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
36
37 namespace WebCore {
38
Pattern(PassRefPtr<Image> image,bool repeatX,bool repeatY)39 Pattern::Pattern(PassRefPtr<Image> image, bool repeatX, bool repeatY)
40 : m_repeatX(repeatX)
41 , m_repeatY(repeatY)
42 , m_externalMemoryAllocated(0)
43 {
44 if (image) {
45 m_tileImage = image->nativeImageForCurrentFrame();
46 }
47 }
48
~Pattern()49 Pattern::~Pattern()
50 {
51 if (m_externalMemoryAllocated)
52 v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externalMemoryAllocated);
53 }
54
shader()55 SkShader* Pattern::shader()
56 {
57 if (m_pattern)
58 return m_pattern.get();
59
60 SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
61
62 // If we don't have a bitmap, return a transparent shader.
63 if (!m_tileImage)
64 m_pattern = adoptRef(new SkColorShader(SK_ColorTRANSPARENT));
65 else if (m_repeatX && m_repeatY)
66 m_pattern = adoptRef(SkShader::CreateBitmapShader(m_tileImage->bitmap(), SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &localMatrix));
67 else {
68 // Skia does not have a "draw the tile only once" option. Clamp_TileMode
69 // repeats the last line of the image after drawing one tile. To avoid
70 // filling the space with arbitrary pixels, this workaround forces the
71 // image to have a line of transparent pixels on the "repeated" edge(s),
72 // thus causing extra space to be transparent filled.
73 SkShader::TileMode tileModeX = m_repeatX ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
74 SkShader::TileMode tileModeY = m_repeatY ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
75 int expandW = m_repeatX ? 0 : 1;
76 int expandH = m_repeatY ? 0 : 1;
77
78 // Create a transparent bitmap 1 pixel wider and/or taller than the
79 // original, then copy the orignal into it.
80 // FIXME: Is there a better way to pad (not scale) an image in skia?
81 SkImageInfo info = m_tileImage->bitmap().info();
82 info.fWidth += expandW;
83 info.fHeight += expandH;
84 // we explicitly require non-opaquness, since we are going to add a transparent strip.
85 info.fAlphaType = kPremul_SkAlphaType;
86
87 SkBitmap bm2;
88 bm2.allocPixels(info);
89 bm2.eraseARGB(0x00, 0x00, 0x00, 0x00);
90 SkCanvas canvas(bm2);
91 canvas.drawBitmap(m_tileImage->bitmap(), 0, 0);
92 bm2.setImmutable();
93 m_pattern = adoptRef(SkShader::CreateBitmapShader(bm2, tileModeX, tileModeY, &localMatrix));
94
95 // Clamp to int, since that's what the adjust function takes.
96 m_externalMemoryAllocated = static_cast<int>(std::min(static_cast<size_t>(INT_MAX), bm2.getSafeSize()));
97 v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(m_externalMemoryAllocated);
98 }
99 return m_pattern.get();
100 }
101
setPatternSpaceTransform(const AffineTransform & patternSpaceTransformation)102 void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
103 {
104 m_patternSpaceTransformation = patternSpaceTransformation;
105 if (m_pattern)
106 m_pattern.clear();
107 }
108
109 }
110