencil.ValueMask[0] = mask;
 527    }
 528
 529    if (face != GL_FRONT) {
 530       /* set back */
 531       ctx->Stencil.Function[1] = func;
 532       ctx->Stencil.Ref[1] = ref;
 533       ctx->Stencil.ValueMask[1] = mask;
 534    }
 535
 536    if (ctx->Driver.StencilFuncSeparate) {
 537       ctx->Driver.StencilFuncSeparate(ctx, face, func, ref, mask);
 538    }
 539 }
 540
 541
 542 /* OpenGL 2.0 */
 543 void GLAPIENTRY
 544 _mesa_StencilFuncSeparate_no_error(GLenum face, GLenum func, GLint ref,
 545                                    GLuint mask)
 546 {
 547    GET_CURRENT_CONTEXT(ctx);
 548    stencil_func_separate(ctx, face, func, ref, mask);
 549 }
 550
 551
 552 void GLAPIENTRY
 553 _mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
 554 {
 555    GET_CURRENT_CONTEXT(ctx);
 556
 557    if (MESA_VERBOSE & VERBOSE_API)
 558       _mesa_debug(ctx, "glStencilFuncSeparate()\n");
 559
 560    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 561       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
 562       return;
 563    }
 564
 565    if (!validate_stencil_func(ctx, func)) {
 566       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
 567       return;
 568    }
 569
 570    stencil_func_separate(ctx, face, func, ref, mask);
 571 }
 572
 573
 574 static void
 575 stencil_mask_separate(struct gl_context *ctx, GLenum face, GLuint mask)
 576 {
 577    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewStencil ? 0 : _NEW_STENCIL);
 578    ctx->NewDriverState |= ctx->DriverFlags.NewStencil;
 579
 580    if (face != GL_BACK) {
 581       ctx->Stencil.WriteMask[0] = mask;
 582    }
 583
 584    if (face != GL_FRONT) {
 585       ctx->Stencil.WriteMask[1] = mask;
 586    }
 587
 588    if (ctx->Driver.StencilMaskSeparate) {
 589       ctx->Driver.StencilMaskSeparate(ctx, face, mask);
 590    }
 591 }
 592
 593
 594 /* OpenGL 2.0 */
 595 void GLAPIENTRY
 596 _mesa_StencilMaskSeparate_no_error(GLenum face, GLuint mask)
 597 {
 598    GET_CURRENT_CONTEXT(ctx);
 599    stencil_mask_separate(ctx, face, mask);
 600 }
 601
 602
 603 void GLAPIENTRY
 604 _mesa_StencilMaskSeparate(GLenum face, GLuint mask)
 605 {
 606    GET_CURRENT_CONTEXT(ctx);
 607
 608    if (MESA_VERBOSE & VERBOSE_API)
 609       _mesa_debug(ctx, "glStencilMaskSeparate()\n");
 610
 611    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 612       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilaMaskSeparate(face)");
 613       return;
 614    }
 615
 616    stencil_mask_separate(ctx, face, mask);
 617 }
 618
 619
 620 /**
 621  * Initialize the context stipple state.
 622  *
 623  * \param ctx GL context.
 624  *
 625  * Initializes __struct gl_contextRec::Stencil attribute group.
 626  */
 627 void
 628 _mesa_init_stencil(struct gl_context *ctx)
 629 {
 630    ctx->Stencil.Enabled = GL_FALSE;
 631    ctx->Stencil.TestTwoSide = GL_FALSE;
 632    ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 2 = GL_BACK */
 633    ctx->Stencil.Function[0] = GL_ALWAYS;
 634    ctx->Stencil.Function[1] = GL_ALWAYS;
 635    ctx->Stencil.Function[2] = GL_ALWAYS;
 636    ctx->Stencil.FailFunc[0] = GL_KEEP;
 637    ctx->Stencil.FailFunc[1] = GL_KEEP;
 638    ctx->Stencil.FailFunc[2] = GL_KEEP;
 639    ctx->Stencil.ZPassFunc[0] = GL_KEEP;
 640    ctx->Stencil.ZPassFunc[1] = GL_KEEP;
 641    ctx->Stencil.ZPassFunc[2] = GL_KEEP;
 642    ctx->Stencil.ZFailFunc[0] = GL_KEEP;
 643    ctx->Stencil.ZFailFunc[1] = GL_KEEP;
 644    ctx->Stencil.ZFailFunc[2] = GL_KEEP;
 645    ctx->Stencil.Ref[0] = 0;
 646    ctx->Stencil.Ref[1] = 0;
 647    ctx->Stencil.Ref[2] = 0;
 648
 649    /* 4.1.4 Stencil Test section of the GL-ES 3.0 specification says:
 650     *
 651     *     "In the initial state, [...] the front and back stencil mask are both
 652     *     set to the value 2^s − 1, where s is greater than or equal to the
 653     *     number of bits in the deepest stencil buffer* supported by the GL
 654     *     implementation."
 655     *
 656     * Since the maximum supported precision for stencil buffers is 8 bits,
 657     * mask values should be initialized to 2^8 - 1 = 0xFF.
 658     */
 659    ctx->Stencil.ValueMask[0] = 0xFF;
 660    ctx->Stencil.ValueMask[1] = 0xFF;
 661    ctx->Stencil.ValueMask[2] = 0xFF;
 662    ctx->Stencil.WriteMask[0] = 0xFF;
 663    ctx->Stencil.WriteMask[1] = 0xFF;
 664    ctx->Stencil.WriteMask[2] = 0xFF;
 665
 666    ctx->Stencil.Clear = 0;
 667    ctx->Stencil._BackFace = 1;
 668 }