1 /*
2 * Copyright (C) 2013 Google 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 are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "platform/graphics/DrawLooperBuilder.h"
33
34 #include "platform/geometry/FloatSize.h"
35 #include "platform/graphics/Color.h"
36 #include "third_party/skia/include/core/SkColor.h"
37 #include "third_party/skia/include/core/SkColorFilter.h"
38 #include "third_party/skia/include/core/SkDrawLooper.h"
39 #include "third_party/skia/include/core/SkPaint.h"
40 #include "third_party/skia/include/core/SkXfermode.h"
41 #include "third_party/skia/include/effects/SkBlurMaskFilter.h"
42 #include "wtf/RefPtr.h"
43
44 namespace WebCore {
45
DrawLooperBuilder()46 DrawLooperBuilder::DrawLooperBuilder() { }
47
~DrawLooperBuilder()48 DrawLooperBuilder::~DrawLooperBuilder() { }
49
create()50 PassOwnPtr<DrawLooperBuilder> DrawLooperBuilder::create()
51 {
52 return adoptPtr(new DrawLooperBuilder);
53 }
54
detachDrawLooper()55 PassRefPtr<SkDrawLooper> DrawLooperBuilder::detachDrawLooper()
56 {
57 return adoptRef(m_skDrawLooperBuilder.detachLooper());
58 }
59
addUnmodifiedContent()60 void DrawLooperBuilder::addUnmodifiedContent()
61 {
62 SkLayerDrawLooper::LayerInfo info;
63 m_skDrawLooperBuilder.addLayerOnTop(info);
64 }
65
66 // This replicates the old skia behavior when it used to take radius for blur. Now it takes sigma.
RadiusToSigma(SkScalar radius)67 static SkScalar RadiusToSigma(SkScalar radius)
68 {
69 SkASSERT(radius > 0);
70 return 0.57735f * radius + 0.5f;
71 }
72
addShadow(const FloatSize & offset,float blur,const Color & color,ShadowTransformMode shadowTransformMode,ShadowAlphaMode shadowAlphaMode)73 void DrawLooperBuilder::addShadow(const FloatSize& offset, float blur, const Color& color,
74 ShadowTransformMode shadowTransformMode, ShadowAlphaMode shadowAlphaMode)
75 {
76 // Detect when there's no effective shadow.
77 if (!color.alpha())
78 return;
79
80 SkColor skColor = color.rgb();
81
82 SkLayerDrawLooper::LayerInfo info;
83
84 switch (shadowAlphaMode) {
85 case ShadowRespectsAlpha:
86 info.fColorMode = SkXfermode::kDst_Mode;
87 break;
88 case ShadowIgnoresAlpha:
89 info.fColorMode = SkXfermode::kSrc_Mode;
90 break;
91 default:
92 ASSERT_NOT_REACHED();
93 }
94
95 if (blur)
96 info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit; // our blur
97 info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
98 info.fOffset.set(offset.width(), offset.height());
99 info.fPostTranslate = (shadowTransformMode == ShadowIgnoresTransforms);
100
101 SkPaint* paint = m_skDrawLooperBuilder.addLayerOnTop(info);
102
103 if (blur) {
104 const SkScalar sigma = RadiusToSigma(blur / 2);
105 uint32_t mfFlags = SkBlurMaskFilter::kHighQuality_BlurFlag;
106 if (shadowTransformMode == ShadowIgnoresTransforms)
107 mfFlags |= SkBlurMaskFilter::kIgnoreTransform_BlurFlag;
108 RefPtr<SkMaskFilter> mf = adoptRef(SkBlurMaskFilter::Create(kNormal_SkBlurStyle, sigma, mfFlags));
109 paint->setMaskFilter(mf.get());
110 }
111
112 RefPtr<SkColorFilter> cf = adoptRef(SkColorFilter::CreateModeFilter(skColor, SkXfermode::kSrcIn_Mode));
113 paint->setColorFilter(cf.get());
114 }
115
116 } // namespace WebCore
117