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