src/mesa/main/stencil.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  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  * Also, note that GL_ATI_separate_stencil is different as well:
  43  * glStencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, ...)  vs.
  44  * glStencilFuncSeparate(GLenum face, GLenum func, ...).
  45  */
  46
  47
  48 #include "glheader.h"
  49 #include "imports.h"
  50 #include "context.h"
  51 #include "macros.h"
  52 #include "stencil.h"
  53 #include "mtypes.h"
  54
  55
  56 /**
  57  * Set the clear value for the stencil buffer.
  58  *
  59  * \param s clear value.
  60  *
  61  * \sa glClearStencil().
  62  *
  63  * Updates gl_stencil_attrib::Clear. On change
  64  * flushes the vertices and notifies the driver via
  65  * the dd_function_table::ClearStencil callback.
  66  */
  67 void GLAPIENTRY
  68 _mesa_ClearStencil( GLint s )
  69 {
  70    GET_CURRENT_CONTEXT(ctx);
  71    ASSERT_OUTSIDE_BEGIN_END(ctx);
  72
  73    if (ctx->Stencil.Clear == (GLuint) s)
  74       return;
  75
  76    FLUSH_VERTICES(ctx, _NEW_STENCIL);
  77    ctx->Stencil.Clear = (GLuint) s;
  78
  79    if (ctx->Driver.ClearStencil) {
  80       ctx->Driver.ClearStencil( ctx, s );
  81    }
  82 }
  83
  84
  85 /**
  86  * Set the function and reference value for stencil testing.
  87  *
  88  * \param func test function.
  89  * \param ref reference value.
  90  * \param mask bitmask.
  91  *
  92  * \sa glStencilFunc().
  93  *
  94  * Verifies the parameters and updates the respective values in
  95  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
  96  * driver via the dd_function_table::StencilFunc callback.
  97  */
  98 void GLAPIENTRY
  99 _mesa_StencilFunc( GLenum func, GLint ref, GLuint mask )
 100 {
 101    GET_CURRENT_CONTEXT(ctx);
 102    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
 103    ASSERT_OUTSIDE_BEGIN_END(ctx);
 104
 105    switch (func) {
 106       case GL_NEVER:
 107       case GL_LESS:
 108       case GL_LEQUAL:
 109       case GL_GREATER:
 110       case GL_GEQUAL:
 111       case GL_EQUAL:
 112       case GL_NOTEQUAL:
 113       case GL_ALWAYS:
 114          break;
 115       default:
 116          _mesa_error( ctx, GL_INVALID_ENUM, "glStencilFunc (0x%04x)", func );
 117          return;
 118    }
 119
 120    ref = CLAMP( ref, 0, stencilMax );
 121
 122    if (ctx->Extensions.ATI_separate_stencil) {
 123       /* set both front and back state */
 124       if (ctx->Stencil.Function[0] == func &&
 125           ctx->Stencil.Function[1] == func &&
 126           ctx->Stencil.ValueMask[0] == mask &&
 127           ctx->Stencil.ValueMask[1] == mask &&
 128           ctx->Stencil.Ref[0] == ref &&
 129           ctx->Stencil.Ref[1] == ref)
 130          return;
 131       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 132       ctx->Stencil.Function[0]  = ctx->Stencil.Function[1]  = func;
 133       ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
 134       ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
 135       if (ctx->Driver.StencilFuncSeparate) {
 136          ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT_AND_BACK,
 137                                          func, ref, mask);
 138       }
 139    }
 140    else {
 141       /* only set active face state */
 142       const GLint face = ctx->Stencil.ActiveFace;
 143       if (ctx->Stencil.Function[face] == func &&
 144           ctx->Stencil.ValueMask[face] == mask &&
 145           ctx->Stencil.Ref[face] == ref)
 146          return;
 147       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 148       ctx->Stencil.Function[face] = func;
 149       ctx->Stencil.Ref[face] = ref;
 150       ctx->Stencil.ValueMask[face] = mask;
 151       if (ctx->Driver.StencilFuncSeparate) {
 152          ctx->Driver.StencilFuncSeparate(ctx, face ? GL_BACK : GL_FRONT,
 153                                          func, ref, mask);
 154       }
 155    }
 156 }
 157
 158
 159 /**
 160  * Set the stencil writing mask.
 161  *
 162  * \param mask bit-mask to enable/disable writing of individual bits in the
 163  * stencil planes.
 164  *
 165  * \sa glStencilMask().
 166  *
 167  * Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
 168  * notifies the driver via the dd_function_table::StencilMask callback.
 169  */
 170 void GLAPIENTRY
 171 _mesa_StencilMask( GLuint mask )
 172 {
 173    GET_CURRENT_CONTEXT(ctx);
 174    ASSERT_OUTSIDE_BEGIN_END(ctx);
 175
 176    if (ctx->Extensions.ATI_separate_stencil) {
 177       /* set both front and back state */
 178       if (ctx->Stencil.WriteMask[0] == mask &&
 179           ctx->Stencil.WriteMask[1] == mask)
 180          return;
 181       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 182       ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
 183       if (ctx->Driver.StencilMaskSeparate) {
 184          ctx->Driver.StencilMaskSeparate(ctx, GL_FRONT_AND_BACK, mask);
 185       }
 186    }
 187    else {
 188       /* only set active face state */
 189       const GLint face = ctx->Stencil.ActiveFace;
 190       if (ctx->Stencil.WriteMask[face] == mask)
 191          return;
 192       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 193       ctx->Stencil.WriteMask[face] = mask;
 194       if (ctx->Driver.StencilMaskSeparate) {
 195          ctx->Driver.StencilMaskSeparate(ctx, face ? GL_BACK : GL_FRONT, mask);
 196       }
 197    }
 198 }
 199
 200
 201 /**
 202  * Set the stencil test actions.
 203  *
 204  * \param fail action to take when stencil test fails.
 205  * \param zfail action to take when stencil test passes, but depth test fails.
 206  * \param zpass action to take when stencil test passes and the depth test
 207  * passes (or depth testing is not enabled).
 208  *
 209  * \sa glStencilOp().
 210  *
 211  * Verifies the parameters and updates the respective fields in
 212  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
 213  * driver via the dd_function_table::StencilOp callback.
 214  */
 215 void GLAPIENTRY
 216 _mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
 217 {
 218    GET_CURRENT_CONTEXT(ctx);
 219    ASSERT_OUTSIDE_BEGIN_END(ctx);
 220
 221    switch (fail) {
 222       case GL_KEEP:
 223       case GL_ZERO:
 224       case GL_REPLACE:
 225       case GL_INCR:
 226       case GL_DECR:
 227       case GL_INVERT:
 228          break;
 229       case GL_INCR_WRAP_EXT:
 230       case GL_DECR_WRAP_EXT:
 231          if (ctx->Extensions.EXT_stencil_wrap) {
 232             break;
 233          }
 234          /* FALL-THROUGH */
 235       default:
 236          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 237          return;
 238    }
 239    switch (zfail) {
 240       case GL_KEEP:
 241       case GL_ZERO:
 242       case GL_REPLACE:
 243       case GL_INCR:
 244       case GL_DECR:
 245       case GL_INVERT:
 246          break;
 247       case GL_INCR_WRAP_EXT:
 248       case GL_DECR_WRAP_EXT:
 249          if (ctx->Extensions.EXT_stencil_wrap) {
 250             break;
 251          }
 252          /* FALL-THROUGH */
 253       default:
 254          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 255          return;
 256    }
 257    switch (zpass) {
 258       case GL_KEEP:
 259       case GL_ZERO:
 260       case GL_REPLACE:
 261       case GL_INCR:
 262       case GL_DECR:
 263       case GL_INVERT:
 264          break;
 265       case GL_INCR_WRAP_EXT:
 266       case GL_DECR_WRAP_EXT:
 267          if (ctx->Extensions.EXT_stencil_wrap) {
 268             break;
 269          }
 270          /* FALL-THROUGH */
 271       default:
 272          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 273          return;
 274    }
 275
 276    if (ctx->Extensions.ATI_separate_stencil) {
 277       /* set both front and back state */
 278       if (ctx->Stencil.ZFailFunc[0] == zfail &&
 279           ctx->Stencil.ZFailFunc[1] == zfail &&
 280           ctx->Stencil.ZPassFunc[0] == zpass &&
 281           ctx->Stencil.ZPassFunc[1] == zpass &&
 282           ctx->Stencil.FailFunc[0] == fail &&
 283           ctx->Stencil.FailFunc[1] == fail)
 284          return;
 285       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 286       ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
 287       ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
 288       ctx->Stencil.FailFunc[0]  = ctx->Stencil.FailFunc[1]  = fail;
 289       if (ctx->Driver.StencilOpSeparate) {
 290          ctx->Driver.StencilOpSeparate(ctx, GL_FRONT_AND_BACK,
 291                                        fail, zfail, zpass);
 292       }
 293    }
 294    else {
 295       /* only set active face state */
 296       const GLint face = ctx->Stencil.ActiveFace;
 297       if (ctx->Stencil.ZFailFunc[face] == zfail &&
 298           ctx->Stencil.ZPassFunc[face] == zpass &&
 299           ctx->Stencil.FailFunc[face] == fail)
 300          return;
 301       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 302       ctx->Stencil.ZFailFunc[face] = zfail;
 303       ctx->Stencil.ZPassFunc[face] = zpass;
 304       ctx->Stencil.FailFunc[face] = fail;
 305       if (ctx->Driver.StencilOpSeparate) {
 306          ctx->Driver.StencilOpSeparate(ctx, face ? GL_BACK : GL_FRONT,
 307                                        fail, zfail, zpass);
 308       }
 309    }
 310 }
 311
 312
 313
 314 #if _HAVE_FULL_GL
 315 /* GL_EXT_stencil_two_side */
 316 void GLAPIENTRY
 317 _mesa_ActiveStencilFaceEXT(GLenum face)
 318 {
 319    GET_CURRENT_CONTEXT(ctx);
 320    ASSERT_OUTSIDE_BEGIN_END(ctx);
 321
 322    if (!ctx->Extensions.EXT_stencil_two_side) {
 323       _mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
 324       return;
 325    }
 326
 327    if (face == GL_FRONT || face == GL_BACK) {
 328       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 329       ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 1;
 330    }
 331    else {
 332       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
 333    }
 334 }
 335 #endif
 336
 337
 338
 339 /**
 340  * OpenGL 2.0 function.
 341  * \todo Make StencilOp() call this function.  And eventually remove the
 342  * ctx->Driver.StencilOp function and use ctx->Driver.StencilOpSeparate
 343  * instead.
 344  */
 345 void GLAPIENTRY
 346 _mesa_StencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)
 347 {
 348    GET_CURRENT_CONTEXT(ctx);
 349    ASSERT_OUTSIDE_BEGIN_END(ctx);
 350
 351    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 352       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
 353       return;
 354    }
 355
 356    switch (fail) {
 357       case GL_KEEP:
 358       case GL_ZERO:
 359       case GL_REPLACE:
 360       case GL_INCR:
 361       case GL_DECR:
 362       case GL_INVERT:
 363          break;
 364       case GL_INCR_WRAP_EXT:
 365       case GL_DECR_WRAP_EXT:
 366          if (ctx->Extensions.EXT_stencil_wrap) {
 367             break;
 368          }
 369          /* FALL-THROUGH */
 370       default:
 371          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(fail)");
 372          return;
 373    }
 374    switch (zfail) {
 375       case GL_KEEP:
 376       case GL_ZERO:
 377       case GL_REPLACE:
 378       case GL_INCR:
 379       case GL_DECR:
 380       case GL_INVERT:
 381          break;
 382       case GL_INCR_WRAP_EXT:
 383       case GL_DECR_WRAP_EXT:
 384          if (ctx->Extensions.EXT_stencil_wrap) {
 385             break;
 386          }
 387          /* FALL-THROUGH */
 388       default:
 389          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
 390          return;
 391    }
 392    switch (zpass) {
 393       case GL_KEEP:
 394       case GL_ZERO:
 395       case GL_REPLACE:
 396       case GL_INCR:
 397       case GL_DECR:
 398       case GL_INVERT:
 399          break;
 400       case GL_INCR_WRAP_EXT:
 401       case GL_DECR_WRAP_EXT:
 402          if (ctx->Extensions.EXT_stencil_wrap) {
 403             break;
 404          }
 405          /* FALL-THROUGH */
 406       default:
 407          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
 408          return;
 409    }
 410
 411    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 412
 413    if (face != GL_BACK) {
 414       ctx->Stencil.FailFunc[0] = fail;
 415       ctx->Stencil.ZFailFunc[0] = zfail;
 416       ctx->Stencil.ZPassFunc[0] = zpass;
 417    }
 418    if (face != GL_FRONT) {
 419       ctx->Stencil.FailFunc[1] = fail;
 420       ctx->Stencil.ZFailFunc[1] = zfail;
 421       ctx->Stencil.ZPassFunc[1] = zpass;
 422    }
 423    if (ctx->Driver.StencilOpSeparate) {
 424       ctx->Driver.StencilOpSeparate(ctx, face, fail, zfail, zpass);
 425    }
 426 }
 427
 428
 429 /* OpenGL 2.0 */
 430 void GLAPIENTRY
 431 _mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
 432 {
 433    GET_CURRENT_CONTEXT(ctx);
 434    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
 435    ASSERT_OUTSIDE_BEGIN_END(ctx);
 436
 437    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 438       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
 439       return;
 440    }
 441
 442    switch (func) {
 443       case GL_NEVER:
 444       case GL_LESS:
 445       case GL_LEQUAL:
 446       case GL_GREATER:
 447       case GL_GEQUAL:
 448       case GL_EQUAL:
 449       case GL_NOTEQUAL:
 450       case GL_ALWAYS:
 451          break;
 452       default:
 453          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
 454          return;
 455    }
 456
 457    ref = CLAMP(ref, 0, stencilMax);
 458
 459    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 460
 461    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 462       ctx->Stencil.Function[0] = func;
 463       ctx->Stencil.Ref[0] = ref;
 464       ctx->Stencil.ValueMask[0] = mask;
 465    }
 466    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 467       ctx->Stencil.Function[1] = func;
 468       ctx->Stencil.Ref[1] = ref;
 469       ctx->Stencil.ValueMask[1] = mask;
 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_BACK) {
 492       ctx->Stencil.WriteMask[0] = mask;
 493    }
 494    if (face != GL_FRONT) {
 495       ctx->Stencil.WriteMask[1] = mask;
 496    }
 497    if (ctx->Driver.StencilMaskSeparate) {
 498       ctx->Driver.StencilMaskSeparate(ctx, face, mask);
 499    }
 500 }
 501
 502
 503 /**
 504  * Update derived stencil state.
 505  */
 506 void
 507 _mesa_update_stencil(GLcontext *ctx)
 508 {
 509    if (ctx->Extensions.EXT_stencil_two_side) {
 510       ctx->Stencil._TestTwoSide = ctx->Stencil.TestTwoSide;
 511    }
 512    else {
 513       ctx->Stencil._TestTwoSide =
 514          (ctx->Stencil.Function[0] != ctx->Stencil.Function[1] ||
 515           ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[1] ||
 516           ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[1] ||
 517           ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[1] ||
 518           ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1] ||
 519           ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[1] ||
 520           ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[1]);
 521    }
 522 }
 523
 524
 525 /**
 526  * Initialize the context stipple state.
 527  *
 528  * \param ctx GL context.
 529  *
 530  * Initializes __GLcontextRec::Stencil attribute group.
 531  */
 532 void
 533 _mesa_init_stencil(GLcontext *ctx)
 534 {
 535    ctx->Stencil.Enabled = GL_FALSE;
 536    ctx->Stencil.TestTwoSide = GL_FALSE;
 537    ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 1 = GL_BACK */
 538    ctx->Stencil.Function[0] = GL_ALWAYS;
 539    ctx->Stencil.Function[1] = GL_ALWAYS;
 540    ctx->Stencil.FailFunc[0] = GL_KEEP;
 541    ctx->Stencil.FailFunc[1] = GL_KEEP;
 542    ctx->Stencil.ZPassFunc[0] = GL_KEEP;
 543    ctx->Stencil.ZPassFunc[1] = GL_KEEP;
 544    ctx->Stencil.ZFailFunc[0] = GL_KEEP;
 545    ctx->Stencil.ZFailFunc[1] = GL_KEEP;
 546    ctx->Stencil.Ref[0] = 0;
 547    ctx->Stencil.Ref[1] = 0;
 548    ctx->Stencil.ValueMask[0] = ~0U;
 549    ctx->Stencil.ValueMask[1] = ~0U;
 550    ctx->Stencil.WriteMask[0] = ~0U;
 551    ctx->Stencil.WriteMask[1] = ~0U;
 552    ctx->Stencil.Clear = 0;
 553 }