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
 119    if (rb) {
 120       for (c = 0; c < 4; c++) {
 121          if (GET_COLORMASK_BIT(ctx->Color.ColorMask, idx, c) &&
 122              _mesa_format_has_color_component(rb->Format, c)) {
 123             return true;
 124          }
 125       }
 126    }
 127
 128    return false;
 129 }
 130
 131
 132 /**
 133  * Clear buffers.
 134  *
 135  * \param mask bit-mask indicating the buffers to be cleared.
 136  *
 137  * Flushes the vertices and verifies the parameter.
 138  * If __struct gl_contextRec::NewState is set then calls _mesa_update_state()
 139  * to update gl_frame_buffer::_Xmin, etc.  If the rasterization mode is set to
 140  * GL_RENDER then requests the driver to clear the buffers, via the
 141  * dd_function_table::Clear callback.
 142  */
 143 static ALWAYS_INLINE void
 144 clear(struct gl_context *ctx, GLbitfield mask, bool no_error)
 145 {
 146    FLUSH_VERTICES(ctx, 0);
 147
 148    if (!no_error) {
 149       if (mask & ~(GL_COLOR_BUFFER_BIT |
 150                    GL_DEPTH_BUFFER_BIT |
 151                    GL_STENCIL_BUFFER_BIT |
 152                    GL_ACCUM_BUFFER_BIT)) {
 153          _mesa_error( ctx, GL_INVALID_VALUE, "glClear(0x%x)", mask);
 154          return;
 155       }
 156
 157       /* Accumulation buffers were removed in core contexts, and they never
 158        * existed in OpenGL ES.
 159        */
 160       if ((mask & GL_ACCUM_BUFFER_BIT) != 0
 161           && (ctx->API == API_OPENGL_CORE || _mesa_is_gles(ctx))) {
 162          _mesa_error( ctx, GL_INVALID_VALUE, "glClear(GL_ACCUM_BUFFER_BIT)");
 163          return;
 164       }
 165    }
 166
 167    if (ctx->NewState) {
 168       _mesa_update_state( ctx );        /* update _Xmin, etc */
 169    }
 170
 171    if (!no_error && ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 172       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 173                   "glClear(incomplete framebuffer)");
 174       return;
 175    }
 176
 177    if (ctx->RasterDiscard)
 178       return;
 179
 180    if (ctx->RenderMode == GL_RENDER) {
 181       GLbitfield bufferMask;
 182
 183       /* don't clear depth buffer if depth writing disabled */
 184       if (!ctx->Depth.Mask)
 185          mask &= ~GL_DEPTH_BUFFER_BIT;
 186
 187       /* Build the bitmask to send to device driver's Clear function.
 188        * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
 189        * of the BUFFER_BIT_FRONT/BACK_LEFT/RIGHT flags, or one of the
 190        * BUFFER_BIT_COLORn flags.
 191        */
 192       bufferMask = 0;
 193       if (mask & GL_COLOR_BUFFER_BIT) {
 194          GLuint i;
 195          for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 196             gl_buffer_index buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
 197
 198             if (buf != BUFFER_NONE && color_buffer_writes_enabled(ctx, i)) {
 199                bufferMask |= 1 << buf;
 200             }
 201          }
 202       }
 203
 204       if ((mask & GL_DEPTH_BUFFER_BIT)
 205           && ctx->DrawBuffer->Visual.depthBits > 0) {
 206          bufferMask |= BUFFER_BIT_DEPTH;
 207       }
 208
 209       if ((mask & GL_STENCIL_BUFFER_BIT)
 210           && ctx->DrawBuffer->Visual.stencilBits > 0) {
 211          bufferMask |= BUFFER_BIT_STENCIL;
 212       }
 213
 214       if ((mask & GL_ACCUM_BUFFER_BIT)
 215           && ctx->DrawBuffer->Visual.accumRedBits > 0) {
 216          bufferMask |= BUFFER_BIT_ACCUM;
 217       }
 218
 219       assert(ctx->Driver.Clear);
 220       ctx->Driver.Clear(ctx, bufferMask);
 221    }
 222 }
 223
 224
 225 void GLAPIENTRY
 226 _mesa_Clear_no_error(GLbitfield mask)
 227 {
 228    GET_CURRENT_CONTEXT(ctx);
 229    clear(ctx, mask, true);
 230 }
 231
 232
 233 void GLAPIENTRY
 234 _mesa_Clear(GLbitfield mask)
 235 {
 236    GET_CURRENT_CONTEXT(ctx);
 237
 238    if (MESA_VERBOSE & VERBOSE_API)
 239       _mesa_debug(ctx, "glClear 0x%x\n", mask);
 240
 241    clear(ctx, mask, false);
 242 }
 243
 244
 245 /** Returned by make_color_buffer_mask() for errors */
 246 #define INVALID_MASK ~0x0U
 247
 248
 249 /**
 250  * Convert the glClearBuffer 'drawbuffer' parameter into a bitmask of
 251  * BUFFER_BIT_x values.
 252  * Return INVALID_MASK if the drawbuffer value is invalid.
 253  */
 254 static GLbitfield
 255 make_color_buffer_mask(struct gl_context *ctx, GLint drawbuffer)
 256 {
 257    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 258    GLbitfield mask = 0x0;
 259
 260    /* From the GL 4.0 specification:
 261     *   If buffer is COLOR, a particular draw buffer DRAW_BUFFERi is
 262     *   specified by passing i as the parameter drawbuffer, and value
 263     *   points to a four-element vector specifying the R, G, B, and A
 264     *   color to clear that draw buffer to. If the draw buffer is one
 265     *   of FRONT, BACK, LEFT, RIGHT, or FRONT_AND_BACK, identifying
 266     *   multiple buffers, each selected buffer is cleared to the same
 267     *   value.
 268     *
 269     * Note that "drawbuffer" and "draw buffer" have different meaning.
 270     * "drawbuffer" specifies DRAW_BUFFERi, while "draw buffer" is what's
 271     * assigned to DRAW_BUFFERi. It could be COLOR_ATTACHMENT0, FRONT, BACK,
 272     * etc.
 273     */
 274    if (drawbuffer < 0 || drawbuffer >= (GLint)ctx->Const.MaxDrawBuffers) {
 275       return INVALID_MASK;
 276    }
 277
 278    switch (ctx->DrawBuffer->ColorDrawBuffer[drawbuffer]) {
 279    case GL_FRONT:
 280       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 281          mask |= BUFFER_BIT_FRONT_LEFT;
 282       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 283          mask |= BUFFER_BIT_FRONT_RIGHT;
 284       break;
 285    case GL_BACK:
 286       /* For GLES contexts with a single buffered configuration, we actually
 287        * only have a front renderbuffer, so any clear calls to GL_BACK should
 288        * affect that buffer. See draw_buffer_enum_to_bitmask for details.
 289        */
 290       if (_mesa_is_gles(ctx))
 291          if (!ctx->DrawBuffer->Visual.doubleBufferMode)
 292             if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 293                mask |= BUFFER_BIT_FRONT_LEFT;
 294       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 295          mask |= BUFFER_BIT_BACK_LEFT;
 296       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 297          mask |= BUFFER_BIT_BACK_RIGHT;
 298       break;
 299    case GL_LEFT:
 300       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 301          mask |= BUFFER_BIT_FRONT_LEFT;
 302       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 303          mask |= BUFFER_BIT_BACK_LEFT;
 304       break;
 305    case GL_RIGHT:
 306       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 307          mask |= BUFFER_BIT_FRONT_RIGHT;
 308       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 309          mask |= BUFFER_BIT_BACK_RIGHT;
 310       break;
 311    case GL_FRONT_AND_BACK:
 312       if (att[BUFFER_FRONT_LEFT].Renderbuffer)
 313          mask |= BUFFER_BIT_FRONT_LEFT;
 314       if (att[BUFFER_BACK_LEFT].Renderbuffer)
 315          mask |= BUFFER_BIT_BACK_LEFT;
 316       if (att[BUFFER_FRONT_RIGHT].Renderbuffer)
 317          mask |= BUFFER_BIT_FRONT_RIGHT;
 318       if (att[BUFFER_BACK_RIGHT].Renderbuffer)
 319          mask |= BUFFER_BIT_BACK_RIGHT;
 320       break;
 321    default:
 322       {
 323          gl_buffer_index buf =
 324             ctx->DrawBuffer->_ColorDrawBufferIndexes[drawbuffer];
 325
 326          if (buf != BUFFER_NONE && att[buf].Renderbuffer) {
 327             mask |= 1 << buf;
 328          }
 329       }
 330    }
 331
 332    return mask;
 333 }
 334
 335
 336
 337 /**
 338  * New in GL 3.0
 339  * Clear signed integer color buffer or stencil buffer (not depth).
 340  */
 341 static ALWAYS_INLINE void
 342 clear_bufferiv(struct gl_context *ctx, GLenum buffer, GLint drawbuffer,
 343                const GLint *value, bool no_error)
 344 {
 345    FLUSH_VERTICES(ctx, 0);
 346
 347    if (ctx->NewState) {
 348       _mesa_update_state( ctx );
 349    }
 350
 351    if (!no_error && ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 352       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 353                   "glClearBufferiv(incomplete framebuffer)");
 354       return;
 355    }
 356
 357    switch (buffer) {
 358    case GL_STENCIL:
 359       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 360        *
 361        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 362        *     COLOR and drawbuffer is less than zero, or greater than the
 363        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 364        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 365        */
 366       if (!no_error && drawbuffer != 0) {
 367          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 368                      drawbuffer);
 369          return;
 370       }
 371       else if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer
 372                && !ctx->RasterDiscard) {
 373          /* Save current stencil clear value, set to 'value', do the
 374           * stencil clear and restore the clear value.
 375           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 376           * hook instead.
 377           */
 378          const GLuint clearSave = ctx->Stencil.Clear;
 379          ctx->Stencil.Clear = *value;
 380          ctx->Driver.Clear(ctx, BUFFER_BIT_STENCIL);
 381          ctx->Stencil.Clear = clearSave;
 382       }
 383       break;
 384    case GL_COLOR:
 385       {
 386          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 387          if (!no_error && mask == INVALID_MASK) {
 388             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferiv(drawbuffer=%d)",
 389                         drawbuffer);
 390             return;
 391          }
 392          else if (mask && !ctx->RasterDiscard) {
 393             union gl_color_union clearSave;
 394
 395             /* save color */
 396             clearSave = ctx->Color.ClearColor;
 397             /* set color */
 398             COPY_4V(ctx->Color.ClearColor.i, value);
 399             /* clear buffer(s) */
 400             ctx->Driver.Clear(ctx, mask);
 401             /* restore color */
 402             ctx->Color.ClearColor = clearSave;
 403          }
 404       }
 405       break;
 406    default:
 407       if (!no_error) {
 408          /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 409           * of the OpenGL 4.5 spec states:
 410           *
 411           *    "An INVALID_ENUM error is generated by ClearBufferiv and
 412           *     ClearNamedFramebufferiv if buffer is not COLOR or STENCIL."
 413           */
 414          _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferiv(buffer=%s)",
 415                      _mesa_enum_to_string(buffer));
 416       }
 417       return;
 418    }
 419 }
 420
 421
 422 void GLAPIENTRY
 423 _mesa_ClearBufferiv_no_error(GLenum buffer, GLint drawbuffer, const GLint *value)
 424 {
 425    GET_CURRENT_CONTEXT(ctx);
 426    clear_bufferiv(ctx, buffer, drawbuffer, value, true);
 427 }
 428
 429
 430 void GLAPIENTRY
 431 _mesa_ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint *value)
 432 {
 433    GET_CURRENT_CONTEXT(ctx);
 434    clear_bufferiv(ctx, buffer, drawbuffer, value, false);
 435 }
 436
 437
 438 /**
 439  * The ClearBuffer framework is so complicated and so riddled with the
 440  * assumption that the framebuffer is bound that, for now, we will just fake
 441  * direct state access clearing for the user.
 442  */
 443 void GLAPIENTRY
 444 _mesa_ClearNamedFramebufferiv(GLuint framebuffer, GLenum buffer,
 445                               GLint drawbuffer, const GLint *value)
 446 {
 447    GLint oldfb;
 448
 449    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 450    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 451    _mesa_ClearBufferiv(buffer, drawbuffer, value);
 452    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 453 }
 454
 455
 456 /**
 457  * New in GL 3.0
 458  * Clear unsigned integer color buffer (not depth, not stencil).
 459  */
 460 static ALWAYS_INLINE void
 461 clear_bufferuiv(struct gl_context *ctx, GLenum buffer, GLint drawbuffer,
 462                 const GLuint *value, bool no_error)
 463 {
 464    FLUSH_VERTICES(ctx, 0);
 465
 466    if (ctx->NewState) {
 467       _mesa_update_state( ctx );
 468    }
 469
 470    switch (buffer) {
 471    case GL_COLOR:
 472       {
 473          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 474          if (!no_error && mask == INVALID_MASK) {
 475             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferuiv(drawbuffer=%d)",
 476                         drawbuffer);
 477             return;
 478          }
 479          else if (mask && !ctx->RasterDiscard) {
 480             union gl_color_union clearSave;
 481
 482             /* save color */
 483             clearSave = ctx->Color.ClearColor;
 484             /* set color */
 485             COPY_4V(ctx->Color.ClearColor.ui, value);
 486             /* clear buffer(s) */
 487             ctx->Driver.Clear(ctx, mask);
 488             /* restore color */
 489             ctx->Color.ClearColor = clearSave;
 490          }
 491       }
 492       break;
 493    default:
 494       if (!no_error) {
 495          /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 496           * of the OpenGL 4.5 spec states:
 497           *
 498           *    "An INVALID_ENUM error is generated by ClearBufferuiv and
 499           *     ClearNamedFramebufferuiv if buffer is not COLOR."
 500           */
 501          _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferuiv(buffer=%s)",
 502                      _mesa_enum_to_string(buffer));
 503       }
 504       return;
 505    }
 506 }
 507
 508
 509 void GLAPIENTRY
 510 _mesa_ClearBufferuiv_no_error(GLenum buffer, GLint drawbuffer,
 511                               const GLuint *value)
 512 {
 513    GET_CURRENT_CONTEXT(ctx);
 514    clear_bufferuiv(ctx, buffer, drawbuffer, value, true);
 515 }
 516
 517
 518 void GLAPIENTRY
 519 _mesa_ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint *value)
 520 {
 521    GET_CURRENT_CONTEXT(ctx);
 522    clear_bufferuiv(ctx, buffer, drawbuffer, value, false);
 523 }
 524
 525
 526 /**
 527  * The ClearBuffer framework is so complicated and so riddled with the
 528  * assumption that the framebuffer is bound that, for now, we will just fake
 529  * direct state access clearing for the user.
 530  */
 531 void GLAPIENTRY
 532 _mesa_ClearNamedFramebufferuiv(GLuint framebuffer, GLenum buffer,
 533                                GLint drawbuffer, const GLuint *value)
 534 {
 535    GLint oldfb;
 536
 537    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 538    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 539    _mesa_ClearBufferuiv(buffer, drawbuffer, value);
 540    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 541 }
 542
 543
 544 /**
 545  * New in GL 3.0
 546  * Clear fixed-pt or float color buffer or depth buffer (not stencil).
 547  */
 548 static ALWAYS_INLINE void
 549 clear_bufferfv(struct gl_context *ctx, GLenum buffer, GLint drawbuffer,
 550                const GLfloat *value, bool no_error)
 551 {
 552    FLUSH_VERTICES(ctx, 0);
 553
 554    if (ctx->NewState) {
 555       _mesa_update_state( ctx );
 556    }
 557
 558    switch (buffer) {
 559    case GL_DEPTH:
 560       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 561        *
 562        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 563        *     COLOR and drawbuffer is less than zero, or greater than the
 564        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 565        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 566        */
 567       if (!no_error && drawbuffer != 0) {
 568          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 569                      drawbuffer);
 570          return;
 571       }
 572       else if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer
 573                && !ctx->RasterDiscard) {
 574          /* Save current depth clear value, set to 'value', do the
 575           * depth clear and restore the clear value.
 576           * XXX in the future we may have a new ctx->Driver.ClearBuffer()
 577           * hook instead.
 578           */
 579          const GLclampd clearSave = ctx->Depth.Clear;
 580          ctx->Depth.Clear = *value;
 581          ctx->Driver.Clear(ctx, BUFFER_BIT_DEPTH);
 582          ctx->Depth.Clear = clearSave;
 583       }
 584       /* clear depth buffer to value */
 585       break;
 586    case GL_COLOR:
 587       {
 588          const GLbitfield mask = make_color_buffer_mask(ctx, drawbuffer);
 589          if (!no_error && mask == INVALID_MASK) {
 590             _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfv(drawbuffer=%d)",
 591                         drawbuffer);
 592             return;
 593          }
 594          else if (mask && !ctx->RasterDiscard) {
 595             union gl_color_union clearSave;
 596
 597             /* save color */
 598             clearSave = ctx->Color.ClearColor;
 599             /* set color */
 600             COPY_4V(ctx->Color.ClearColor.f, value);
 601             /* clear buffer(s) */
 602             ctx->Driver.Clear(ctx, mask);
 603             /* restore color */
 604             ctx->Color.ClearColor = clearSave;
 605          }
 606       }
 607       break;
 608    default:
 609       if (!no_error) {
 610          /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
 611           * of the OpenGL 4.5 spec states:
 612           *
 613           *    "An INVALID_ENUM error is generated by ClearBufferfv and
 614           *     ClearNamedFramebufferfv if buffer is not COLOR or DEPTH."
 615           */
 616          _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfv(buffer=%s)",
 617                      _mesa_enum_to_string(buffer));
 618       }
 619       return;
 620    }
 621 }
 622
 623
 624 void GLAPIENTRY
 625 _mesa_ClearBufferfv_no_error(GLenum buffer, GLint drawbuffer,
 626                              const GLfloat *value)
 627 {
 628    GET_CURRENT_CONTEXT(ctx);
 629    clear_bufferfv(ctx, buffer, drawbuffer, value, true);
 630 }
 631
 632
 633 void GLAPIENTRY
 634 _mesa_ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat *value)
 635 {
 636    GET_CURRENT_CONTEXT(ctx);
 637    clear_bufferfv(ctx, buffer, drawbuffer, value, false);
 638 }
 639
 640
 641 /**
 642  * The ClearBuffer framework is so complicated and so riddled with the
 643  * assumption that the framebuffer is bound that, for now, we will just fake
 644  * direct state access clearing for the user.
 645  */
 646 void GLAPIENTRY
 647 _mesa_ClearNamedFramebufferfv(GLuint framebuffer, GLenum buffer,
 648                               GLint drawbuffer, const GLfloat *value)
 649 {
 650    GLint oldfb;
 651
 652    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 653    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 654    _mesa_ClearBufferfv(buffer, drawbuffer, value);
 655    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 656 }
 657
 658
 659 /**
 660  * New in GL 3.0
 661  * Clear depth/stencil buffer only.
 662  */
 663 static ALWAYS_INLINE void
 664 clear_bufferfi(struct gl_context *ctx, GLenum buffer, GLint drawbuffer,
 665                GLfloat depth, GLint stencil, bool no_error)
 666 {
 667    GLbitfield mask = 0;
 668
 669    FLUSH_VERTICES(ctx, 0);
 670
 671    if (!no_error) {
 672       if (buffer != GL_DEPTH_STENCIL) {
 673          _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfi(buffer=%s)",
 674                      _mesa_enum_to_string(buffer));
 675          return;
 676       }
 677
 678       /* Page 264 (page 280 of the PDF) of the OpenGL 3.0 spec says:
 679        *
 680        *     "ClearBuffer generates an INVALID VALUE error if buffer is
 681        *     COLOR and drawbuffer is less than zero, or greater than the
 682        *     value of MAX DRAW BUFFERS minus one; or if buffer is DEPTH,
 683        *     STENCIL, or DEPTH STENCIL and drawbuffer is not zero."
 684        */
 685       if (drawbuffer != 0) {
 686          _mesa_error(ctx, GL_INVALID_VALUE, "glClearBufferfi(drawbuffer=%d)",
 687                      drawbuffer);
 688          return;
 689       }
 690    }
 691
 692    if (ctx->RasterDiscard)
 693       return;
 694
 695    if (ctx->NewState) {
 696       _mesa_update_state( ctx );
 697    }
 698
 699    if (!no_error && ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 700       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 701                   "glClearBufferfi(incomplete framebuffer)");
 702       return;
 703    }
 704
 705    if (ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer)
 706       mask |= BUFFER_BIT_DEPTH;
 707    if (ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer)
 708       mask |= BUFFER_BIT_STENCIL;
 709
 710    if (mask) {
 711       /* save current clear values */
 712       const GLclampd clearDepthSave = ctx->Depth.Clear;
 713       const GLuint clearStencilSave = ctx->Stencil.Clear;
 714
 715       /* set new clear values */
 716       ctx->Depth.Clear = depth;
 717       ctx->Stencil.Clear = stencil;
 718
 719       /* clear buffers */
 720       ctx->Driver.Clear(ctx, mask);
 721
 722       /* restore */
 723       ctx->Depth.Clear = clearDepthSave;
 724       ctx->Stencil.Clear = clearStencilSave;
 725    }
 726 }
 727
 728
 729 void GLAPIENTRY
 730 _mesa_ClearBufferfi_no_error(GLenum buffer, GLint drawbuffer,
 731                              GLfloat depth, GLint stencil)
 732 {
 733    GET_CURRENT_CONTEXT(ctx);
 734    clear_bufferfi(ctx, buffer, drawbuffer, depth, stencil, true);
 735 }
 736
 737
 738 void GLAPIENTRY
 739 _mesa_ClearBufferfi(GLenum buffer, GLint drawbuffer,
 740                     GLfloat depth, GLint stencil)
 741 {
 742    GET_CURRENT_CONTEXT(ctx);
 743    clear_bufferfi(ctx, buffer, drawbuffer, depth, stencil, false);
 744 }
 745
 746
 747 /**
 748  * The ClearBuffer framework is so complicated and so riddled with the
 749  * assumption that the framebuffer is bound that, for now, we will just fake
 750  * direct state access clearing for the user.
 751  */
 752 void GLAPIENTRY
 753 _mesa_ClearNamedFramebufferfi(GLuint framebuffer, GLenum buffer,
 754                               GLint drawbuffer, GLfloat depth, GLint stencil)
 755 {
 756    GLint oldfb;
 757
 758    _mesa_GetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldfb);
 759    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);
 760    _mesa_ClearBufferfi(buffer, drawbuffer, depth, stencil);
 761    _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint) oldfb);
 762 }