src/mesa/main/readpix.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2008  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 #include "glheader.h"
  26 #include "imports.h"
  27 #include "bufferobj.h"
  28 #include "context.h"
  29 #include "readpix.h"
  30 #include "framebuffer.h"
  31 #include "image.h"
  32 #include "state.h"
  33
  34
  35 /**
  36  * Do error checking of the format/type parameters to glReadPixels and
  37  * glDrawPixels.
  38  * \param drawing if GL_TRUE do checking for DrawPixels, else do checking
  39  *                for ReadPixels.
  40  * \return GL_TRUE if error detected, GL_FALSE if no errors
  41  */
  42 GLboolean
  43 _mesa_error_check_format_type(struct gl_context *ctx, GLenum format, GLenum type,
  44                               GLboolean drawing)
  45 {
  46    const char *readDraw = drawing ? "Draw" : "Read";
  47    const GLboolean reading = !drawing;
  48
  49    /* state validation should have already been done */
  50    ASSERT(ctx->NewState == 0x0);
  51
  52    if (ctx->Extensions.EXT_packed_depth_stencil
  53        && type == GL_UNSIGNED_INT_24_8_EXT
  54        && format != GL_DEPTH_STENCIL_EXT) {
  55       _mesa_error(ctx, GL_INVALID_OPERATION,
  56                   "gl%sPixels(format is not GL_DEPTH_STENCIL_EXT)", readDraw);
  57       return GL_TRUE;
  58    }
  59
  60    /* basic combinations test */
  61    if (!_mesa_is_legal_format_and_type(ctx, format, type)) {
  62       _mesa_error(ctx, GL_INVALID_ENUM,
  63                   "gl%sPixels(format or type)", readDraw);
  64       return GL_TRUE;
  65    }
  66
  67    /* additional checks */
  68    switch (format) {
  69    case GL_RG:
  70    case GL_RED:
  71    case GL_GREEN:
  72    case GL_BLUE:
  73    case GL_ALPHA:
  74    case GL_LUMINANCE:
  75    case GL_LUMINANCE_ALPHA:
  76    case GL_RGB:
  77    case GL_BGR:
  78    case GL_RGBA:
  79    case GL_BGRA:
  80    case GL_ABGR_EXT:
  81       if (!drawing) {
  82          /* reading */
  83          if (!_mesa_source_buffer_exists(ctx, GL_COLOR)) {
  84             _mesa_error(ctx, GL_INVALID_OPERATION,
  85                         "glReadPixels(no color buffer)");
  86             return GL_TRUE;
  87          }
  88       }
  89       break;
  90    case GL_COLOR_INDEX:
  91       if (drawing) {
  92          if (ctx->PixelMaps.ItoR.Size == 0 ||
  93              ctx->PixelMaps.ItoG.Size == 0 ||
  94              ctx->PixelMaps.ItoB.Size == 0) {
  95             _mesa_error(ctx, GL_INVALID_OPERATION,
  96                    "glDrawPixels(drawing color index pixels into RGB buffer)");
  97             return GL_TRUE;
  98          }
  99       }
 100       else {
 101          /* reading */
 102          if (!_mesa_source_buffer_exists(ctx, GL_COLOR)) {
 103             _mesa_error(ctx, GL_INVALID_OPERATION,
 104                         "glReadPixels(no color buffer)");
 105             return GL_TRUE;
 106          }
 107          /* We no longer support CI-mode color buffers so trying to read
 108           * GL_COLOR_INDEX pixels is always an error.
 109           */
 110          _mesa_error(ctx, GL_INVALID_OPERATION,
 111                      "glReadPixels(color buffer is RGB)");
 112          return GL_TRUE;
 113       }
 114       break;
 115    case GL_STENCIL_INDEX:
 116       if ((drawing && !_mesa_dest_buffer_exists(ctx, format)) ||
 117           (reading && !_mesa_source_buffer_exists(ctx, format))) {
 118          _mesa_error(ctx, GL_INVALID_OPERATION,
 119                      "gl%sPixels(no stencil buffer)", readDraw);
 120          return GL_TRUE;
 121       }
 122       break;
 123    case GL_DEPTH_COMPONENT:
 124       if ((drawing && !_mesa_dest_buffer_exists(ctx, format))) {
 125          _mesa_error(ctx, GL_INVALID_OPERATION,
 126                      "gl%sPixels(no depth buffer)", readDraw);
 127          return GL_TRUE;
 128       }
 129       break;
 130    case GL_DEPTH_STENCIL_EXT:
 131       if (!ctx->Extensions.EXT_packed_depth_stencil ||
 132           type != GL_UNSIGNED_INT_24_8_EXT) {
 133          _mesa_error(ctx, GL_INVALID_ENUM, "gl%sPixels(type)", readDraw);
 134          return GL_TRUE;
 135       }
 136       if ((drawing && !_mesa_dest_buffer_exists(ctx, format)) ||
 137           (reading && !_mesa_source_buffer_exists(ctx, format))) {
 138          _mesa_error(ctx, GL_INVALID_OPERATION,
 139                      "gl%sPixels(no depth or stencil buffer)", readDraw);
 140          return GL_TRUE;
 141       }
 142       break;
 143    default:
 144       /* this should have been caught in _mesa_is_legal_format_type() */
 145       _mesa_problem(ctx, "unexpected format in _mesa_%sPixels", readDraw);
 146       return GL_TRUE;
 147    }
 148
 149    /* no errors */
 150    return GL_FALSE;
 151 }
 152
 153
 154
 155 void GLAPIENTRY
 156 _mesa_ReadPixels( GLint x, GLint y, GLsizei width, GLsizei height,
 157                   GLenum format, GLenum type, GLvoid *pixels )
 158 {
 159    GET_CURRENT_CONTEXT(ctx);
 160    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 161
 162    FLUSH_CURRENT(ctx, 0);
 163
 164    if (width < 0 || height < 0) {
 165       _mesa_error( ctx, GL_INVALID_VALUE,
 166                    "glReadPixels(width=%d height=%d)", width, height );
 167       return;
 168    }
 169
 170    if (ctx->NewState)
 171       _mesa_update_state(ctx);
 172
 173    if (_mesa_error_check_format_type(ctx, format, type, GL_FALSE)) {
 174       /* found an error */
 175       return;
 176    }
 177
 178    if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 179       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 180                   "glReadPixels(incomplete framebuffer)" );
 181       return;
 182    }
 183
 184    if (!_mesa_source_buffer_exists(ctx, format)) {
 185       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(no readbuffer)");
 186       return;
 187    }
 188
 189    if (width == 0 || height == 0)
 190       return; /* nothing to do */
 191
 192    if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
 193       if (!_mesa_validate_pbo_access(2, &ctx->Pack, width, height, 1,
 194                                      format, type, pixels)) {
 195          _mesa_error(ctx, GL_INVALID_OPERATION,
 196                      "glReadPixels(invalid PBO access)");
 197          return;
 198       }
 199
 200       if (_mesa_bufferobj_mapped(ctx->Pack.BufferObj)) {
 201          /* buffer is mapped - that's an error */
 202          _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
 203          return;
 204       }
 205    }
 206
 207    ctx->Driver.ReadPixels(ctx, x, y, width, height,
 208                           format, type, &ctx->Pack, pixels);
 209 }