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 46 DrawLooperBuilder::DrawLooperBuilder() { } 47 48 DrawLooperBuilder::~DrawLooperBuilder() { } 49 50 PassOwnPtr<DrawLooperBuilder> DrawLooperBuilder::create() 51 { 52 return adoptPtr(new DrawLooperBuilder); 53 } 54 55 PassRefPtr<SkDrawLooper> DrawLooperBuilder::detachDrawLooper() 56 { 57 return adoptRef(m_skDrawLooperBuilder.detachLooper()); 58 } 59 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. 67 static SkScalar RadiusToSigma(SkScalar radius) 68 { 69 SkASSERT(radius > 0); 70 return 0.57735f * radius + 0.5f; 71 } 72 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