src/mesa/swrast/s_readpix.c

   1 /* $Id: s_readpix.c,v 1.15 2002/07/09 01:22:52 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  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 #include "glheader.h"
  29 #include "colormac.h"
  30 #include "convolve.h"
  31 #include "context.h"
  32 #include "feedback.h"
  33 #include "image.h"
  34 #include "macros.h"
  35 #include "mem.h"
  36 #include "pixel.h"
  37
  38 #include "s_alphabuf.h"
  39 #include "s_context.h"
  40 #include "s_depth.h"
  41 #include "s_span.h"
  42 #include "s_stencil.h"
  43
  44
  45
  46 /*
  47  * Read a block of color index pixels.
  48  */
  49 static void
  50 read_index_pixels( GLcontext *ctx,
  51                    GLint x, GLint y,
  52                    GLsizei width, GLsizei height,
  53                    GLenum type, GLvoid *pixels,
  54                    const struct gl_pixelstore_attrib *packing )
  55 {
  56    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  57    GLint i, readWidth;
  58
  59    /* error checking */
  60    if (ctx->Visual.rgbMode) {
  61       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
  62       return;
  63    }
  64
  65    _swrast_use_read_buffer(ctx);
  66
  67    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
  68
  69    /* process image row by row */
  70    for (i = 0; i < height; i++) {
  71       GLuint index[MAX_WIDTH];
  72       GLvoid *dest;
  73
  74       (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y + i, index);
  75
  76       dest = _mesa_image_address(packing, pixels, width, height,
  77                                  GL_COLOR_INDEX, type, 0, i, 0);
  78
  79       _mesa_pack_index_span(ctx, readWidth, type, dest, index,
  80                             &ctx->Pack, ctx->_ImageTransferState);
  81    }
  82
  83    _swrast_use_draw_buffer(ctx);
  84 }
  85
  86
  87
  88 static void
  89 read_depth_pixels( GLcontext *ctx,
  90                    GLint x, GLint y,
  91                    GLsizei width, GLsizei height,
  92                    GLenum type, GLvoid *pixels,
  93                    const struct gl_pixelstore_attrib *packing )
  94 {
  95    GLint readWidth;
  96    GLboolean bias_or_scale;
  97
  98    /* Error checking */
  99    if (ctx->Visual.depthBits <= 0) {
 100       /* No depth buffer */
 101       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 102       return;
 103    }
 104
 105    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 106
 107    if (type != GL_BYTE &&
 108        type != GL_UNSIGNED_BYTE &&
 109        type != GL_SHORT &&
 110        type != GL_UNSIGNED_SHORT &&
 111        type != GL_INT &&
 112        type != GL_UNSIGNED_INT &&
 113        type != GL_FLOAT) {
 114       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(depth type)");
 115       return;
 116    }
 117
 118    bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 119
 120    if (type==GL_UNSIGNED_SHORT && ctx->Visual.depthBits == 16
 121        && !bias_or_scale && !packing->SwapBytes) {
 122       /* Special case: directly read 16-bit unsigned depth values. */
 123       GLint j;
 124       for (j=0;j<height;j++,y++) {
 125          GLdepth depth[MAX_WIDTH];
 126          GLushort *dst = (GLushort*) _mesa_image_address( packing, pixels,
 127                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 128          GLint i;
 129          _mesa_read_depth_span(ctx, width, x, y, depth);
 130          for (i = 0; i < width; i++)
 131             dst[i] = depth[i];
 132       }
 133    }
 134    else if (type==GL_UNSIGNED_INT && ctx->Visual.depthBits == 32
 135             && !bias_or_scale && !packing->SwapBytes) {
 136       /* Special case: directly read 32-bit unsigned depth values. */
 137       GLint j;
 138       for (j=0;j<height;j++,y++) {
 139          GLdepth *dst = (GLdepth *) _mesa_image_address( packing, pixels,
 140                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 141          _mesa_read_depth_span(ctx, width, x, y, dst);
 142       }
 143    }
 144    else {
 145       /* General case (slower) */
 146       GLint j;
 147       for (j=0;j<height;j++,y++) {
 148          GLfloat depth[MAX_WIDTH];
 149          GLvoid *dest;
 150
 151          _mesa_read_depth_span_float(ctx, readWidth, x, y, depth);
 152
 153          dest = _mesa_image_address(packing, pixels, width, height,
 154                                     GL_DEPTH_COMPONENT, type, 0, j, 0);
 155
 156          _mesa_pack_depth_span(ctx, readWidth, (GLdepth *) dest, type,
 157                                depth, &ctx->Pack);
 158       }
 159    }
 160 }
 161
 162
 163
 164 static void
 165 read_stencil_pixels( GLcontext *ctx,
 166                      GLint x, GLint y,
 167                      GLsizei width, GLsizei height,
 168                      GLenum type, GLvoid *pixels,
 169                      const struct gl_pixelstore_attrib *packing )
 170 {
 171    GLint j, readWidth;
 172
 173    if (type != GL_BYTE &&
 174        type != GL_UNSIGNED_BYTE &&
 175        type != GL_SHORT &&
 176        type != GL_UNSIGNED_SHORT &&
 177        type != GL_INT &&
 178        type != GL_UNSIGNED_INT &&
 179        type != GL_FLOAT &&
 180        type != GL_BITMAP) {
 181       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 182       return;
 183    }
 184
 185    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 186
 187    if (ctx->Visual.stencilBits <= 0) {
 188       /* No stencil buffer */
 189       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 190       return;
 191    }
 192
 193    /* process image row by row */
 194    for (j=0;j<height;j++,y++) {
 195       GLvoid *dest;
 196       GLstencil stencil[MAX_WIDTH];
 197
 198       _mesa_read_stencil_span(ctx, readWidth, x, y, stencil);
 199
 200       dest = _mesa_image_address(packing, pixels, width, height,
 201                                  GL_STENCIL_INDEX, type, 0, j, 0);
 202
 203       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 204    }
 205 }
 206
 207
 208
 209 /*
 210  * Optimized glReadPixels for particular pixel formats:
 211  *   GL_UNSIGNED_BYTE, GL_RGBA
 212  * when pixel scaling, biasing and mapping are disabled.
 213  */
 214 static GLboolean
 215 read_fast_rgba_pixels( GLcontext *ctx,
 216                        GLint x, GLint y,
 217                        GLsizei width, GLsizei height,
 218                        GLenum format, GLenum type,
 219                        GLvoid *pixels,
 220                        const struct gl_pixelstore_attrib *packing )
 221 {
 222    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 223    /* can't do scale, bias, mapping, etc */
 224    if (ctx->_ImageTransferState)
 225        return GL_FALSE;
 226
 227    /* can't do fancy pixel packing */
 228    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 229       return GL_FALSE;
 230
 231    {
 232       GLint srcX = x;
 233       GLint srcY = y;
 234       GLint readWidth = width;           /* actual width read */
 235       GLint readHeight = height;         /* actual height read */
 236       GLint skipPixels = packing->SkipPixels;
 237       GLint skipRows = packing->SkipRows;
 238       GLint rowLength;
 239
 240       if (packing->RowLength > 0)
 241          rowLength = packing->RowLength;
 242       else
 243          rowLength = width;
 244
 245       /* horizontal clipping */
 246       if (srcX < 0) {
 247          skipPixels -= srcX;
 248          readWidth += srcX;
 249          srcX = 0;
 250       }
 251       if (srcX + readWidth > (GLint) ctx->ReadBuffer->Width)
 252          readWidth -= (srcX + readWidth - (GLint) ctx->ReadBuffer->Width);
 253       if (readWidth <= 0)
 254          return GL_TRUE;
 255
 256       /* vertical clipping */
 257       if (srcY < 0) {
 258          skipRows -= srcY;
 259          readHeight += srcY;
 260          srcY = 0;
 261       }
 262       if (srcY + readHeight > (GLint) ctx->ReadBuffer->Height)
 263          readHeight -= (srcY + readHeight - (GLint) ctx->ReadBuffer->Height);
 264       if (readHeight <= 0)
 265          return GL_TRUE;
 266
 267       /*
 268        * Ready to read!
 269        * The window region at (destX, destY) of size (readWidth, readHeight)
 270        * will be read back.
 271        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 272        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 273        */
 274 #if CHAN_BITS == 8
 275       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 276 #elif CHAN_BITS == 16
 277       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) {
 278 #else
 279       if (0) {
 280 #endif
 281          GLchan *dest = (GLchan *) pixels
 282                          + (skipRows * rowLength + skipPixels) * 4;
 283          GLint row;
 284          for (row=0; row<readHeight; row++) {
 285             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 286                                         (GLchan (*)[4]) dest);
 287             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 288                _mesa_read_alpha_span(ctx, readWidth, srcX, srcY,
 289                                      (GLchan (*)[4]) dest);
 290             }
 291             dest += rowLength * 4;
 292             srcY++;
 293          }
 294          return GL_TRUE;
 295       }
 296       else {
 297          /* can't do this format/type combination */
 298          return GL_FALSE;
 299       }
 300    }
 301 }
 302
 303
 304
 305 /*
 306  * Read R, G, B, A, RGB, L, or LA pixels.
 307  */
 308 static void
 309 read_rgba_pixels( GLcontext *ctx,
 310                   GLint x, GLint y,
 311                   GLsizei width, GLsizei height,
 312                   GLenum format, GLenum type, GLvoid *pixels,
 313                   const struct gl_pixelstore_attrib *packing )
 314 {
 315    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 316    GLint readWidth;
 317
 318    _swrast_use_read_buffer(ctx);
 319
 320    /* Try optimized path first */
 321    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 322                               format, type, pixels, packing )) {
 323
 324       _swrast_use_draw_buffer(ctx);
 325       return; /* done! */
 326    }
 327
 328    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 329
 330    /* do error checking on pixel type, format was already checked by caller */
 331    switch (type) {
 332       case GL_UNSIGNED_BYTE:
 333       case GL_BYTE:
 334       case GL_UNSIGNED_SHORT:
 335       case GL_SHORT:
 336       case GL_UNSIGNED_INT:
 337       case GL_INT:
 338       case GL_FLOAT:
 339       case GL_UNSIGNED_BYTE_3_3_2:
 340       case GL_UNSIGNED_BYTE_2_3_3_REV:
 341       case GL_UNSIGNED_SHORT_5_6_5:
 342       case GL_UNSIGNED_SHORT_5_6_5_REV:
 343       case GL_UNSIGNED_SHORT_4_4_4_4:
 344       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 345       case GL_UNSIGNED_SHORT_5_5_5_1:
 346       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 347       case GL_UNSIGNED_INT_8_8_8_8:
 348       case GL_UNSIGNED_INT_8_8_8_8_REV:
 349       case GL_UNSIGNED_INT_10_10_10_2:
 350       case GL_UNSIGNED_INT_2_10_10_10_REV:
 351          /* valid pixel type */
 352          break;
 353       default:
 354          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 355          return;
 356    }
 357
 358    if (!_mesa_is_legal_format_and_type(format, type) ||
 359        format == GL_INTENSITY) {
 360       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 361       return;
 362    }
 363
 364    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 365       const GLuint transferOps = ctx->_ImageTransferState;
 366       GLfloat *dest, *src, *tmpImage, *convImage;
 367       GLint row;
 368
 369       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 370       if (!tmpImage) {
 371          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 372          return;
 373       }
 374       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 375       if (!convImage) {
 376          FREE(tmpImage);
 377          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 378          return;
 379       }
 380
 381       /* read full RGBA, FLOAT image */
 382       dest = tmpImage;
 383       for (row = 0; row < height; row++, y++) {
 384          GLchan rgba[MAX_WIDTH][4];
 385          if (ctx->Visual.rgbMode) {
 386             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 387          }
 388          else {
 389             GLuint index[MAX_WIDTH];
 390             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 391             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 392                _mesa_map_ci(ctx, readWidth, index);
 393             }
 394             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 395          }
 396          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 397                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 398                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 399          dest += width * 4;
 400       }
 401
 402       /* do convolution */
 403       if (ctx->Pixel.Convolution2DEnabled) {
 404          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 405       }
 406       else {
 407          ASSERT(ctx->Pixel.Separable2DEnabled);
 408          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 409       }
 410       FREE(tmpImage);
 411
 412       /* finish transfer ops and pack the resulting image */
 413       src = convImage;
 414       for (row = 0; row < height; row++) {
 415          GLvoid *dest;
 416          dest = _mesa_image_address(packing, pixels, readWidth, height,
 417                                     format, type, 0, row, 0);
 418          _mesa_pack_float_rgba_span(ctx, readWidth,
 419                                     (const GLfloat (*)[4]) src,
 420                                     format, type, dest, packing,
 421                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 422          src += readWidth * 4;
 423       }
 424    }
 425    else {
 426       /* no convolution */
 427       GLint row;
 428       for (row = 0; row < height; row++, y++) {
 429          GLchan rgba[MAX_WIDTH][4];
 430          GLvoid *dst;
 431          if (ctx->Visual.rgbMode) {
 432             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 433          }
 434          else {
 435             GLuint index[MAX_WIDTH];
 436             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 437             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 438                _mesa_map_ci(ctx, readWidth, index);
 439             }
 440             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 441          }
 442          dst = _mesa_image_address(packing, pixels, width, height,
 443                                    format, type, 0, row, 0);
 444          if (ctx->Visual.redBits < CHAN_BITS ||
 445              ctx->Visual.greenBits < CHAN_BITS ||
 446              ctx->Visual.blueBits < CHAN_BITS) {
 447             /* Requantize the color values into floating point and go from
 448              * there.  This fixes conformance failures with 16-bit color
 449              * buffers, for example.
 450              */
 451             DEFMARRAY(GLfloat, rgbaf, MAX_WIDTH, 4);  /* mac 32k limitation */
 452             CHECKARRAY(rgbaf, return);  /* mac 32k limitation */
 453             _mesa_chan_to_float_span(ctx, readWidth,
 454                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 455             _mesa_pack_float_rgba_span(ctx, readWidth,
 456                                        (CONST GLfloat (*)[4]) rgbaf,
 457                                        format, type, dst, packing,
 458                                        ctx->_ImageTransferState);
 459             UNDEFARRAY(rgbaf);  /* mac 32k limitation */
 460          }
 461          else {
 462             /* GLubytes are fine */
 463             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 464                                  format, type, dst, packing,
 465                                  ctx->_ImageTransferState);
 466          }
 467       }
 468    }
 469
 470    _swrast_use_draw_buffer(ctx);
 471 }
 472
 473
 474
 475 void
 476 _swrast_ReadPixels( GLcontext *ctx,
 477                     GLint x, GLint y, GLsizei width, GLsizei height,
 478                     GLenum format, GLenum type,
 479                     const struct gl_pixelstore_attrib *pack,
 480                     GLvoid *pixels )
 481 {
 482    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 483    (void) pack;
 484
 485    if (swrast->NewState)
 486       _swrast_validate_derived( ctx );
 487
 488    RENDER_START(swrast,ctx);
 489
 490    switch (format) {
 491       case GL_COLOR_INDEX:
 492          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 493          break;
 494       case GL_STENCIL_INDEX:
 495          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 496          break;
 497       case GL_DEPTH_COMPONENT:
 498          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 499          break;
 500       case GL_RED:
 501       case GL_GREEN:
 502       case GL_BLUE:
 503       case GL_ALPHA:
 504       case GL_RGB:
 505       case GL_LUMINANCE:
 506       case GL_LUMINANCE_ALPHA:
 507       case GL_RGBA:
 508       case GL_BGR:
 509       case GL_BGRA:
 510       case GL_ABGR_EXT:
 511          read_rgba_pixels(ctx, x, y, width, height,
 512                           format, type, pixels, &ctx->Pack);
 513          break;
 514       default:
 515          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 516    }
 517
 518    RENDER_FINISH(swrast,ctx);
 519 }