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 "third_party/blink/renderer/platform/graphics/draw_looper_builder.h"
32
33 #include <memory>
34 #include "base/memory/scoped_refptr.h"
35 #include "third_party/blink/renderer/platform/geometry/float_size.h"
36 #include "third_party/blink/renderer/platform/graphics/color.h"
37 #include "third_party/blink/renderer/platform/graphics/skia/skia_utils.h"
38 #include "third_party/skia/include/core/SkColor.h"
39 #include "third_party/skia/include/core/SkColorFilter.h"
40 #include "third_party/skia/include/core/SkDrawLooper.h"
41 #include "third_party/skia/include/core/SkMaskFilter.h"
42 #include "third_party/skia/include/core/SkPaint.h"
43
44 namespace blink {
45
46 DrawLooperBuilder::DrawLooperBuilder() = default;
47
48 DrawLooperBuilder::~DrawLooperBuilder() = default;
49
DetachDrawLooper()50 sk_sp<SkDrawLooper> DrawLooperBuilder::DetachDrawLooper() {
51 return sk_draw_looper_builder_.detach();
52 }
53
AddUnmodifiedContent()54 void DrawLooperBuilder::AddUnmodifiedContent() {
55 SkLayerDrawLooper::LayerInfo info;
56 sk_draw_looper_builder_.addLayerOnTop(info);
57 }
58
AddShadow(const FloatSize & offset,float blur,const Color & color,ShadowTransformMode shadow_transform_mode,ShadowAlphaMode shadow_alpha_mode)59 void DrawLooperBuilder::AddShadow(const FloatSize& offset,
60 float blur,
61 const Color& color,
62 ShadowTransformMode shadow_transform_mode,
63 ShadowAlphaMode shadow_alpha_mode) {
64 DCHECK_GE(blur, 0);
65
66 // Detect when there's no effective shadow.
67 if (!color.Alpha())
68 return;
69
70 SkColor sk_color = color.Rgb();
71
72 SkLayerDrawLooper::LayerInfo info;
73
74 switch (shadow_alpha_mode) {
75 case kShadowRespectsAlpha:
76 info.fColorMode = SkBlendMode::kDst;
77 break;
78 case kShadowIgnoresAlpha:
79 info.fColorMode = SkBlendMode::kSrc;
80 break;
81 default:
82 NOTREACHED();
83 }
84
85 if (blur)
86 info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit; // our blur
87 info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
88 info.fOffset.set(offset.Width(), offset.Height());
89 info.fPostTranslate = (shadow_transform_mode == kShadowIgnoresTransforms);
90
91 SkPaint* paint = sk_draw_looper_builder_.addLayerOnTop(info);
92
93 if (blur) {
94 const auto sigma = BlurRadiusToStdDev(blur);
95 const bool respectCTM = shadow_transform_mode != kShadowIgnoresTransforms;
96 paint->setMaskFilter(
97 SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, sigma, respectCTM));
98 }
99
100 paint->setColorFilter(SkColorFilters::Blend(sk_color, SkBlendMode::kSrcIn));
101 }
102
103 } // namespace blink
104