src/mesa/swrast/s_copypix.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.1
   4  *
   5  * Copyright (C) 1999-2006  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 #include "glheader.h"
  27 #include "context.h"
  28 #include "colormac.h"
  29 #include "convolve.h"
  30 #include "histogram.h"
  31 #include "image.h"
  32 #include "macros.h"
  33 #include "imports.h"
  34 #include "pixel.h"
  35
  36 #include "s_context.h"
  37 #include "s_depth.h"
  38 #include "s_span.h"
  39 #include "s_stencil.h"
  40 #include "s_zoom.h"
  41
  42
  43
  44 /*
  45  * Determine if there's overlap in an image copy.
  46  * This test also compensates for the fact that copies are done from
  47  * bottom to top and overlaps can sometimes be handled correctly
  48  * without making a temporary image copy.
  49  */
  50 static GLboolean
  51 regions_overlap(GLint srcx, GLint srcy,
  52                 GLint dstx, GLint dsty,
  53                 GLint width, GLint height,
  54                 GLfloat zoomX, GLfloat zoomY)
  55 {
  56    if (zoomX == 1.0 && zoomY == 1.0) {
  57       /* no zoom */
  58       if (srcx >= dstx + width || (srcx + width <= dstx)) {
  59          return GL_FALSE;
  60       }
  61       else if (srcy < dsty) { /* this is OK */
  62          return GL_FALSE;
  63       }
  64       else if (srcy > dsty + height) {
  65          return GL_FALSE;
  66       }
  67       else {
  68          return GL_TRUE;
  69       }
  70    }
  71    else {
  72       /* add one pixel of slop when zooming, just to be safe */
  73       if ((srcx > dstx + (width * zoomX) + 1) || (srcx + width + 1 < dstx)) {
  74          return GL_FALSE;
  75       }
  76       else if ((srcy < dsty) && (srcy + height < dsty + (height * zoomY))) {
  77          return GL_FALSE;
  78       }
  79       else if ((srcy > dsty) && (srcy + height > dsty + (height * zoomY))) {
  80          return GL_FALSE;
  81       }
  82       else {
  83          return GL_TRUE;
  84       }
  85    }
  86 }
  87
  88
  89 /**
  90  * Convert GLfloat[n][4] colors to GLchan[n][4].
  91  * XXX maybe move into image.c
  92  */
  93 static void
  94 float_span_to_chan(GLuint n, CONST GLfloat in[][4], GLchan out[][4])
  95 {
  96    GLuint i;
  97    for (i = 0; i < n; i++) {
  98       UNCLAMPED_FLOAT_TO_CHAN(out[i][RCOMP], in[i][RCOMP]);
  99       UNCLAMPED_FLOAT_TO_CHAN(out[i][GCOMP], in[i][GCOMP]);
 100       UNCLAMPED_FLOAT_TO_CHAN(out[i][BCOMP], in[i][BCOMP]);
 101       UNCLAMPED_FLOAT_TO_CHAN(out[i][ACOMP], in[i][ACOMP]);
 102    }
 103 }
 104
 105
 106 /**
 107  * Convert GLchan[n][4] colors to GLfloat[n][4].
 108  * XXX maybe move into image.c
 109  */
 110 static void
 111 chan_span_to_float(GLuint n, CONST GLchan in[][4], GLfloat out[][4])
 112 {
 113    GLuint i;
 114    for (i = 0; i < n; i++) {
 115       out[i][RCOMP] = CHAN_TO_FLOAT(in[i][RCOMP]);
 116       out[i][GCOMP] = CHAN_TO_FLOAT(in[i][GCOMP]);
 117       out[i][BCOMP] = CHAN_TO_FLOAT(in[i][BCOMP]);
 118       out[i][ACOMP] = CHAN_TO_FLOAT(in[i][ACOMP]);
 119    }
 120 }
 121
 122
 123
 124 /*
 125  * RGBA copypixels with convolution.
 126  */
 127 static void
 128 copy_conv_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
 129                       GLint width, GLint height, GLint destx, GLint desty)
 130 {
 131    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 132    struct gl_renderbuffer *drawRb = NULL;
 133    GLboolean quick_draw;
 134    GLint row;
 135    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 136    const GLuint transferOps = ctx->_ImageTransferState;
 137    GLfloat *dest, *tmpImage, *convImage;
 138    SWspan span;
 139
 140    INIT_SPAN(span, GL_BITMAP, 0, 0, SPAN_RGBA);
 141
 142    if (ctx->Depth.Test)
 143       _swrast_span_default_z(ctx, &span);
 144    if (swrast->_FogEnabled)
 145       _swrast_span_default_fog(ctx, &span);
 146
 147
 148    if (SWRAST_CONTEXT(ctx)->_RasterMask == 0
 149        && !zoom
 150        && destx >= 0
 151        && destx + width <= (GLint) ctx->DrawBuffer->Width) {
 152       quick_draw = GL_TRUE;
 153       drawRb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
 154    }
 155    else {
 156       quick_draw = GL_FALSE;
 157    }
 158
 159    /* allocate space for GLfloat image */
 160    tmpImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
 161    if (!tmpImage) {
 162       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyPixels");
 163       return;
 164    }
 165    convImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
 166    if (!convImage) {
 167       _mesa_free(tmpImage);
 168       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyPixels");
 169       return;
 170    }
 171
 172    /* read source image */
 173    dest = tmpImage;
 174    for (row = 0; row < height; row++) {
 175       GLchan rgba[MAX_WIDTH][4];
 176       /* Read GLchan and convert to GLfloat */
 177       _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer,
 178                              width, srcx, srcy + row, rgba);
 179       chan_span_to_float(width, (CONST GLchan (*)[4]) rgba,
 180                          (GLfloat (*)[4]) dest);
 181       dest += 4 * width;
 182    }
 183
 184    /* do the image transfer ops which preceed convolution */
 185    for (row = 0; row < height; row++) {
 186       GLfloat (*rgba)[4] = (GLfloat (*)[4]) (tmpImage + row * width * 4);
 187       _mesa_apply_rgba_transfer_ops(ctx,
 188                                     transferOps & IMAGE_PRE_CONVOLUTION_BITS,
 189                                     width, rgba);
 190    }
 191
 192    /* do convolution */
 193    if (ctx->Pixel.Convolution2DEnabled) {
 194       _mesa_convolve_2d_image(ctx, &width, &height, tmpImage, convImage);
 195    }
 196    else {
 197       ASSERT(ctx->Pixel.Separable2DEnabled);
 198       _mesa_convolve_sep_image(ctx, &width, &height, tmpImage, convImage);
 199    }
 200    _mesa_free(tmpImage);
 201
 202    /* do remaining post-convolution image transfer ops */
 203    for (row = 0; row < height; row++) {
 204       GLfloat (*rgba)[4] = (GLfloat (*)[4]) (convImage + row * width * 4);
 205       _mesa_apply_rgba_transfer_ops(ctx,
 206                                     transferOps & IMAGE_POST_CONVOLUTION_BITS,
 207                                     width, rgba);
 208    }
 209
 210    /* write the new image */
 211    for (row = 0; row < height; row++) {
 212       const GLfloat *src = convImage + row * width * 4;
 213       GLint dy;
 214
 215       /* convert floats back to chan */
 216       float_span_to_chan(width, (const GLfloat (*)[4]) src, span.array->rgba);
 217
 218       /* write row to framebuffer */
 219       dy = desty + row;
 220       if (quick_draw && dy >= 0 && dy < (GLint) ctx->DrawBuffer->Height) {
 221          drawRb->PutRow(ctx, drawRb, width, destx, dy, span.array->rgba, NULL);
 222       }
 223       else {
 224          span.x = destx;
 225          span.y = dy;
 226          span.end = width;
 227          if (zoom) {
 228             _swrast_write_zoomed_rgba_span(ctx, destx, desty, &span,
 229                                         (CONST GLchan (*)[4])span.array->rgba);
 230          }
 231          else {
 232             _swrast_write_rgba_span(ctx, &span);
 233          }
 234       }
 235    }
 236
 237    _mesa_free(convImage);
 238 }
 239
 240
 241 /*
 242  * RGBA copypixels
 243  */
 244 static void
 245 copy_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
 246                  GLint width, GLint height, GLint destx, GLint desty)
 247 {
 248    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 249    struct gl_renderbuffer *drawRb;
 250    GLchan *tmpImage,*p;
 251    GLboolean quick_draw;
 252    GLint sy, dy, stepy, j;
 253    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 254    GLint overlapping;
 255    const GLuint transferOps = ctx->_ImageTransferState;
 256    SWspan span;
 257
 258    if (!ctx->ReadBuffer->_ColorReadBuffer) {
 259       /* no readbuffer - OK */
 260       return;
 261    }
 262
 263    INIT_SPAN(span, GL_BITMAP, 0, 0, SPAN_RGBA);
 264
 265    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 266       copy_conv_rgba_pixels(ctx, srcx, srcy, width, height, destx, desty);
 267       return;
 268    }
 269
 270    /* Determine if copy should be done bottom-to-top or top-to-bottom */
 271    if (srcy < desty) {
 272       /* top-down  max-to-min */
 273       sy = srcy + height - 1;
 274       dy = desty + height - 1;
 275       stepy = -1;
 276    }
 277    else {
 278       /* bottom-up  min-to-max */
 279       sy = srcy;
 280       dy = desty;
 281       stepy = 1;
 282    }
 283
 284    if (ctx->DrawBuffer == ctx->ReadBuffer) {
 285       overlapping = regions_overlap(srcx, srcy, destx, desty, width, height,
 286                                     ctx->Pixel.ZoomX, ctx->Pixel.ZoomY);
 287    }
 288    else {
 289       overlapping = GL_FALSE;
 290    }
 291
 292    if (ctx->Depth.Test)
 293       _swrast_span_default_z(ctx, &span);
 294    if (swrast->_FogEnabled)
 295       _swrast_span_default_fog(ctx, &span);
 296
 297    if (SWRAST_CONTEXT(ctx)->_RasterMask == 0
 298        && !zoom
 299        && destx >= 0
 300        && destx + width <= (GLint) ctx->DrawBuffer->Width) {
 301       quick_draw = GL_TRUE;
 302       drawRb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
 303    }
 304    else {
 305       quick_draw = GL_FALSE;
 306       drawRb = NULL;
 307    }
 308
 309    if (overlapping) {
 310       GLint ssy = sy;
 311       tmpImage = (GLchan *) _mesa_malloc(width * height * sizeof(GLchan) * 4);
 312       if (!tmpImage) {
 313          _mesa_error( ctx, GL_OUT_OF_MEMORY, "glCopyPixels" );
 314          return;
 315       }
 316       /* read the source image */
 317       p = tmpImage;
 318       for (j = 0; j < height; j++, ssy += stepy) {
 319          _swrast_read_rgba_span( ctx, ctx->ReadBuffer->_ColorReadBuffer,
 320                                  width, srcx, ssy, (GLchan (*)[4]) p );
 321          p += width * 4;
 322       }
 323       p = tmpImage;
 324    }
 325    else {
 326       tmpImage = NULL;  /* silence compiler warnings */
 327       p = NULL;
 328    }
 329
 330    for (j = 0; j < height; j++, sy += stepy, dy += stepy) {
 331       /* Get source pixels */
 332       if (overlapping) {
 333          /* get from buffered image */
 334          ASSERT(width < MAX_WIDTH);
 335          _mesa_memcpy(span.array->rgba, p, width * sizeof(GLchan) * 4);
 336          p += width * 4;
 337       }
 338       else {
 339          /* get from framebuffer */
 340          ASSERT(width < MAX_WIDTH);
 341          _swrast_read_rgba_span( ctx, ctx->ReadBuffer->_ColorReadBuffer,
 342                                  width, srcx, sy, span.array->rgba );
 343       }
 344
 345       if (transferOps) {
 346          GLfloat rgbaFloat[MAX_WIDTH][4];
 347          /* convert to float, transfer, convert back to chan */
 348          chan_span_to_float(width, (CONST GLchan (*)[4]) span.array->rgba,
 349                             rgbaFloat);
 350          _mesa_apply_rgba_transfer_ops(ctx, transferOps, width, rgbaFloat);
 351          float_span_to_chan(width, (CONST GLfloat (*)[4]) rgbaFloat,
 352                             span.array->rgba);
 353       }
 354
 355       /* Write color span */
 356       if (quick_draw && dy >= 0 && dy < (GLint) ctx->DrawBuffer->Height) {
 357          drawRb->PutRow(ctx, drawRb, width, destx, dy, span.array->rgba, NULL);
 358       }
 359       else {
 360          span.x = destx;
 361          span.y = dy;
 362          span.end = width;
 363          if (zoom) {
 364             _swrast_write_zoomed_rgba_span(ctx, destx, desty, &span,
 365                                        (CONST GLchan (*)[4]) span.array->rgba);
 366          }
 367          else {
 368             _swrast_write_rgba_span(ctx, &span);
 369          }
 370       }
 371    }
 372
 373    if (overlapping)
 374       _mesa_free(tmpImage);
 375 }
 376
 377
 378 static void
 379 copy_ci_pixels( GLcontext *ctx, GLint srcx, GLint srcy,
 380                 GLint width, GLint height,
 381                 GLint destx, GLint desty )
 382 {
 383    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 384    GLuint *tmpImage,*p;
 385    GLint sy, dy, stepy;
 386    GLint j;
 387    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 388    const GLboolean shift_or_offset = ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset;
 389    GLint overlapping;
 390    SWspan span;
 391
 392    if (!ctx->ReadBuffer->_ColorReadBuffer) {
 393       /* no readbuffer - OK */
 394       return;
 395    }
 396
 397    INIT_SPAN(span, GL_BITMAP, 0, 0, SPAN_INDEX);
 398
 399    /* Determine if copy should be bottom-to-top or top-to-bottom */
 400    if (srcy<desty) {
 401       /* top-down  max-to-min */
 402       sy = srcy + height - 1;
 403       dy = desty + height - 1;
 404       stepy = -1;
 405    }
 406    else {
 407       /* bottom-up  min-to-max */
 408       sy = srcy;
 409       dy = desty;
 410       stepy = 1;
 411    }
 412
 413    if (ctx->DrawBuffer == ctx->ReadBuffer) {
 414       overlapping = regions_overlap(srcx, srcy, destx, desty, width, height,
 415                                     ctx->Pixel.ZoomX, ctx->Pixel.ZoomY);
 416    }
 417    else {
 418       overlapping = GL_FALSE;
 419    }
 420
 421    if (ctx->Depth.Test)
 422       _swrast_span_default_z(ctx, &span);
 423    if (swrast->_FogEnabled)
 424       _swrast_span_default_fog(ctx, &span);
 425
 426    if (overlapping) {
 427       GLint ssy = sy;
 428       tmpImage = (GLuint *) _mesa_malloc(width * height * sizeof(GLuint));
 429       if (!tmpImage) {
 430          _mesa_error( ctx, GL_OUT_OF_MEMORY, "glCopyPixels" );
 431          return;
 432       }
 433       /* read the image */
 434       p = tmpImage;
 435       for (j = 0; j < height; j++, ssy += stepy) {
 436          _swrast_read_index_span( ctx, ctx->ReadBuffer->_ColorReadBuffer,
 437                                   width, srcx, ssy, p );
 438          p += width;
 439       }
 440       p = tmpImage;
 441    }
 442    else {
 443       tmpImage = NULL;  /* silence compiler warning */
 444       p = NULL;
 445    }
 446
 447    for (j = 0; j < height; j++, sy += stepy, dy += stepy) {
 448       /* Get color indexes */
 449       if (overlapping) {
 450          _mesa_memcpy(span.array->index, p, width * sizeof(GLuint));
 451          p += width;
 452       }
 453       else {
 454          _swrast_read_index_span( ctx, ctx->ReadBuffer->_ColorReadBuffer,
 455                                   width, srcx, sy, span.array->index );
 456       }
 457
 458       /* Apply shift, offset, look-up table */
 459       if (shift_or_offset) {
 460          _mesa_shift_and_offset_ci( ctx, width, span.array->index );
 461       }
 462       if (ctx->Pixel.MapColorFlag) {
 463          _mesa_map_ci( ctx, width, span.array->index );
 464       }
 465
 466       /* write color indexes */
 467       span.x = destx;
 468       span.y = dy;
 469       span.end = width;
 470       if (zoom)
 471          _swrast_write_zoomed_index_span(ctx, destx, desty, &span);
 472       else
 473          _swrast_write_index_span(ctx, &span);
 474    }
 475
 476    if (overlapping)
 477       _mesa_free(tmpImage);
 478 }
 479
 480
 481 /**
 482  * Convert floating point Z values to integer Z values with pixel transfer's
 483  * Z scale and bias.
 484  */
 485 static void
 486 scale_and_bias_z(GLcontext *ctx, GLuint width,
 487                  const GLfloat depth[], GLuint z[])
 488 {
 489    const GLuint depthMax = ctx->DrawBuffer->_DepthMax;
 490    GLuint i;
 491
 492    if (depthMax <= 0xffffff &&
 493        ctx->Pixel.DepthScale == 1.0 &&
 494        ctx->Pixel.DepthBias == 0.0) {
 495       /* no scale or bias and no clamping and no worry of overflow */
 496       const GLfloat depthMaxF = ctx->DrawBuffer->_DepthMaxF;
 497       for (i = 0; i < width; i++) {
 498          z[i] = (GLuint) (depth[i] * depthMaxF);
 499       }
 500    }
 501    else {
 502       /* need to be careful with overflow */
 503       const GLdouble depthMaxF = ctx->DrawBuffer->_DepthMaxF;
 504       for (i = 0; i < width; i++) {
 505          GLdouble d = depth[i] * ctx->Pixel.DepthScale + ctx->Pixel.DepthBias;
 506          d = CLAMP(d, 0.0, 1.0) * depthMaxF;
 507          if (d >= depthMaxF)
 508             z[i] = depthMax;
 509          else
 510             z[i] = (GLuint) d;
 511       }
 512    }
 513 }
 514
 515
 516
 517 /*
 518  * TODO: Optimize!!!!
 519  */
 520 static void
 521 copy_depth_pixels( GLcontext *ctx, GLint srcx, GLint srcy,
 522                    GLint width, GLint height,
 523                    GLint destx, GLint desty )
 524 {
 525    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 526    struct gl_framebuffer *fb = ctx->ReadBuffer;
 527    struct gl_renderbuffer *readRb = fb->_DepthBuffer;
 528    GLfloat *p, *tmpImage;
 529    GLint sy, dy, stepy;
 530    GLint j;
 531    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 532    GLint overlapping;
 533    SWspan span;
 534
 535    if (!readRb) {
 536       /* no readbuffer - OK */
 537       return;
 538    }
 539
 540    INIT_SPAN(span, GL_BITMAP, 0, 0, SPAN_Z);
 541
 542    /* Determine if copy should be bottom-to-top or top-to-bottom */
 543    if (srcy<desty) {
 544       /* top-down  max-to-min */
 545       sy = srcy + height - 1;
 546       dy = desty + height - 1;
 547       stepy = -1;
 548    }
 549    else {
 550       /* bottom-up  min-to-max */
 551       sy = srcy;
 552       dy = desty;
 553       stepy = 1;
 554    }
 555
 556    if (ctx->DrawBuffer == ctx->ReadBuffer) {
 557       overlapping = regions_overlap(srcx, srcy, destx, desty, width, height,
 558                                     ctx->Pixel.ZoomX, ctx->Pixel.ZoomY);
 559    }
 560    else {
 561       overlapping = GL_FALSE;
 562    }
 563
 564    _swrast_span_default_color(ctx, &span);
 565    if (swrast->_FogEnabled)
 566       _swrast_span_default_fog(ctx, &span);
 567
 568    if (overlapping) {
 569       GLint ssy = sy;
 570       tmpImage = (GLfloat *) _mesa_malloc(width * height * sizeof(GLfloat));
 571       if (!tmpImage) {
 572          _mesa_error( ctx, GL_OUT_OF_MEMORY, "glCopyPixels" );
 573          return;
 574       }
 575       p = tmpImage;
 576       for (j = 0; j < height; j++, ssy += stepy) {
 577          _swrast_read_depth_span_float(ctx, readRb, width, srcx, ssy, p);
 578          p += width;
 579       }
 580       p = tmpImage;
 581    }
 582    else {
 583       tmpImage = NULL;  /* silence compiler warning */
 584       p = NULL;
 585    }
 586
 587    for (j = 0; j < height; j++, sy += stepy, dy += stepy) {
 588       GLfloat depth[MAX_WIDTH];
 589       /* get depth values */
 590       if (overlapping) {
 591          _mesa_memcpy(depth, p, width * sizeof(GLfloat));
 592          p += width;
 593       }
 594       else {
 595          _swrast_read_depth_span_float(ctx, readRb, width, srcx, sy, depth);
 596       }
 597
 598       /* apply scale and bias */
 599       scale_and_bias_z(ctx, width, depth, span.array->z);
 600
 601       /* write depth values */
 602       span.x = destx;
 603       span.y = dy;
 604       span.end = width;
 605       if (fb->Visual.rgbMode) {
 606          if (zoom)
 607             _swrast_write_zoomed_rgba_span(ctx, destx, desty, &span,
 608                                        (const GLchan (*)[4]) span.array->rgba);
 609          else
 610             _swrast_write_rgba_span(ctx, &span);
 611       }
 612       else {
 613          if (zoom)
 614             _swrast_write_zoomed_index_span(ctx, destx, desty, &span);
 615          else
 616             _swrast_write_index_span(ctx, &span);
 617       }
 618    }
 619
 620    if (overlapping)
 621       _mesa_free(tmpImage);
 622 }
 623
 624
 625
 626 static void
 627 copy_stencil_pixels( GLcontext *ctx, GLint srcx, GLint srcy,
 628                      GLint width, GLint height,
 629                      GLint destx, GLint desty )
 630 {
 631    struct gl_framebuffer *fb = ctx->ReadBuffer;
 632    struct gl_renderbuffer *rb = fb->_StencilBuffer;
 633    GLint sy, dy, stepy;
 634    GLint j;
 635    GLstencil *p, *tmpImage;
 636    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 637    const GLboolean shift_or_offset = ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset;
 638    GLint overlapping;
 639
 640    if (!rb) {
 641       /* no readbuffer - OK */
 642       return;
 643    }
 644
 645    /* Determine if copy should be bottom-to-top or top-to-bottom */
 646    if (srcy < desty) {
 647       /* top-down  max-to-min */
 648       sy = srcy + height - 1;
 649       dy = desty + height - 1;
 650       stepy = -1;
 651    }
 652    else {
 653       /* bottom-up  min-to-max */
 654       sy = srcy;
 655       dy = desty;
 656       stepy = 1;
 657    }
 658
 659    if (ctx->DrawBuffer == ctx->ReadBuffer) {
 660       overlapping = regions_overlap(srcx, srcy, destx, desty, width, height,
 661                                     ctx->Pixel.ZoomX, ctx->Pixel.ZoomY);
 662    }
 663    else {
 664       overlapping = GL_FALSE;
 665    }
 666
 667    if (overlapping) {
 668       GLint ssy = sy;
 669       tmpImage = (GLstencil *) _mesa_malloc(width * height * sizeof(GLstencil));
 670       if (!tmpImage) {
 671          _mesa_error( ctx, GL_OUT_OF_MEMORY, "glCopyPixels" );
 672          return;
 673       }
 674       p = tmpImage;
 675       for (j = 0; j < height; j++, ssy += stepy) {
 676          _swrast_read_stencil_span( ctx, rb, width, srcx, ssy, p );
 677          p += width;
 678       }
 679       p = tmpImage;
 680    }
 681    else {
 682       tmpImage = NULL;  /* silence compiler warning */
 683       p = NULL;
 684    }
 685
 686    for (j = 0; j < height; j++, sy += stepy, dy += stepy) {
 687       GLstencil stencil[MAX_WIDTH];
 688
 689       /* Get stencil values */
 690       if (overlapping) {
 691          _mesa_memcpy(stencil, p, width * sizeof(GLstencil));
 692          p += width;
 693       }
 694       else {
 695          _swrast_read_stencil_span( ctx, rb, width, srcx, sy, stencil );
 696       }
 697
 698       /* Apply shift, offset, look-up table */
 699       if (shift_or_offset) {
 700          _mesa_shift_and_offset_stencil( ctx, width, stencil );
 701       }
 702       if (ctx->Pixel.MapStencilFlag) {
 703          _mesa_map_stencil( ctx, width, stencil );
 704       }
 705
 706       /* Write stencil values */
 707       if (zoom) {
 708          _swrast_write_zoomed_stencil_span(ctx, destx, desty, width,
 709                                            destx, dy, stencil);
 710       }
 711       else {
 712          _swrast_write_stencil_span( ctx, width, destx, dy, stencil );
 713       }
 714    }
 715
 716    if (overlapping)
 717       _mesa_free(tmpImage);
 718 }
 719
 720
 721 /**
 722  * This isn't terribly efficient.  If a driver really has combined
 723  * depth/stencil buffers the driver should implement an optimized
 724  * CopyPixels function.
 725  */
 726 static void
 727 copy_depth_stencil_pixels(GLcontext *ctx,
 728                           const GLint srcX, const GLint srcY,
 729                           const GLint width, const GLint height,
 730                           const GLint destX, const GLint destY)
 731 {
 732    struct gl_renderbuffer *stencilReadRb, *depthReadRb, *depthDrawRb;
 733    GLint sy, dy, stepy;
 734    GLint j;
 735    GLstencil *tempStencilImage = NULL, *stencilPtr = NULL;
 736    GLfloat *tempDepthImage = NULL, *depthPtr = NULL;
 737    const GLfloat depthScale = ctx->DrawBuffer->_DepthMaxF;
 738    const GLuint stencilMask = ctx->Stencil.WriteMask[0];
 739    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F;
 740    const GLboolean shiftOrOffset
 741       = ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset;
 742    const GLboolean scaleOrBias
 743       = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
 744    GLint overlapping;
 745
 746    depthDrawRb = ctx->DrawBuffer->_DepthBuffer;
 747    depthReadRb = ctx->ReadBuffer->_DepthBuffer;
 748    stencilReadRb = ctx->ReadBuffer->_StencilBuffer;
 749
 750    ASSERT(depthDrawRb);
 751    ASSERT(depthReadRb);
 752    ASSERT(stencilReadRb);
 753
 754    /* Determine if copy should be bottom-to-top or top-to-bottom */
 755    if (srcY < destY) {
 756       /* top-down  max-to-min */
 757       sy = srcY + height - 1;
 758       dy = destY + height - 1;
 759       stepy = -1;
 760    }
 761    else {
 762       /* bottom-up  min-to-max */
 763       sy = srcY;
 764       dy = destY;
 765       stepy = 1;
 766    }
 767
 768    if (ctx->DrawBuffer == ctx->ReadBuffer) {
 769       overlapping = regions_overlap(srcX, srcY, destX, destY, width, height,
 770                                     ctx->Pixel.ZoomX, ctx->Pixel.ZoomY);
 771    }
 772    else {
 773       overlapping = GL_FALSE;
 774    }
 775
 776    if (overlapping) {
 777       GLint ssy = sy;
 778
 779       if (stencilMask != 0x0) {
 780          tempStencilImage
 781             = (GLstencil *) _mesa_malloc(width * height * sizeof(GLstencil));
 782          if (!tempStencilImage) {
 783             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyPixels");
 784             return;
 785          }
 786
 787          /* get copy of stencil pixels */
 788          stencilPtr = tempStencilImage;
 789          for (j = 0; j < height; j++, ssy += stepy) {
 790             _swrast_read_stencil_span(ctx, stencilReadRb,
 791                                       width, srcX, ssy, stencilPtr);
 792             stencilPtr += width;
 793          }
 794          stencilPtr = tempStencilImage;
 795       }
 796
 797       if (ctx->Depth.Mask) {
 798          tempDepthImage
 799             = (GLfloat *) _mesa_malloc(width * height * sizeof(GLfloat));
 800          if (!tempDepthImage) {
 801             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyPixels");
 802             _mesa_free(tempStencilImage);
 803             return;
 804          }
 805
 806          /* get copy of depth pixels */
 807          depthPtr = tempDepthImage;
 808          for (j = 0; j < height; j++, ssy += stepy) {
 809             _swrast_read_depth_span_float(ctx, depthReadRb,
 810                                           width, srcX, ssy, depthPtr);
 811             depthPtr += width;
 812          }
 813          depthPtr = tempDepthImage;
 814       }
 815    }
 816
 817    for (j = 0; j < height; j++, sy += stepy, dy += stepy) {
 818       if (stencilMask != 0x0) {
 819          GLstencil stencil[MAX_WIDTH];
 820
 821          /* Get stencil values */
 822          if (overlapping) {
 823             _mesa_memcpy(stencil, stencilPtr, width * sizeof(GLstencil));
 824             stencilPtr += width;
 825          }
 826          else {
 827             _swrast_read_stencil_span(ctx, stencilReadRb,
 828                                       width, srcX, sy, stencil);
 829          }
 830
 831          /* Apply shift, offset, look-up table */
 832          if (shiftOrOffset) {
 833             _mesa_shift_and_offset_stencil(ctx, width, stencil);
 834          }
 835          if (ctx->Pixel.MapStencilFlag) {
 836             _mesa_map_stencil(ctx, width, stencil);
 837          }
 838
 839          /* Write values */
 840          if (zoom) {
 841             _swrast_write_zoomed_stencil_span(ctx, destX, destY, width,
 842                                               destX, dy, stencil);
 843          }
 844          else {
 845             _swrast_write_stencil_span( ctx, width, destX, dy, stencil );
 846          }
 847       }
 848
 849       if (ctx->Depth.Mask) {
 850          GLfloat depth[MAX_WIDTH];
 851          GLuint zVals32[MAX_WIDTH];
 852          GLushort zVals16[MAX_WIDTH];
 853          GLvoid *zVals;
 854          GLuint zBytes;
 855
 856          /* get depth values */
 857          if (overlapping) {
 858             _mesa_memcpy(depth, depthPtr, width * sizeof(GLfloat));
 859             depthPtr += width;
 860          }
 861          else {
 862             _swrast_read_depth_span_float(ctx, depthReadRb,
 863                                           width, srcX, sy, depth);
 864          }
 865
 866          /* scale & bias */
 867          if (scaleOrBias) {
 868             _mesa_scale_and_bias_depth(ctx, width, depth);
 869          }
 870          /* convert to integer Z values */
 871          if (depthDrawRb->DataType == GL_UNSIGNED_SHORT) {
 872             GLint k;
 873             for (k = 0; k < width; k++)
 874                zVals16[k] = (GLushort) (depth[k] * depthScale);
 875             zVals = zVals16;
 876             zBytes = 2;
 877          }
 878          else {
 879             GLint k;
 880             for (k = 0; k < width; k++)
 881                zVals32[k] = (GLuint) (depth[k] * depthScale);
 882             zVals = zVals32;
 883             zBytes = 4;
 884          }
 885
 886          /* Write values */
 887          if (zoom) {
 888             _swrast_write_zoomed_z_span(ctx, destX, destY, width,
 889                                         destX, dy, zVals);
 890          }
 891          else {
 892             _swrast_put_row(ctx, depthDrawRb, width, destX, dy, zVals, zBytes);
 893          }
 894       }
 895    }
 896
 897    if (tempStencilImage)
 898       _mesa_free(tempStencilImage);
 899
 900    if (tempDepthImage)
 901       _mesa_free(tempDepthImage);
 902 }
 903
 904
 905 /**
 906  * Do software-based glCopyPixels.
 907  * By time we get here, all parameters will have been error-checked.
 908  */
 909 void
 910 _swrast_CopyPixels( GLcontext *ctx,
 911                     GLint srcx, GLint srcy, GLsizei width, GLsizei height,
 912                     GLint destx, GLint desty, GLenum type )
 913 {
 914    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 915    RENDER_START(swrast,ctx);
 916
 917    if (swrast->NewState)
 918       _swrast_validate_derived( ctx );
 919
 920    switch (type) {
 921    case GL_COLOR:
 922       if (ctx->Visual.rgbMode) {
 923          copy_rgba_pixels( ctx, srcx, srcy, width, height, destx, desty );
 924       }
 925       else {
 926          copy_ci_pixels( ctx, srcx, srcy, width, height, destx, desty );
 927       }
 928       break;
 929    case GL_DEPTH:
 930       copy_depth_pixels( ctx, srcx, srcy, width, height, destx, desty );
 931       break;
 932    case GL_STENCIL:
 933       copy_stencil_pixels( ctx, srcx, srcy, width, height, destx, desty );
 934       break;
 935    case GL_DEPTH_STENCIL_EXT:
 936       copy_depth_stencil_pixels(ctx, srcx, srcy, width, height, destx, desty);
 937       break;
 938    default:
 939       _mesa_problem(ctx, "unexpected type in _swrast_CopyPixels");
 940    }
 941
 942    RENDER_FINISH(swrast,ctx);
 943 }