src/mesa/swrast/s_readpix.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  4.1
   5  *
   6  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 #include "glheader.h"
  28 #include "colormac.h"
  29 #include "convolve.h"
  30 #include "context.h"
  31 #include "feedback.h"
  32 #include "image.h"
  33 #include "macros.h"
  34 #include "imports.h"
  35 #include "pixel.h"
  36
  37 #include "s_alphabuf.h"
  38 #include "s_context.h"
  39 #include "s_depth.h"
  40 #include "s_span.h"
  41 #include "s_stencil.h"
  42
  43
  44
  45 /*
  46  * Read a block of color index pixels.
  47  */
  48 static void
  49 read_index_pixels( GLcontext *ctx,
  50                    GLint x, GLint y,
  51                    GLsizei width, GLsizei height,
  52                    GLenum type, GLvoid *pixels,
  53                    const struct gl_pixelstore_attrib *packing )
  54 {
  55    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  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    _swrast_use_read_buffer(ctx);
  65
  66    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
  67
  68    /* process image row by row */
  69    for (i = 0; i < height; i++) {
  70       GLuint index[MAX_WIDTH];
  71       GLvoid *dest;
  72
  73       (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y + i, index);
  74
  75       dest = _mesa_image_address(packing, pixels, width, height,
  76                                  GL_COLOR_INDEX, type, 0, i, 0);
  77
  78       _mesa_pack_index_span(ctx, readWidth, type, dest, index,
  79                             &ctx->Pack, ctx->_ImageTransferState);
  80    }
  81
  82    _swrast_use_draw_buffer(ctx);
  83 }
  84
  85
  86
  87 static void
  88 read_depth_pixels( GLcontext *ctx,
  89                    GLint x, GLint y,
  90                    GLsizei width, GLsizei height,
  91                    GLenum type, GLvoid *pixels,
  92                    const struct gl_pixelstore_attrib *packing )
  93 {
  94    GLint readWidth;
  95    GLboolean bias_or_scale;
  96
  97    /* Error checking */
  98    if (ctx->Visual.depthBits <= 0) {
  99       /* No depth buffer */
 100       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 101       return;
 102    }
 103
 104    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 105
 106    if (type != GL_BYTE &&
 107        type != GL_UNSIGNED_BYTE &&
 108        type != GL_SHORT &&
 109        type != GL_UNSIGNED_SHORT &&
 110        type != GL_INT &&
 111        type != GL_UNSIGNED_INT &&
 112        type != GL_FLOAT) {
 113       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(depth type)");
 114       return;
 115    }
 116
 117    bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 118
 119    if (type==GL_UNSIGNED_SHORT && ctx->Visual.depthBits == 16
 120        && !bias_or_scale && !packing->SwapBytes) {
 121       /* Special case: directly read 16-bit unsigned depth values. */
 122       GLint j;
 123       for (j=0;j<height;j++,y++) {
 124          GLdepth depth[MAX_WIDTH];
 125          GLushort *dst = (GLushort*) _mesa_image_address( packing, pixels,
 126                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 127          GLint i;
 128          _swrast_read_depth_span(ctx, width, x, y, depth);
 129          for (i = 0; i < width; i++)
 130             dst[i] = depth[i];
 131       }
 132    }
 133    else if (type==GL_UNSIGNED_INT && ctx->Visual.depthBits == 32
 134             && !bias_or_scale && !packing->SwapBytes) {
 135       /* Special case: directly read 32-bit unsigned depth values. */
 136       GLint j;
 137       for (j=0;j<height;j++,y++) {
 138          GLdepth *dst = (GLdepth *) _mesa_image_address( packing, pixels,
 139                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 140          _swrast_read_depth_span(ctx, width, x, y, dst);
 141       }
 142    }
 143    else {
 144       /* General case (slower) */
 145       GLint j;
 146       for (j=0;j<height;j++,y++) {
 147          GLfloat depth[MAX_WIDTH];
 148          GLvoid *dest;
 149
 150          _swrast_read_depth_span_float(ctx, readWidth, x, y, depth);
 151
 152          dest = _mesa_image_address(packing, pixels, width, height,
 153                                     GL_DEPTH_COMPONENT, type, 0, j, 0);
 154
 155          _mesa_pack_depth_span(ctx, readWidth, (GLdepth *) dest, type,
 156                                depth, &ctx->Pack);
 157       }
 158    }
 159 }
 160
 161
 162
 163 static void
 164 read_stencil_pixels( GLcontext *ctx,
 165                      GLint x, GLint y,
 166                      GLsizei width, GLsizei height,
 167                      GLenum type, GLvoid *pixels,
 168                      const struct gl_pixelstore_attrib *packing )
 169 {
 170    GLint j, readWidth;
 171
 172    if (type != GL_BYTE &&
 173        type != GL_UNSIGNED_BYTE &&
 174        type != GL_SHORT &&
 175        type != GL_UNSIGNED_SHORT &&
 176        type != GL_INT &&
 177        type != GL_UNSIGNED_INT &&
 178        type != GL_FLOAT &&
 179        type != GL_BITMAP) {
 180       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 181       return;
 182    }
 183
 184    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 185
 186    if (ctx->Visual.stencilBits <= 0) {
 187       /* No stencil buffer */
 188       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 189       return;
 190    }
 191
 192    /* process image row by row */
 193    for (j=0;j<height;j++,y++) {
 194       GLvoid *dest;
 195       GLstencil stencil[MAX_WIDTH];
 196
 197       _swrast_read_stencil_span(ctx, readWidth, x, y, stencil);
 198
 199       dest = _mesa_image_address(packing, pixels, width, height,
 200                                  GL_STENCIL_INDEX, type, 0, j, 0);
 201
 202       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 203    }
 204 }
 205
 206
 207
 208 /*
 209  * Optimized glReadPixels for particular pixel formats:
 210  *   GL_UNSIGNED_BYTE, GL_RGBA
 211  * when pixel scaling, biasing and mapping are disabled.
 212  */
 213 static GLboolean
 214 read_fast_rgba_pixels( GLcontext *ctx,
 215                        GLint x, GLint y,
 216                        GLsizei width, GLsizei height,
 217                        GLenum format, GLenum type,
 218                        GLvoid *pixels,
 219                        const struct gl_pixelstore_attrib *packing )
 220 {
 221    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 222    /* can't do scale, bias, mapping, etc */
 223    if (ctx->_ImageTransferState)
 224        return GL_FALSE;
 225
 226    /* can't do fancy pixel packing */
 227    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 228       return GL_FALSE;
 229
 230    {
 231       GLint srcX = x;
 232       GLint srcY = y;
 233       GLint readWidth = width;           /* actual width read */
 234       GLint readHeight = height;         /* actual height read */
 235       GLint skipPixels = packing->SkipPixels;
 236       GLint skipRows = packing->SkipRows;
 237       GLint rowLength;
 238
 239       if (packing->RowLength > 0)
 240          rowLength = packing->RowLength;
 241       else
 242          rowLength = width;
 243
 244       /* horizontal clipping */
 245       if (srcX < 0) {
 246          skipPixels -= srcX;
 247          readWidth += srcX;
 248          srcX = 0;
 249       }
 250       if (srcX + readWidth > (GLint) ctx->ReadBuffer->Width)
 251          readWidth -= (srcX + readWidth - (GLint) ctx->ReadBuffer->Width);
 252       if (readWidth <= 0)
 253          return GL_TRUE;
 254
 255       /* vertical clipping */
 256       if (srcY < 0) {
 257          skipRows -= srcY;
 258          readHeight += srcY;
 259          srcY = 0;
 260       }
 261       if (srcY + readHeight > (GLint) ctx->ReadBuffer->Height)
 262          readHeight -= (srcY + readHeight - (GLint) ctx->ReadBuffer->Height);
 263       if (readHeight <= 0)
 264          return GL_TRUE;
 265
 266       /*
 267        * Ready to read!
 268        * The window region at (destX, destY) of size (readWidth, readHeight)
 269        * will be read back.
 270        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 271        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 272        */
 273 #if CHAN_BITS == 8
 274       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 275 #elif CHAN_BITS == 16
 276       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) {
 277 #else
 278       if (0) {
 279 #endif
 280          GLchan *dest = (GLchan *) pixels
 281                       + (skipRows * rowLength + skipPixels) * 4;
 282          GLint row;
 283
 284          if (packing->Invert) {
 285             /* start at top and go down */
 286             dest += (readHeight - 1) * rowLength * 4;
 287             rowLength = -rowLength;
 288          }
 289
 290          for (row=0; row<readHeight; row++) {
 291             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 292                                         (GLchan (*)[4]) dest);
 293             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 294                _swrast_read_alpha_span(ctx, readWidth, srcX, srcY,
 295                                      (GLchan (*)[4]) dest);
 296             }
 297             dest += rowLength * 4;
 298             srcY++;
 299          }
 300          return GL_TRUE;
 301       }
 302       else {
 303          /* can't do this format/type combination */
 304          return GL_FALSE;
 305       }
 306    }
 307 }
 308
 309
 310
 311 /*
 312  * Read R, G, B, A, RGB, L, or LA pixels.
 313  */
 314 static void
 315 read_rgba_pixels( GLcontext *ctx,
 316                   GLint x, GLint y,
 317                   GLsizei width, GLsizei height,
 318                   GLenum format, GLenum type, GLvoid *pixels,
 319                   const struct gl_pixelstore_attrib *packing )
 320 {
 321    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 322    GLint readWidth;
 323
 324    _swrast_use_read_buffer(ctx);
 325
 326    /* Try optimized path first */
 327    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 328                               format, type, pixels, packing )) {
 329
 330       _swrast_use_draw_buffer(ctx);
 331       return; /* done! */
 332    }
 333
 334    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 335
 336    /* do error checking on pixel type, format was already checked by caller */
 337    switch (type) {
 338       case GL_UNSIGNED_BYTE:
 339       case GL_BYTE:
 340       case GL_UNSIGNED_SHORT:
 341       case GL_SHORT:
 342       case GL_UNSIGNED_INT:
 343       case GL_INT:
 344       case GL_FLOAT:
 345       case GL_UNSIGNED_BYTE_3_3_2:
 346       case GL_UNSIGNED_BYTE_2_3_3_REV:
 347       case GL_UNSIGNED_SHORT_5_6_5:
 348       case GL_UNSIGNED_SHORT_5_6_5_REV:
 349       case GL_UNSIGNED_SHORT_4_4_4_4:
 350       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 351       case GL_UNSIGNED_SHORT_5_5_5_1:
 352       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 353       case GL_UNSIGNED_INT_8_8_8_8:
 354       case GL_UNSIGNED_INT_8_8_8_8_REV:
 355       case GL_UNSIGNED_INT_10_10_10_2:
 356       case GL_UNSIGNED_INT_2_10_10_10_REV:
 357          /* valid pixel type */
 358          break;
 359       default:
 360          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 361          return;
 362    }
 363
 364    if (!_mesa_is_legal_format_and_type(format, type) ||
 365        format == GL_INTENSITY) {
 366       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 367       return;
 368    }
 369
 370    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 371       const GLuint transferOps = ctx->_ImageTransferState;
 372       GLfloat *dest, *src, *tmpImage, *convImage;
 373       GLint row;
 374
 375       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 376       if (!tmpImage) {
 377          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 378          return;
 379       }
 380       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 381       if (!convImage) {
 382          FREE(tmpImage);
 383          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 384          return;
 385       }
 386
 387       /* read full RGBA, FLOAT image */
 388       dest = tmpImage;
 389       for (row = 0; row < height; row++, y++) {
 390          GLchan rgba[MAX_WIDTH][4];
 391          if (ctx->Visual.rgbMode) {
 392             _swrast_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 393          }
 394          else {
 395             GLuint index[MAX_WIDTH];
 396             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 397             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 398                _mesa_map_ci(ctx, readWidth, index);
 399             }
 400             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 401          }
 402          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 403                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 404                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 405          dest += width * 4;
 406       }
 407
 408       /* do convolution */
 409       if (ctx->Pixel.Convolution2DEnabled) {
 410          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 411       }
 412       else {
 413          ASSERT(ctx->Pixel.Separable2DEnabled);
 414          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 415       }
 416       FREE(tmpImage);
 417
 418       /* finish transfer ops and pack the resulting image */
 419       src = convImage;
 420       for (row = 0; row < height; row++) {
 421          GLvoid *dest;
 422          dest = _mesa_image_address(packing, pixels, readWidth, height,
 423                                     format, type, 0, row, 0);
 424          _mesa_pack_float_rgba_span(ctx, readWidth,
 425                                     (const GLfloat (*)[4]) src,
 426                                     format, type, dest, packing,
 427                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 428          src += readWidth * 4;
 429       }
 430    }
 431    else {
 432       /* no convolution */
 433       GLint row;
 434       for (row = 0; row < height; row++, y++) {
 435          GLchan rgba[MAX_WIDTH][4];
 436          GLvoid *dst;
 437          if (ctx->Visual.rgbMode) {
 438             _swrast_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 439          }
 440          else {
 441             GLuint index[MAX_WIDTH];
 442             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 443             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 444                _mesa_map_ci(ctx, readWidth, index);
 445             }
 446             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 447          }
 448          dst = _mesa_image_address(packing, pixels, width, height,
 449                                    format, type, 0, row, 0);
 450          if (ctx->Visual.redBits < CHAN_BITS ||
 451              ctx->Visual.greenBits < CHAN_BITS ||
 452              ctx->Visual.blueBits < CHAN_BITS) {
 453             /* Requantize the color values into floating point and go from
 454              * there.  This fixes conformance failures with 16-bit color
 455              * buffers, for example.
 456              */
 457             DEFMARRAY(GLfloat, rgbaf, MAX_WIDTH, 4);  /* mac 32k limitation */
 458             CHECKARRAY(rgbaf, return);  /* mac 32k limitation */
 459             _mesa_chan_to_float_span(ctx, readWidth,
 460                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 461             _mesa_pack_float_rgba_span(ctx, readWidth,
 462                                        (CONST GLfloat (*)[4]) rgbaf,
 463                                        format, type, dst, packing,
 464                                        ctx->_ImageTransferState);
 465             UNDEFARRAY(rgbaf);  /* mac 32k limitation */
 466          }
 467          else {
 468             /* GLubytes are fine */
 469             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 470                                  format, type, dst, packing,
 471                                  ctx->_ImageTransferState);
 472          }
 473       }
 474    }
 475
 476    _swrast_use_draw_buffer(ctx);
 477 }
 478
 479
 480
 481 void
 482 _swrast_ReadPixels( GLcontext *ctx,
 483                     GLint x, GLint y, GLsizei width, GLsizei height,
 484                     GLenum format, GLenum type,
 485                     const struct gl_pixelstore_attrib *pack,
 486                     GLvoid *pixels )
 487 {
 488    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 489    (void) pack;
 490
 491    if (swrast->NewState)
 492       _swrast_validate_derived( ctx );
 493
 494    RENDER_START(swrast,ctx);
 495
 496    switch (format) {
 497       case GL_COLOR_INDEX:
 498          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 499          break;
 500       case GL_STENCIL_INDEX:
 501          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 502          break;
 503       case GL_DEPTH_COMPONENT:
 504          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 505          break;
 506       case GL_RED:
 507       case GL_GREEN:
 508       case GL_BLUE:
 509       case GL_ALPHA:
 510       case GL_RGB:
 511       case GL_LUMINANCE:
 512       case GL_LUMINANCE_ALPHA:
 513       case GL_RGBA:
 514       case GL_BGR:
 515       case GL_BGRA:
 516       case GL_ABGR_EXT:
 517          read_rgba_pixels(ctx, x, y, width, height,
 518                           format, type, pixels, &ctx->Pack);
 519          break;
 520       default:
 521          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 522    }
 523
 524    RENDER_FINISH(swrast,ctx);
 525 }