1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
3 * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
4 * Copyright (C) 2013 Google, Inc. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "config.h"
29#include "platform/graphics/Pattern.h"
30
31#include <v8.h>
32#include "SkCanvas.h"
33#include "SkColorShader.h"
34#include "platform/graphics/skia/SkiaUtils.h"
35
36namespace blink {
37
38PassRefPtr<Pattern> Pattern::createBitmapPattern(PassRefPtr<Image> tileImage, RepeatMode repeatMode)
39{
40    return adoptRef(new Pattern(tileImage, repeatMode));
41}
42
43Pattern::Pattern(PassRefPtr<Image> image, RepeatMode repeatMode)
44    : m_repeatMode(repeatMode)
45    , m_externalMemoryAllocated(0)
46{
47    if (image) {
48        m_tileImage = image->nativeImageForCurrentFrame();
49    }
50}
51
52Pattern::~Pattern()
53{
54    if (m_externalMemoryAllocated)
55        v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externalMemoryAllocated);
56}
57
58SkShader* Pattern::shader()
59{
60    if (m_pattern)
61        return m_pattern.get();
62
63    SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
64
65    // If we don't have a bitmap, return a transparent shader.
66    if (!m_tileImage) {
67        m_pattern = adoptRef(new SkColorShader(SK_ColorTRANSPARENT));
68    } else if (m_repeatMode == RepeatModeXY) {
69        m_pattern = adoptRef(SkShader::CreateBitmapShader(m_tileImage->bitmap(),
70            SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &localMatrix));
71    } else {
72        // Skia does not have a "draw the tile only once" option. Clamp_TileMode
73        // repeats the last line of the image after drawing one tile. To avoid
74        // filling the space with arbitrary pixels, this workaround forces the
75        // image to have a line of transparent pixels on the "repeated" edge(s),
76        // thus causing extra space to be transparent filled.
77        SkShader::TileMode tileModeX = (m_repeatMode & RepeatModeX)
78            ? SkShader::kRepeat_TileMode
79            : SkShader::kClamp_TileMode;
80        SkShader::TileMode tileModeY = (m_repeatMode & RepeatModeY)
81            ? SkShader::kRepeat_TileMode
82            : SkShader::kClamp_TileMode;
83        int expandW = (m_repeatMode & RepeatModeX) ? 0 : 1;
84        int expandH = (m_repeatMode & RepeatModeY) ? 0 : 1;
85
86        // Create a transparent bitmap 1 pixel wider and/or taller than the
87        // original, then copy the orignal into it.
88        // FIXME: Is there a better way to pad (not scale) an image in skia?
89        SkImageInfo info = m_tileImage->bitmap().info();
90        info.fWidth += expandW;
91        info.fHeight += expandH;
92        // we explicitly require non-opaquness, since we are going to add a transparent strip.
93        info.fAlphaType = kPremul_SkAlphaType;
94
95        SkBitmap bm2;
96        bm2.allocPixels(info);
97        bm2.eraseARGB(0x00, 0x00, 0x00, 0x00);
98        SkCanvas canvas(bm2);
99        canvas.drawBitmap(m_tileImage->bitmap(), 0, 0);
100        bm2.setImmutable();
101        m_pattern = adoptRef(SkShader::CreateBitmapShader(bm2, tileModeX, tileModeY, &localMatrix));
102
103        // Clamp to int, since that's what the adjust function takes.
104        m_externalMemoryAllocated = static_cast<int>(std::min(static_cast<size_t>(INT_MAX), bm2.getSafeSize()));
105        v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(m_externalMemoryAllocated);
106    }
107    return m_pattern.get();
108}
109
110void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
111{
112    if (patternSpaceTransformation == m_patternSpaceTransformation)
113        return;
114
115    m_patternSpaceTransformation = patternSpaceTransformation;
116    m_pattern.clear();
117}
118
119} // namespace blink
120