reactos/dll/opengl/mesa/src/mesa/main/clear.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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 clear.c
  28  * glClearColor, glClearIndex, glClear() functions.
  29  */
  30
  31
  32
  33 #include "glheader.h"
  34 #include "clear.h"
  35 #include "context.h"
  36 #include "colormac.h"
  37 #include "enums.h"
  38 #include "macros.h"
  39 #include "mtypes.h"
  40 #include "state.h"
  41
  42
  43
  44 #if _HAVE_FULL_GL
  45 void GLAPIENTRY
  46 _mesa_ClearIndex( GLfloat c )
  47 {
  48    GET_CURRENT_CONTEXT(ctx);
  49    ASSERT_OUTSIDE_BEGIN_END(ctx);
  50
  51    if (ctx->Color.ClearIndex == (GLuint) c)
  52       return;
  53
  54    FLUSH_VERTICES(ctx, _NEW_COLOR);
  55    ctx->Color.ClearIndex = (GLuint) c;
  56 }
  57 #endif
  58
  59
  60 /**
  61  * Specify the clear values for the color buffers.
  62  *
  63  * \param red red color component.
  64  * \param green green color component.
  65  * \param blue blue color component.
  66  * \param alpha alpha component.
  67  *
  68  * \sa glClearColor().
  69  *
  70  * Clamps the parameters and updates gl_colorbuffer_attrib::ClearColor.  On a
  71  * change, flushes the vertices and notifies the driver via the
  72  * dd_function_table::ClearColor callback.
  73  */
  74 void GLAPIENTRY
  75 _mesa_ClearColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
  76 {
  77    GLfloat tmp[4];
  78    GET_CURRENT_CONTEXT(ctx);
  79    ASSERT_OUTSIDE_BEGIN_END(ctx);
  80
  81    tmp[0] = red;
  82    tmp[1] = green;
  83    tmp[2] = blue;
  84    tmp[3] = alpha;
  85
  86    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor.f))
  87       return; /* no change */
  88
  89    FLUSH_VERTICES(ctx, _NEW_COLOR);
  90    COPY_4V(ctx->Color.ClearColor.f, tmp);
  91
  92    if (ctx->Driver.ClearColor) {
  93       /* it's OK to call glClearColor in CI mode but it should be a NOP */
  94       /* we pass the clamped color, since all drivers that need this don't
  95        * support GL_ARB_color_buffer_float
  96        */
  97       (*ctx->Driver.ClearColor)(ctx, ctx->Color.ClearColor);
  98    }
  99 }
 100
 101
 102 /**
 103  * GL_EXT_texture_integer
 104  */
 105 void GLAPIENTRY
 106 _mesa_ClearColorIiEXT(GLint r, GLint g, GLint b, GLint a)
 107 {
 108    GLint tmp[4];
 109    GET_CURRENT_CONTEXT(ctx);
 110    ASSERT_OUTSIDE_BEGIN_END(ctx);
 111
 112    tmp[0] = r;
 113    tmp[1] = g;
 114    tmp[2] = b;
 115    tmp[3] = a;
 116
 117    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor.i))
 118       return; /* no change */
 119
 120    FLUSH_VERTICES(ctx, _NEW_COLOR);
 121    COPY_4V(ctx->Color.ClearColor.i, tmp);
 122
 123    /* these should be NOP calls for drivers supporting EXT_texture_integer */
 124    if (ctx->Driver.ClearColor) {
 125       ctx->Driver.ClearColor(ctx, ctx->Color.ClearColor);
 126    }
 127 }
 128
 129
 130 /**
 131  * GL_EXT_texture_integer
 132  */
 133 void GLAPIENTRY
 134 _mesa_ClearColorIuiEXT(GLuint r, GLuint g, GLuint b, GLuint a)
 135 {
 136    GLuint tmp[4];
 137    GET_CURRENT_CONTEXT(ctx);
 138    ASSERT_OUTSIDE_BEGIN_END(ctx);
 139
 140    tmp[0] = r;
 141    tmp[1] = g;
 142    tmp[2] = b;
 143    tmp[3] = a;
 144
 145    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor.ui))
 146       return; /* no change */
 147
 148    FLUSH_VERTICES(ctx, _NEW_COLOR);
 149    COPY_4V(ctx->Color.ClearColor.ui, tmp);
 150
 151    /* these should be NOP calls for drivers supporting EXT_texture_integer */
 152    if (ctx->Driver.ClearColor) {
 153       ctx->Driver.ClearColor(ctx, ctx->Color.ClearColor);
 154    }
 155 }
 156
 157
 158 /**
 159  * Clear buffers.
 160  *
 161  * \param mask bit-mask indicating the buffers to be cleared.
 162  *
 163  * Flushes the vertices and verifies the parameter. If __struct gl_contextRec::NewState
 164  * is set then calls _mesa_update_state() to update gl_frame_buffer::_Xmin,
 165  * etc. If the rasterization mode is set to GL_RENDER then requests the driver
 166  * to clear the buffers, via the dd_function_table::Clear callback.
 167  */
 168 void GLAPIENTRY
 169 _mesa_Clear( GLbitfield mask )
 170 {
 171    GET_CURRENT_CONTEXT(ctx);
 172    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 173
 174    FLUSH_CURRENT(ctx, 0);
 175
 176    if (MESA_VERBOSE & VERBOSE_API)
 177       _mesa_debug(ctx, "glClear 0x%x\n", mask);
 178
 179    if (mask & ~(GL_COLOR_BUFFER_BIT |
 180                 GL_DEPTH_BUFFER_BIT |
 181                 GL_STENCIL_BUFFER_BIT |
 182                 GL_ACCUM_BUFFER_BIT)) {
 183       /* invalid bit set */
 184       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(0x%x)", mask);
 185       return;
 186    }
 187
 188    if (ctx->NewState) {
 189       _mesa_update_state( ctx );        /* update _Xmin, etc */
 190    }
 191
 192    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 193       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 194                   "glClear(incomplete framebuffer)");
 195       return;
 196    }
 197
 198    if (ctx->DrawBuffer->Width == 0 || ctx->DrawBuffer->Height == 0 ||
 199        ctx->DrawBuffer->_Xmin >= ctx->DrawBuffer->_Xmax ||
 200        ctx->DrawBuffer->_Ymin >= ctx->DrawBuffer->_Ymax)
 201       return;
 202
 203    if (ctx->RasterDiscard)
 204       return;
 205
 206    if (ctx->RenderMode == GL_RENDER) {
 207       GLbitfield bufferMask;
 208
 209       /* don't clear depth buffer if depth writing disabled */
 210       if (!ctx->Depth.Mask)
 211          mask &= ~GL_DEPTH_BUFFER_BIT;
 212
 213       /* Build the bitmask to send to device driver's Clear function.
 214        * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
 215        * of the BUFFER_BIT_FRONT/BACK_LEFT/RIGHT flags, or one of the
 216        * BUFFER_BIT_COLORn flags.
 217        */
 218       bufferMask = 0;
 219       if (mask & GL_COLOR_BUFFER_BIT) {
 220          GLuint i;
 221          for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 222             bufferMask |= (1 << ctx->DrawBuffer->_ColorDrawBufferIndexes[i]);
 223          }
 224       }
 225
 226       if ((mask & GL_DEPTH_BUFFER_BIT)
 227           && ctx->DrawBuffer->Visual.haveDepthBuffer) {
 228          bufferMask |= BUFFER_BIT_DEPTH;
 229       }
 230
 231       if ((mask & GL_STENCIL_BUFFER_BIT)
 232           && ctx->DrawBuffer->Visual.haveStencilBuffer) {
 233          bufferMask |= BUFFER_BIT_STENCIL;
 234       }
 235
 236       if ((mask & GL_ACCUM_BUFFER_BIT)
 237           && ctx->DrawBuffer->Visual.haveAccumBuffer) {
 238          bufferMask |= BUFFER_BIT_ACCUM;
 239       }
 240
 241       ASSERT(ctx->Driver.Clear);
 242       ctx->Driver.Clear(ctx, bufferMask);
 243    }
 244 }
 245
 246
 247 /** Returned by make_color_buffer_mask() for errors */
 248 #define INVALID_MASK ~0x0
 249
 250
 251 /**
 252  * Convert the glClearBuffer 'drawbuffer' parameter into a bitmask of
 253  * BUFFER_BIT_x values.
 254  * Return INVALID_MASK if the drawbuffer value is invalid.
 255  */
 256 static GLbitfield
 257 make_color_buffer_mask(struct gl_context *ctx, GLint drawbuffer)
 258 {
 259    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 260    GLbitfield mask = 0x0;
 261
 262    switch (drawbuffer) {
 263    case GL_FRONT:
 264       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 265          mask |= BUFFER_BIT_FRONT_LEFT;
 266       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 267          mask |= BUFFER_BIT_FRONT_RIGHT;
 268       break;
 269    case GL_BACK:
 270       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 271          mask |= BUFFER_BIT_BACK_LEFT;
 272       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 273          mask |= BUFFER_BIT_BACK_RIGHT;
 274       break;
 275    case GL_LEFT:
 276       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 277          mask |= BUFFER_BIT_FRONT_LEFT;
 278       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 279          mask |= BUFFER_BIT_BACK_LEFT;
 280       break;
 281    case GL_RIGHT:
 282       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 283          mask |= BUFFER_BIT_FRONT_RIGHT;
 284       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 285          mask |= BUFFER_BIT_BACK_RIGHT;
 286       break;
 287    case GL_FRONT_AND_BACK:
 288       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 289          mask |= BUFFER_BIT_FRONT_LEFT;
 290       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 291          mask |= BUFFER_BIT_BACK_LEFT;
 292       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 293          mask |= BUFFER_BIT_FRONT_RIGHT;
 294       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 295          mask |= BUFFER_BIT_BACK_RIGHT;
 296       break;
 297    default:
 298       if (drawbuffer < 0 || drawbuffer >= (GLint)ctx->Const.MaxDrawBuffers) {
 299          mask = INVALID_MASK;
 300       }
 301       else if (att[BUFFER_COLOR0 + drawbuffer].Renderbuffer) {
 302          mask |= (BUFFER_BIT_COLOR0 << drawbuffer);
 303       }
 304    }
 305
 306    return mask;
 307 }
 308
 309
 310
 311 /**
 312  * New in GL 3.0
 313  * Clear signed integer color buffer or stencil buffer (not depth).
 314  */
 315 void GLAPIENTRY
 316 _mesa_ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint *value)
 317 {
 318    GET_CURRENT_CONTEXT(ctx);
 319    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 320
 321    FLUSH_CURRENT(ctx, 0);
 322
 323    if (ctx->NewState) {
 324       _mesa_update_state( ctx );
 325    }
 326
 327    switch (buffer) {
 328    case GL_STENCIL:
 329       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 330        *
 331        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 332        *     COLOR and drawbuffer is less than zero, or greater than the
 333        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 334        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 335        */
 336       if (drawbuffer != 0) {
 337          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 338                      drawbuffer);
 339          return;
 340       }
 341       else if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer && !ctx->RasterDiscard) {
 342          /* Save current stencil clear value, set to 'value', do the
 343           * stencil clear and restore the clear value.
 344           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 345           * hook instead.
 346           */
 347          const GLuint clearSave = ctx->Stencil.Clear;
 348          ctx->Stencil.Clear = *value;
 349          if (ctx->Driver.ClearStencil)
 350             ctx->Driver.ClearStencil(ctx, *value);
 351          ctx->Driver.Clear(ctx, BUFFER_BIT_STENCIL);
 352          ctx->Stencil.Clear = clearSave;
 353          if (ctx->Driver.ClearStencil)
 354             ctx->Driver.ClearStencil(ctx, clearSave);
 355       }
 356       break;
 357    case GL_COLOR:
 358       {
 359          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 360          if (mask == INVALID_MASK) {
 361             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 362                         drawbuffer);
 363             return;
 364          }
 365          else if (mask && !ctx->RasterDiscard) {
 366             union gl_color_union clearSave;
 367
 368             /* save color */
 369             clearSave = ctx->Color.ClearColor;
 370             /* set color */
 371             COPY_4V(ctx->Color.ClearColor.i, value);
 372             if (ctx->Driver.ClearColor)
 373                ctx->Driver.ClearColor(ctx, ctx->Color.ClearColor);
 374             /* clear buffer(s) */
 375             ctx->Driver.Clear(ctx, mask);
 376             /* restore color */
 377             ctx->Color.ClearColor = clearSave;
 378             if (ctx->Driver.ClearColor)
 379                ctx->Driver.ClearColor(ctx, clearSave);
 380          }
 381       }
 382       break;
 383    case GL_DEPTH:
 384       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 385        *
 386        *     "The result of ClearBuffer is undefined if no conversion between
 387        *     the type of the specified value and the type of the buffer being
 388        *     cleared is defined (for example, if ClearBufferiv is called for a
 389        *     fixed- or floating-point buffer, or if ClearBufferfv is called
 390        *     for a signed or unsigned integer buffer). This is not an error."
 391        *
 392        * In this case we take "undefined" and "not an error" to mean "ignore."
 393        * Note that we still need to generate an error for the invalid
 394        * drawbuffer case (see the GL_STENCIL case above).
 395        */
 396       if (drawbuffer != 0) {
 397          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 398                      drawbuffer);
 399          return;
 400       }
 401       return;
 402    default:
 403       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferiv(buffer=%s)",
 404                   _mesa_lookup_enum_by_nr(buffer));
 405       return;
 406    }
 407 }
 408
 409
 410 /**
 411  * New in GL 3.0
 412  * Clear unsigned integer color buffer (not depth, not stencil).
 413  */
 414 void GLAPIENTRY
 415 _mesa_ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint *value)
 416 {
 417    GET_CURRENT_CONTEXT(ctx);
 418    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 419
 420    FLUSH_CURRENT(ctx, 0);
 421
 422    if (ctx->NewState) {
 423       _mesa_update_state( ctx );
 424    }
 425
 426    switch (buffer) {
 427    case GL_COLOR:
 428       {
 429          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 430          if (mask == INVALID_MASK) {
 431             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferuiv(drawbuffer=%d)",
 432                         drawbuffer);
 433             return;
 434          }
 435          else if (mask && !ctx->RasterDiscard) {
 436             union gl_color_union clearSave;
 437
 438             /* save color */
 439             clearSave = ctx->Color.ClearColor;
 440             /* set color */
 441             COPY_4V(ctx->Color.ClearColor.ui, value);
 442             if (ctx->Driver.ClearColor)
 443                ctx->Driver.ClearColor(ctx, ctx->Color.ClearColor);
 444             /* clear buffer(s) */
 445             ctx->Driver.Clear(ctx, mask);
 446             /* restore color */
 447             ctx->Color.ClearColor = clearSave;
 448             if (ctx->Driver.ClearColor)
 449                ctx->Driver.ClearColor(ctx, clearSave);
 450          }
 451       }
 452       break;
 453    case GL_DEPTH:
 454    case GL_STENCIL:
 455       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 456        *
 457        *     "The result of ClearBuffer is undefined if no conversion between
 458        *     the type of the specified value and the type of the buffer being
 459        *     cleared is defined (for example, if ClearBufferiv is called for a
 460        *     fixed- or floating-point buffer, or if ClearBufferfv is called
 461        *     for a signed or unsigned integer buffer). This is not an error."
 462        *
 463        * In this case we take "undefined" and "not an error" to mean "ignore."
 464        * Even though we could do something sensible for GL_STENCIL, page 263
 465        * (page 279 of the PDF) says:
 466        *
 467        *     "Only ClearBufferiv should be used to clear stencil buffers."
 468        *
 469        * Note that we still need to generate an error for the invalid
 470        * drawbuffer case (see the GL_STENCIL case in _mesa_ClearBufferiv).
 471        */
 472       if (drawbuffer != 0) {
 473          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferuiv(drawbuffer=%d)",
 474                      drawbuffer);
 475          return;
 476       }
 477       return;
 478    default:
 479       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferuiv(buffer=%s)",
 480                   _mesa_lookup_enum_by_nr(buffer));
 481       return;
 482    }
 483 }
 484
 485
 486 /**
 487  * New in GL 3.0
 488  * Clear fixed-pt or float color buffer or depth buffer (not stencil).
 489  */
 490 void GLAPIENTRY
 491 _mesa_ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat *value)
 492 {
 493    GET_CURRENT_CONTEXT(ctx);
 494    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 495
 496    FLUSH_CURRENT(ctx, 0);
 497
 498    if (ctx->NewState) {
 499       _mesa_update_state( ctx );
 500    }
 501
 502    switch (buffer) {
 503    case GL_DEPTH:
 504       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 505        *
 506        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 507        *     COLOR and drawbuffer is less than zero, or greater than the
 508        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 509        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 510        */
 511       if (drawbuffer != 0) {
 512          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 513                      drawbuffer);
 514          return;
 515       }
 516       else if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer && !ctx->RasterDiscard) {
 517          /* Save current depth clear value, set to 'value', do the
 518           * depth clear and restore the clear value.
 519           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 520           * hook instead.
 521           */
 522          const GLclampd clearSave = ctx->Depth.Clear;
 523          ctx->Depth.Clear = *value;
 524          if (ctx->Driver.ClearDepth)
 525             ctx->Driver.ClearDepth(ctx, *value);
 526          ctx->Driver.Clear(ctx, BUFFER_BIT_DEPTH);
 527          ctx->Depth.Clear = clearSave;
 528          if (ctx->Driver.ClearDepth)
 529             ctx->Driver.ClearDepth(ctx, clearSave);
 530       }
 531       /* clear depth buffer to value */
 532       break;
 533    case GL_COLOR:
 534       {
 535          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 536          if (mask == INVALID_MASK) {
 537             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 538                         drawbuffer);
 539             return;
 540          }
 541          else if (mask && !ctx->RasterDiscard) {
 542             union gl_color_union clearSave;
 543
 544             /* save color */
 545             clearSave = ctx->Color.ClearColor;
 546             /* set color */
 547             COPY_4V_CAST(ctx->Color.ClearColor.f, value, GLclampf);
 548             if (ctx->Driver.ClearColor)
 549                ctx->Driver.ClearColor(ctx, ctx->Color.ClearColor);
 550             /* clear buffer(s) */
 551             ctx->Driver.Clear(ctx, mask);
 552             /* restore color */
 553             ctx->Color.ClearColor = clearSave;
 554             if (ctx->Driver.ClearColor)
 555                ctx->Driver.ClearColor(ctx, clearSave);
 556          }
 557       }
 558       break;
 559    case GL_STENCIL:
 560       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 561        *
 562        *     "The result of ClearBuffer is undefined if no conversion between
 563        *     the type of the specified value and the type of the buffer being
 564        *     cleared is defined (for example, if ClearBufferiv is called for a
 565        *     fixed- or floating-point buffer, or if ClearBufferfv is called
 566        *     for a signed or unsigned integer buffer). This is not an error."
 567        *
 568        * In this case we take "undefined" and "not an error" to mean "ignore."
 569        * Note that we still need to generate an error for the invalid
 570        * drawbuffer case (see the GL_DEPTH case above).
 571        */
 572       if (drawbuffer != 0) {
 573          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 574                      drawbuffer);
 575          return;
 576       }
 577       return;
 578    default:
 579       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfv(buffer=%s)",
 580                   _mesa_lookup_enum_by_nr(buffer));
 581       return;
 582    }
 583 }
 584
 585
 586 /**
 587  * New in GL 3.0
 588  * Clear depth/stencil buffer only.
 589  */
 590 void GLAPIENTRY
 591 _mesa_ClearBufferfi(GLenum buffer, GLint drawbuffer,
 592                     GLfloat depth, GLint stencil)
 593 {
 594    GET_CURRENT_CONTEXT(ctx);
 595    GLbitfield mask = 0;
 596
 597    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 598
 599    FLUSH_CURRENT(ctx, 0);
 600
 601    if (buffer != GL_DEPTH_STENCIL) {
 602       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfi(buffer=%s)",
 603                   _mesa_lookup_enum_by_nr(buffer));
 604       return;
 605    }
 606
 607    /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 608     *
 609     *     "ClearBuffer generates an INVALID VALUE error if buffer is
 610     *     COLOR and drawbuffer is less than zero, or greater than the
 611     *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 612     *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 613     */
 614    if (drawbuffer != 0) {
 615       _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfi(drawbuffer=%d)",
 616                   drawbuffer);
 617       return;
 618    }
 619
 620    if (ctx->RasterDiscard)
 621       return;
 622
 623    if (ctx->NewState) {
 624       _mesa_update_state( ctx );
 625    }
 626
 627    if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer)
 628       mask |= BUFFER_BIT_DEPTH;
 629    if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer)
 630       mask |= BUFFER_BIT_STENCIL;
 631
 632    if (mask) {
 633       /* save current clear values */
 634       const GLclampd clearDepthSave = ctx->Depth.Clear;
 635       const GLuint clearStencilSave = ctx->Stencil.Clear;
 636
 637       /* set new clear values */
 638       ctx->Depth.Clear = depth;
 639       ctx->Stencil.Clear = stencil;
 640       if (ctx->Driver.ClearDepth)
 641          ctx->Driver.ClearDepth(ctx, depth);
 642       if (ctx->Driver.ClearStencil)
 643          ctx->Driver.ClearStencil(ctx, stencil);
 644
 645       /* clear buffers */
 646       ctx->Driver.Clear(ctx, mask);
 647
 648       /* restore */
 649       ctx->Depth.Clear = clearDepthSave;
 650       ctx->Stencil.Clear = clearStencilSave;
 651       if (ctx->Driver.ClearDepth)
 652          ctx->Driver.ClearDepth(ctx, clearDepthSave);
 653       if (ctx->Driver.ClearStencil)
 654          ctx->Driver.ClearStencil(ctx, clearStencilSave);
 655    }
 656 }