src/mesa/main/buffers.c

   1 /* $Id: buffers.c,v 1.13 2000/10/17 00:42:02 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #ifdef PC_HEADER
  29 #include "all.h"
  30 #else
  31 #include "glheader.h"
  32 #include "accum.h"
  33 #include "alphabuf.h"
  34 #include "buffers.h"
  35 #include "context.h"
  36 #include "depth.h"
  37 #include "enums.h"
  38 #include "macros.h"
  39 #include "masking.h"
  40 #include "mem.h"
  41 #include "stencil.h"
  42 #include "state.h"
  43 #include "types.h"
  44 #endif
  45
  46
  47
  48 void
  49 _mesa_ClearIndex( GLfloat c )
  50 {
  51    GET_CURRENT_CONTEXT(ctx);
  52    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClearIndex");
  53    ctx->Color.ClearIndex = (GLuint) c;
  54    if (!ctx->Visual.RGBAflag) {
  55       /* it's OK to call glClearIndex in RGBA mode but it should be a NOP */
  56       (*ctx->Driver.ClearIndex)( ctx, ctx->Color.ClearIndex );
  57    }
  58 }
  59
  60
  61
  62 void
  63 _mesa_ClearColor( GLclampf red, GLclampf green,
  64                   GLclampf blue, GLclampf alpha )
  65 {
  66    GET_CURRENT_CONTEXT(ctx);
  67    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClearColor");
  68
  69    ctx->Color.ClearColor[0] = CLAMP( red,   0.0F, 1.0F );
  70    ctx->Color.ClearColor[1] = CLAMP( green, 0.0F, 1.0F );
  71    ctx->Color.ClearColor[2] = CLAMP( blue,  0.0F, 1.0F );
  72    ctx->Color.ClearColor[3] = CLAMP( alpha, 0.0F, 1.0F );
  73
  74    if (ctx->Visual.RGBAflag) {
  75       GLubyte r = (GLint) (ctx->Color.ClearColor[0] * 255.0F);
  76       GLubyte g = (GLint) (ctx->Color.ClearColor[1] * 255.0F);
  77       GLubyte b = (GLint) (ctx->Color.ClearColor[2] * 255.0F);
  78       GLubyte a = (GLint) (ctx->Color.ClearColor[3] * 255.0F);
  79       (*ctx->Driver.ClearColor)( ctx, r, g, b, a );
  80    }
  81 }
  82
  83
  84
  85
  86 /*
  87  * Clear the color buffer when glColorMask or glIndexMask is in effect.
  88  */
  89 static void
  90 clear_color_buffer_with_masking( GLcontext *ctx )
  91 {
  92    const GLint x = ctx->DrawBuffer->Xmin;
  93    const GLint y = ctx->DrawBuffer->Ymin;
  94    const GLint height = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin;
  95    const GLint width  = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin;
  96
  97    if (ctx->Visual.RGBAflag) {
  98       /* RGBA mode */
  99       const GLubyte r = (GLint) (ctx->Color.ClearColor[0] * 255.0F);
 100       const GLubyte g = (GLint) (ctx->Color.ClearColor[1] * 255.0F);
 101       const GLubyte b = (GLint) (ctx->Color.ClearColor[2] * 255.0F);
 102       const GLubyte a = (GLint) (ctx->Color.ClearColor[3] * 255.0F);
 103       GLint i;
 104       for (i = 0; i < height; i++) {
 105          GLubyte rgba[MAX_WIDTH][4];
 106          GLint j;
 107          for (j=0; j<width; j++) {
 108             rgba[j][RCOMP] = r;
 109             rgba[j][GCOMP] = g;
 110             rgba[j][BCOMP] = b;
 111             rgba[j][ACOMP] = a;
 112          }
 113          _mesa_mask_rgba_span( ctx, width, x, y + i, rgba );
 114          (*ctx->Driver.WriteRGBASpan)( ctx, width, x, y + i,
 115                                        (CONST GLubyte (*)[4])rgba, NULL );
 116       }
 117    }
 118    else {
 119       /* Color index mode */
 120       GLuint span[MAX_WIDTH];
 121       GLubyte mask[MAX_WIDTH];
 122       GLint i, j;
 123       MEMSET( mask, 1, width );
 124       for (i=0;i<height;i++) {
 125          for (j=0;j<width;j++) {
 126             span[j] = ctx->Color.ClearIndex;
 127          }
 128          _mesa_mask_index_span( ctx, width, x, y + i, span );
 129          (*ctx->Driver.WriteCI32Span)( ctx, width, x, y + i, span, mask );
 130       }
 131    }
 132 }
 133
 134
 135
 136 /*
 137  * Clear a color buffer without index/channel masking.
 138  */
 139 static void
 140 clear_color_buffer(GLcontext *ctx)
 141 {
 142    const GLint x = ctx->DrawBuffer->Xmin;
 143    const GLint y = ctx->DrawBuffer->Ymin;
 144    const GLint height = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin;
 145    const GLint width  = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin;
 146    const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
 147
 148    if (ctx->Visual.RGBAflag) {
 149       /* RGBA mode */
 150       const GLubyte r = (GLint) (ctx->Color.ClearColor[0] * 255.0F);
 151       const GLubyte g = (GLint) (ctx->Color.ClearColor[1] * 255.0F);
 152       const GLubyte b = (GLint) (ctx->Color.ClearColor[2] * 255.0F);
 153       const GLubyte a = (GLint) (ctx->Color.ClearColor[3] * 255.0F);
 154       GLubyte span[MAX_WIDTH][4];
 155       GLint i;
 156
 157       ASSERT(colorMask == 0xffffffff);
 158
 159       for (i = 0; i < width; i++) {
 160          span[i][RCOMP] = r;
 161          span[i][GCOMP] = g;
 162          span[i][BCOMP] = b;
 163          span[i][ACOMP] = a;
 164       }
 165       for (i = 0; i < height; i++) {
 166          (*ctx->Driver.WriteRGBASpan)( ctx, width, x, y + i,
 167                                        (CONST GLubyte (*)[4]) span, NULL );
 168       }
 169    }
 170    else {
 171       /* Color index mode */
 172       ASSERT(ctx->Color.IndexMask == ~0);
 173       if (ctx->Visual.IndexBits == 8) {
 174          /* 8-bit clear */
 175          GLubyte span[MAX_WIDTH];
 176          GLint i;
 177          MEMSET(span, ctx->Color.ClearIndex, width);
 178          for (i = 0; i < height; i++) {
 179             (*ctx->Driver.WriteCI8Span)( ctx, width, x, y + i, span, NULL );
 180          }
 181       }
 182       else {
 183          /* non 8-bit clear */
 184          GLuint span[MAX_WIDTH];
 185          GLint i;
 186          for (i = 0; i < width; i++) {
 187             span[i] = ctx->Color.ClearIndex;
 188          }
 189          for (i = 0; i < height; i++) {
 190             (*ctx->Driver.WriteCI32Span)( ctx, width, x, y + i, span, NULL );
 191          }
 192       }
 193    }
 194 }
 195
 196
 197
 198 /*
 199  * Clear the front/back/left/right color buffers.
 200  * This function is usually only called if we need to clear the
 201  * buffers with masking.
 202  */
 203 static void
 204 clear_color_buffers(GLcontext *ctx)
 205 {
 206    const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
 207    GLuint bufferBit;
 208
 209    /* loop over four possible dest color buffers */
 210    for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) {
 211       if (bufferBit & ctx->Color.DrawDestMask) {
 212          if (bufferBit == FRONT_LEFT_BIT) {
 213             (void) (*ctx->Driver.SetDrawBuffer)( ctx, GL_FRONT_LEFT);
 214          }
 215          else if (bufferBit == FRONT_RIGHT_BIT) {
 216             (void) (*ctx->Driver.SetDrawBuffer)( ctx, GL_FRONT_RIGHT);
 217          }
 218          else if (bufferBit == BACK_LEFT_BIT) {
 219             (void) (*ctx->Driver.SetDrawBuffer)( ctx, GL_BACK_LEFT);
 220          }
 221          else {
 222             (void) (*ctx->Driver.SetDrawBuffer)( ctx, GL_BACK_RIGHT);
 223          }
 224
 225          if (colorMask != 0xffffffff) {
 226             clear_color_buffer_with_masking(ctx);
 227          }
 228          else {
 229             clear_color_buffer(ctx);
 230          }
 231       }
 232    }
 233
 234    /* restore default dest buffer */
 235    (void) (*ctx->Driver.SetDrawBuffer)( ctx, ctx->Color.DriverDrawBuffer );
 236 }
 237
 238
 239
 240 void
 241 _mesa_Clear( GLbitfield mask )
 242 {
 243    GET_CURRENT_CONTEXT(ctx);
 244 #ifdef PROFILE
 245    GLdouble t0 = gl_time();
 246 #endif
 247    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClear");
 248
 249    if (MESA_VERBOSE & VERBOSE_API)
 250       fprintf(stderr, "glClear 0x%x\n", mask);
 251
 252    if (ctx->NewState) {
 253       gl_update_state( ctx );
 254    }
 255
 256    if (ctx->RenderMode==GL_RENDER) {
 257       const GLint x = ctx->DrawBuffer->Xmin;
 258       const GLint y = ctx->DrawBuffer->Ymin;
 259       const GLint height = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin;
 260       const GLint width  = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin;
 261       GLbitfield ddMask;
 262       GLbitfield newMask;
 263
 264       /* don't clear depth buffer if depth writing disabled */
 265       if (!ctx->Depth.Mask)
 266          CLEAR_BITS(mask, GL_DEPTH_BUFFER_BIT);
 267
 268       /* Build bitmask to send to driver Clear function */
 269       ddMask = mask & (GL_DEPTH_BUFFER_BIT |
 270                        GL_STENCIL_BUFFER_BIT |
 271                        GL_ACCUM_BUFFER_BIT);
 272       if (mask & GL_COLOR_BUFFER_BIT) {
 273          ddMask |= ctx->Color.DrawDestMask;
 274       }
 275
 276       ASSERT(ctx->Driver.Clear);
 277       newMask = (*ctx->Driver.Clear)( ctx, ddMask, !ctx->Scissor.Enabled,
 278                                       x, y, width, height );
 279
 280 #ifdef DEBUG
 281       {
 282          GLbitfield legalBits = DD_FRONT_LEFT_BIT |
 283                                 DD_FRONT_RIGHT_BIT |
 284                                 DD_BACK_LEFT_BIT |
 285                                 DD_BACK_RIGHT_BIT |
 286                                 DD_DEPTH_BIT |
 287                                 DD_STENCIL_BIT |
 288                                 DD_ACCUM_BIT;
 289          assert((newMask & (~legalBits)) == 0);
 290       }
 291 #endif
 292
 293       RENDER_START(ctx);
 294
 295       /* do software clearing here */
 296       if (newMask) {
 297          if (newMask & ctx->Color.DrawDestMask)   clear_color_buffers(ctx);
 298          if (newMask & GL_DEPTH_BUFFER_BIT)    _mesa_clear_depth_buffer(ctx);
 299          if (newMask & GL_ACCUM_BUFFER_BIT)    _mesa_clear_accum_buffer(ctx);
 300          if (newMask & GL_STENCIL_BUFFER_BIT)  _mesa_clear_stencil_buffer(ctx);
 301       }
 302
 303       /* clear software-based alpha buffer(s) */
 304       if ( (mask & GL_COLOR_BUFFER_BIT)
 305            && ctx->DrawBuffer->UseSoftwareAlphaBuffers
 306            && ctx->Color.ColorMask[ACOMP]) {
 307          _mesa_clear_alpha_buffers( ctx );
 308       }
 309
 310       RENDER_FINISH(ctx);
 311
 312 #ifdef PROFILE
 313       ctx->ClearTime += gl_time() - t0;
 314       ctx->ClearCount++;
 315 #endif
 316    }
 317 }
 318
 319
 320 void
 321 _mesa_DrawBuffer( GLenum mode )
 322 {
 323    GET_CURRENT_CONTEXT(ctx);
 324    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glDrawBuffer");
 325
 326    if (MESA_VERBOSE & VERBOSE_API)
 327       fprintf(stderr, "glDrawBuffer %s\n", gl_lookup_enum_by_nr(mode));
 328
 329    switch (mode) {
 330       case GL_AUX0:
 331       case GL_AUX1:
 332       case GL_AUX2:
 333       case GL_AUX3:
 334          /* AUX buffers not implemented in Mesa at this time */
 335          gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 336          return;
 337       case GL_RIGHT:
 338          if (!ctx->Visual.StereoFlag) {
 339             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 340             return;}
 341          if (ctx->Visual.DBflag)
 342             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 343          else
 344             ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 345          break;
 346       case GL_FRONT_RIGHT:
 347          if (!ctx->Visual.StereoFlag) {
 348             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 349             return;
 350          }
 351          ctx->Color.DrawDestMask = FRONT_RIGHT_BIT;
 352          break;
 353       case GL_BACK_RIGHT:
 354          if (!ctx->Visual.StereoFlag) {
 355             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 356             return;
 357          }
 358          if (!ctx->Visual.DBflag) {
 359             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 360             return;
 361          }
 362          ctx->Color.DrawDestMask = BACK_RIGHT_BIT;
 363          break;
 364       case GL_BACK_LEFT:
 365          if (!ctx->Visual.DBflag) {
 366             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 367             return;
 368          }
 369          ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 370          break;
 371       case GL_FRONT_AND_BACK:
 372          if (!ctx->Visual.DBflag) {
 373             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 374             return;
 375          }
 376          if (ctx->Visual.StereoFlag)
 377             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT
 378                                     | FRONT_RIGHT_BIT | BACK_RIGHT_BIT;
 379          else
 380             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 381          break;
 382       case GL_BACK:
 383          if (!ctx->Visual.DBflag) {
 384             gl_error( ctx, GL_INVALID_OPERATION, "glDrawBuffer" );
 385             return;
 386          }
 387          if (ctx->Visual.StereoFlag)
 388             ctx->Color.DrawDestMask = BACK_LEFT_BIT | BACK_RIGHT_BIT;
 389          else
 390             ctx->Color.DrawDestMask = BACK_LEFT_BIT;
 391          break;
 392       case GL_LEFT:
 393          /* never an error */
 394          if (ctx->Visual.DBflag)
 395             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | BACK_LEFT_BIT;
 396          else
 397             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 398          break;
 399       case GL_FRONT_LEFT:
 400          /* never an error */
 401          ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 402          break;
 403       case GL_FRONT:
 404          /* never an error */
 405          if (ctx->Visual.StereoFlag)
 406             ctx->Color.DrawDestMask = FRONT_LEFT_BIT | FRONT_RIGHT_BIT;
 407          else
 408             ctx->Color.DrawDestMask = FRONT_LEFT_BIT;
 409          break;
 410       case GL_NONE:
 411          /* never an error */
 412          ctx->Color.DrawDestMask = 0;
 413          break;
 414       default:
 415          gl_error( ctx, GL_INVALID_ENUM, "glDrawBuffer" );
 416          return;
 417    }
 418
 419    /*
 420     * Make the dest buffer mode more precise if possible
 421     */
 422    if (mode == GL_LEFT && !ctx->Visual.DBflag)
 423       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 424    else if (mode == GL_RIGHT && !ctx->Visual.DBflag)
 425       ctx->Color.DriverDrawBuffer = GL_FRONT_RIGHT;
 426    else if (mode == GL_FRONT && !ctx->Visual.StereoFlag)
 427       ctx->Color.DriverDrawBuffer = GL_FRONT_LEFT;
 428    else if (mode == GL_BACK && !ctx->Visual.StereoFlag)
 429       ctx->Color.DriverDrawBuffer = GL_BACK_LEFT;
 430    else
 431       ctx->Color.DriverDrawBuffer = mode;
 432
 433    /*
 434     * Set current alpha buffer pointer
 435     */
 436    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 437       if (ctx->Color.DriverDrawBuffer == GL_FRONT_LEFT)
 438          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontLeftAlpha;
 439       else if (ctx->Color.DriverDrawBuffer == GL_BACK_LEFT)
 440          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackLeftAlpha;
 441       else if (ctx->Color.DriverDrawBuffer == GL_FRONT_RIGHT)
 442          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->FrontRightAlpha;
 443       else if (ctx->Color.DriverDrawBuffer == GL_BACK_RIGHT)
 444          ctx->DrawBuffer->Alpha = ctx->DrawBuffer->BackRightAlpha;
 445    }
 446
 447    /*
 448     * If we get here there can't have been an error.
 449     * Now see if device driver can implement the drawing to the target
 450     * buffer(s).  The driver may not be able to do GL_FRONT_AND_BACK mode
 451     * for example.  We'll take care of that in the core code by looping
 452     * over the individual buffers.
 453     */
 454    ASSERT(ctx->Driver.SetDrawBuffer);
 455    if ( (*ctx->Driver.SetDrawBuffer)(ctx, ctx->Color.DriverDrawBuffer) ) {
 456       /* All OK, the driver will do all buffer writes */
 457       ctx->Color.MultiDrawBuffer = GL_FALSE;
 458    }
 459    else {
 460       /* We'll have to loop over the multiple draw buffer targets */
 461       ctx->Color.MultiDrawBuffer = GL_TRUE;
 462       /* Set drawing buffer to front for now */
 463       (void) (*ctx->Driver.SetDrawBuffer)(ctx, GL_FRONT_LEFT);
 464    }
 465
 466    ctx->Color.DrawBuffer = mode;
 467    ctx->NewState |= NEW_RASTER_OPS;
 468 }
 469
 470
 471
 472 void
 473 _mesa_ReadBuffer( GLenum mode )
 474 {
 475    GET_CURRENT_CONTEXT(ctx);
 476    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glReadBuffer");
 477
 478    if (MESA_VERBOSE & VERBOSE_API)
 479       fprintf(stderr, "glReadBuffer %s\n", gl_lookup_enum_by_nr(mode));
 480
 481    switch (mode) {
 482       case GL_AUX0:
 483       case GL_AUX1:
 484       case GL_AUX2:
 485       case GL_AUX3:
 486          /* AUX buffers not implemented in Mesa at this time */
 487          gl_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 488          return;
 489       case GL_LEFT:
 490       case GL_FRONT:
 491       case GL_FRONT_LEFT:
 492          /* Front-Left buffer, always exists */
 493          ctx->Pixel.DriverReadBuffer = GL_FRONT_LEFT;
 494          break;
 495       case GL_BACK:
 496       case GL_BACK_LEFT:
 497          /* Back-Left buffer, requires double buffering */
 498          if (!ctx->Visual.DBflag) {
 499             gl_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 500             return;
 501          }
 502          ctx->Pixel.DriverReadBuffer = GL_BACK_LEFT;
 503          break;
 504       case GL_FRONT_RIGHT:
 505       case GL_RIGHT:
 506          if (!ctx->Visual.StereoFlag) {
 507             gl_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 508             return;
 509          }
 510          ctx->Pixel.DriverReadBuffer = GL_FRONT_RIGHT;
 511          break;
 512       case GL_BACK_RIGHT:
 513          if (!ctx->Visual.StereoFlag || !ctx->Visual.DBflag) {
 514             gl_error( ctx, GL_INVALID_OPERATION, "glReadBuffer" );
 515             return;
 516          }
 517          ctx->Pixel.DriverReadBuffer = GL_BACK_RIGHT;
 518          break;
 519       default:
 520          gl_error( ctx, GL_INVALID_ENUM, "glReadBuffer" );
 521          return;
 522    }
 523
 524    ctx->Pixel.ReadBuffer = mode;
 525    ctx->NewState |= NEW_RASTER_OPS;
 526 }
 527
 528
 529 /*
 530  * GL_MESA_resize_buffers extension
 531  */
 532 void
 533 _mesa_ResizeBuffersMESA( void )
 534 {
 535    GLcontext *ctx = _mesa_get_current_context();
 536
 537    GLuint buf_width, buf_height;
 538
 539    if (MESA_VERBOSE & VERBOSE_API)
 540       fprintf(stderr, "glResizeBuffersMESA\n");
 541
 542    /* ask device driver for size of output buffer */
 543    (*ctx->Driver.GetBufferSize)( ctx, &buf_width, &buf_height );
 544
 545    /* see if size of device driver's color buffer (window) has changed */
 546    if (ctx->DrawBuffer->Width == (GLint) buf_width &&
 547        ctx->DrawBuffer->Height == (GLint) buf_height)
 548       return;
 549
 550    ctx->NewState |= NEW_RASTER_OPS;  /* to update scissor / window bounds */
 551
 552    /* save buffer size */
 553    ctx->DrawBuffer->Width = buf_width;
 554    ctx->DrawBuffer->Height = buf_height;
 555
 556    /* Reallocate other buffers if needed. */
 557    if (ctx->DrawBuffer->UseSoftwareDepthBuffer) {
 558       _mesa_alloc_depth_buffer( ctx );
 559    }
 560    if (ctx->DrawBuffer->UseSoftwareStencilBuffer) {
 561       _mesa_alloc_stencil_buffer( ctx );
 562    }
 563    if (ctx->DrawBuffer->UseSoftwareAccumBuffer) {
 564       _mesa_alloc_accum_buffer( ctx );
 565    }
 566    if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 567       _mesa_alloc_alpha_buffers( ctx );
 568    }
 569 }