src/mesa/main/clear.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * 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 "enums.h"
  37 #include "fbobject.h"
  38 #include "get.h"
  39 #include "macros.h"
  40 #include "mtypes.h"
  41 #include "state.h"
  42
  43
  44
  45 void GLAPIENTRY
  46 _mesa_ClearIndex( GLfloat c )
  47 {
  48    GET_CURRENT_CONTEXT(ctx);
  49
  50    ctx->Color.ClearIndex = (GLuint) c;
  51 }
  52
  53
  54 /**
  55  * Specify the clear values for the color buffers.
  56  *
  57  * \param red red color component.
  58  * \param green green color component.
  59  * \param blue blue color component.
  60  * \param alpha alpha component.
  61  *
  62  * \sa glClearColor().
  63  */
  64 void GLAPIENTRY
  65 _mesa_ClearColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
  66 {
  67    GET_CURRENT_CONTEXT(ctx);
  68
  69    ctx->Color.ClearColor.f[0] = red;
  70    ctx->Color.ClearColor.f[1] = green;
  71    ctx->Color.ClearColor.f[2] = blue;
  72    ctx->Color.ClearColor.f[3] = alpha;
  73 }
  74
  75
  76 /**
  77  * GL_EXT_texture_integer
  78  */
  79 void GLAPIENTRY
  80 _mesa_ClearColorIiEXT(GLint r, GLint g, GLint b, GLint a)
  81 {
  82    GET_CURRENT_CONTEXT(ctx);
  83
  84    ctx->Color.ClearColor.i[0] = r;
  85    ctx->Color.ClearColor.i[1] = g;
  86    ctx->Color.ClearColor.i[2] = b;
  87    ctx->Color.ClearColor.i[3] = a;
  88 }
  89
  90
  91 /**
  92  * GL_EXT_texture_integer
  93  */
  94 void GLAPIENTRY
  95 _mesa_ClearColorIuiEXT(GLuint r, GLuint g, GLuint b, GLuint a)
  96 {
  97    GET_CURRENT_CONTEXT(ctx);
  98
  99    ctx->Color.ClearColor.ui[0] = r;
 100    ctx->Color.ClearColor.ui[1] = g;
 101    ctx->Color.ClearColor.ui[2] = b;
 102    ctx->Color.ClearColor.ui[3] = a;
 103 }
 104
 105
 106 /**
 107  * Returns true if color writes are enabled for the given color attachment.
 108  *
 109  * Beyond checking ColorMask, this uses _mesa_format_has_color_component to
 110  * ignore components that don't actually exist in the format (such as X in
 111  * XRGB).
 112  */
 113 static bool
 114 color_buffer_writes_enabled(const struct gl_context *ctx, unsigned idx)
 115 {
 116    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[idx];
 117    GLuint c;
 118    GLubyte colorMask = 0;
 119
 120    if (rb) {
 121       for (c = 0; c < 4; c++) {
 122          if (_mesa_format_has_color_component(rb->Format, c))
 123             colorMask |= ctx->Color.ColorMask[idx][c];
 124       }
 125    }
 126
 127    return colorMask != 0;
 128 }
 129
 130
 131 /**
 132  * Clear buffers.
 133  *
 134  * \param mask bit-mask indicating the buffers to be cleared.
 135  *
 136  * Flushes the vertices and verifies the parameter.
 137  * If __struct gl_contextRec::NewState is set then calls _mesa_update_state()
 138  * to update gl_frame_buffer::_Xmin, etc.  If the rasterization mode is set to
 139  * GL_RENDER then requests the driver to clear the buffers, via the
 140  * dd_function_table::Clear callback.
 141  */
 142 void GLAPIENTRY
 143 _mesa_Clear( GLbitfield mask )
 144 {
 145    GET_CURRENT_CONTEXT(ctx);
 146    FLUSH_VERTICES(ctx, 0);
 147
 148    FLUSH_CURRENT(ctx, 0);
 149
 150    if (MESA_VERBOSE & VERBOSE_API)
 151       _mesa_debug(ctx, "glClear 0x%x\n", mask);
 152
 153    if (mask & ~(GL_COLOR_BUFFER_BIT |
 154                 GL_DEPTH_BUFFER_BIT |
 155                 GL_STENCIL_BUFFER_BIT |
 156                 GL_ACCUM_BUFFER_BIT)) {
 157       /* invalid bit set */
 158       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(0x%x)", mask);
 159       return;
 160    }
 161
 162    /* Accumulation buffers were removed in core contexts, and they never
 163     * existed in OpenGL ES.
 164     */
 165    if ((mask & GL_ACCUM_BUFFER_BIT) != 0
 166        && (ctx->API == API_OPENGL_CORE || _mesa_is_gles(ctx))) {
 167       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(GL_ACCUM_BUFFER_BIT)");
 168       return;
 169    }
 170
 171    if (ctx->NewState) {
 172       _mesa_update_state( ctx );        /* update _Xmin, etc */
 173    }
 174
 175    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 176       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 177                   "glClear(incomplete framebuffer)");
 178       return;
 179    }
 180
 181    if (ctx->RasterDiscard)
 182       return;
 183
 184    if (ctx->RenderMode == GL_RENDER) {
 185       GLbitfield bufferMask;
 186
 187       /* don't clear depth buffer if depth writing disabled */
 188       if (!ctx->Depth.Mask)
 189          mask &= ~GL_DEPTH_BUFFER_BIT;
 190
 191       /* Build the bitmask to send to device driver's Clear function.
 192        * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
 193        * of the BUFFER_BIT_FRONT/BACK_LEFT/RIGHT flags, or one of the
 194        * BUFFER_BIT_COLORn flags.
 195        */
 196       bufferMask = 0;
 197       if (mask & GL_COLOR_BUFFER_BIT) {
 198          GLuint i;
 199          for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 200             GLint buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
 201
 202             if (buf >= 0 && color_buffer_writes_enabled(ctx, i)) {
 203                bufferMask |= 1 << buf;
 204             }
 205          }
 206       }
 207
 208       if ((mask & GL_DEPTH_BUFFER_BIT)
 209           && ctx->DrawBuffer->Visual.haveDepthBuffer) {
 210          bufferMask |= BUFFER_BIT_DEPTH;
 211       }
 212
 213       if ((mask & GL_STENCIL_BUFFER_BIT)
 214           && ctx->DrawBuffer->Visual.haveStencilBuffer) {
 215          bufferMask |= BUFFER_BIT_STENCIL;
 216       }
 217
 218       if ((mask & GL_ACCUM_BUFFER_BIT)
 219           && ctx->DrawBuffer->Visual.haveAccumBuffer) {
 220          bufferMask |= BUFFER_BIT_ACCUM;
 221       }
 222
 223       assert(ctx->Driver.Clear);
 224       ctx->Driver.Clear(ctx, bufferMask);
 225    }
 226 }
 227
 228
 229 /** Returned by make_color_buffer_mask() for errors */
 230 #define INVALID_MASK ~0x0U
 231
 232
 233 /**
 234  * Convert the glClearBuffer 'drawbuffer' parameter into a bitmask of
 235  * BUFFER_BIT_x values.
 236  * Return INVALID_MASK if the drawbuffer value is invalid.
 237  */
 238 static GLbitfield
 239 make_color_buffer_mask(struct gl_context *ctx, GLint drawbuffer)
 240 {
 241    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 242    GLbitfield mask = 0x0;
 243
 244    /* From the GL 4.0 specification:
 245     *   If buffer is COLOR, a particular draw buffer DRAW_BUFFERi is
 246     *   specified by passing i as the parameter drawbuffer, and value
 247     *   points to a four-element vector specifying the R, G, B, and A
 248     *   color to clear that draw buffer to. If the draw buffer is one
 249     *   of FRONT, BACK, LEFT, RIGHT, or FRONT_AND_BACK, identifying
 250     *   multiple buffers, each selected buffer is cleared to the same
 251     *   value.
 252     *
 253     * Note that "drawbuffer" and "draw buffer" have different meaning.
 254     * "drawbuffer" specifies DRAW_BUFFERi, while "draw buffer" is what's
 255     * assigned to DRAW_BUFFERi. It could be COLOR_ATTACHMENT0, FRONT, BACK,
 256     * etc.
 257     */
 258    if (drawbuffer < 0 || drawbuffer >= (GLint)ctx->Const.MaxDrawBuffers) {
 259       return INVALID_MASK;
 260    }
 261
 262    switch (ctx->DrawBuffer->ColorDrawBuffer[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       {
 299          GLint buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[drawbuffer];
 300
 301          if (buf >= 0 && att[buf].Renderbuffer) {
 302             mask |= 1 << buf;
 303          }
 304       }
 305    }
 306
 307    return mask;
 308 }
 309
 310
 311
 312 /**
 313  * New in GL 3.0
 314  * Clear signed integer color buffer or stencil buffer (not depth).
 315  */
 316 void GLAPIENTRY
 317 _mesa_ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint *value)
 318 {
 319    GET_CURRENT_CONTEXT(ctx);
 320    FLUSH_VERTICES(ctx, 0);
 321
 322    FLUSH_CURRENT(ctx, 0);
 323
 324    if (ctx->NewState) {
 325       _mesa_update_state( ctx );
 326    }
 327
 328    switch (buffer) {
 329    case GL_STENCIL:
 330       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 331        *
 332        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 333        *     COLOR and drawbuffer is less than zero, or greater than the
 334        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 335        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 336        */
 337       if (drawbuffer != 0) {
 338          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 339                      drawbuffer);
 340          return;
 341       }
 342       else if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer
 343                && !ctx->RasterDiscard) {
 344          /* Save current stencil clear value, set to 'value', do the
 345           * stencil clear and restore the clear value.
 346           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 347           * hook instead.
 348           */
 349          const GLuint clearSave = ctx->Stencil.Clear;
 350          ctx->Stencil.Clear = *value;
 351          ctx->Driver.Clear(ctx, BUFFER_BIT_STENCIL);
 352          ctx->Stencil.Clear = clearSave;
 353       }
 354       break;
 355    case GL_COLOR:
 356       {
 357          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 358          if (mask == INVALID_MASK) {
 359             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 360                         drawbuffer);
 361             return;
 362          }
 363          else if (mask && !ctx->RasterDiscard) {
 364             union gl_color_union clearSave;
 365
 366             /* save color */
 367             clearSave = ctx->Color.ClearColor;
 368             /* set color */
 369             COPY_4V(ctx->Color.ClearColor.i, value);
 370             /* clear buffer(s) */
 371             ctx->Driver.Clear(ctx, mask);
 372             /* restore color */
 373             ctx->Color.ClearColor = clearSave;
 374          }
 375       }
 376       break;
 377    default:
 378       /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 379        * of the OpenGL 4.5 spec states:
 380        *
 381        *    "An INVALID_ENUM error is generated by ClearBufferiv and
 382        *     ClearNamedFramebufferiv if buffer is not COLOR or STENCIL."
 383        */
 384       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferiv(buffer=%s)",
 385                   _mesa_enum_to_string(buffer));
 386       return;
 387    }
 388 }
 389
 390
 391 /**
 392  * The ClearBuffer framework is so complicated and so riddled with the
 393  * assumption that the framebuffer is bound that, for now, we will just fake
 394  * direct state access clearing for the user.
 395  */
 396 void GLAPIENTRY
 397 _mesa_ClearNamedFramebufferiv(GLuint framebuffer, GLenum buffer,
 398                               GLint drawbuffer, const GLint *value)
 399 {
 400    GLint oldfb;
 401
 402    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 403    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 404    _mesa_ClearBufferiv(buffer, drawbuffer, value);
 405    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 406 }
 407
 408
 409 /**
 410  * New in GL 3.0
 411  * Clear unsigned integer color buffer (not depth, not stencil).
 412  */
 413 void GLAPIENTRY
 414 _mesa_ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint *value)
 415 {
 416    GET_CURRENT_CONTEXT(ctx);
 417
 418    FLUSH_VERTICES(ctx, 0);
 419    FLUSH_CURRENT(ctx, 0);
 420
 421    if (ctx->NewState) {
 422       _mesa_update_state( ctx );
 423    }
 424
 425    switch (buffer) {
 426    case GL_COLOR:
 427       {
 428          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 429          if (mask == INVALID_MASK) {
 430             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferuiv(drawbuffer=%d)",
 431                         drawbuffer);
 432             return;
 433          }
 434          else if (mask && !ctx->RasterDiscard) {
 435             union gl_color_union clearSave;
 436
 437             /* save color */
 438             clearSave = ctx->Color.ClearColor;
 439             /* set color */
 440             COPY_4V(ctx->Color.ClearColor.ui, value);
 441             /* clear buffer(s) */
 442             ctx->Driver.Clear(ctx, mask);
 443             /* restore color */
 444             ctx->Color.ClearColor = clearSave;
 445          }
 446       }
 447       break;
 448    default:
 449       /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 450        * of the OpenGL 4.5 spec states:
 451        *
 452        *    "An INVALID_ENUM error is generated by ClearBufferuiv and
 453        *     ClearNamedFramebufferuiv if buffer is not COLOR."
 454        */
 455       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferuiv(buffer=%s)",
 456                   _mesa_enum_to_string(buffer));
 457       return;
 458    }
 459 }
 460
 461
 462 /**
 463  * The ClearBuffer framework is so complicated and so riddled with the
 464  * assumption that the framebuffer is bound that, for now, we will just fake
 465  * direct state access clearing for the user.
 466  */
 467 void GLAPIENTRY
 468 _mesa_ClearNamedFramebufferuiv(GLuint framebuffer, GLenum buffer,
 469                                GLint drawbuffer, const GLuint *value)
 470 {
 471    GLint oldfb;
 472
 473    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 474    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 475    _mesa_ClearBufferuiv(buffer, drawbuffer, value);
 476    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 477 }
 478
 479
 480 /**
 481  * New in GL 3.0
 482  * Clear fixed-pt or float color buffer or depth buffer (not stencil).
 483  */
 484 void GLAPIENTRY
 485 _mesa_ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat *value)
 486 {
 487    GET_CURRENT_CONTEXT(ctx);
 488
 489    FLUSH_VERTICES(ctx, 0);
 490    FLUSH_CURRENT(ctx, 0);
 491
 492    if (ctx->NewState) {
 493       _mesa_update_state( ctx );
 494    }
 495
 496    switch (buffer) {
 497    case GL_DEPTH:
 498       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 499        *
 500        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 501        *     COLOR and drawbuffer is less than zero, or greater than the
 502        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 503        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 504        */
 505       if (drawbuffer != 0) {
 506          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 507                      drawbuffer);
 508          return;
 509       }
 510       else if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer
 511                && !ctx->RasterDiscard) {
 512          /* Save current depth clear value, set to 'value', do the
 513           * depth clear and restore the clear value.
 514           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 515           * hook instead.
 516           */
 517          const GLclampd clearSave = ctx->Depth.Clear;
 518          ctx->Depth.Clear = *value;
 519          ctx->Driver.Clear(ctx, BUFFER_BIT_DEPTH);
 520          ctx->Depth.Clear = clearSave;
 521       }
 522       /* clear depth buffer to value */
 523       break;
 524    case GL_COLOR:
 525       {
 526          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 527          if (mask == INVALID_MASK) {
 528             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 529                         drawbuffer);
 530             return;
 531          }
 532          else if (mask && !ctx->RasterDiscard) {
 533             union gl_color_union clearSave;
 534
 535             /* save color */
 536             clearSave = ctx->Color.ClearColor;
 537             /* set color */
 538             COPY_4V(ctx->Color.ClearColor.f, value);
 539             /* clear buffer(s) */
 540             ctx->Driver.Clear(ctx, mask);
 541             /* restore color */
 542             ctx->Color.ClearColor = clearSave;
 543          }
 544       }
 545       break;
 546    default:
 547       /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 548        * of the OpenGL 4.5 spec states:
 549        *
 550        *    "An INVALID_ENUM error is generated by ClearBufferfv and
 551        *     ClearNamedFramebufferfv if buffer is not COLOR or DEPTH."
 552        */
 553       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfv(buffer=%s)",
 554                   _mesa_enum_to_string(buffer));
 555       return;
 556    }
 557 }
 558
 559
 560 /**
 561  * The ClearBuffer framework is so complicated and so riddled with the
 562  * assumption that the framebuffer is bound that, for now, we will just fake
 563  * direct state access clearing for the user.
 564  */
 565 void GLAPIENTRY
 566 _mesa_ClearNamedFramebufferfv(GLuint framebuffer, GLenum buffer,
 567                               GLint drawbuffer, const GLfloat *value)
 568 {
 569    GLint oldfb;
 570
 571    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 572    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 573    _mesa_ClearBufferfv(buffer, drawbuffer, value);
 574    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 575 }
 576
 577
 578 /**
 579  * New in GL 3.0
 580  * Clear depth/stencil buffer only.
 581  */
 582 void GLAPIENTRY
 583 _mesa_ClearBufferfi(GLenum buffer, GLint drawbuffer,
 584                     GLfloat depth, GLint stencil)
 585 {
 586    GET_CURRENT_CONTEXT(ctx);
 587    GLbitfield mask = 0;
 588
 589    FLUSH_VERTICES(ctx, 0);
 590    FLUSH_CURRENT(ctx, 0);
 591
 592    if (buffer != GL_DEPTH_STENCIL) {
 593       _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfi(buffer=%s)",
 594                   _mesa_enum_to_string(buffer));
 595       return;
 596    }
 597
 598    /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 599     *
 600     *     "ClearBuffer generates an INVALID VALUE error if buffer is
 601     *     COLOR and drawbuffer is less than zero, or greater than the
 602     *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 603     *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 604     */
 605    if (drawbuffer != 0) {
 606       _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfi(drawbuffer=%d)",
 607                   drawbuffer);
 608       return;
 609    }
 610
 611    if (ctx->RasterDiscard)
 612       return;
 613
 614    if (ctx->NewState) {
 615       _mesa_update_state( ctx );
 616    }
 617
 618    if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer)
 619       mask |= BUFFER_BIT_DEPTH;
 620    if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer)
 621       mask |= BUFFER_BIT_STENCIL;
 622
 623    if (mask) {
 624       /* save current clear values */
 625       const GLclampd clearDepthSave = ctx->Depth.Clear;
 626       const GLuint clearStencilSave = ctx->Stencil.Clear;
 627
 628       /* set new clear values */
 629       ctx->Depth.Clear = depth;
 630       ctx->Stencil.Clear = stencil;
 631
 632       /* clear buffers */
 633       ctx->Driver.Clear(ctx, mask);
 634
 635       /* restore */
 636       ctx->Depth.Clear = clearDepthSave;
 637       ctx->Stencil.Clear = clearStencilSave;
 638    }
 639 }
 640
 641
 642 /**
 643  * The ClearBuffer framework is so complicated and so riddled with the
 644  * assumption that the framebuffer is bound that, for now, we will just fake
 645  * direct state access clearing for the user.
 646  */
 647 void GLAPIENTRY
 648 _mesa_ClearNamedFramebufferfi(GLuint framebuffer, GLenum buffer,
 649                               GLfloat depth, GLint stencil)
 650 {
 651    GLint oldfb;
 652
 653    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 654    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 655    _mesa_ClearBufferfi(buffer, 0, depth, stencil);
 656    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 657 }