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    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
  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    ref = CLAMP( ref, 0, stencilMax );
 117
 118    if (ctx->Extensions.EXT_stencil_two_side) {
 119       /* only set active face state */
 120       const GLint face = ctx->Stencil.ActiveFace;
 121       if (ctx->Stencil.Function[face] == func &&
 122           ctx->Stencil.ValueMask[face] == mask &&
 123           ctx->Stencil.Ref[face] == ref)
 124          return;
 125       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 126       ctx->Stencil.Function[face] = func;
 127       ctx->Stencil.Ref[face] = ref;
 128       ctx->Stencil.ValueMask[face] = mask;
 129       if (ctx->Driver.StencilFuncSeparate) {
 130          ctx->Driver.StencilFuncSeparate(ctx, face ? GL_BACK : GL_FRONT,
 131                                          func, ref, mask);
 132       }
 133    }
 134    else {
 135       /* set both front and back state */
 136       if (ctx->Stencil.Function[0] == func &&
 137           ctx->Stencil.Function[1] == func &&
 138           ctx->Stencil.ValueMask[0] == mask &&
 139           ctx->Stencil.ValueMask[1] == mask &&
 140           ctx->Stencil.Ref[0] == ref &&
 141           ctx->Stencil.Ref[1] == ref)
 142          return;
 143       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 144       ctx->Stencil.Function[0]  = ctx->Stencil.Function[1]  = func;
 145       ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
 146       ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
 147       if (ctx->Driver.StencilFuncSeparate) {
 148          ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT_AND_BACK,
 149                                          func, ref, mask);
 150       }
 151    }
 152 }
 153
 154
 155 /**
 156  * Set the stencil writing mask.
 157  *
 158  * \param mask bit-mask to enable/disable writing of individual bits in the
 159  * stencil planes.
 160  *
 161  * \sa glStencilMask().
 162  *
 163  * Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
 164  * notifies the driver via the dd_function_table::StencilMask callback.
 165  */
 166 void GLAPIENTRY
 167 _mesa_StencilMask( GLuint mask )
 168 {
 169    GET_CURRENT_CONTEXT(ctx);
 170    ASSERT_OUTSIDE_BEGIN_END(ctx);
 171
 172    if (ctx->Extensions.EXT_stencil_two_side) {
 173       /* only set active face state */
 174       const GLint face = ctx->Stencil.ActiveFace;
 175       if (ctx->Stencil.WriteMask[face] == mask)
 176          return;
 177       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 178       ctx->Stencil.WriteMask[face] = mask;
 179       if (ctx->Driver.StencilMaskSeparate) {
 180          ctx->Driver.StencilMaskSeparate(ctx, face ? GL_BACK : GL_FRONT, mask);
 181       }
 182    }
 183    else {
 184       /* set both front and back state */
 185       if (ctx->Stencil.WriteMask[0] == mask &&
 186           ctx->Stencil.WriteMask[1] == mask)
 187          return;
 188       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 189       ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
 190       if (ctx->Driver.StencilMaskSeparate) {
 191          ctx->Driver.StencilMaskSeparate(ctx, GL_FRONT_AND_BACK, mask);
 192       }
 193    }
 194 }
 195
 196
 197 /**
 198  * Set the stencil test actions.
 199  *
 200  * \param fail action to take when stencil test fails.
 201  * \param zfail action to take when stencil test passes, but depth test fails.
 202  * \param zpass action to take when stencil test passes and the depth test
 203  * passes (or depth testing is not enabled).
 204  *
 205  * \sa glStencilOp().
 206  *
 207  * Verifies the parameters and updates the respective fields in
 208  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
 209  * driver via the dd_function_table::StencilOp callback.
 210  */
 211 void GLAPIENTRY
 212 _mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
 213 {
 214    GET_CURRENT_CONTEXT(ctx);
 215    ASSERT_OUTSIDE_BEGIN_END(ctx);
 216
 217    switch (fail) {
 218       case GL_KEEP:
 219       case GL_ZERO:
 220       case GL_REPLACE:
 221       case GL_INCR:
 222       case GL_DECR:
 223       case GL_INVERT:
 224          break;
 225       case GL_INCR_WRAP_EXT:
 226       case GL_DECR_WRAP_EXT:
 227          if (ctx->Extensions.EXT_stencil_wrap) {
 228             break;
 229          }
 230          /* FALL-THROUGH */
 231       default:
 232          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 233          return;
 234    }
 235    switch (zfail) {
 236       case GL_KEEP:
 237       case GL_ZERO:
 238       case GL_REPLACE:
 239       case GL_INCR:
 240       case GL_DECR:
 241       case GL_INVERT:
 242          break;
 243       case GL_INCR_WRAP_EXT:
 244       case GL_DECR_WRAP_EXT:
 245          if (ctx->Extensions.EXT_stencil_wrap) {
 246             break;
 247          }
 248          /* FALL-THROUGH */
 249       default:
 250          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 251          return;
 252    }
 253    switch (zpass) {
 254       case GL_KEEP:
 255       case GL_ZERO:
 256       case GL_REPLACE:
 257       case GL_INCR:
 258       case GL_DECR:
 259       case GL_INVERT:
 260          break;
 261       case GL_INCR_WRAP_EXT:
 262       case GL_DECR_WRAP_EXT:
 263          if (ctx->Extensions.EXT_stencil_wrap) {
 264             break;
 265          }
 266          /* FALL-THROUGH */
 267       default:
 268          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp");
 269          return;
 270    }
 271
 272    if (ctx->Extensions.EXT_stencil_two_side) {
 273       /* only set active face state */
 274       const GLint face = ctx->Stencil.ActiveFace;
 275       if (ctx->Stencil.ZFailFunc[face] == zfail &&
 276           ctx->Stencil.ZPassFunc[face] == zpass &&
 277           ctx->Stencil.FailFunc[face] == fail)
 278          return;
 279       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 280       ctx->Stencil.ZFailFunc[face] = zfail;
 281       ctx->Stencil.ZPassFunc[face] = zpass;
 282       ctx->Stencil.FailFunc[face] = fail;
 283       if (ctx->Driver.StencilOpSeparate) {
 284          ctx->Driver.StencilOpSeparate(ctx, face ? GL_BACK : GL_FRONT,
 285                                        fail, zfail, zpass);
 286       }
 287    }
 288    else {
 289       /* set both front and back state */
 290       if (ctx->Stencil.ZFailFunc[0] == zfail &&
 291           ctx->Stencil.ZFailFunc[1] == zfail &&
 292           ctx->Stencil.ZPassFunc[0] == zpass &&
 293           ctx->Stencil.ZPassFunc[1] == zpass &&
 294           ctx->Stencil.FailFunc[0] == fail &&
 295           ctx->Stencil.FailFunc[1] == fail)
 296          return;
 297       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 298       ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
 299       ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
 300       ctx->Stencil.FailFunc[0]  = ctx->Stencil.FailFunc[1]  = fail;
 301       if (ctx->Driver.StencilOpSeparate) {
 302          ctx->Driver.StencilOpSeparate(ctx, GL_FRONT_AND_BACK,
 303                                        fail, zfail, zpass);
 304       }
 305    }
 306 }
 307
 308
 309
 310 #if _HAVE_FULL_GL
 311 /* GL_EXT_stencil_two_side */
 312 void GLAPIENTRY
 313 _mesa_ActiveStencilFaceEXT(GLenum face)
 314 {
 315    GET_CURRENT_CONTEXT(ctx);
 316    ASSERT_OUTSIDE_BEGIN_END(ctx);
 317
 318    if (!ctx->Extensions.EXT_stencil_two_side) {
 319       _mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
 320       return;
 321    }
 322
 323    if (face == GL_FRONT || face == GL_BACK) {
 324       FLUSH_VERTICES(ctx, _NEW_STENCIL);
 325       ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 1;
 326    }
 327    else {
 328       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
 329    }
 330 }
 331 #endif
 332
 333
 334
 335 /**
 336  * OpenGL 2.0 function.
 337  * \todo Make StencilOp() call this function.  And eventually remove the
 338  * ctx->Driver.StencilOp function and use ctx->Driver.StencilOpSeparate
 339  * instead.
 340  */
 341 void GLAPIENTRY
 342 _mesa_StencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)
 343 {
 344    GET_CURRENT_CONTEXT(ctx);
 345    ASSERT_OUTSIDE_BEGIN_END(ctx);
 346
 347    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 348       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
 349       return;
 350    }
 351
 352    switch (fail) {
 353       case GL_KEEP:
 354       case GL_ZERO:
 355       case GL_REPLACE:
 356       case GL_INCR:
 357       case GL_DECR:
 358       case GL_INVERT:
 359          break;
 360       case GL_INCR_WRAP_EXT:
 361       case GL_DECR_WRAP_EXT:
 362          if (ctx->Extensions.EXT_stencil_wrap) {
 363             break;
 364          }
 365          /* FALL-THROUGH */
 366       default:
 367          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(fail)");
 368          return;
 369    }
 370    switch (zfail) {
 371       case GL_KEEP:
 372       case GL_ZERO:
 373       case GL_REPLACE:
 374       case GL_INCR:
 375       case GL_DECR:
 376       case GL_INVERT:
 377          break;
 378       case GL_INCR_WRAP_EXT:
 379       case GL_DECR_WRAP_EXT:
 380          if (ctx->Extensions.EXT_stencil_wrap) {
 381             break;
 382          }
 383          /* FALL-THROUGH */
 384       default:
 385          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
 386          return;
 387    }
 388    switch (zpass) {
 389       case GL_KEEP:
 390       case GL_ZERO:
 391       case GL_REPLACE:
 392       case GL_INCR:
 393       case GL_DECR:
 394       case GL_INVERT:
 395          break;
 396       case GL_INCR_WRAP_EXT:
 397       case GL_DECR_WRAP_EXT:
 398          if (ctx->Extensions.EXT_stencil_wrap) {
 399             break;
 400          }
 401          /* FALL-THROUGH */
 402       default:
 403          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
 404          return;
 405    }
 406
 407    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 408
 409    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 410       ctx->Stencil.FailFunc[0] = fail;
 411       ctx->Stencil.ZFailFunc[0] = zfail;
 412       ctx->Stencil.ZPassFunc[0] = zpass;
 413    }
 414    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 415       ctx->Stencil.FailFunc[1] = fail;
 416       ctx->Stencil.ZFailFunc[1] = zfail;
 417       ctx->Stencil.ZPassFunc[1] = zpass;
 418    }
 419
 420    if (ctx->Driver.StencilOpSeparate) {
 421       ctx->Driver.StencilOpSeparate(ctx, face, fail, zfail, zpass);
 422    }
 423 }
 424
 425
 426 /* OpenGL 2.0 */
 427 void GLAPIENTRY
 428 _mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
 429 {
 430    GET_CURRENT_CONTEXT(ctx);
 431    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
 432    ASSERT_OUTSIDE_BEGIN_END(ctx);
 433
 434    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 435       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
 436       return;
 437    }
 438
 439    switch (func) {
 440       case GL_NEVER:
 441       case GL_LESS:
 442       case GL_LEQUAL:
 443       case GL_GREATER:
 444       case GL_GEQUAL:
 445       case GL_EQUAL:
 446       case GL_NOTEQUAL:
 447       case GL_ALWAYS:
 448          break;
 449       default:
 450          _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
 451          return;
 452    }
 453
 454    ref = CLAMP(ref, 0, stencilMax);
 455
 456    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 457
 458    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 459       ctx->Stencil.Function[0] = func;
 460       ctx->Stencil.Ref[0] = ref;
 461       ctx->Stencil.ValueMask[0] = mask;
 462    }
 463    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 464       ctx->Stencil.Function[1] = func;
 465       ctx->Stencil.Ref[1] = ref;
 466       ctx->Stencil.ValueMask[1] = mask;
 467    }
 468
 469    if (ctx->Driver.StencilFuncSeparate) {
 470       ctx->Driver.StencilFuncSeparate(ctx, face, func, ref, mask);
 471    }
 472 }
 473
 474
 475 /* OpenGL 2.0 */
 476 void GLAPIENTRY
 477 _mesa_StencilMaskSeparate(GLenum face, GLuint mask)
 478 {
 479    GET_CURRENT_CONTEXT(ctx);
 480    ASSERT_OUTSIDE_BEGIN_END(ctx);
 481
 482    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
 483       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilaMaskSeparate(face)");
 484       return;
 485    }
 486
 487    FLUSH_VERTICES(ctx, _NEW_STENCIL);
 488
 489    if (face == GL_FRONT || face == GL_FRONT_AND_BACK) {
 490       ctx->Stencil.WriteMask[0] = mask;
 491    }
 492    if (face == GL_BACK || face == GL_FRONT_AND_BACK) {
 493       ctx->Stencil.WriteMask[1] = mask;
 494    }
 495
 496    if (ctx->Driver.StencilMaskSeparate) {
 497       ctx->Driver.StencilMaskSeparate(ctx, face, mask);
 498    }
 499 }
 500
 501
 502 /**
 503  * Update derived stencil state.
 504  */
 505 void
 506 _mesa_update_stencil(GLcontext *ctx)
 507 {
 508    if (ctx->Extensions.EXT_stencil_two_side) {
 509       ctx->Stencil._TestTwoSide = ctx->Stencil.TestTwoSide;
 510    }
 511    else {
 512       ctx->Stencil._TestTwoSide =
 513          (ctx->Stencil.Function[0] != ctx->Stencil.Function[1] ||
 514           ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[1] ||
 515           ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[1] ||
 516           ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[1] ||
 517           ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1] ||
 518           ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[1] ||
 519           ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[1]);
 520    }
 521 }
 522
 523
 524 /**
 525  * Initialize the context stipple state.
 526  *
 527  * \param ctx GL context.
 528  *
 529  * Initializes __GLcontextRec::Stencil attribute group.
 530  */
 531 void
 532 _mesa_init_stencil(GLcontext *ctx)
 533 {
 534    ctx->Stencil.Enabled = GL_FALSE;
 535    ctx->Stencil.TestTwoSide = GL_FALSE;
 536    ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 1 = GL_BACK */
 537    ctx->Stencil.Function[0] = GL_ALWAYS;
 538    ctx->Stencil.Function[1] = GL_ALWAYS;
 539    ctx->Stencil.FailFunc[0] = GL_KEEP;
 540    ctx->Stencil.FailFunc[1] = GL_KEEP;
 541    ctx->Stencil.ZPassFunc[0] = GL_KEEP;
 542    ctx->Stencil.ZPassFunc[1] = GL_KEEP;
 543    ctx->Stencil.ZFailFunc[0] = GL_KEEP;
 544    ctx->Stencil.ZFailFunc[1] = GL_KEEP;
 545    ctx->Stencil.Ref[0] = 0;
 546    ctx->Stencil.Ref[1] = 0;
 547    ctx->Stencil.ValueMask[0] = ~0U;
 548    ctx->Stencil.ValueMask[1] = ~0U;
 549    ctx->Stencil.WriteMask[0] = ~0U;
 550    ctx->Stencil.WriteMask[1] = ~0U;
 551    ctx->Stencil.Clear = 0;
 552 }