src/mesa/swrast/s_readpix.c

   1 /* $Id: s_readpix.c,v 1.17 2002/10/24 23:57:24 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 "imports.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
 285          if (packing->Invert) {
 286             /* start at top and go down */
 287             dest += (readHeight - 1) * rowLength * 4;
 288             rowLength = -rowLength;
 289          }
 290
 291          for (row=0; row<readHeight; row++) {
 292             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 293                                         (GLchan (*)[4]) dest);
 294             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 295                _mesa_read_alpha_span(ctx, readWidth, srcX, srcY,
 296                                      (GLchan (*)[4]) dest);
 297             }
 298             dest += rowLength * 4;
 299             srcY++;
 300          }
 301          return GL_TRUE;
 302       }
 303       else {
 304          /* can't do this format/type combination */
 305          return GL_FALSE;
 306       }
 307    }
 308 }
 309
 310
 311
 312 /*
 313  * Read R, G, B, A, RGB, L, or LA pixels.
 314  */
 315 static void
 316 read_rgba_pixels( GLcontext *ctx,
 317                   GLint x, GLint y,
 318                   GLsizei width, GLsizei height,
 319                   GLenum format, GLenum type, GLvoid *pixels,
 320                   const struct gl_pixelstore_attrib *packing )
 321 {
 322    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 323    GLint readWidth;
 324
 325    _swrast_use_read_buffer(ctx);
 326
 327    /* Try optimized path first */
 328    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 329                               format, type, pixels, packing )) {
 330
 331       _swrast_use_draw_buffer(ctx);
 332       return; /* done! */
 333    }
 334
 335    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 336
 337    /* do error checking on pixel type, format was already checked by caller */
 338    switch (type) {
 339       case GL_UNSIGNED_BYTE:
 340       case GL_BYTE:
 341       case GL_UNSIGNED_SHORT:
 342       case GL_SHORT:
 343       case GL_UNSIGNED_INT:
 344       case GL_INT:
 345       case GL_FLOAT:
 346       case GL_UNSIGNED_BYTE_3_3_2:
 347       case GL_UNSIGNED_BYTE_2_3_3_REV:
 348       case GL_UNSIGNED_SHORT_5_6_5:
 349       case GL_UNSIGNED_SHORT_5_6_5_REV:
 350       case GL_UNSIGNED_SHORT_4_4_4_4:
 351       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 352       case GL_UNSIGNED_SHORT_5_5_5_1:
 353       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 354       case GL_UNSIGNED_INT_8_8_8_8:
 355       case GL_UNSIGNED_INT_8_8_8_8_REV:
 356       case GL_UNSIGNED_INT_10_10_10_2:
 357       case GL_UNSIGNED_INT_2_10_10_10_REV:
 358          /* valid pixel type */
 359          break;
 360       default:
 361          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 362          return;
 363    }
 364
 365    if (!_mesa_is_legal_format_and_type(format, type) ||
 366        format == GL_INTENSITY) {
 367       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 368       return;
 369    }
 370
 371    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 372       const GLuint transferOps = ctx->_ImageTransferState;
 373       GLfloat *dest, *src, *tmpImage, *convImage;
 374       GLint row;
 375
 376       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 377       if (!tmpImage) {
 378          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 379          return;
 380       }
 381       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 382       if (!convImage) {
 383          FREE(tmpImage);
 384          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 385          return;
 386       }
 387
 388       /* read full RGBA, FLOAT image */
 389       dest = tmpImage;
 390       for (row = 0; row < height; row++, y++) {
 391          GLchan rgba[MAX_WIDTH][4];
 392          if (ctx->Visual.rgbMode) {
 393             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 394          }
 395          else {
 396             GLuint index[MAX_WIDTH];
 397             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 398             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 399                _mesa_map_ci(ctx, readWidth, index);
 400             }
 401             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 402          }
 403          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 404                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 405                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 406          dest += width * 4;
 407       }
 408
 409       /* do convolution */
 410       if (ctx->Pixel.Convolution2DEnabled) {
 411          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 412       }
 413       else {
 414          ASSERT(ctx->Pixel.Separable2DEnabled);
 415          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 416       }
 417       FREE(tmpImage);
 418
 419       /* finish transfer ops and pack the resulting image */
 420       src = convImage;
 421       for (row = 0; row < height; row++) {
 422          GLvoid *dest;
 423          dest = _mesa_image_address(packing, pixels, readWidth, height,
 424                                     format, type, 0, row, 0);
 425          _mesa_pack_float_rgba_span(ctx, readWidth,
 426                                     (const GLfloat (*)[4]) src,
 427                                     format, type, dest, packing,
 428                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 429          src += readWidth * 4;
 430       }
 431    }
 432    else {
 433       /* no convolution */
 434       GLint row;
 435       for (row = 0; row < height; row++, y++) {
 436          GLchan rgba[MAX_WIDTH][4];
 437          GLvoid *dst;
 438          if (ctx->Visual.rgbMode) {
 439             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 440          }
 441          else {
 442             GLuint index[MAX_WIDTH];
 443             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 444             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 445                _mesa_map_ci(ctx, readWidth, index);
 446             }
 447             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 448          }
 449          dst = _mesa_image_address(packing, pixels, width, height,
 450                                    format, type, 0, row, 0);
 451          if (ctx->Visual.redBits < CHAN_BITS ||
 452              ctx->Visual.greenBits < CHAN_BITS ||
 453              ctx->Visual.blueBits < CHAN_BITS) {
 454             /* Requantize the color values into floating point and go from
 455              * there.  This fixes conformance failures with 16-bit color
 456              * buffers, for example.
 457              */
 458             DEFMARRAY(GLfloat, rgbaf, MAX_WIDTH, 4);  /* mac 32k limitation */
 459             CHECKARRAY(rgbaf, return);  /* mac 32k limitation */
 460             _mesa_chan_to_float_span(ctx, readWidth,
 461                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 462             _mesa_pack_float_rgba_span(ctx, readWidth,
 463                                        (CONST GLfloat (*)[4]) rgbaf,
 464                                        format, type, dst, packing,
 465                                        ctx->_ImageTransferState);
 466             UNDEFARRAY(rgbaf);  /* mac 32k limitation */
 467          }
 468          else {
 469             /* GLubytes are fine */
 470             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 471                                  format, type, dst, packing,
 472                                  ctx->_ImageTransferState);
 473          }
 474       }
 475    }
 476
 477    _swrast_use_draw_buffer(ctx);
 478 }
 479
 480
 481
 482 void
 483 _swrast_ReadPixels( GLcontext *ctx,
 484                     GLint x, GLint y, GLsizei width, GLsizei height,
 485                     GLenum format, GLenum type,
 486                     const struct gl_pixelstore_attrib *pack,
 487                     GLvoid *pixels )
 488 {
 489    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 490    (void) pack;
 491
 492    if (swrast->NewState)
 493       _swrast_validate_derived( ctx );
 494
 495    RENDER_START(swrast,ctx);
 496
 497    switch (format) {
 498       case GL_COLOR_INDEX:
 499          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 500          break;
 501       case GL_STENCIL_INDEX:
 502          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 503          break;
 504       case GL_DEPTH_COMPONENT:
 505          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 506          break;
 507       case GL_RED:
 508       case GL_GREEN:
 509       case GL_BLUE:
 510       case GL_ALPHA:
 511       case GL_RGB:
 512       case GL_LUMINANCE:
 513       case GL_LUMINANCE_ALPHA:
 514       case GL_RGBA:
 515       case GL_BGR:
 516       case GL_BGRA:
 517       case GL_ABGR_EXT:
 518          read_rgba_pixels(ctx, x, y, width, height,
 519                           format, type, pixels, &ctx->Pack);
 520          break;
 521       default:
 522          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 523    }
 524
 525    RENDER_FINISH(swrast,ctx);
 526 }