src/mesa/state_tracker/st_cb_readpixels.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * 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
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * glReadPixels interface to pipe
  31  *
  32  * \author Brian Paul
  33  */
  34
  35
  36 #include "main/imports.h"
  37 #include "main/bufferobj.h"
  38 #include "main/context.h"
  39 #include "main/image.h"
  40 #include "main/pack.h"
  41 #include "main/pbo.h"
  42
  43 #include "pipe/p_context.h"
  44 #include "pipe/p_defines.h"
  45 #include "util/u_format.h"
  46 #include "util/u_inlines.h"
  47 #include "util/u_tile.h"
  48
  49 #include "st_debug.h"
  50 #include "st_context.h"
  51 #include "st_atom.h"
  52 #include "st_cb_bitmap.h"
  53 #include "st_cb_readpixels.h"
  54 #include "st_cb_fbo.h"
  55
  56 /**
  57  * Special case for reading stencil buffer.
  58  * For color/depth we use get_tile().  For stencil, map the stencil buffer.
  59  */
  60 void
  61 st_read_stencil_pixels(struct gl_context *ctx, GLint x, GLint y,
  62                        GLsizei width, GLsizei height,
  63                        GLenum format, GLenum type,
  64                        const struct gl_pixelstore_attrib *packing,
  65                        GLvoid *pixels)
  66 {
  67    struct gl_framebuffer *fb = ctx->ReadBuffer;
  68    struct pipe_context *pipe = st_context(ctx)->pipe;
  69    struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer);
  70    struct pipe_transfer *pt;
  71    ubyte *stmap;
  72    GLint j;
  73
  74    if (strb->Base.Wrapped) {
  75       strb = st_renderbuffer(strb->Base.Wrapped);
  76    }
  77
  78    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  79       y = ctx->DrawBuffer->Height - y - height;
  80    }
  81
  82    /* Create a read transfer from the renderbuffer's texture */
  83
  84    pt = pipe_get_transfer(pipe, strb->texture,
  85                           strb->rtt_level,
  86                           strb->rtt_face + strb->rtt_slice,
  87                           PIPE_TRANSFER_READ,
  88                           x, y, width, height);
  89
  90    /* map the stencil buffer */
  91    stmap = pipe_transfer_map(pipe, pt);
  92
  93    /* width should never be > MAX_WIDTH since we did clipping earlier */
  94    ASSERT(width <= MAX_WIDTH);
  95
  96    /* process image row by row */
  97    for (j = 0; j < height; j++) {
  98       GLvoid *dest;
  99       GLstencil sValues[MAX_WIDTH];
 100       GLfloat zValues[MAX_WIDTH];
 101       GLint srcY;
 102
 103       if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
 104          srcY = height - j - 1;
 105       }
 106       else {
 107          srcY = j;
 108       }
 109
 110       /* get stencil (and Z) values */
 111       switch (pt->resource->format) {
 112       case PIPE_FORMAT_S8_USCALED:
 113          {
 114             const ubyte *src = stmap + srcY * pt->stride;
 115             memcpy(sValues, src, width);
 116          }
 117          break;
 118       case PIPE_FORMAT_Z24_UNORM_S8_USCALED:
 119          if (format == GL_DEPTH_STENCIL) {
 120             const uint *src = (uint *) (stmap + srcY * pt->stride);
 121             const GLfloat scale = 1.0f / (0xffffff);
 122             GLint k;
 123             for (k = 0; k < width; k++) {
 124                sValues[k] = src[k] >> 24;
 125                zValues[k] = (src[k] & 0xffffff) * scale;
 126             }
 127          }
 128          else {
 129             const uint *src = (uint *) (stmap + srcY * pt->stride);
 130             GLint k;
 131             for (k = 0; k < width; k++) {
 132                sValues[k] = src[k] >> 24;
 133             }
 134          }
 135          break;
 136       case PIPE_FORMAT_S8_USCALED_Z24_UNORM:
 137          if (format == GL_DEPTH_STENCIL) {
 138             const uint *src = (uint *) (stmap + srcY * pt->stride);
 139             const GLfloat scale = 1.0f / (0xffffff);
 140             GLint k;
 141             for (k = 0; k < width; k++) {
 142                sValues[k] = src[k] & 0xff;
 143                zValues[k] = (src[k] >> 8) * scale;
 144             }
 145          }
 146          else {
 147             const uint *src = (uint *) (stmap + srcY * pt->stride);
 148             GLint k;
 149             for (k = 0; k < width; k++) {
 150                sValues[k] = src[k] & 0xff;
 151             }
 152          }
 153          break;
 154       case PIPE_FORMAT_Z32_FLOAT_S8X24_USCALED:
 155          if (format == GL_DEPTH_STENCIL) {
 156             const uint *src = (uint *) (stmap + srcY * pt->stride);
 157             const GLfloat *srcf = (const GLfloat*)src;
 158             GLint k;
 159             for (k = 0; k < width; k++) {
 160                zValues[k] = srcf[k*2];
 161                sValues[k] = src[k*2+1] & 0xff;
 162             }
 163          }
 164          else {
 165             const uint *src = (uint *) (stmap + srcY * pt->stride);
 166             GLint k;
 167             for (k = 0; k < width; k++) {
 168                sValues[k] = src[k*2+1] & 0xff;
 169             }
 170          }
 171          break;
 172       default:
 173          assert(0);
 174       }
 175
 176       /* store */
 177       dest = _mesa_image_address2d(packing, pixels, width, height,
 178                                    format, type, j, 0);
 179       if (format == GL_DEPTH_STENCIL) {
 180          _mesa_pack_depth_stencil_span(ctx, width, type, dest,
 181                                        zValues, sValues, packing);
 182       }
 183       else {
 184          _mesa_pack_stencil_span(ctx, width, type, dest, sValues, packing);
 185       }
 186    }
 187
 188    /* unmap the stencil buffer */
 189    pipe_transfer_unmap(pipe, pt);
 190    pipe->transfer_destroy(pipe, pt);
 191 }
 192
 193
 194 /**
 195  * Return renderbuffer to use for reading color pixels for glRead/CopyPixel
 196  * commands.
 197  */
 198 struct st_renderbuffer *
 199 st_get_color_read_renderbuffer(struct gl_context *ctx)
 200 {
 201    struct gl_framebuffer *fb = ctx->ReadBuffer;
 202    struct st_renderbuffer *strb =
 203       st_renderbuffer(fb->_ColorReadBuffer);
 204
 205    return strb;
 206 }
 207
 208
 209 /**
 210  * Try to do glReadPixels in a fast manner for common cases.
 211  * \return GL_TRUE for success, GL_FALSE for failure
 212  */
 213 static GLboolean
 214 st_fast_readpixels(struct gl_context *ctx, struct st_renderbuffer *strb,
 215                    GLint x, GLint y, GLsizei width, GLsizei height,
 216                    GLenum format, GLenum type,
 217                    const struct gl_pixelstore_attrib *pack,
 218                    GLvoid *dest)
 219 {
 220    GLubyte alphaORoperand;
 221    enum combination {
 222       A8R8G8B8_UNORM_TO_RGBA_UBYTE,
 223       A8R8G8B8_UNORM_TO_RGB_UBYTE,
 224       A8R8G8B8_UNORM_TO_BGRA_UINT,
 225       A8R8G8B8_UNORM_TO_RGBA_UINT
 226    } combo;
 227
 228    if (ctx->_ImageTransferState)
 229       return GL_FALSE;
 230
 231    if (strb->format == PIPE_FORMAT_B8G8R8A8_UNORM) {
 232       alphaORoperand = 0;
 233    }
 234    else if (strb->format == PIPE_FORMAT_B8G8R8X8_UNORM ) {
 235       alphaORoperand = 0xff;
 236    }
 237    else {
 238       return GL_FALSE;
 239    }
 240
 241    if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 242       combo = A8R8G8B8_UNORM_TO_RGBA_UBYTE;
 243    }
 244    else if (format == GL_RGB && type == GL_UNSIGNED_BYTE) {
 245       combo = A8R8G8B8_UNORM_TO_RGB_UBYTE;
 246    }
 247    else if (format == GL_BGRA && type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 248       combo = A8R8G8B8_UNORM_TO_BGRA_UINT;
 249    }
 250    else if (format == GL_RGBA && type == GL_UNSIGNED_INT_8_8_8_8) {
 251       combo = A8R8G8B8_UNORM_TO_RGBA_UINT;
 252    }
 253    else {
 254       return GL_FALSE;
 255    }
 256
 257    /*printf("st_fast_readpixels combo %d\n", (GLint) combo);*/
 258
 259    {
 260       struct pipe_context *pipe = st_context(ctx)->pipe;
 261       struct pipe_transfer *trans;
 262       const GLubyte *map;
 263       GLubyte *dst;
 264       GLint row, col, dy, dstStride;
 265
 266       if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 267          /* convert GL Y to Gallium Y */
 268          y = strb->texture->height0 - y - height;
 269       }
 270
 271       trans = pipe_get_transfer(pipe, strb->texture,
 272                                 strb->rtt_level,
 273                                 strb->rtt_face + strb->rtt_slice,
 274                                 PIPE_TRANSFER_READ,
 275                                 x, y, width, height);
 276       if (!trans) {
 277          return GL_FALSE;
 278       }
 279
 280       map = pipe_transfer_map(pipe, trans);
 281       if (!map) {
 282          pipe->transfer_destroy(pipe, trans);
 283          return GL_FALSE;
 284       }
 285
 286       /* We always write to the user/dest buffer from low addr to high addr
 287        * but the read order depends on renderbuffer orientation
 288        */
 289       if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 290          /* read source rows from bottom to top */
 291          y = height - 1;
 292          dy = -1;
 293       }
 294       else {
 295          /* read source rows from top to bottom */
 296          y = 0;
 297          dy = 1;
 298       }
 299
 300       dst = _mesa_image_address2d(pack, dest, width, height,
 301                                   format, type, 0, 0);
 302       dstStride = _mesa_image_row_stride(pack, width, format, type);
 303
 304       switch (combo) {
 305       case A8R8G8B8_UNORM_TO_RGBA_UBYTE:
 306          for (row = 0; row < height; row++) {
 307             const GLubyte *src = map + y * trans->stride;
 308             for (col = 0; col < width; col++) {
 309                GLuint pixel = ((GLuint *) src)[col];
 310                dst[col*4+0] = (pixel >> 16) & 0xff;
 311                dst[col*4+1] = (pixel >>  8) & 0xff;
 312                dst[col*4+2] = (pixel >>  0) & 0xff;
 313                dst[col*4+3] = ((pixel >> 24) & 0xff) | alphaORoperand;
 314             }
 315             dst += dstStride;
 316             y += dy;
 317          }
 318          break;
 319       case A8R8G8B8_UNORM_TO_RGB_UBYTE:
 320          for (row = 0; row < height; row++) {
 321             const GLubyte *src = map + y * trans->stride;
 322             for (col = 0; col < width; col++) {
 323                GLuint pixel = ((GLuint *) src)[col];
 324                dst[col*3+0] = (pixel >> 16) & 0xff;
 325                dst[col*3+1] = (pixel >>  8) & 0xff;
 326                dst[col*3+2] = (pixel >>  0) & 0xff;
 327             }
 328             dst += dstStride;
 329             y += dy;
 330          }
 331          break;
 332       case A8R8G8B8_UNORM_TO_BGRA_UINT:
 333          for (row = 0; row < height; row++) {
 334             const GLubyte *src = map + y * trans->stride;
 335             memcpy(dst, src, 4 * width);
 336             if (alphaORoperand) {
 337                assert(alphaORoperand == 0xff);
 338                for (col = 0; col < width; col++) {
 339                   dst[col*4+3] = 0xff;
 340                }
 341             }
 342             dst += dstStride;
 343             y += dy;
 344          }
 345          break;
 346       case A8R8G8B8_UNORM_TO_RGBA_UINT:
 347          for (row = 0; row < height; row++) {
 348             const GLubyte *src = map + y * trans->stride;
 349             for (col = 0; col < width; col++) {
 350                GLuint pixel = ((GLuint *) src)[col];
 351                dst[col*4+0] = ((pixel >> 24) & 0xff) | alphaORoperand;
 352                dst[col*4+1] = (pixel >> 0) & 0xff;
 353                dst[col*4+2] = (pixel >> 8) & 0xff;
 354                dst[col*4+3] = (pixel >> 16) & 0xff;
 355             }
 356             dst += dstStride;
 357             y += dy;
 358          }
 359          break;
 360       default:
 361          ; /* nothing */
 362       }
 363
 364       pipe_transfer_unmap(pipe, trans);
 365       pipe->transfer_destroy(pipe, trans);
 366    }
 367
 368    return GL_TRUE;
 369 }
 370
 371
 372 /**
 373  * Do glReadPixels by getting rows from the framebuffer transfer with
 374  * get_tile().  Convert to requested format/type with Mesa image routines.
 375  * Image transfer ops are done in software too.
 376  */
 377 static void
 378 st_readpixels(struct gl_context *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 379               GLenum format, GLenum type,
 380               const struct gl_pixelstore_attrib *pack,
 381               GLvoid *dest)
 382 {
 383    struct st_context *st = st_context(ctx);
 384    struct pipe_context *pipe = st->pipe;
 385    GLfloat (*temp)[4];
 386    GLbitfield transferOps = ctx->_ImageTransferState;
 387    GLsizei i, j;
 388    GLint yStep, dfStride;
 389    GLfloat *df;
 390    struct st_renderbuffer *strb;
 391    struct gl_pixelstore_attrib clippedPacking = *pack;
 392    struct pipe_transfer *trans;
 393    enum pipe_format pformat;
 394
 395    assert(ctx->ReadBuffer->Width > 0);
 396
 397    st_validate_state(st);
 398
 399    /* Do all needed clipping here, so that we can forget about it later */
 400    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
 401       /* The ReadPixels transfer is totally outside the window bounds */
 402       return;
 403    }
 404
 405    st_flush_bitmap_cache(st);
 406
 407    dest = _mesa_map_pbo_dest(ctx, &clippedPacking, dest);
 408    if (!dest)
 409       return;
 410
 411    if (format == GL_STENCIL_INDEX ||
 412        format == GL_DEPTH_STENCIL) {
 413       st_read_stencil_pixels(ctx, x, y, width, height,
 414                              format, type, pack, dest);
 415       return;
 416    }
 417    else if (format == GL_DEPTH_COMPONENT) {
 418       strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer);
 419       if (strb->Base.Wrapped) {
 420          strb = st_renderbuffer(strb->Base.Wrapped);
 421       }
 422    }
 423    else {
 424       /* Read color buffer */
 425       strb = st_get_color_read_renderbuffer(ctx);
 426    }
 427
 428    if (!strb)
 429       return;
 430
 431    /* try a fast-path readpixels before anything else */
 432    if (st_fast_readpixels(ctx, strb, x, y, width, height,
 433                           format, type, pack, dest)) {
 434       /* success! */
 435       _mesa_unmap_pbo_dest(ctx, &clippedPacking);
 436       return;
 437    }
 438
 439    /* allocate temp pixel row buffer */
 440    temp = (GLfloat (*)[4]) malloc(4 * width * sizeof(GLfloat));
 441    if (!temp) {
 442       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 443       return;
 444    }
 445
 446    if(ctx->Color._ClampReadColor)
 447       transferOps |= IMAGE_CLAMP_BIT;
 448
 449    if (format == GL_RGBA && type == GL_FLOAT && !transferOps) {
 450       /* write tile(row) directly into user's buffer */
 451       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 452                                              height, format, type, 0, 0);
 453       dfStride = width * 4;
 454    }
 455    else {
 456       /* write tile(row) into temp row buffer */
 457       df = (GLfloat *) temp;
 458       dfStride = 0;
 459    }
 460
 461    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 462       /* convert GL Y to Gallium Y */
 463       y = strb->Base.Height - y - height;
 464    }
 465
 466    /* Create a read transfer from the renderbuffer's texture */
 467    trans = pipe_get_transfer(pipe, strb->texture,
 468                              strb->rtt_level, /* level */
 469                              strb->rtt_face + strb->rtt_slice, /* layer */
 470                              PIPE_TRANSFER_READ,
 471                              x, y, width, height);
 472
 473    /* determine bottom-to-top vs. top-to-bottom order */
 474    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 475       y = height - 1;
 476       yStep = -1;
 477    }
 478    else {
 479       y = 0;
 480       yStep = 1;
 481    }
 482
 483    /* possibly convert sRGB format to linear RGB format */
 484    pformat = util_format_linear(trans->resource->format);
 485
 486    if (ST_DEBUG & DEBUG_FALLBACK)
 487       debug_printf("%s: fallback processing\n", __FUNCTION__);
 488
 489    /*
 490     * Copy pixels from pipe_transfer to user memory
 491     */
 492    {
 493       /* dest of first pixel in client memory */
 494       GLubyte *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 495                                            height, format, type, 0, 0);
 496       /* dest row stride */
 497       const GLint dstStride = _mesa_image_row_stride(&clippedPacking, width,
 498                                                      format, type);
 499
 500       if (pformat == PIPE_FORMAT_Z24_UNORM_S8_USCALED ||
 501           pformat == PIPE_FORMAT_Z24X8_UNORM) {
 502          if (format == GL_DEPTH_COMPONENT) {
 503             for (i = 0; i < height; i++) {
 504                GLuint ztemp[MAX_WIDTH];
 505                GLfloat zfloat[MAX_WIDTH];
 506                const double scale = 1.0 / ((1 << 24) - 1);
 507                pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0);
 508                y += yStep;
 509                for (j = 0; j < width; j++) {
 510                   zfloat[j] = (float) (scale * (ztemp[j] & 0xffffff));
 511                }
 512                _mesa_pack_depth_span(ctx, width, dst, type,
 513                                      zfloat, &clippedPacking);
 514                dst += dstStride;
 515             }
 516          }
 517          else {
 518             /* XXX: unreachable code -- should be before st_read_stencil_pixels */
 519             assert(format == GL_DEPTH_STENCIL_EXT);
 520             for (i = 0; i < height; i++) {
 521                GLuint *zshort = (GLuint *)dst;
 522                pipe_get_tile_raw(pipe, trans, 0, y, width, 1, dst, 0);
 523                y += yStep;
 524                /* Reverse into 24/8 */
 525                for (j = 0; j < width; j++) {
 526                   zshort[j] = (zshort[j] << 8) | (zshort[j] >> 24);
 527                }
 528                dst += dstStride;
 529             }
 530          }
 531       }
 532       else if (pformat == PIPE_FORMAT_S8_USCALED_Z24_UNORM ||
 533                pformat == PIPE_FORMAT_X8Z24_UNORM) {
 534          if (format == GL_DEPTH_COMPONENT) {
 535             for (i = 0; i < height; i++) {
 536                GLuint ztemp[MAX_WIDTH];
 537                GLfloat zfloat[MAX_WIDTH];
 538                const double scale = 1.0 / ((1 << 24) - 1);
 539                pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0);
 540                y += yStep;
 541                for (j = 0; j < width; j++) {
 542                   zfloat[j] = (float) (scale * ((ztemp[j] >> 8) & 0xffffff));
 543                }
 544                _mesa_pack_depth_span(ctx, width, dst, type,
 545                                      zfloat, &clippedPacking);
 546                dst += dstStride;
 547             }
 548          }
 549          else {
 550             /* XXX: unreachable code -- should be before st_read_stencil_pixels */
 551             assert(format == GL_DEPTH_STENCIL_EXT);
 552             for (i = 0; i < height; i++) {
 553                pipe_get_tile_raw(pipe, trans, 0, y, width, 1, dst, 0);
 554                y += yStep;
 555                dst += dstStride;
 556             }
 557          }
 558       }
 559       else if (pformat == PIPE_FORMAT_Z16_UNORM) {
 560          for (i = 0; i < height; i++) {
 561             GLushort ztemp[MAX_WIDTH];
 562             GLfloat zfloat[MAX_WIDTH];
 563             const double scale = 1.0 / 0xffff;
 564             pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0);
 565             y += yStep;
 566             for (j = 0; j < width; j++) {
 567                zfloat[j] = (float) (scale * ztemp[j]);
 568             }
 569             _mesa_pack_depth_span(ctx, width, dst, type,
 570                                   zfloat, &clippedPacking);
 571             dst += dstStride;
 572          }
 573       }
 574       else if (pformat == PIPE_FORMAT_Z32_UNORM) {
 575          for (i = 0; i < height; i++) {
 576             GLuint ztemp[MAX_WIDTH];
 577             GLfloat zfloat[MAX_WIDTH];
 578             const double scale = 1.0 / 0xffffffff;
 579             pipe_get_tile_raw(pipe, trans, 0, y, width, 1, ztemp, 0);
 580             y += yStep;
 581             for (j = 0; j < width; j++) {
 582                zfloat[j] = (float) (scale * ztemp[j]);
 583             }
 584             _mesa_pack_depth_span(ctx, width, dst, type,
 585                                   zfloat, &clippedPacking);
 586             dst += dstStride;
 587          }
 588       }
 589       else if (pformat == PIPE_FORMAT_Z32_FLOAT) {
 590          for (i = 0; i < height; i++) {
 591             GLfloat zfloat[MAX_WIDTH];
 592             pipe_get_tile_raw(pipe, trans, 0, y, width, 1, zfloat, 0);
 593             y += yStep;
 594             _mesa_pack_depth_span(ctx, width, dst, type,
 595                                   zfloat, &clippedPacking);
 596             dst += dstStride;
 597          }
 598       }
 599       else if (pformat == PIPE_FORMAT_Z32_FLOAT_S8X24_USCALED) {
 600          assert(format == GL_DEPTH_COMPONENT);
 601          for (i = 0; i < height; i++) {
 602             GLfloat zfloat[MAX_WIDTH];    /* Z32 */
 603             GLfloat zfloat2[MAX_WIDTH*2]; /* Z32X32 */
 604             pipe_get_tile_raw(pipe, trans, 0, y, width, 1, zfloat2, 0);
 605             y += yStep;
 606             for (j = 0; j < width; j++) {
 607                zfloat[j] = zfloat2[j*2];
 608             }
 609             _mesa_pack_depth_span(ctx, width, dst, type,
 610                                   zfloat, &clippedPacking);
 611             dst += dstStride;
 612          }
 613       }
 614       else {
 615          /* RGBA format */
 616          /* Do a row at a time to flip image data vertically */
 617          for (i = 0; i < height; i++) {
 618             pipe_get_tile_rgba_format(pipe, trans, 0, y, width, 1,
 619                                       pformat, df);
 620             y += yStep;
 621             df += dfStride;
 622             if (!dfStride) {
 623                _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 624                                           &clippedPacking, transferOps);
 625                dst += dstStride;
 626             }
 627          }
 628       }
 629    }
 630
 631    free(temp);
 632
 633    pipe->transfer_destroy(pipe, trans);
 634
 635    _mesa_unmap_pbo_dest(ctx, &clippedPacking);
 636 }
 637
 638
 639 void st_init_readpixels_functions(struct dd_function_table *functions)
 640 {
 641    functions->ReadPixels = st_readpixels;
 642 }