CGUtilities.cpp revision 65f03d4f644ce73618e5f4f50dd694b26f55ae12 
1/*
2 * Copyright (C) 2011 Apple Inc. 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 "CGUtilities.h"
27
28#include <wtf/RetainPtr.h>
29
30namespace WebKit {
31
32void paintBitmapContext(CGContextRef context, CGContextRef bitmapContext, CGPoint destination, CGRect source)
33{
34    void* bitmapData = CGBitmapContextGetData(bitmapContext);
35    ASSERT(bitmapData);
36
37    size_t imageWidth = CGBitmapContextGetWidth(bitmapContext);
38    size_t imageHeight = CGBitmapContextGetHeight(bitmapContext);
39
40    size_t bytesPerRow = CGBitmapContextGetBytesPerRow(bitmapContext);
41
42    RetainPtr<CGDataProviderRef> dataProvider(AdoptCF, CGDataProviderCreateWithData(0, bitmapData, bytesPerRow * imageHeight, 0));
43    RetainPtr<CGImageRef> image(AdoptCF, CGImageCreate(imageWidth, imageHeight,
44                                                       CGBitmapContextGetBitsPerComponent(bitmapContext),
45                                                       CGBitmapContextGetBitsPerPixel(bitmapContext),
46                                                       bytesPerRow,
47                                                       CGBitmapContextGetColorSpace(bitmapContext),
48                                                       CGBitmapContextGetBitmapInfo(bitmapContext),
49                                                       dataProvider.get(), 0, false, kCGRenderingIntentDefault));
50
51    CGContextSaveGState(context);
52
53    CGContextClipToRect(context, CGRectMake(destination.x, destination.y, source.size.width, source.size.height));
54    CGContextScaleCTM(context, 1, -1);
55
56    CGFloat destX = destination.x - source.origin.x;
57    CGFloat destY = -static_cast<CGFloat>(imageHeight) - destination.y + source.origin.y;
58
59    CGContextDrawImage(context, CGRectMake(destX, destY, imageWidth, imageHeight), image.get());
60    CGContextRestoreGState(context);
61}
62
63} // namespace WebKit
64
65