1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
3 * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "Pattern.h"
29
30#include "AffineTransform.h"
31#include "GraphicsContext.h"
32
33#include <ApplicationServices/ApplicationServices.h>
34
35namespace WebCore {
36
37static void patternCallback(void* info, CGContextRef context)
38{
39    CGImageRef platformImage = static_cast<Image*>(info)->getCGImageRef();
40    if (!platformImage)
41        return;
42
43    CGRect rect = GraphicsContext(context).roundToDevicePixels(
44        FloatRect(0, 0, CGImageGetWidth(platformImage), CGImageGetHeight(platformImage)));
45    CGContextDrawImage(context, rect, platformImage);
46}
47
48static void patternReleaseCallback(void* info)
49{
50    static_cast<Image*>(info)->deref();
51}
52
53CGPatternRef Pattern::createPlatformPattern(const AffineTransform& userSpaceTransformation) const
54{
55    IntRect tileRect = tileImage()->rect();
56
57    AffineTransform patternTransform = m_patternSpaceTransformation;
58    patternTransform.multiply(userSpaceTransformation);
59    patternTransform.scaleNonUniform(1, -1);
60    patternTransform.translate(0, -tileRect.height());
61
62    // If FLT_MAX should also be used for xStep or yStep, nothing is rendered. Using fractions of FLT_MAX also
63    // result in nothing being rendered.
64    // INT_MAX is almost correct, but there seems to be some number wrapping occurring making the fill
65    // pattern is not filled correctly.
66    // To make error of floating point less than 0.5, we use the half of the number of mantissa of float (1 << 22).
67    CGFloat xStep = m_repeatX ? tileRect.width() : (1 << 22);
68    CGFloat yStep = m_repeatY ? tileRect.height() : (1 << 22);
69
70    // The pattern will release the tile when it's done rendering in patternReleaseCallback
71    tileImage()->ref();
72
73    const CGPatternCallbacks patternCallbacks = { 0, patternCallback, patternReleaseCallback };
74    return CGPatternCreate(tileImage(), tileRect, patternTransform, xStep, yStep,
75        kCGPatternTilingConstantSpacing, TRUE, &patternCallbacks);
76}
77
78}
79