readpix.c revision cdc920a0 
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 */
42GLboolean
43_mesa_error_check_format_type(GLcontext *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_RED:
70   case GL_GREEN:
71   case GL_BLUE:
72   case GL_ALPHA:
73   case GL_LUMINANCE:
74   case GL_LUMINANCE_ALPHA:
75   case GL_RGB:
76   case GL_BGR:
77   case GL_RGBA:
78   case GL_BGRA:
79   case GL_ABGR_EXT:
80      if (!drawing) {
81         /* reading */
82         if (!_mesa_source_buffer_exists(ctx, GL_COLOR)) {
83            _mesa_error(ctx, GL_INVALID_OPERATION,
84                        "glReadPixels(no color buffer)");
85            return GL_TRUE;
86         }
87      }
88      break;
89   case GL_COLOR_INDEX:
90      if (drawing) {
91         if (ctx->PixelMaps.ItoR.Size == 0 ||
92	     ctx->PixelMaps.ItoG.Size == 0 ||
93	     ctx->PixelMaps.ItoB.Size == 0) {
94            _mesa_error(ctx, GL_INVALID_OPERATION,
95                   "glDrawPixels(drawing color index pixels into RGB buffer)");
96            return GL_TRUE;
97         }
98      }
99      else {
100         /* reading */
101         if (!_mesa_source_buffer_exists(ctx, GL_COLOR)) {
102            _mesa_error(ctx, GL_INVALID_OPERATION,
103                        "glReadPixels(no color buffer)");
104            return GL_TRUE;
105         }
106      }
107      break;
108   case GL_STENCIL_INDEX:
109      if ((drawing && !_mesa_dest_buffer_exists(ctx, format)) ||
110          (reading && !_mesa_source_buffer_exists(ctx, format))) {
111         _mesa_error(ctx, GL_INVALID_OPERATION,
112                     "gl%sPixels(no stencil buffer)", readDraw);
113         return GL_TRUE;
114      }
115      break;
116   case GL_DEPTH_COMPONENT:
117      if ((drawing && !_mesa_dest_buffer_exists(ctx, format))) {
118         _mesa_error(ctx, GL_INVALID_OPERATION,
119                     "gl%sPixels(no depth buffer)", readDraw);
120         return GL_TRUE;
121      }
122      break;
123   case GL_DEPTH_STENCIL_EXT:
124      if (!ctx->Extensions.EXT_packed_depth_stencil ||
125          type != GL_UNSIGNED_INT_24_8_EXT) {
126         _mesa_error(ctx, GL_INVALID_ENUM, "gl%sPixels(type)", readDraw);
127         return GL_TRUE;
128      }
129      if ((drawing && !_mesa_dest_buffer_exists(ctx, format)) ||
130          (reading && !_mesa_source_buffer_exists(ctx, format))) {
131         _mesa_error(ctx, GL_INVALID_OPERATION,
132                     "gl%sPixels(no depth or stencil buffer)", readDraw);
133         return GL_TRUE;
134      }
135      break;
136   default:
137      /* this should have been caught in _mesa_is_legal_format_type() */
138      _mesa_problem(ctx, "unexpected format in _mesa_%sPixels", readDraw);
139      return GL_TRUE;
140   }
141
142   /* no errors */
143   return GL_FALSE;
144}
145
146
147
148void GLAPIENTRY
149_mesa_ReadPixels( GLint x, GLint y, GLsizei width, GLsizei height,
150		  GLenum format, GLenum type, GLvoid *pixels )
151{
152   GET_CURRENT_CONTEXT(ctx);
153   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
154
155   FLUSH_CURRENT(ctx, 0);
156
157   if (width < 0 || height < 0) {
158      _mesa_error( ctx, GL_INVALID_VALUE,
159                   "glReadPixels(width=%d height=%d)", width, height );
160      return;
161   }
162
163   if (ctx->NewState)
164      _mesa_update_state(ctx);
165
166   if (_mesa_error_check_format_type(ctx, format, type, GL_FALSE)) {
167      /* found an error */
168      return;
169   }
170
171   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
172      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
173                  "glReadPixels(incomplete framebuffer)" );
174      return;
175   }
176
177   if (!_mesa_source_buffer_exists(ctx, format)) {
178      _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(no readbuffer)");
179      return;
180   }
181
182   if (width == 0 || height == 0)
183      return; /* nothing to do */
184
185   if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
186      if (!_mesa_validate_pbo_access(2, &ctx->Pack, width, height, 1,
187                                     format, type, pixels)) {
188         _mesa_error(ctx, GL_INVALID_OPERATION,
189                     "glReadPixels(invalid PBO access)");
190         return;
191      }
192
193      if (_mesa_bufferobj_mapped(ctx->Pack.BufferObj)) {
194         /* buffer is mapped - that's an error */
195         _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
196         return;
197      }
198   }
199
200   ctx->Driver.ReadPixels(ctx, x, y, width, height,
201			  format, type, &ctx->Pack, pixels);
202}
203