1/*
2 * Copyright (C) 2012 Intel Corporation. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24*/
25
26#include "config.h"
27#include "SnapshotImageGL.h"
28
29#include <cairo.h>
30
31#if USE(OPENGL_ES_2)
32#include <GLES2/gl2.h>
33#include <GLES2/gl2ext.h>
34#else
35#include "OpenGLShims.h"
36#endif
37
38PassRefPtr<cairo_surface_t> getImageSurfaceFromFrameBuffer(int x, int y, int width, int height)
39{
40    RefPtr<cairo_surface_t> newSurface = adoptRef(cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height));
41    unsigned char* data = cairo_image_surface_get_data(newSurface.get());
42
43#if USE(OPENGL_ES_2)
44    GLenum format = GL_RGBA;
45#else
46    GLenum format = GL_BGRA;
47#endif
48
49    glReadPixels(x, y, width, height, format, GL_UNSIGNED_BYTE, data);
50
51#if USE(OPENGL_ES_2)
52    // Convert to BGRA.
53    int totalBytes = width * height * 4;
54
55    for (int i = 0; i < totalBytes; i += 4)
56        std::swap(data[i], data[i + 2]);
57#endif
58
59    // Textures are flipped on the Y axis, so we need to flip the image back.
60    unsigned* buf = reinterpret_cast<unsigned*>(data);
61
62    for (int i = 0; i < height / 2; ++i) {
63        for (int j = 0; j < width; ++j) {
64            unsigned tmp = buf[i * width + j];
65            buf[i * width + j] = buf[(height - i - 1) * width + j];
66            buf[(height - i - 1) * width + j] = tmp;
67        }
68    }
69
70    cairo_surface_mark_dirty(newSurface.get());
71    return newSurface;
72}
73