src/mesa/swrast/s_readpix.c

   1 /* $Id: s_readpix.c,v 1.12 2001/05/16 20:27:12 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    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    ASSERT(swrast->Driver.SetReadBuffer);
  66    (*swrast->Driver.SetReadBuffer)(ctx, ctx->ReadBuffer,
  67                                 ctx->Pixel.DriverReadBuffer);
  68
  69    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
  70
  71    /* process image row by row */
  72    for (i = 0; i < height; i++) {
  73       GLuint index[MAX_WIDTH];
  74       GLvoid *dest;
  75
  76       (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y + i, index);
  77
  78       dest = _mesa_image_address(packing, pixels, width, height,
  79                                  GL_COLOR_INDEX, type, 0, i, 0);
  80
  81       _mesa_pack_index_span(ctx, readWidth, type, dest, index,
  82                             &ctx->Pack, ctx->_ImageTransferState);
  83    }
  84
  85    (*swrast->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer,
  86                                 ctx->Color.DriverDrawBuffer);
  87 }
  88
  89
  90
  91 static void
  92 read_depth_pixels( GLcontext *ctx,
  93                    GLint x, GLint y,
  94                    GLsizei width, GLsizei height,
  95                    GLenum type, GLvoid *pixels,
  96                    const struct gl_pixelstore_attrib *packing )
  97 {
  98    GLint readWidth;
  99    GLboolean bias_or_scale;
 100
 101    /* Error checking */
 102    if (ctx->Visual.depthBits <= 0) {
 103       /* No depth buffer */
 104       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 105       return;
 106    }
 107
 108    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 109
 110    if (type != GL_BYTE &&
 111        type != GL_UNSIGNED_BYTE &&
 112        type != GL_SHORT &&
 113        type != GL_UNSIGNED_SHORT &&
 114        type != GL_INT &&
 115        type != GL_UNSIGNED_INT &&
 116        type != GL_FLOAT) {
 117       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(depth type)");
 118       return;
 119    }
 120
 121    bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 122
 123    if (type==GL_UNSIGNED_SHORT && ctx->Visual.depthBits == 16
 124        && !bias_or_scale && !packing->SwapBytes) {
 125       /* Special case: directly read 16-bit unsigned depth values. */
 126       GLint j;
 127       for (j=0;j<height;j++,y++) {
 128          GLdepth depth[MAX_WIDTH];
 129          GLushort *dst = (GLushort*) _mesa_image_address( packing, pixels,
 130                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 131          GLint i;
 132          _mesa_read_depth_span(ctx, width, x, y, depth);
 133          for (i = 0; i < width; i++)
 134             dst[i] = depth[i];
 135       }
 136    }
 137    else if (type==GL_UNSIGNED_INT && ctx->Visual.depthBits == 32
 138             && !bias_or_scale && !packing->SwapBytes) {
 139       /* Special case: directly read 32-bit unsigned depth values. */
 140       GLint j;
 141       for (j=0;j<height;j++,y++) {
 142          GLdepth *dst = (GLdepth *) _mesa_image_address( packing, pixels,
 143                          width, height, GL_DEPTH_COMPONENT, type, 0, j, 0 );
 144          _mesa_read_depth_span(ctx, width, x, y, dst);
 145       }
 146    }
 147    else {
 148       /* General case (slower) */
 149       GLint j;
 150       for (j=0;j<height;j++,y++) {
 151          GLfloat depth[MAX_WIDTH];
 152          GLvoid *dest;
 153
 154          _mesa_read_depth_span_float(ctx, readWidth, x, y, depth);
 155
 156          dest = _mesa_image_address(packing, pixels, width, height,
 157                                     GL_DEPTH_COMPONENT, type, 0, j, 0);
 158
 159          _mesa_pack_depth_span(ctx, readWidth, (GLdepth *) dest, type,
 160                                depth, &ctx->Pack);
 161       }
 162    }
 163 }
 164
 165
 166
 167 static void
 168 read_stencil_pixels( GLcontext *ctx,
 169                      GLint x, GLint y,
 170                      GLsizei width, GLsizei height,
 171                      GLenum type, GLvoid *pixels,
 172                      const struct gl_pixelstore_attrib *packing )
 173 {
 174    GLint j, readWidth;
 175
 176    if (type != GL_BYTE &&
 177        type != GL_UNSIGNED_BYTE &&
 178        type != GL_SHORT &&
 179        type != GL_UNSIGNED_SHORT &&
 180        type != GL_INT &&
 181        type != GL_UNSIGNED_INT &&
 182        type != GL_FLOAT &&
 183        type != GL_BITMAP) {
 184       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels(stencil type)");
 185       return;
 186    }
 187
 188    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 189
 190    if (ctx->Visual.stencilBits <= 0) {
 191       /* No stencil buffer */
 192       _mesa_error( ctx, GL_INVALID_OPERATION, "glReadPixels" );
 193       return;
 194    }
 195
 196    /* process image row by row */
 197    for (j=0;j<height;j++,y++) {
 198       GLvoid *dest;
 199       GLstencil stencil[MAX_WIDTH];
 200
 201       _mesa_read_stencil_span(ctx, readWidth, x, y, stencil);
 202
 203       dest = _mesa_image_address(packing, pixels, width, height,
 204                                  GL_STENCIL_INDEX, type, 0, j, 0);
 205
 206       _mesa_pack_stencil_span(ctx, readWidth, type, dest, stencil, &ctx->Pack);
 207    }
 208 }
 209
 210
 211
 212 /*
 213  * Optimized glReadPixels for particular pixel formats:
 214  *   GL_UNSIGNED_BYTE, GL_RGBA
 215  * when pixel scaling, biasing and mapping are disabled.
 216  */
 217 static GLboolean
 218 read_fast_rgba_pixels( GLcontext *ctx,
 219                        GLint x, GLint y,
 220                        GLsizei width, GLsizei height,
 221                        GLenum format, GLenum type,
 222                        GLvoid *pixels,
 223                        const struct gl_pixelstore_attrib *packing )
 224 {
 225    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 226    /* can't do scale, bias, mapping, etc */
 227    if (ctx->_ImageTransferState)
 228        return GL_FALSE;
 229
 230    /* can't do fancy pixel packing */
 231    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 232       return GL_FALSE;
 233
 234    {
 235       GLint srcX = x;
 236       GLint srcY = y;
 237       GLint readWidth = width;           /* actual width read */
 238       GLint readHeight = height;         /* actual height read */
 239       GLint skipPixels = packing->SkipPixels;
 240       GLint skipRows = packing->SkipRows;
 241       GLint rowLength;
 242
 243       if (packing->RowLength > 0)
 244          rowLength = packing->RowLength;
 245       else
 246          rowLength = width;
 247
 248       /* horizontal clipping */
 249       if (srcX < ctx->ReadBuffer->_Xmin) {
 250          skipPixels += (ctx->ReadBuffer->_Xmin - srcX);
 251          readWidth  -= (ctx->ReadBuffer->_Xmin - srcX);
 252          srcX = ctx->ReadBuffer->_Xmin;
 253       }
 254       if (srcX + readWidth > ctx->ReadBuffer->_Xmax)
 255          readWidth -= (srcX + readWidth - ctx->ReadBuffer->_Xmax);
 256       if (readWidth <= 0)
 257          return GL_TRUE;
 258
 259       /* vertical clipping */
 260       if (srcY < ctx->ReadBuffer->_Ymin) {
 261          skipRows   += (ctx->ReadBuffer->_Ymin - srcY);
 262          readHeight -= (ctx->ReadBuffer->_Ymin - srcY);
 263          srcY = ctx->ReadBuffer->_Ymin;
 264       }
 265       if (srcY + readHeight > ctx->ReadBuffer->_Ymax)
 266          readHeight -= (srcY + readHeight - ctx->ReadBuffer->_Ymax);
 267       if (readHeight <= 0)
 268          return GL_TRUE;
 269
 270       /*
 271        * Ready to read!
 272        * The window region at (destX, destY) of size (readWidth, readHeight)
 273        * will be read back.
 274        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 275        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 276        */
 277 #if CHAN_BITS == 8
 278       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 279 #elif CHAN_BITS == 16
 280       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) {
 281 #else
 282       if (0) {
 283 #endif
 284          GLchan *dest = (GLchan *) pixels
 285                          + (skipRows * rowLength + skipPixels) * 4;
 286          GLint row;
 287          for (row=0; row<readHeight; row++) {
 288             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
 289                                         (GLchan (*)[4]) dest);
 290             if (ctx->DrawBuffer->UseSoftwareAlphaBuffers) {
 291                _mesa_read_alpha_span(ctx, readWidth, srcX, srcY,
 292                                      (GLchan (*)[4]) dest);
 293             }
 294             dest += rowLength * 4;
 295             srcY++;
 296          }
 297          return GL_TRUE;
 298       }
 299       else {
 300          /* can't do this format/type combination */
 301          return GL_FALSE;
 302       }
 303    }
 304 }
 305
 306
 307
 308 /*
 309  * Read R, G, B, A, RGB, L, or LA pixels.
 310  */
 311 static void
 312 read_rgba_pixels( GLcontext *ctx,
 313                   GLint x, GLint y,
 314                   GLsizei width, GLsizei height,
 315                   GLenum format, GLenum type, GLvoid *pixels,
 316                   const struct gl_pixelstore_attrib *packing )
 317 {
 318    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 319    GLint readWidth;
 320
 321    (*swrast->Driver.SetReadBuffer)(ctx, ctx->ReadBuffer, ctx->Pixel.DriverReadBuffer);
 322
 323    /* Try optimized path first */
 324    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 325                               format, type, pixels, packing )) {
 326
 327       (*swrast->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 328       return; /* done! */
 329    }
 330
 331    readWidth = (width > MAX_WIDTH) ? MAX_WIDTH : width;
 332
 333    /* do error checking on pixel type, format was already checked by caller */
 334    switch (type) {
 335       case GL_UNSIGNED_BYTE:
 336       case GL_BYTE:
 337       case GL_UNSIGNED_SHORT:
 338       case GL_SHORT:
 339       case GL_UNSIGNED_INT:
 340       case GL_INT:
 341       case GL_FLOAT:
 342       case GL_UNSIGNED_BYTE_3_3_2:
 343       case GL_UNSIGNED_BYTE_2_3_3_REV:
 344       case GL_UNSIGNED_SHORT_5_6_5:
 345       case GL_UNSIGNED_SHORT_5_6_5_REV:
 346       case GL_UNSIGNED_SHORT_4_4_4_4:
 347       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 348       case GL_UNSIGNED_SHORT_5_5_5_1:
 349       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 350       case GL_UNSIGNED_INT_8_8_8_8:
 351       case GL_UNSIGNED_INT_8_8_8_8_REV:
 352       case GL_UNSIGNED_INT_10_10_10_2:
 353       case GL_UNSIGNED_INT_2_10_10_10_REV:
 354          /* valid pixel type */
 355          break;
 356       default:
 357          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(type)" );
 358          return;
 359    }
 360
 361    if (!_mesa_is_legal_format_and_type(format, type) ||
 362        format == GL_INTENSITY) {
 363       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(format or type)");
 364       return;
 365    }
 366
 367    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 368       const GLuint transferOps = ctx->_ImageTransferState;
 369       GLfloat *dest, *src, *tmpImage, *convImage;
 370       GLint row;
 371
 372       tmpImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 373       if (!tmpImage) {
 374          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 375          return;
 376       }
 377       convImage = (GLfloat *) MALLOC(width * height * 4 * sizeof(GLfloat));
 378       if (!convImage) {
 379          FREE(tmpImage);
 380          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 381          return;
 382       }
 383
 384       /* read full RGBA, FLOAT image */
 385       dest = tmpImage;
 386       for (row = 0; row < height; row++, y++) {
 387          GLchan rgba[MAX_WIDTH][4];
 388          if (ctx->Visual.rgbMode) {
 389             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 390          }
 391          else {
 392             GLuint index[MAX_WIDTH];
 393             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 394             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 395                _mesa_map_ci(ctx, readWidth, index);
 396             }
 397             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 398          }
 399          _mesa_pack_rgba_span(ctx, readWidth, (const GLchan (*)[4]) rgba,
 400                               GL_RGBA, GL_FLOAT, dest, &_mesa_native_packing,
 401                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 402          dest += width * 4;
 403       }
 404
 405       /* do convolution */
 406       if (ctx->Pixel.Convolution2DEnabled) {
 407          _mesa_convolve_2d_image(ctx, &readWidth, &height, tmpImage, convImage);
 408       }
 409       else {
 410          ASSERT(ctx->Pixel.Separable2DEnabled);
 411          _mesa_convolve_sep_image(ctx, &readWidth, &height, tmpImage, convImage);
 412       }
 413       FREE(tmpImage);
 414
 415       /* finish transfer ops and pack the resulting image */
 416       src = convImage;
 417       for (row = 0; row < height; row++) {
 418          GLvoid *dest;
 419          dest = _mesa_image_address(packing, pixels, readWidth, height,
 420                                     format, type, 0, row, 0);
 421          _mesa_pack_float_rgba_span(ctx, readWidth,
 422                                     (const GLfloat (*)[4]) src,
 423                                     format, type, dest, packing,
 424                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 425          src += readWidth * 4;
 426       }
 427    }
 428    else {
 429       /* no convolution */
 430       GLint row;
 431       for (row = 0; row < height; row++, y++) {
 432          GLchan rgba[MAX_WIDTH][4];
 433          GLvoid *dst;
 434          if (ctx->Visual.rgbMode) {
 435             _mesa_read_rgba_span(ctx, ctx->ReadBuffer, readWidth, x, y, rgba);
 436          }
 437          else {
 438             GLuint index[MAX_WIDTH];
 439             (*swrast->Driver.ReadCI32Span)(ctx, readWidth, x, y, index);
 440             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 441                _mesa_map_ci(ctx, readWidth, index);
 442             }
 443             _mesa_map_ci_to_rgba_chan(ctx, readWidth, index, rgba);
 444          }
 445          dst = _mesa_image_address(packing, pixels, width, height,
 446                                    format, type, 0, row, 0);
 447          if (ctx->Visual.redBits < CHAN_BITS ||
 448              ctx->Visual.greenBits < CHAN_BITS ||
 449              ctx->Visual.blueBits < CHAN_BITS) {
 450             /* Requantize the color values into floating point and go from
 451              * there.  This fixes conformance failures with 16-bit color
 452              * buffers, for example.
 453              */
 454             DEFMARRAY(GLfloat, rgbaf, MAX_WIDTH, 4);  /* mac 32k limitation */
 455             CHECKARRAY(rgbaf, return);  /* mac 32k limitation */
 456             _mesa_chan_to_float_span(ctx, readWidth,
 457                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 458             _mesa_pack_float_rgba_span(ctx, readWidth,
 459                                        (CONST GLfloat (*)[4]) rgbaf,
 460                                        format, type, dst, packing,
 461                                        ctx->_ImageTransferState);
 462             UNDEFARRAY(rgbaf);  /* mac 32k limitation */
 463          }
 464          else {
 465             /* GLubytes are fine */
 466             _mesa_pack_rgba_span(ctx, readWidth, (CONST GLchan (*)[4]) rgba,
 467                                  format, type, dst, packing,
 468                                  ctx->_ImageTransferState);
 469          }
 470       }
 471    }
 472
 473    (*swrast->Driver.SetReadBuffer)(ctx, ctx->DrawBuffer, ctx->Color.DriverDrawBuffer);
 474 }
 475
 476
 477
 478 void
 479 _swrast_ReadPixels( GLcontext *ctx,
 480                     GLint x, GLint y, GLsizei width, GLsizei height,
 481                     GLenum format, GLenum type,
 482                     const struct gl_pixelstore_attrib *pack,
 483                     GLvoid *pixels )
 484 {
 485    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 486    (void) pack;
 487
 488    if (swrast->NewState)
 489       _swrast_validate_derived( ctx );
 490
 491    RENDER_START(swrast,ctx);
 492
 493    switch (format) {
 494       case GL_COLOR_INDEX:
 495          read_index_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 496          break;
 497       case GL_STENCIL_INDEX:
 498          read_stencil_pixels(ctx, x,y, width,height, type, pixels, &ctx->Pack);
 499          break;
 500       case GL_DEPTH_COMPONENT:
 501          read_depth_pixels(ctx, x, y, width, height, type, pixels, &ctx->Pack);
 502          break;
 503       case GL_RED:
 504       case GL_GREEN:
 505       case GL_BLUE:
 506       case GL_ALPHA:
 507       case GL_RGB:
 508       case GL_LUMINANCE:
 509       case GL_LUMINANCE_ALPHA:
 510       case GL_RGBA:
 511       case GL_BGR:
 512       case GL_BGRA:
 513       case GL_ABGR_EXT:
 514          read_rgba_pixels(ctx, x, y, width, height,
 515                           format, type, pixels, &ctx->Pack);
 516          break;
 517       default:
 518          _mesa_error( ctx, GL_INVALID_ENUM, "glReadPixels(format)" );
 519    }
 520
 521    RENDER_FINISH(swrast,ctx);
 522 }