src/mesa/swrast/s_readpix.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  5.1
   4  *
   5  * Copyright (C) 1999-2003  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 "colormac.h"
  28 #include "convolve.h"
  29 #include "context.h"
  30 #include "feedback.h"
  31 #include "image.h"
  32 #include "macros.h"
  33 #include "imports.h"
  34 #include "pixel.h"
  35
  36 #include "s_alphabuf.h"
  37 #include "s_context.h"
  38 #include "s_depth.h"
  39 #include "s_span.h"
  40 #include "s_stencil.h"
  41
  42
  43
  44 /*
  45  * Read a block of color index pixels.
  46  */
  47 static void
  48 read_index_pixels( GLcontext *ctx,
  49                    GLint x, GLint y,
  50                    GLsizei width, GLsizei height,
  51                    GLenum type, GLvoid *pixels,
  52                    const struct gl_pixelstore_attrib *packing )
  53 {
  54    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  55    GLint i, readWidth;
  56
  57    /* error checking */
  58    if (ctx->Visual.rgbMode) {
  59       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
  60       return;
  61    }
  62
  63    if (type != GL_BYTE &&
  64        type != GL_UNSIGNED_BYTE &&
  65        type != GL_SHORT &&
  66        type != GL_UNSIGNED_SHORT &&
  67        type != GL_INT &&
  68        type != GL_UNSIGNED_INT &&
  69        type != GL_FLOAT) {
  70       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(index type)");
  71       return;
  72    }
  73
  74    _swrast_use_read_buffer(ctx);
  75
  76    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
  77
  78    /* process image row by row */
  79    for (i = 0; i < height; i++) {
  80       GLuint index[MAX_WIDTH];
  81       GLvoid *dest;
  82
  83       (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y + i, index);
  84
  85       dest = _mesa_image_address(packing, pixels, width, height,
  86                                  GL_COLOR_INDEX, type, 0, i, 0);
  87
  88       _mesa_pack_index_span(ctx, readWidth, type, dest, index,
  89                             &ctx->Pack, ctx->_ImageTransferState);
  90    }
  91
  92    _swrast_use_draw_buffer(ctx);
  93 }
  94
  95
  96
  97 static void
  98 read_depth_pixels( GLcontext *ctx,
  99                    GLint x, GLint y,
 100                    GLsizei width, GLsizei height,
 101                    GLenum type, GLvoid *pixels,
 102                    const struct gl_pixelstore_attrib *packing )
 103 {
 104    GLint readWidth;
 105    GLboolean bias_or_scale;
 106
 107    /* Error checking */
 108    if (ctx->Visual.depthBits <= 0) {
 109       /* No depth buffer */
 110       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 111       return;
 112    }
 113
 114    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 115
 116    if (type != GL_BYTE &&
 117        type != GL_UNSIGNED_BYTE &&
 118        type != GL_SHORT &&
 119        type != GL_UNSIGNED_SHORT &&
 120        type != GL_INT &&
 121        type != GL_UNSIGNED_INT &&
 122        type != GL_FLOAT) {
 123       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(depth type)");
 124       return;
 125    }
 126
 127    bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 128
 129    if (type==GL_UNSIGNED_SHORT && ctx->Visual.depthBits == 16
 130        && !bias_or_scale && !packing->SwapBytes) {
 131       /* Special case: directly read 16-bit unsigned depth values. */
 132       GLint j;
 133       for (j=0;j<height;j++,y++) {
 134          GLdepth depth[MAX_WIDTH];
 135          GLushort *dst = (GLushort*) _mesa_image_address( packing, pixels,
 136                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 137          GLint i;
 138          _swrast_read_depth_span(ctx, width, x, y, depth);
 139          for (i = 0; i < width; i++)
 140             dst[i] = depth[i];
 141       }
 142    }
 143    else if (type==GL_UNSIGNED_INT && ctx->Visual.depthBits == 32
 144             && !bias_or_scale && !packing->SwapBytes) {
 145       /* Special case: directly read 32-bit unsigned depth values. */
 146       GLint j;
 147       for (j=0;j<height;j++,y++) {
 148          GLdepth *dst = (GLdepth *) _mesa_image_address( packing, pixels,
 149                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 150          _swrast_read_depth_span(ctx, width, x, y, dst);
 151       }
 152    }
 153    else {
 154       /* General case (slower) */
 155       GLint j;
 156       for (j=0;j<height;j++,y++) {
 157          GLfloat depth[MAX_WIDTH];
 158          GLvoid *dest;
 159
 160          _swrast_read_depth_span_float(ctx, readWidth, x, y, depth);
 161
 162          dest = _mesa_image_address(packing, pixels, width, height,
 163                                     GL_DEPTH_COMPONENT, type, 0, j, 0);
 164
 165          _mesa_pack_depth_span(ctx, readWidth, (GLdepth *) dest, type,
 166                                depth, &ctx->Pack);
 167       }
 168    }
 169 }
 170
 171
 172
 173 static void
 174 read_stencil_pixels( GLcontext *ctx,
 175                      GLint x, GLint y,
 176                      GLsizei width, GLsizei height,
 177                      GLenum type, GLvoid *pixels,
 178                      const struct gl_pixelstore_attrib *packing )
 179 {
 180    GLint j, readWidth;
 181
 182    if (type != GL_BYTE &&
 183        type != GL_UNSIGNED_BYTE &&
 184        type != GL_SHORT &&
 185        type != GL_UNSIGNED_SHORT &&
 186        type != GL_INT &&
 187        type != GL_UNSIGNED_INT &&
 188        type != GL_FLOAT &&
 189        type != GL_BITMAP) {
 190       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 191       return;
 192    }
 193
 194    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 195
 196    if (ctx->Visual.stencilBits <= 0) {
 197       /* No stencil buffer */
 198       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 199       return;
 200    }
 201
 202    /* process image row by row */
 203    for (j=0;j<height;j++,y++) {
 204       GLvoid *dest;
 205       GLstencil stencil[MAX_WIDTH];
 206
 207       _swrast_read_stencil_span(ctx, readWidth, x, y, stencil);
 208
 209       dest = _mesa_image_address(packing, pixels, width, height,
 210                                  GL_STENCIL_INDEX, type, 0, j, 0);
 211
 212       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 213    }
 214 }
 215
 216
 217
 218 /*
 219  * Optimized glReadPixels for particular pixel formats:
 220  *   GL_UNSIGNED_BYTE, GL_RGBA
 221  * when pixel scaling, biasing and mapping are disabled.
 222  */
 223 static GLboolean
 224 read_fast_rgba_pixels( GLcontext *ctx,
 225                        GLint x, GLint y,
 226                        GLsizei width, GLsizei height,
 227                        GLenum format, GLenum type,
 228                        GLvoid *pixels,
 229                        const struct gl_pixelstore_attrib *packing )
 230 {
 231    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 232    /* can't do scale, bias, mapping, etc */
 233    if (ctx->_ImageTransferState)
 234        return GL_FALSE;
 235
 236    /* can't do fancy pixel packing */
 237    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 238       return GL_FALSE;
 239
 240    {
 241       GLint srcX = x;
 242       GLint srcY = y;
 243       GLint readWidth = width;           /* actual width read */
 244       GLint readHeight = height;         /* actual height read */
 245       GLint skipPixels = packing->SkipPixels;
 246       GLint skipRows = packing->SkipRows;
 247       GLint rowLength;
 248
 249       if (packing->RowLength > 0)
 250          rowLength = packing->RowLength;
 251       else
 252          rowLength = width;
 253
 254       /* horizontal clipping */
 255       if (srcX < 0) {
 256          skipPixels -= srcX;
 257          readWidth += srcX;
 258          srcX = 0;
 259       }
 260       if (srcX + readWidth > (GLint) ctx->ReadBuffer->Width)
 261          readWidth -= (srcX + readWidth - (GLint) ctx->ReadBuffer->Width);
 262       if (readWidth <= 0)
 263          return GL_TRUE;
 264
 265       /* vertical clipping */
 266       if (srcY < 0) {
 267          skipRows -= srcY;
 268          readHeight += srcY;
 269          srcY = 0;
 270       }
 271       if (srcY + readHeight > (GLint) ctx->ReadBuffer->Height)
 272          readHeight -= (srcY + readHeight - (GLint) ctx->ReadBuffer->Height);
 273       if (readHeight <= 0)
 274          return GL_TRUE;
 275
 276       /*
 277        * Ready to read!
 278        * The window region at (destX, destY) of size (readWidth, readHeight)
 279        * will be read back.
 280        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 281        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 282        */
 283 #if CHAN_BITS == 8
 284       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 285 #elif CHAN_BITS == 16
 286       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) {
 287 #else
 288       if (0) {
 289 #endif
 290          GLchan *dest = (GLchan *) pixels
 291                       + (skipRows * rowLength + skipPixels) * 4;
 292          GLint row;
 293
 294          if (packing->Invert) {
 295             /* start at top and go down */
 296             dest += (readHeight - 1) * rowLength * 4;
 297             rowLength = -rowLength;
 298          }
 299
 300          for (row=0; row<readHeight; row++) {
 301             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 302                                         (GLchan (*)[4]) dest);
 303             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 304                _swrast_read_alpha_span(ctx, readWidth, srcX, srcY,
 305                                      (GLchan (*)[4]) dest);
 306             }
 307             dest += rowLength * 4;
 308             srcY++;
 309          }
 310          return GL_TRUE;
 311       }
 312       else {
 313          /* can't do this format/type combination */
 314          return GL_FALSE;
 315       }
 316    }
 317 }
 318
 319
 320
 321 /*
 322  * Read R, G, B, A, RGB, L, or LA pixels.
 323  */
 324 static void
 325 read_rgba_pixels( GLcontext *ctx,
 326                   GLint x, GLint y,
 327                   GLsizei width, GLsizei height,
 328                   GLenum format, GLenum type, GLvoid *pixels,
 329                   const struct gl_pixelstore_attrib *packing )
 330 {
 331    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 332    GLint readWidth;
 333
 334    _swrast_use_read_buffer(ctx);
 335
 336    /* Try optimized path first */
 337    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 338                               format, type, pixels, packing )) {
 339
 340       _swrast_use_draw_buffer(ctx);
 341       return; /* done! */
 342    }
 343
 344    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 345
 346    /* do error checking on pixel type, format was already checked by caller */
 347    switch (type) {
 348       case GL_UNSIGNED_BYTE:
 349       case GL_BYTE:
 350       case GL_UNSIGNED_SHORT:
 351       case GL_SHORT:
 352       case GL_UNSIGNED_INT:
 353       case GL_INT:
 354       case GL_FLOAT:
 355       case GL_UNSIGNED_BYTE_3_3_2:
 356       case GL_UNSIGNED_BYTE_2_3_3_REV:
 357       case GL_UNSIGNED_SHORT_5_6_5:
 358       case GL_UNSIGNED_SHORT_5_6_5_REV:
 359       case GL_UNSIGNED_SHORT_4_4_4_4:
 360       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 361       case GL_UNSIGNED_SHORT_5_5_5_1:
 362       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 363       case GL_UNSIGNED_INT_8_8_8_8:
 364       case GL_UNSIGNED_INT_8_8_8_8_REV:
 365       case GL_UNSIGNED_INT_10_10_10_2:
 366       case GL_UNSIGNED_INT_2_10_10_10_REV:
 367          /* valid pixel type */
 368          break;
 369       default:
 370          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 371          return;
 372    }
 373
 374    if (!_mesa_is_legal_format_and_type(format, type) ||
 375        format == GL_INTENSITY) {
 376       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 377       return;
 378    }
 379
 380    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 381       const GLuint transferOps = ctx->_ImageTransferState;
 382       GLfloat *dest, *src, *tmpImage, *convImage;
 383       GLint row;
 384
 385       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 386       if (!tmpImage) {
 387          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 388          return;
 389       }
 390       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 391       if (!convImage) {
 392          FREE(tmpImage);
 393          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 394          return;
 395       }
 396
 397       /* read full RGBA, FLOAT image */
 398       dest = tmpImage;
 399       for (row = 0; row < height; row++, y++) {
 400          GLchan rgba[MAX_WIDTH][4];
 401          if (ctx->Visual.rgbMode) {
 402             _swrast_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 403          }
 404          else {
 405             GLuint index[MAX_WIDTH];
 406             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 407             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 408                _mesa_map_ci(ctx, readWidth, index);
 409             }
 410             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 411          }
 412          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 413                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 414                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 415          dest += width * 4;
 416       }
 417
 418       /* do convolution */
 419       if (ctx->Pixel.Convolution2DEnabled) {
 420          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 421       }
 422       else {
 423          ASSERT(ctx->Pixel.Separable2DEnabled);
 424          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 425       }
 426       FREE(tmpImage);
 427
 428       /* finish transfer ops and pack the resulting image */
 429       src = convImage;
 430       for (row = 0; row < height; row++) {
 431          GLvoid *dest;
 432          dest = _mesa_image_address(packing, pixels, readWidth, height,
 433                                     format, type, 0, row, 0);
 434          _mesa_pack_float_rgba_span(ctx, readWidth,
 435                                     (const GLfloat (*)[4]) src,
 436                                     format, type, dest, packing,
 437                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 438          src += readWidth * 4;
 439       }
 440    }
 441    else {
 442       /* no convolution */
 443       GLint row;
 444       for (row = 0; row < height; row++, y++) {
 445          GLchan rgba[MAX_WIDTH][4];
 446          GLvoid *dst;
 447          if (ctx->Visual.rgbMode) {
 448             _swrast_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 449          }
 450          else {
 451             GLuint index[MAX_WIDTH];
 452             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 453             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 454                _mesa_map_ci(ctx, readWidth, index);
 455             }
 456             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 457          }
 458          dst = _mesa_image_address(packing, pixels, width, height,
 459                                    format, type, 0, row, 0);
 460          if (ctx->Visual.redBits < CHAN_BITS ||
 461              ctx->Visual.greenBits < CHAN_BITS ||
 462              ctx->Visual.blueBits < CHAN_BITS) {
 463             /* Requantize the color values into floating point and go from
 464              * there.  This fixes conformance failures with 16-bit color
 465              * buffers, for example.
 466              */
 467             DEFMARRAY(GLfloat, rgbaf, MAX_WIDTH, 4);  /* mac 32k limitation */
 468             CHECKARRAY(rgbaf, return);  /* mac 32k limitation */
 469             _mesa_chan_to_float_span(ctx, readWidth,
 470                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 471             _mesa_pack_float_rgba_span(ctx, readWidth,
 472                                        (CONST GLfloat (*)[4]) rgbaf,
 473                                        format, type, dst, packing,
 474                                        ctx->_ImageTransferState);
 475             UNDEFARRAY(rgbaf);  /* mac 32k limitation */
 476          }
 477          else {
 478             /* GLubytes are fine */
 479             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 480                                  format, type, dst, packing,
 481                                  ctx->_ImageTransferState);
 482          }
 483       }
 484    }
 485
 486    _swrast_use_draw_buffer(ctx);
 487 }
 488
 489
 490
 491 void
 492 _swrast_ReadPixels( GLcontext *ctx,
 493                     GLint x, GLint y, GLsizei width, GLsizei height,
 494                     GLenum format, GLenum type,
 495                     const struct gl_pixelstore_attrib *pack,
 496                     GLvoid *pixels )
 497 {
 498    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 499    (void) pack;
 500
 501    if (swrast->NewState)
 502       _swrast_validate_derived( ctx );
 503
 504    RENDER_START(swrast,ctx);
 505
 506    switch (format) {
 507       case GL_COLOR_INDEX:
 508          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 509          break;
 510       case GL_STENCIL_INDEX:
 511          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 512          break;
 513       case GL_DEPTH_COMPONENT:
 514          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 515          break;
 516       case GL_RED:
 517       case GL_GREEN:
 518       case GL_BLUE:
 519       case GL_ALPHA:
 520       case GL_RGB:
 521       case GL_LUMINANCE:
 522       case GL_LUMINANCE_ALPHA:
 523       case GL_RGBA:
 524       case GL_BGR:
 525       case GL_BGRA:
 526       case GL_ABGR_EXT:
 527          read_rgba_pixels(ctx, x, y, width, height,
 528                           format, type, pixels, &ctx->Pack);
 529          break;
 530       default:
 531          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 532    }
 533
 534    RENDER_FINISH(swrast,ctx);
 535 }