third_party/WebKit/Source/platform/graphics/DrawLooperBuilder.cpp

   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 "platform/graphics/skia/SkiaUtils.h"
  37 #include "third_party/skia/include/core/SkColor.h"
  38 #include "third_party/skia/include/core/SkColorFilter.h"
  39 #include "third_party/skia/include/core/SkDrawLooper.h"
  40 #include "third_party/skia/include/core/SkPaint.h"
  41 #include "third_party/skia/include/core/SkXfermode.h"
  42 #include "third_party/skia/include/effects/SkBlurMaskFilter.h"
  43 #include "wtf/RefPtr.h"
  44
  45 namespace blink {
  46
  47 DrawLooperBuilder::DrawLooperBuilder() { }
  48
  49 DrawLooperBuilder::~DrawLooperBuilder() { }
  50
  51 PassOwnPtr<DrawLooperBuilder> DrawLooperBuilder::create()
  52 {
  53     return adoptPtr(new DrawLooperBuilder);
  54 }
  55
  56 PassRefPtr<SkDrawLooper> DrawLooperBuilder::detachDrawLooper()
  57 {
  58     return adoptRef(m_skDrawLooperBuilder.detachLooper());
  59 }
  60
  61 void DrawLooperBuilder::addUnmodifiedContent()
  62 {
  63     SkLayerDrawLooper::LayerInfo info;
  64     m_skDrawLooperBuilder.addLayerOnTop(info);
  65 }
  66
  67 void DrawLooperBuilder::addShadow(const FloatSize& offset, float blur, const Color& color,
  68     ShadowTransformMode shadowTransformMode, ShadowAlphaMode shadowAlphaMode)
  69 {
  70     // Detect when there's no effective shadow.
  71     if (!color.alpha())
  72         return;
  73
  74     SkColor skColor = color.rgb();
  75
  76     SkLayerDrawLooper::LayerInfo info;
  77
  78     switch (shadowAlphaMode) {
  79     case ShadowRespectsAlpha:
  80         info.fColorMode = SkXfermode::kDst_Mode;
  81         break;
  82     case ShadowIgnoresAlpha:
  83         info.fColorMode = SkXfermode::kSrc_Mode;
  84         break;
  85     default:
  86         ASSERT_NOT_REACHED();
  87     }
  88
  89     if (blur)
  90         info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit; // our blur
  91     info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
  92     info.fOffset.set(offset.width(), offset.height());
  93     info.fPostTranslate = (shadowTransformMode == ShadowIgnoresTransforms);
  94
  95     SkPaint* paint = m_skDrawLooperBuilder.addLayerOnTop(info);
  96
  97     if (blur) {
  98         const SkScalar sigma = skBlurRadiusToSigma(blur);
  99         uint32_t mfFlags = SkBlurMaskFilter::kHighQuality_BlurFlag;
 100         if (shadowTransformMode == ShadowIgnoresTransforms)
 101             mfFlags |= SkBlurMaskFilter::kIgnoreTransform_BlurFlag;
 102         RefPtr<SkMaskFilter> mf = adoptRef(SkBlurMaskFilter::Create(kNormal_SkBlurStyle, sigma, mfFlags));
 103         paint->setMaskFilter(mf.get());
 104     }
 105
 106     RefPtr<SkColorFilter> cf = adoptRef(SkColorFilter::CreateModeFilter(skColor, SkXfermode::kSrcIn_Mode));
 107     paint->setColorFilter(cf.get());
 108 }
 109
 110 } // namespace blink