1/*
2 * Copyright 2019 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "modules/skottie/src/effects/Effects.h"
9
10#include "include/private/SkTPin.h"
11#include "modules/skottie/src/SkottieValue.h"
12#include "modules/sksg/include/SkSGRenderEffect.h"
13#include "src/utils/SkJSON.h"
14
15namespace skottie {
16namespace internal {
17
18namespace  {
19
20class DropShadowAdapter final : public AnimatablePropertyContainer {
21public:
22    static sk_sp<DropShadowAdapter> Make(const skjson::ArrayValue& jprops,
23                                         sk_sp<sksg::RenderNode> layer,
24                                         const AnimationBuilder& abuilder) {
25        enum : size_t {
26            kShadowColor_Index = 0,
27                kOpacity_Index = 1,
28              kDirection_Index = 2,
29               kDistance_Index = 3,
30               kSoftness_Index = 4,
31             kShadowOnly_Index = 5,
32        };
33
34        sk_sp<DropShadowAdapter> adapter(new DropShadowAdapter(std::move(layer)));
35
36        EffectBinder(jprops, abuilder, adapter.get())
37                .bind(kShadowColor_Index, adapter->fColor    )
38                .bind(    kOpacity_Index, adapter->fOpacity  )
39                .bind(  kDirection_Index, adapter->fDirection)
40                .bind(   kDistance_Index, adapter->fDistance )
41                .bind(   kSoftness_Index, adapter->fSoftness )
42                .bind( kShadowOnly_Index, adapter->fShdwOnly );
43
44        return adapter;
45    }
46
47    const sk_sp<sksg::RenderNode>& node() const { return fImageFilterEffect; }
48
49private:
50    explicit DropShadowAdapter(sk_sp<sksg::RenderNode> layer)
51        : fDropShadow(sksg::DropShadowImageFilter::Make())
52        , fImageFilterEffect(sksg::ImageFilterEffect::Make(std::move(layer), fDropShadow)) {}
53
54    void onSync() override {
55        // fColor -> RGB, fOpacity -> A
56        const SkColor color = fColor;
57        fDropShadow->setColor(SkColorSetA(color, SkTPin(SkScalarRoundToInt(fOpacity), 0, 255)));
58
59        // The offset is specified in terms of a bearing + distance.
60        const auto rad = SkDegreesToRadians(90 - fDirection);
61        fDropShadow->setOffset(SkVector::Make( fDistance * SkScalarCos(rad),
62                                              -fDistance * SkScalarSin(rad)));
63
64        const auto sigma = fSoftness * kBlurSizeToSigma;
65        fDropShadow->setSigma(SkVector::Make(sigma, sigma));
66
67        fDropShadow->setMode(SkToBool(fShdwOnly)
68                                ? sksg::DropShadowImageFilter::Mode::kShadowOnly
69                                : sksg::DropShadowImageFilter::Mode::kShadowAndForeground);
70    }
71
72    const sk_sp<sksg::DropShadowImageFilter> fDropShadow;
73    const sk_sp<sksg::RenderNode>            fImageFilterEffect;
74
75    VectorValue fColor     = { 0, 0, 0, 1 };
76    ScalarValue fOpacity   = 255,
77                fDirection = 0,
78                fDistance  = 0,
79                fSoftness  = 0,
80                fShdwOnly  = 0;
81};
82
83}  // namespace
84
85sk_sp<sksg::RenderNode> EffectBuilder::attachDropShadowEffect(const skjson::ArrayValue& jprops,
86                                                              sk_sp<sksg::RenderNode> layer) const {
87    return fBuilder->attachDiscardableAdapter<DropShadowAdapter>(jprops,
88                                                                 std::move(layer),
89                                                                 *fBuilder);
90}
91
92} // namespace internal
93} // namespace skottie
94