src/mesa/main/stencil.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file stencil.c
  28  * Stencil operations.
  29  *
  30  * Note: There's an incompatibility 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  * So either we advertise the GL_EXT_stencil_two_side extension, or OpenGL
  40  * 2.0, but not both.
  41  */
  42
  43
  44 #include "glheader.h"
  45 #include "imports.h"
  46 #include "context.h"
  47 #include "macros.h"
  48 #include "stencil.h"
  49 #include "mtypes.h"
  50
  51
  52 /**
  53  * Set the clear value for the stencil buffer.
  54  *
  55  * \param s clear value.
  56  *
  57  * \sa glClearStencil().
  58  *
  59  * Updates gl_stencil_attrib::Clear. On change
  60  * flushes the vertices and notifies the driver via
  61  * the dd_function_table::ClearStencil callback.
  62  */
  63 void GLAPIENTRY
  64 _mesa_ClearStencil( GLint s )
  65 {
  66    GET_CURRENT_CONTEXT(ctx);
  67    ASSERT_OUTSIDE_BEGIN_END(ctx);
  68
  69    if (ctx->Stencil.Clear == (GLuint) s)
  70       return;
  71
  72    FLUSH_VERTICES(ctx, _NEW_STENCIL);
  73    ctx->Stencil.Clear = (GLuint) s;
  74
  75    if (ctx->Driver.ClearStencil) {
  76       ctx->Driver.ClearStencil( ctx, s );
  77    }
  78 }
  79
  80
  81 /**
  82  * Set the function and reference value for stencil testing.
  83  *
  84  * \param func test function.
  85  * \param ref reference value.
  86  * \param mask bitmask.
  87  *
  88  * \sa glStencilFunc().
  89  *
  90  * Verifies the parameters and updates the respective values in
  91  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
  92  * driver via the dd_function_table::StencilFunc callback.
  93  */
  94 void GLAPIENTRY
  95 _mesa_StencilFunc( GLenum func, GLint ref, GLuint mask )
  96 {
  97    GET_CURRENT_CONTEXT(ctx);
  98    GLint maxref;
  99    ASSERT_OUTSIDE_BEGIN_END(ctx);
 100
 101    switch (func) {
 102       case GL_NEVER:
 103       case GL_LESS:
 104       case GL_LEQUAL:
 105       case GL_GREATER:
 106       case GL_GEQUAL:
 107       case GL_EQUAL:
 108       case GL_NOTEQUAL:
 109       case GL_ALWAYS:
 110          break;
 111       default:
 112          _mesa_error( ctx, GL_INVALID_ENUM, "glStencilFunc" );
 113          return;
 114    }
 115
 116    maxref = (1 << STENCIL_BITS) - 1;
 117    ref = CLAMP( ref, 0, maxref );
 118
 119    if (ctx->Extensions.EXT_stencil_two_side) {
 120       /* only set active face state */
 121       const GLint face = ctx->Stencil.ActiveFace;
 122       if (ctx->Stencil.Function[face] == func &&
 123           ctx->Stencil.ValueMask[face] == mask &&
 124           ctx->Stencil.Ref[face] == ref)
 125          return;
 126       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 127       ctx->Stencil.Function[face] = func;
 128       ctx->Stencil.Ref[face] = ref;
 129       ctx->Stencil.ValueMask[face] = mask;
 130       if (ctx->Driver.StencilFuncSeparate) {
 131          ctx->Driver.StencilFuncSeparate(ctx, face ? GL_BACK : GL_FRONT,
 132                                          func, ref, mask);
 133       }
 134    }
 135    else {
 136       /* set both front and back state */
 137       if (ctx->Stencil.Function[0] == func &&
 138           ctx->Stencil.Function[1] == func &&
 139           ctx->Stencil.ValueMask[0] == mask &&
 140           ctx->Stencil.ValueMask[1] == mask &&
 141           ctx->Stencil.Ref[0] == ref &&
 142           ctx->Stencil.Ref[1] == ref)
 143          return;
 144       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 145       ctx->Stencil.Function[0]  = ctx->Stencil.Function[1]  = func;
 146       ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
 147       ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
 148       if (ctx->Driver.StencilFuncSeparate) {
 149          ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT_AND_BACK,
 150                                          func, ref, mask);
 151       }
 152    }
 153 }
 154
 155
 156 /**
 157  * Set the stencil writing mask.
 158  *
 159  * \param mask bit-mask to enable/disable writing of individual bits in the
 160  * stencil planes.
 161  *
 162  * \sa glStencilMask().
 163  *
 164  * Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
 165  * notifies the driver via the dd_function_table::StencilMask callback.
 166  */
 167 void GLAPIENTRY
 168 _mesa_StencilMask( GLuint mask )
 169 {
 170    GET_CURRENT_CONTEXT(ctx);
 171    ASSERT_OUTSIDE_BEGIN_END(ctx);
 172
 173    if (ctx->Extensions.EXT_stencil_two_side) {
 174       /* only set active face state */
 175       const GLint face = ctx->Stencil.ActiveFace;
 176       if (ctx->Stencil.WriteMask[face] == mask)
 177          return;
 178       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 179       ctx->Stencil.WriteMask[face] = mask;
 180       if (ctx->Driver.StencilMaskSeparate) {
 181          ctx->Driver.StencilMaskSeparate(ctx, face ? GL_BACK : GL_FRONT, mask);
 182       }
 183    }
 184    else {
 185       /* set both front and back state */
 186       if (ctx->Stencil.WriteMask[0] == mask &&
 187           ctx->Stencil.WriteMask[1] == mask)
 188          return;
 189       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 190       ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
 191       if (ctx->Driver.StencilMaskSeparate) {
 192          ctx->Driver.StencilMaskSeparate(ctx, GL_FRONT_AND_BACK, mask);
 193       }
 194    }
 195 }
 196
 197
 198 /**
 199  * Set the stencil test actions.
 200  *
 201  * \param fail action to take when stencil test fails.
 202  * \param zfail action to take when stencil test passes, but depth test fails.
 203  * \param zpass action to take when stencil test passes and the depth test
 204  * passes (or depth testing is not enabled).
 205  *
 206  * \sa glStencilOp().
 207  *
 208  * Verifies the parameters and updates the respective fields in
 209  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
 210  * driver via the dd_function_table::StencilOp callback.
 211  */
 212 void GLAPIENTRY
 213 _mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
 214 {
 215    GET_CURRENT_CONTEXT(ctx);
 216    ASSERT_OUTSIDE_BEGIN_END(ctx);
 217
 218    switch (fail) {
 219       case GL_KEEP:
 220       case GL_ZERO:
 221       case GL_REPLACE:
 222       case GL_INCR:
 223       case GL_DECR:
 224       case GL_INVERT:
 225          break;
 226       case GL_INCR_WRAP_EXT:
 227       case GL_DECR_WRAP_EXT:
 228          if (ctx->Extensions.EXT_stencil_wrap) {
 229             break;
 230          }
 231          /* FALL-THROUGH */
 232       default:
 233          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 234          return;
 235    }
 236    switch (zfail) {
 237       case GL_KEEP:
 238       case GL_ZERO:
 239       case GL_REPLACE:
 240       case GL_INCR:
 241       case GL_DECR:
 242       case GL_INVERT:
 243          break;
 244       case GL_INCR_WRAP_EXT:
 245       case GL_DECR_WRAP_EXT:
 246          if (ctx->Extensions.EXT_stencil_wrap) {
 247             break;
 248          }
 249          /* FALL-THROUGH */
 250       default:
 251          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 252          return;
 253    }
 254    switch (zpass) {
 255       case GL_KEEP:
 256       case GL_ZERO:
 257       case GL_REPLACE:
 258       case GL_INCR:
 259       case GL_DECR:
 260       case GL_INVERT:
 261          break;
 262       case GL_INCR_WRAP_EXT:
 263       case GL_DECR_WRAP_EXT:
 264          if (ctx->Extensions.EXT_stencil_wrap) {
 265             break;
 266          }
 267          /* FALL-THROUGH */
 268       default:
 269          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 270          return;
 271    }
 272
 273    if (ctx->Extensions.EXT_stencil_two_side) {
 274       /* only set active face state */
 275       const GLint face = ctx->Stencil.ActiveFace;
 276       if (ctx->Stencil.ZFailFunc[face] == zfail &&
 277           ctx->Stencil.ZPassFunc[face] == zpass &&
 278           ctx->Stencil.FailFunc[face] == fail)
 279          return;
 280       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 281       ctx->Stencil.ZFailFunc[face] = zfail;
 282       ctx->Stencil.ZPassFunc[face] = zpass;
 283       ctx->Stencil.FailFunc[face] = fail;
 284       if (ctx->Driver.StencilOpSeparate) {
 285          ctx->Driver.StencilOpSeparate(ctx, face ? GL_BACK : GL_FRONT,
 286                                        fail, zfail, zpass);
 287       }
 288    }
 289    else {
 290       /* set both front and back state */
 291       if (ctx->Stencil.ZFailFunc[0] == zfail &&
 292           ctx->Stencil.ZFailFunc[1] == zfail &&
 293           ctx->Stencil.ZPassFunc[0] == zpass &&
 294           ctx->Stencil.ZPassFunc[1] == zpass &&
 295           ctx->Stencil.FailFunc[0] == fail &&
 296           ctx->Stencil.FailFunc[1] == fail)
 297          return;
 298       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 299       ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
 300       ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
 301       ctx->Stencil.FailFunc[0]  = ctx->Stencil.FailFunc[1]  = fail;
 302       if (ctx->Driver.StencilOpSeparate) {
 303          ctx->Driver.StencilOpSeparate(ctx, GL_FRONT_AND_BACK,
 304                                        fail, zfail, zpass);
 305       }
 306    }
 307 }
 308
 309
 310
 311 #if _HAVE_FULL_GL
 312 /* GL_EXT_stencil_two_side */
 313 void GLAPIENTRY
 314 _mesa_ActiveStencilFaceEXT(GLenum face)
 315 {
 316    GET_CURRENT_CONTEXT(ctx);
 317    ASSERT_OUTSIDE_BEGIN_END(ctx);
 318
 319    if (!ctx->Extensions.EXT_stencil_two_side) {
 320       _mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
 321       return;
 322    }
 323
 324    if (face == GL_FRONT || face == GL_BACK) {
 325       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 326       ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 1;
 327    }
 328    else {
 329       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
 330    }
 331 }
 332 #endif
 333
 334
 335
 336 /**
 337  * OpenGL 2.0 function.
 338  * \todo Make StencilOp() call this function.  And eventually remove the
 339  * ctx->Driver.StencilOp function and use ctx->Driver.StencilOpSeparate
 340  * instead.
 341  */
 342 void GLAPIENTRY
 343 _mesa_StencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)
 344 {
 345    GET_CURRENT_CONTEXT(ctx);
 346    ASSERT_OUTSIDE_BEGIN_END(ctx);
 347
 348    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 349       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
 350       return;
 351    }
 352
 353    switch (fail) {
 354       case GL_KEEP:
 355       case GL_ZERO:
 356       case GL_REPLACE:
 357       case GL_INCR:
 358       case GL_DECR:
 359       case GL_INVERT:
 360          break;
 361       case GL_INCR_WRAP_EXT:
 362       case GL_DECR_WRAP_EXT:
 363          if (ctx->Extensions.EXT_stencil_wrap) {
 364             break;
 365          }
 366          /* FALL-THROUGH */
 367       default:
 368          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(fail)");
 369          return;
 370    }
 371    switch (zfail) {
 372       case GL_KEEP:
 373       case GL_ZERO:
 374       case GL_REPLACE:
 375       case GL_INCR:
 376       case GL_DECR:
 377       case GL_INVERT:
 378          break;
 379       case GL_INCR_WRAP_EXT:
 380       case GL_DECR_WRAP_EXT:
 381          if (ctx->Extensions.EXT_stencil_wrap) {
 382             break;
 383          }
 384          /* FALL-THROUGH */
 385       default:
 386          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
 387          return;
 388    }
 389    switch (zpass) {
 390       case GL_KEEP:
 391       case GL_ZERO:
 392       case GL_REPLACE:
 393       case GL_INCR:
 394       case GL_DECR:
 395       case GL_INVERT:
 396          break;
 397       case GL_INCR_WRAP_EXT:
 398       case GL_DECR_WRAP_EXT:
 399          if (ctx->Extensions.EXT_stencil_wrap) {
 400             break;
 401          }
 402          /* FALL-THROUGH */
 403       default:
 404          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
 405          return;
 406    }
 407
 408    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 409
 410    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 411       ctx->Stencil.FailFunc[0] = fail;
 412       ctx->Stencil.ZFailFunc[0] = zfail;
 413       ctx->Stencil.ZPassFunc[0] = zpass;
 414    }
 415    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 416       ctx->Stencil.FailFunc[1] = fail;
 417       ctx->Stencil.ZFailFunc[1] = zfail;
 418       ctx->Stencil.ZPassFunc[1] = zpass;
 419    }
 420
 421    if (ctx->Driver.StencilOpSeparate) {
 422       ctx->Driver.StencilOpSeparate(ctx, face, fail, zfail, zpass);
 423    }
 424 }
 425
 426
 427 /* OpenGL 2.0 */
 428 void GLAPIENTRY
 429 _mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
 430 {
 431    GET_CURRENT_CONTEXT(ctx);
 432    GLint maxref;
 433    ASSERT_OUTSIDE_BEGIN_END(ctx);
 434
 435    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 436       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
 437       return;
 438    }
 439
 440    switch (func) {
 441       case GL_NEVER:
 442       case GL_LESS:
 443       case GL_LEQUAL:
 444       case GL_GREATER:
 445       case GL_GEQUAL:
 446       case GL_EQUAL:
 447       case GL_NOTEQUAL:
 448       case GL_ALWAYS:
 449          break;
 450       default:
 451          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
 452          return;
 453    }
 454
 455    maxref = (1 << STENCIL_BITS) - 1;
 456    ref = CLAMP(ref, 0, maxref);
 457
 458    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 459
 460    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 461       ctx->Stencil.Function[0] = func;
 462       ctx->Stencil.Ref[0] = ref;
 463       ctx->Stencil.ValueMask[0] = mask;
 464    }
 465    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 466       ctx->Stencil.Function[1] = func;
 467       ctx->Stencil.Ref[1] = ref;
 468       ctx->Stencil.ValueMask[1] = mask;
 469    }
 470
 471    if (ctx->Driver.StencilFuncSeparate) {
 472       ctx->Driver.StencilFuncSeparate(ctx, face, func, ref, mask);
 473    }
 474 }
 475
 476
 477 /* OpenGL 2.0 */
 478 void GLAPIENTRY
 479 _mesa_StencilMaskSeparate(GLenum face, GLuint mask)
 480 {
 481    GET_CURRENT_CONTEXT(ctx);
 482    ASSERT_OUTSIDE_BEGIN_END(ctx);
 483
 484    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 485       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilaMaskSeparate(face)");
 486       return;
 487    }
 488
 489    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 490
 491    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 492       ctx->Stencil.WriteMask[0] = mask;
 493    }
 494    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 495       ctx->Stencil.WriteMask[1] = mask;
 496    }
 497
 498    if (ctx->Driver.StencilMaskSeparate) {
 499       ctx->Driver.StencilMaskSeparate(ctx, face, mask);
 500    }
 501 }
 502
 503
 504 /**
 505  * Update derived stencil state.
 506  */
 507 void
 508 _mesa_update_stencil(GLcontext *ctx)
 509 {
 510    if (ctx->Extensions.EXT_stencil_two_side) {
 511       ctx->Stencil._TestTwoSide = ctx->Stencil.TestTwoSide;
 512    }
 513    else {
 514       ctx->Stencil._TestTwoSide =
 515          (ctx->Stencil.Function[0] != ctx->Stencil.Function[1] ||
 516           ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[1] ||
 517           ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[1] ||
 518           ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[1] ||
 519           ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1] ||
 520           ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[1] ||
 521           ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[1]);
 522    }
 523 }
 524
 525
 526 /**
 527  * Initialize the context stipple state.
 528  *
 529  * \param ctx GL context.
 530  *
 531  * Initializes __GLcontextRec::Stencil attribute group.
 532  */
 533 void
 534 _mesa_init_stencil(GLcontext *ctx)
 535 {
 536    ctx->Stencil.Enabled = GL_FALSE;
 537    ctx->Stencil.TestTwoSide = GL_FALSE;
 538    ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 1 = GL_BACK */
 539    ctx->Stencil.Function[0] = GL_ALWAYS;
 540    ctx->Stencil.Function[1] = GL_ALWAYS;
 541    ctx->Stencil.FailFunc[0] = GL_KEEP;
 542    ctx->Stencil.FailFunc[1] = GL_KEEP;
 543    ctx->Stencil.ZPassFunc[0] = GL_KEEP;
 544    ctx->Stencil.ZPassFunc[1] = GL_KEEP;
 545    ctx->Stencil.ZFailFunc[0] = GL_KEEP;
 546    ctx->Stencil.ZFailFunc[1] = GL_KEEP;
 547    ctx->Stencil.Ref[0] = 0;
 548    ctx->Stencil.Ref[1] = 0;
 549    ctx->Stencil.ValueMask[0] = ~0U;
 550    ctx->Stencil.ValueMask[1] = ~0U;
 551    ctx->Stencil.WriteMask[0] = ~0U;
 552    ctx->Stencil.WriteMask[1] = ~0U;
 553    ctx->Stencil.Clear = 0;
 554 }