src/mesa/swrast/s_readpix.c

   1 /* $Id: s_readpix.c,v 1.8 2001/03/03 20:33:30 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, dest, type, depth, &ctx->Pack);
 159       }
 160    }
 161 }
 162
 163
 164
 165 static void
 166 read_stencil_pixels( GLcontext *ctx,
 167                      GLint x, GLint y,
 168                      GLsizei width, GLsizei height,
 169                      GLenum type, GLvoid *pixels,
 170                      const struct gl_pixelstore_attrib *packing )
 171 {
 172    GLint j, readWidth;
 173
 174    if (type != GL_BYTE &&
 175        type != GL_UNSIGNED_BYTE &&
 176        type != GL_SHORT &&
 177        type != GL_UNSIGNED_SHORT &&
 178        type != GL_INT &&
 179        type != GL_UNSIGNED_INT &&
 180        type != GL_FLOAT &&
 181        type != GL_BITMAP) {
 182       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 183       return;
 184    }
 185
 186    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 187
 188    if (ctx->Visual.stencilBits <= 0) {
 189       /* No stencil buffer */
 190       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 191       return;
 192    }
 193
 194    /* process image row by row */
 195    for (j=0;j<height;j++,y++) {
 196       GLvoid *dest;
 197       GLstencil stencil[MAX_WIDTH];
 198
 199       _mesa_read_stencil_span(ctx, readWidth, x, y, stencil);
 200
 201       dest = _mesa_image_address(packing, pixels, width, height,
 202                                  GL_STENCIL_INDEX, type, 0, j, 0);
 203
 204       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 205    }
 206 }
 207
 208
 209
 210 /*
 211  * Optimized glReadPixels for particular pixel formats:
 212  *   GL_UNSIGNED_BYTE, GL_RGBA
 213  * when pixel scaling, biasing and mapping are disabled.
 214  */
 215 static GLboolean
 216 read_fast_rgba_pixels( GLcontext *ctx,
 217                        GLint x, GLint y,
 218                        GLsizei width, GLsizei height,
 219                        GLenum format, GLenum type,
 220                        GLvoid *pixels,
 221                        const struct gl_pixelstore_attrib *packing )
 222 {
 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 < ctx->ReadBuffer->_Xmin) {
 247          skipPixels += (ctx->ReadBuffer->_Xmin - srcX);
 248          readWidth  -= (ctx->ReadBuffer->_Xmin - srcX);
 249          srcX = ctx->ReadBuffer->_Xmin;
 250       }
 251       if (srcX + readWidth > ctx->ReadBuffer->_Xmax)
 252          readWidth -= (srcX + readWidth - ctx->ReadBuffer->_Xmax);
 253       if (readWidth <= 0)
 254          return GL_TRUE;
 255
 256       /* vertical clipping */
 257       if (srcY < ctx->ReadBuffer->_Ymin) {
 258          skipRows   += (ctx->ReadBuffer->_Ymin - srcY);
 259          readHeight -= (ctx->ReadBuffer->_Ymin - srcY);
 260          srcY = ctx->ReadBuffer->_Ymin;
 261       }
 262       if (srcY + readHeight > ctx->ReadBuffer->_Ymax)
 263          readHeight -= (srcY + readHeight - ctx->ReadBuffer->_Ymax);
 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             (*ctx->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    GLint readWidth;
 316
 317    (*ctx->Driver.SetReadBuffer)(ctx, ctx->ReadBuffer, ctx->Pixel.DriverReadBuffer);
 318
 319    /* Try optimized path first */
 320    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 321                               format, type, pixels, packing )) {
 322
 323       (*ctx->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 324       return; /* done! */
 325    }
 326
 327    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 328
 329    /* do error checking on pixel type, format was already checked by caller */
 330    switch (type) {
 331       case GL_UNSIGNED_BYTE:
 332       case GL_BYTE:
 333       case GL_UNSIGNED_SHORT:
 334       case GL_SHORT:
 335       case GL_UNSIGNED_INT:
 336       case GL_INT:
 337       case GL_FLOAT:
 338       case GL_UNSIGNED_BYTE_3_3_2:
 339       case GL_UNSIGNED_BYTE_2_3_3_REV:
 340       case GL_UNSIGNED_SHORT_5_6_5:
 341       case GL_UNSIGNED_SHORT_5_6_5_REV:
 342       case GL_UNSIGNED_SHORT_4_4_4_4:
 343       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 344       case GL_UNSIGNED_SHORT_5_5_5_1:
 345       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 346       case GL_UNSIGNED_INT_8_8_8_8:
 347       case GL_UNSIGNED_INT_8_8_8_8_REV:
 348       case GL_UNSIGNED_INT_10_10_10_2:
 349       case GL_UNSIGNED_INT_2_10_10_10_REV:
 350          /* valid pixel type */
 351          break;
 352       default:
 353          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 354          return;
 355    }
 356
 357    if (!_mesa_is_legal_format_and_type(format, type) ||
 358        format == GL_INTENSITY) {
 359       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 360       return;
 361    }
 362
 363    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 364       const GLuint transferOps = ctx->_ImageTransferState;
 365       GLfloat *dest, *src, *tmpImage, *convImage;
 366       GLint row;
 367
 368       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 369       if (!tmpImage) {
 370          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 371          return;
 372       }
 373       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 374       if (!convImage) {
 375          FREE(tmpImage);
 376          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 377          return;
 378       }
 379
 380       /* read full RGBA, FLOAT image */
 381       dest = tmpImage;
 382       for (row = 0; row < height; row++, y++) {
 383          GLchan rgba[MAX_WIDTH][4];
 384          if (ctx->Visual.rgbMode) {
 385             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 386          }
 387          else {
 388             GLuint index[MAX_WIDTH];
 389             (*ctx->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 390             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 391                _mesa_map_ci(ctx, readWidth, index);
 392             }
 393             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 394          }
 395          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 396                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 397                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 398          dest += width * 4;
 399       }
 400
 401       /* do convolution */
 402       if (ctx->Pixel.Convolution2DEnabled) {
 403          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 404       }
 405       else {
 406          ASSERT(ctx->Pixel.Separable2DEnabled);
 407          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 408       }
 409       FREE(tmpImage);
 410
 411       /* finish transfer ops and pack the resulting image */
 412       src = convImage;
 413       for (row = 0; row < height; row++) {
 414          GLvoid *dest;
 415          dest = _mesa_image_address(packing, pixels, readWidth, height,
 416                                     format, type, 0, row, 0);
 417          _mesa_pack_float_rgba_span(ctx, readWidth,
 418                                     (const GLfloat (*)[4]) src,
 419                                     format, type, dest, packing,
 420                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 421          src += readWidth * 4;
 422       }
 423    }
 424    else {
 425       /* no convolution */
 426       GLint row;
 427       for (row = 0; row < height; row++, y++) {
 428          GLchan rgba[MAX_WIDTH][4];
 429          GLvoid *dst;
 430          if (ctx->Visual.rgbMode) {
 431             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 432          }
 433          else {
 434             GLuint index[MAX_WIDTH];
 435             (*ctx->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 436             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 437                _mesa_map_ci(ctx, readWidth, index);
 438             }
 439             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 440          }
 441          dst = _mesa_image_address(packing, pixels, width, height,
 442                                    format, type, 0, row, 0);
 443          if (ctx->Visual.redBits < CHAN_BITS ||
 444              ctx->Visual.greenBits < CHAN_BITS ||
 445              ctx->Visual.blueBits < CHAN_BITS) {
 446             /* Requantize the color values into floating point and go from
 447              * there.  This fixes conformance failures with 16-bit color
 448              * buffers, for example.
 449              */
 450             GLfloat rgbaf[MAX_WIDTH][4];
 451             _mesa_chan_to_float_span(ctx, readWidth,
 452                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 453             _mesa_pack_float_rgba_span(ctx, readWidth,
 454                                        (CONST GLfloat (*)[4]) rgbaf,
 455                                        format, type, dst, packing,
 456                                        ctx->_ImageTransferState);
 457          }
 458          else {
 459             /* GLubytes are fine */
 460             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 461                                  format, type, dst, packing,
 462                                  ctx->_ImageTransferState);
 463          }
 464       }
 465    }
 466
 467    (*ctx->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 468 }
 469
 470
 471
 472 void
 473 _swrast_ReadPixels( GLcontext *ctx,
 474                     GLint x, GLint y, GLsizei width, GLsizei height,
 475                     GLenum format, GLenum type,
 476                     const struct gl_pixelstore_attrib *pack,
 477                     GLvoid *pixels )
 478 {
 479    (void) pack;
 480
 481    if (SWRAST_CONTEXT(ctx)->NewState)
 482       _swrast_validate_derived( ctx );
 483
 484    switch (format) {
 485       case GL_COLOR_INDEX:
 486          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 487          break;
 488       case GL_STENCIL_INDEX:
 489          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 490          break;
 491       case GL_DEPTH_COMPONENT:
 492          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 493          break;
 494       case GL_RED:
 495       case GL_GREEN:
 496       case GL_BLUE:
 497       case GL_ALPHA:
 498       case GL_RGB:
 499       case GL_LUMINANCE:
 500       case GL_LUMINANCE_ALPHA:
 501       case GL_RGBA:
 502       case GL_BGR:
 503       case GL_BGRA:
 504       case GL_ABGR_EXT:
 505          read_rgba_pixels(ctx, x, y, width, height,
 506                           format, type, pixels, &ctx->Pack);
 507          break;
 508       default:
 509          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 510    }
 511 }