src/mesa/swrast/s_readpix.c

   1 /* $Id: s_readpix.c,v 1.9 2001/03/07 05:06:12 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2001  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    GLint i, readWidth;
  57
  58    /* error checking */
  59    if (ctx->Visual.rgbMode) {
  60       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
  61       return;
  62    }
  63
  64    ASSERT(ctx->Driver.SetReadBuffer);
  65    (*ctx->Driver.SetReadBuffer)(ctx, ctx->ReadBuffer,
  66                                 ctx->Pixel.DriverReadBuffer);
  67
  68    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
  69
  70    /* process image row by row */
  71    for (i = 0; i < height; i++) {
  72       GLuint index[MAX_WIDTH];
  73       GLvoid *dest;
  74
  75       (*ctx->Driver.ReadCI32Span)(ctx, readWidth, x, y + i, index);
  76
  77       dest = _mesa_image_address(packing, pixels, width, height,
  78                                  GL_COLOR_INDEX, type, 0, i, 0);
  79
  80       _mesa_pack_index_span(ctx, readWidth, type, dest, index,
  81                             &ctx->Pack, ctx->_ImageTransferState);
  82    }
  83
  84    (*ctx->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer,
  85                                 ctx->Color.DriverDrawBuffer);
  86 }
  87
  88
  89
  90 static void
  91 read_depth_pixels( GLcontext *ctx,
  92                    GLint x, GLint y,
  93                    GLsizei width, GLsizei height,
  94                    GLenum type, GLvoid *pixels,
  95                    const struct gl_pixelstore_attrib *packing )
  96 {
  97    GLint readWidth;
  98    GLboolean bias_or_scale;
  99
 100    /* Error checking */
 101    if (ctx->Visual.depthBits <= 0) {
 102       /* No depth buffer */
 103       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 104       return;
 105    }
 106
 107    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 108
 109    if (type != GL_BYTE &&
 110        type != GL_UNSIGNED_BYTE &&
 111        type != GL_SHORT &&
 112        type != GL_UNSIGNED_SHORT &&
 113        type != GL_INT &&
 114        type != GL_UNSIGNED_INT &&
 115        type != GL_FLOAT) {
 116       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(depth type)");
 117       return;
 118    }
 119
 120    bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 121
 122    if (type==GL_UNSIGNED_SHORT && ctx->Visual.depthBits == 16
 123        && !bias_or_scale && !packing->SwapBytes) {
 124       /* Special case: directly read 16-bit unsigned depth values. */
 125       GLint j;
 126       for (j=0;j<height;j++,y++) {
 127          GLdepth depth[MAX_WIDTH];
 128          GLushort *dst = (GLushort*) _mesa_image_address( packing, pixels,
 129                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 130          GLint i;
 131          _mesa_read_depth_span(ctx, width, x, y, depth);
 132          for (i = 0; i < width; i++)
 133             dst[i] = depth[i];
 134       }
 135    }
 136    else if (type==GL_UNSIGNED_INT && ctx->Visual.depthBits == 32
 137             && !bias_or_scale && !packing->SwapBytes) {
 138       /* Special case: directly read 32-bit unsigned depth values. */
 139       GLint j;
 140       for (j=0;j<height;j++,y++) {
 141          GLdepth *dst = (GLdepth *) _mesa_image_address( packing, pixels,
 142                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 143          _mesa_read_depth_span(ctx, width, x, y, dst);
 144       }
 145    }
 146    else {
 147       /* General case (slower) */
 148       GLint j;
 149       for (j=0;j<height;j++,y++) {
 150          GLfloat depth[MAX_WIDTH];
 151          GLvoid *dest;
 152
 153          _mesa_read_depth_span_float(ctx, readWidth, x, y, depth);
 154
 155          dest = _mesa_image_address(packing, pixels, width, height,
 156                                     GL_DEPTH_COMPONENT, type, 0, j, 0);
 157
 158          _mesa_pack_depth_span(ctx, readWidth, (GLdepth *) dest, type,
 159                                depth, &ctx->Pack);
 160       }
 161    }
 162 }
 163
 164
 165
 166 static void
 167 read_stencil_pixels( GLcontext *ctx,
 168                      GLint x, GLint y,
 169                      GLsizei width, GLsizei height,
 170                      GLenum type, GLvoid *pixels,
 171                      const struct gl_pixelstore_attrib *packing )
 172 {
 173    GLint j, readWidth;
 174
 175    if (type != GL_BYTE &&
 176        type != GL_UNSIGNED_BYTE &&
 177        type != GL_SHORT &&
 178        type != GL_UNSIGNED_SHORT &&
 179        type != GL_INT &&
 180        type != GL_UNSIGNED_INT &&
 181        type != GL_FLOAT &&
 182        type != GL_BITMAP) {
 183       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 184       return;
 185    }
 186
 187    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 188
 189    if (ctx->Visual.stencilBits <= 0) {
 190       /* No stencil buffer */
 191       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 192       return;
 193    }
 194
 195    /* process image row by row */
 196    for (j=0;j<height;j++,y++) {
 197       GLvoid *dest;
 198       GLstencil stencil[MAX_WIDTH];
 199
 200       _mesa_read_stencil_span(ctx, readWidth, x, y, stencil);
 201
 202       dest = _mesa_image_address(packing, pixels, width, height,
 203                                  GL_STENCIL_INDEX, type, 0, j, 0);
 204
 205       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 206    }
 207 }
 208
 209
 210
 211 /*
 212  * Optimized glReadPixels for particular pixel formats:
 213  *   GL_UNSIGNED_BYTE, GL_RGBA
 214  * when pixel scaling, biasing and mapping are disabled.
 215  */
 216 static GLboolean
 217 read_fast_rgba_pixels( GLcontext *ctx,
 218                        GLint x, GLint y,
 219                        GLsizei width, GLsizei height,
 220                        GLenum format, GLenum type,
 221                        GLvoid *pixels,
 222                        const struct gl_pixelstore_attrib *packing )
 223 {
 224    /* can't do scale, bias, mapping, etc */
 225    if (ctx->_ImageTransferState)
 226        return GL_FALSE;
 227
 228    /* can't do fancy pixel packing */
 229    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 230       return GL_FALSE;
 231
 232    {
 233       GLint srcX = x;
 234       GLint srcY = y;
 235       GLint readWidth = width;           /* actual width read */
 236       GLint readHeight = height;         /* actual height read */
 237       GLint skipPixels = packing->SkipPixels;
 238       GLint skipRows = packing->SkipRows;
 239       GLint rowLength;
 240
 241       if (packing->RowLength > 0)
 242          rowLength = packing->RowLength;
 243       else
 244          rowLength = width;
 245
 246       /* horizontal clipping */
 247       if (srcX < ctx->ReadBuffer->_Xmin) {
 248          skipPixels += (ctx->ReadBuffer->_Xmin - srcX);
 249          readWidth  -= (ctx->ReadBuffer->_Xmin - srcX);
 250          srcX = ctx->ReadBuffer->_Xmin;
 251       }
 252       if (srcX + readWidth > ctx->ReadBuffer->_Xmax)
 253          readWidth -= (srcX + readWidth - ctx->ReadBuffer->_Xmax);
 254       if (readWidth <= 0)
 255          return GL_TRUE;
 256
 257       /* vertical clipping */
 258       if (srcY < ctx->ReadBuffer->_Ymin) {
 259          skipRows   += (ctx->ReadBuffer->_Ymin - srcY);
 260          readHeight -= (ctx->ReadBuffer->_Ymin - srcY);
 261          srcY = ctx->ReadBuffer->_Ymin;
 262       }
 263       if (srcY + readHeight > ctx->ReadBuffer->_Ymax)
 264          readHeight -= (srcY + readHeight - ctx->ReadBuffer->_Ymax);
 265       if (readHeight <= 0)
 266          return GL_TRUE;
 267
 268       /*
 269        * Ready to read!
 270        * The window region at (destX, destY) of size (readWidth, readHeight)
 271        * will be read back.
 272        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 273        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 274        */
 275 #if CHAN_BITS == 8
 276       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 277 #elif CHAN_BITS == 16
 278       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) {
 279 #else
 280       if (0) {
 281 #endif
 282          GLchan *dest = (GLchan *) pixels
 283                          + (skipRows * rowLength + skipPixels) * 4;
 284          GLint row;
 285          for (row=0; row<readHeight; row++) {
 286             (*ctx->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 287                                         (GLchan (*)[4]) dest);
 288             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 289                _mesa_read_alpha_span(ctx, readWidth, srcX, srcY,
 290                                      (GLchan (*)[4]) dest);
 291             }
 292             dest += rowLength * 4;
 293             srcY++;
 294          }
 295          return GL_TRUE;
 296       }
 297       else {
 298          /* can't do this format/type combination */
 299          return GL_FALSE;
 300       }
 301    }
 302 }
 303
 304
 305
 306 /*
 307  * Read R, G, B, A, RGB, L, or LA pixels.
 308  */
 309 static void
 310 read_rgba_pixels( GLcontext *ctx,
 311                   GLint x, GLint y,
 312                   GLsizei width, GLsizei height,
 313                   GLenum format, GLenum type, GLvoid *pixels,
 314                   const struct gl_pixelstore_attrib *packing )
 315 {
 316    GLint readWidth;
 317
 318    (*ctx->Driver.SetReadBuffer)(ctx, ctx->ReadBuffer, ctx->Pixel.DriverReadBuffer);
 319
 320    /* Try optimized path first */
 321    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 322                               format, type, pixels, packing )) {
 323
 324       (*ctx->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 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             (*ctx->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             (*ctx->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             GLfloat rgbaf[MAX_WIDTH][4];
 452             _mesa_chan_to_float_span(ctx, readWidth,
 453                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 454             _mesa_pack_float_rgba_span(ctx, readWidth,
 455                                        (CONST GLfloat (*)[4]) rgbaf,
 456                                        format, type, dst, packing,
 457                                        ctx->_ImageTransferState);
 458          }
 459          else {
 460             /* GLubytes are fine */
 461             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 462                                  format, type, dst, packing,
 463                                  ctx->_ImageTransferState);
 464          }
 465       }
 466    }
 467
 468    (*ctx->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 469 }
 470
 471
 472
 473 void
 474 _swrast_ReadPixels( GLcontext *ctx,
 475                     GLint x, GLint y, GLsizei width, GLsizei height,
 476                     GLenum format, GLenum type,
 477                     const struct gl_pixelstore_attrib *pack,
 478                     GLvoid *pixels )
 479 {
 480    (void) pack;
 481
 482    if (SWRAST_CONTEXT(ctx)->NewState)
 483       _swrast_validate_derived( ctx );
 484
 485    switch (format) {
 486       case GL_COLOR_INDEX:
 487          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 488          break;
 489       case GL_STENCIL_INDEX:
 490          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 491          break;
 492       case GL_DEPTH_COMPONENT:
 493          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 494          break;
 495       case GL_RED:
 496       case GL_GREEN:
 497       case GL_BLUE:
 498       case GL_ALPHA:
 499       case GL_RGB:
 500       case GL_LUMINANCE:
 501       case GL_LUMINANCE_ALPHA:
 502       case GL_RGBA:
 503       case GL_BGR:
 504       case GL_BGRA:
 505       case GL_ABGR_EXT:
 506          read_rgba_pixels(ctx, x, y, width, height,
 507                           format, type, pixels, &ctx->Pack);
 508          break;
 509       default:
 510          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 511    }
 512 }