src/mesa/swrast/s_readpix.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "glheader.h"
  27 #include "bufferobj.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_context.h"
  38 #include "s_depth.h"
  39 #include "s_span.h"
  40 #include "s_stencil.h"
  41
  42
  43 /*
  44  * Read a block of color index pixels.
  45  */
  46 static void
  47 read_index_pixels( GLcontext *ctx,
  48                    GLint x, GLint y,
  49                    GLsizei width, GLsizei height,
  50                    GLenum type, GLvoid *pixels,
  51                    const struct gl_pixelstore_attrib *packing )
  52 {
  53    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
  54    GLint i;
  55
  56    if (!rb) {
  57       return;  /* no readbuffer OK */
  58    }
  59
  60    /* width should never be > MAX_WIDTH since we did clipping earlier */
  61    ASSERT(width <= MAX_WIDTH);
  62
  63    /* process image row by row */
  64    for (i = 0; i < height; i++) {
  65       GLuint index[MAX_WIDTH];
  66       GLvoid *dest;
  67       ASSERT(rb->DataType == GL_UNSIGNED_INT);
  68       rb->GetRow(ctx, rb, width, x, y + i, index);
  69
  70       dest = _mesa_image_address2d(packing, pixels, width, height,
  71                                    GL_COLOR_INDEX, type, i, 0);
  72
  73       _mesa_pack_index_span(ctx, width, type, dest, index,
  74                             &ctx->Pack, ctx->_ImageTransferState);
  75    }
  76 }
  77
  78
  79
  80 /**
  81  * Read pixels for format=GL_DEPTH_COMPONENT.
  82  */
  83 static void
  84 read_depth_pixels( GLcontext *ctx,
  85                    GLint x, GLint y,
  86                    GLsizei width, GLsizei height,
  87                    GLenum type, GLvoid *pixels,
  88                    const struct gl_pixelstore_attrib *packing )
  89 {
  90    struct gl_framebuffer *fb = ctx->ReadBuffer;
  91    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
  92    GLboolean bias_or_scale;
  93
  94    /* clipping should have been done already */
  95    ASSERT(x >= 0);
  96    ASSERT(y >= 0);
  97    ASSERT(x + width <= rb->Width);
  98    ASSERT(y + height <= rb->Height);
  99    /* width should never be > MAX_WIDTH since we did clipping earlier */
 100    ASSERT(width <= MAX_WIDTH);
 101
 102    if (!rb) {
 103       return;  /* no readbuffer OK */
 104    }
 105
 106    bias_or_scale = ctx->Pixel.DepthBias != 0.0 || ctx->Pixel.DepthScale != 1.0;
 107
 108    if (type == GL_UNSIGNED_SHORT && fb->Visual.depthBits == 16
 109        && !bias_or_scale && !packing->SwapBytes) {
 110       /* Special case: directly read 16-bit unsigned depth values. */
 111       GLint j;
 112       ASSERT(rb->InternalFormat == GL_DEPTH_COMPONENT16);
 113       ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
 114       for (j = 0; j < height; j++, y++) {
 115          void *dest =_mesa_image_address2d(packing, pixels, width, height,
 116                                            GL_DEPTH_COMPONENT, type, j, 0);
 117          rb->GetRow(ctx, rb, width, x, y, dest);
 118       }
 119    }
 120    else if (type == GL_UNSIGNED_INT && fb->Visual.depthBits == 32
 121             && !bias_or_scale && !packing->SwapBytes) {
 122       /* Special case: directly read 32-bit unsigned depth values. */
 123       GLint j;
 124       ASSERT(rb->InternalFormat == GL_DEPTH_COMPONENT32);
 125       ASSERT(rb->DataType == GL_UNSIGNED_INT);
 126       for (j = 0; j < height; j++, y++) {
 127          void *dest = _mesa_image_address2d(packing, pixels, width, height,
 128                                             GL_DEPTH_COMPONENT, type, j, 0);
 129          rb->GetRow(ctx, rb, width, x, y, dest);
 130       }
 131    }
 132    else {
 133       /* General case (slower) */
 134       GLint j;
 135       for (j = 0; j < height; j++, y++) {
 136          GLfloat depthValues[MAX_WIDTH];
 137          GLvoid *dest = _mesa_image_address2d(packing, pixels, width, height,
 138                                               GL_DEPTH_COMPONENT, type, j, 0);
 139          _swrast_read_depth_span_float(ctx, rb, width, x, y, depthValues);
 140          _mesa_pack_depth_span(ctx, width, dest, type, depthValues, packing);
 141       }
 142    }
 143 }
 144
 145
 146 /**
 147  * Read pixels for format=GL_STENCIL_INDEX.
 148  */
 149 static void
 150 read_stencil_pixels( GLcontext *ctx,
 151                      GLint x, GLint y,
 152                      GLsizei width, GLsizei height,
 153                      GLenum type, GLvoid *pixels,
 154                      const struct gl_pixelstore_attrib *packing )
 155 {
 156    struct gl_framebuffer *fb = ctx->ReadBuffer;
 157    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 158    GLint j;
 159
 160    if (!rb) {
 161       /* no readbuffer - OK */
 162       return;
 163    }
 164
 165    /* width should never be > MAX_WIDTH since we did clipping earlier */
 166    ASSERT(width <= MAX_WIDTH);
 167
 168    /* process image row by row */
 169    for (j=0;j<height;j++,y++) {
 170       GLvoid *dest;
 171       GLstencil stencil[MAX_WIDTH];
 172
 173       _swrast_read_stencil_span(ctx, rb, width, x, y, stencil);
 174
 175       dest = _mesa_image_address2d(packing, pixels, width, height,
 176                                    GL_STENCIL_INDEX, type, j, 0);
 177
 178       _mesa_pack_stencil_span(ctx, width, type, dest, stencil, packing);
 179    }
 180 }
 181
 182
 183
 184 /**
 185  * Optimized glReadPixels for particular pixel formats:
 186  *   GL_UNSIGNED_BYTE, GL_RGBA
 187  * when pixel scaling, biasing and mapping are disabled.
 188  */
 189 static GLboolean
 190 read_fast_rgba_pixels( GLcontext *ctx,
 191                        GLint x, GLint y,
 192                        GLsizei width, GLsizei height,
 193                        GLenum format, GLenum type,
 194                        GLvoid *pixels,
 195                        const struct gl_pixelstore_attrib *packing )
 196 {
 197    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
 198
 199    /* can't do scale, bias, mapping, etc */
 200    if (ctx->_ImageTransferState)
 201        return GL_FALSE;
 202
 203    /* can't do fancy pixel packing */
 204    if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst)
 205       return GL_FALSE;
 206
 207    {
 208       GLint srcX = x;
 209       GLint srcY = y;
 210       GLint readWidth = width;           /* actual width read */
 211       GLint readHeight = height;         /* actual height read */
 212       GLint skipPixels = packing->SkipPixels;
 213       GLint skipRows = packing->SkipRows;
 214       GLint rowLength;
 215
 216       if (packing->RowLength > 0)
 217          rowLength = packing->RowLength;
 218       else
 219          rowLength = width;
 220
 221       /*
 222        * Ready to read!
 223        * The window region at (destX, destY) of size (readWidth, readHeight)
 224        * will be read back.
 225        * We'll write pixel data to buffer pointed to by "pixels" but we'll
 226        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 227        */
 228 #if CHAN_BITS == 8
 229       if (format == GL_RGBA && type == GL_UNSIGNED_BYTE)
 230 #elif CHAN_BITS == 16
 231       if (format == GL_RGBA && type == GL_UNSIGNED_SHORT)
 232 #else
 233       if (0)
 234 #endif
 235       {
 236          GLchan *dest = (GLchan *) pixels
 237                       + (skipRows * rowLength + skipPixels) * 4;
 238          GLint row;
 239
 240          if (packing->Invert) {
 241             /* start at top and go down */
 242             dest += (readHeight - 1) * rowLength * 4;
 243             rowLength = -rowLength;
 244          }
 245
 246          ASSERT(rb->GetRow);
 247          for (row=0; row<readHeight; row++) {
 248             rb->GetRow(ctx, rb, readWidth, srcX, srcY, dest);
 249             dest += rowLength * 4;
 250             srcY++;
 251          }
 252          return GL_TRUE;
 253       }
 254       else {
 255          /* can't do this format/type combination */
 256          return GL_FALSE;
 257       }
 258    }
 259 }
 260
 261
 262
 263 /*
 264  * Read R, G, B, A, RGB, L, or LA pixels.
 265  */
 266 static void
 267 read_rgba_pixels( GLcontext *ctx,
 268                   GLint x, GLint y,
 269                   GLsizei width, GLsizei height,
 270                   GLenum format, GLenum type, GLvoid *pixels,
 271                   const struct gl_pixelstore_attrib *packing )
 272 {
 273    struct gl_framebuffer *fb = ctx->ReadBuffer;
 274    struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
 275
 276    if (!rb) {
 277       /* No readbuffer is OK with GL_EXT_framebuffer_object */
 278       return;
 279    }
 280
 281    /* Try optimized path first */
 282    if (read_fast_rgba_pixels( ctx, x, y, width, height,
 283                               format, type, pixels, packing )) {
 284       return; /* done! */
 285    }
 286
 287    /* width should never be > MAX_WIDTH since we did clipping earlier */
 288    ASSERT(width <= MAX_WIDTH);
 289
 290    if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
 291       const GLuint transferOps = ctx->_ImageTransferState;
 292       GLfloat *dest, *src, *tmpImage, *convImage;
 293       GLint row;
 294
 295       tmpImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
 296       if (!tmpImage) {
 297          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 298          return;
 299       }
 300       convImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
 301       if (!convImage) {
 302          _mesa_free(tmpImage);
 303          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
 304          return;
 305       }
 306
 307       /* read full RGBA, FLOAT image */
 308       dest = tmpImage;
 309       for (row = 0; row < height; row++, y++) {
 310          GLchan rgba[MAX_WIDTH][4];
 311          if (fb->Visual.rgbMode) {
 312             _swrast_read_rgba_span(ctx, rb, width, x, y, rgba);
 313          }
 314          else {
 315             GLuint index[MAX_WIDTH];
 316             ASSERT(rb->DataType == GL_UNSIGNED_INT);
 317             rb->GetRow(ctx, rb, width, x, y, index);
 318             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset !=0 ) {
 319                _mesa_map_ci(ctx, width, index);
 320             }
 321             _mesa_map_ci_to_rgba_chan(ctx, width, index, rgba);
 322          }
 323          _mesa_pack_rgba_span_chan(ctx, width, (const GLchan (*)[4]) rgba,
 324                               GL_RGBA, GL_FLOAT, dest, &ctx->DefaultPacking,
 325                               transferOps & IMAGE_PRE_CONVOLUTION_BITS);
 326          dest += width * 4;
 327       }
 328
 329       /* do convolution */
 330       if (ctx->Pixel.Convolution2DEnabled) {
 331          _mesa_convolve_2d_image(ctx, &width, &height, tmpImage, convImage);
 332       }
 333       else {
 334          ASSERT(ctx->Pixel.Separable2DEnabled);
 335          _mesa_convolve_sep_image(ctx, &width, &height, tmpImage, convImage);
 336       }
 337       _mesa_free(tmpImage);
 338
 339       /* finish transfer ops and pack the resulting image */
 340       src = convImage;
 341       for (row = 0; row < height; row++) {
 342          GLvoid *dest;
 343          dest = _mesa_image_address2d(packing, pixels, width, height,
 344                                       format, type, row, 0);
 345          _mesa_pack_rgba_span_float(ctx, width,
 346                                     (const GLfloat (*)[4]) src,
 347                                     format, type, dest, packing,
 348                                     transferOps & IMAGE_POST_CONVOLUTION_BITS);
 349          src += width * 4;
 350       }
 351    }
 352    else {
 353       /* no convolution */
 354       GLint row;
 355       for (row = 0; row < height; row++, y++) {
 356          GLchan rgba[MAX_WIDTH][4];
 357          GLvoid *dst;
 358          if (fb->Visual.rgbMode) {
 359             _swrast_read_rgba_span(ctx, rb, width, x, y, rgba);
 360          }
 361          else {
 362             GLuint index[MAX_WIDTH];
 363             ASSERT(rb->DataType == GL_UNSIGNED_INT);
 364             rb->GetRow(ctx, rb, width, x, y, index);
 365             if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
 366                _mesa_map_ci(ctx, width, index);
 367             }
 368             _mesa_map_ci_to_rgba_chan(ctx, width, index, rgba);
 369          }
 370          dst = _mesa_image_address2d(packing, pixels, width, height,
 371                                      format, type, row, 0);
 372          if (fb->Visual.redBits < CHAN_BITS ||
 373              fb->Visual.greenBits < CHAN_BITS ||
 374              fb->Visual.blueBits < CHAN_BITS) {
 375             /* Requantize the color values into floating point and go from
 376              * there.  This fixes conformance failures with 16-bit color
 377              * buffers, for example.
 378              */
 379             GLfloat rgbaf[MAX_WIDTH][4];
 380             _mesa_chan_to_float_span(ctx, width,
 381                                      (CONST GLchan (*)[4]) rgba, rgbaf);
 382             _mesa_pack_rgba_span_float(ctx, width,
 383                                        (CONST GLfloat (*)[4]) rgbaf,
 384                                        format, type, dst, packing,
 385                                        ctx->_ImageTransferState);
 386          }
 387          else {
 388             /* GLubytes are fine */
 389             _mesa_pack_rgba_span_chan(ctx, width, (CONST GLchan (*)[4]) rgba,
 390                                  format, type, dst, packing,
 391                                  ctx->_ImageTransferState);
 392          }
 393       }
 394    }
 395 }
 396
 397
 398 /**
 399  * Software fallback routine for ctx->Driver.ReadPixels().
 400  * By time we get here, all error checking will have been done.
 401  */
 402 void
 403 _swrast_ReadPixels( GLcontext *ctx,
 404                     GLint x, GLint y, GLsizei width, GLsizei height,
 405                     GLenum format, GLenum type,
 406                     const struct gl_pixelstore_attrib *packing,
 407                     GLvoid *pixels )
 408 {
 409    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 410    struct gl_pixelstore_attrib clippedPacking;
 411
 412    if (swrast->NewState)
 413       _swrast_validate_derived( ctx );
 414
 415    /* Do all needed clipping here, so that we can forget about it later */
 416    clippedPacking = *packing;
 417    if (clippedPacking.RowLength == 0) {
 418       clippedPacking.RowLength = width;
 419    }
 420    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height,
 421                               &clippedPacking.SkipPixels,
 422                               &clippedPacking.SkipRows)) {
 423       /* The ReadPixels region is totally outside the window bounds */
 424       return;
 425    }
 426
 427    if (clippedPacking.BufferObj->Name) {
 428       /* pack into PBO */
 429       GLubyte *buf;
 430       if (!_mesa_validate_pbo_access(2, &clippedPacking, width, height, 1,
 431                                      format, type, pixels)) {
 432          _mesa_error(ctx, GL_INVALID_OPERATION,
 433                      "glReadPixels(invalid PBO access)");
 434          return;
 435       }
 436       buf = (GLubyte *) ctx->Driver.MapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
 437                                               GL_WRITE_ONLY_ARB,
 438                                               clippedPacking.BufferObj);
 439       if (!buf) {
 440          /* buffer is already mapped - that's an error */
 441          _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
 442          return;
 443       }
 444       pixels = ADD_POINTERS(buf, pixels);
 445    }
 446
 447    RENDER_START(swrast, ctx);
 448
 449    switch (format) {
 450       case GL_COLOR_INDEX:
 451          read_index_pixels(ctx, x, y, width, height, type, pixels,
 452                            &clippedPacking);
 453          break;
 454       case GL_STENCIL_INDEX:
 455          read_stencil_pixels(ctx, x, y, width, height, type, pixels,
 456                              &clippedPacking);
 457          break;
 458       case GL_DEPTH_COMPONENT:
 459          read_depth_pixels(ctx, x, y, width, height, type, pixels,
 460                            &clippedPacking);
 461          break;
 462       case GL_RED:
 463       case GL_GREEN:
 464       case GL_BLUE:
 465       case GL_ALPHA:
 466       case GL_RGB:
 467       case GL_LUMINANCE:
 468       case GL_LUMINANCE_ALPHA:
 469       case GL_RGBA:
 470       case GL_BGR:
 471       case GL_BGRA:
 472       case GL_ABGR_EXT:
 473          read_rgba_pixels(ctx, x, y, width, height,
 474                           format, type, pixels, &clippedPacking);
 475          break;
 476       default:
 477          _mesa_problem(ctx, "unexpected format in _swrast_ReadPixels");
 478          /* don't return yet, clean-up */
 479    }
 480
 481    RENDER_FINISH(swrast, ctx);
 482
 483    if (clippedPacking.BufferObj->Name) {
 484       /* done with PBO so unmap it now */
 485       ctx->Driver.UnmapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
 486                               clippedPacking.BufferObj);
 487    }
 488 }