1/*
2 * Copyright 2020 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/Adapter.h"
9#include "modules/skottie/src/SkottieJson.h"
10#include "modules/skottie/src/SkottiePriv.h"
11#include "modules/skottie/src/SkottieValue.h"
12#include "modules/skottie/src/layers/shapelayer/ShapeLayer.h"
13#include "modules/sksg/include/SkSGPath.h"
14
15namespace skottie {
16namespace internal {
17
18namespace {
19
20class PolystarGeometryAdapter final :
21 public DiscardableAdapterBase<PolystarGeometryAdapter, sksg::Path> {
22public:
23 enum class Type {
24 kStar, kPoly,
25 };
26
27 PolystarGeometryAdapter(const skjson::ObjectValue& jstar,
28 const AnimationBuilder* abuilder, Type t)
29 : fType(t) {
30 this->bind(*abuilder, jstar["pt"], fPointCount );
31 this->bind(*abuilder, jstar["p" ], fPosition );
32 this->bind(*abuilder, jstar["r" ], fRotation );
33 this->bind(*abuilder, jstar["ir"], fInnerRadius );
34 this->bind(*abuilder, jstar["or"], fOuterRadius );
35 this->bind(*abuilder, jstar["is"], fInnerRoundness);
36 this->bind(*abuilder, jstar["os"], fOuterRoundness);
37 }
38
39private:
40 void onSync() override {
41 static constexpr int kMaxPointCount = 100000;
42 const auto count = SkToUInt(SkTPin(SkScalarRoundToInt(fPointCount), 0, kMaxPointCount));
43 const auto arc = sk_ieee_float_divide(SK_ScalarPI * 2, count);
44
45 const auto pt_on_circle = [](const SkV2& c, SkScalar r, SkScalar a) {
46 return SkPoint::Make(c.x + r * std::cos(a),
47 c.y + r * std::sin(a));
48 };
49
50 // TODO: inner/outer "roundness"?
51
52 SkPath poly;
53
54 auto angle = SkDegreesToRadians(fRotation - 90);
55 poly.moveTo(pt_on_circle(fPosition, fOuterRadius, angle));
56 poly.incReserve(fType == Type::kStar ? count * 2 : count);
57
58 for (unsigned i = 0; i < count; ++i) {
59 if (fType == Type::kStar) {
60 poly.lineTo(pt_on_circle(fPosition, fInnerRadius, angle + arc * 0.5f));
61 }
62 angle += arc;
63 poly.lineTo(pt_on_circle(fPosition, fOuterRadius, angle));
64 }
65
66 poly.close();
67 this->node()->setPath(poly);
68 }
69
70 const Type fType;
71
72 Vec2Value fPosition = {0,0};
73 ScalarValue fPointCount = 0,
74 fRotation = 0,
75 fInnerRadius = 0,
76 fOuterRadius = 0,
77 fInnerRoundness = 0,
78 fOuterRoundness = 0;
79};
80
81} // namespace
82
83sk_sp<sksg::GeometryNode> ShapeBuilder::AttachPolystarGeometry(const skjson::ObjectValue& jstar,
84 const AnimationBuilder* abuilder) {
85 static constexpr PolystarGeometryAdapter::Type gTypes[] = {
86 PolystarGeometryAdapter::Type::kStar, // "sy": 1
87 PolystarGeometryAdapter::Type::kPoly, // "sy": 2
88 };
89
90 const auto type = ParseDefault<size_t>(jstar["sy"], 0) - 1;
91 if (type >= SK_ARRAY_COUNT(gTypes)) {
92 abuilder->log(Logger::Level::kError, &jstar, "Unknown polystar type.");
93 return nullptr;
94 }
95
96 return abuilder->attachDiscardableAdapter<PolystarGeometryAdapter>
97 (jstar, abuilder, gTypes[type]);
98}
99
100} // namespace internal
101} // namespace skottie
102