1/*
2* Copyright 2019 Google LLC
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#ifndef SkParticleBinding_DEFINED
9#define SkParticleBinding_DEFINED
10
11#include "include/core/SkString.h"
12#include "modules/particles/include/SkReflected.h"
13#include "src/sksl/SkSLExternalValue.h"
14
15#include <memory>
16
17class SkParticleEffect;
18class SkParticleEffectParams;
19
20namespace skresources {
21 class ResourceProvider;
22} // namespace skresources
23
24namespace SkSL {
25 class Compiler;
26} // namespace SkSL
27
28class SkParticleExternalValue : public SkSL::ExternalValue {
29public:
30 SkParticleExternalValue(const char* name, SkSL::Compiler& compiler, const SkSL::Type& type)
31 : SkSL::ExternalValue(name, type)
32 , fCompiler(compiler)
33 , fEffect(nullptr) {}
34
35 void setEffect(SkParticleEffect* effect) { fEffect = effect; }
36
37protected:
38 SkSL::Compiler& fCompiler;
39
40 SkParticleEffect* fEffect;
41};
42
43class SkParticleBinding : public SkReflected {
44public:
45 SkParticleBinding(const char* name = "name") : fName(name) {}
46
47 REFLECTED_ABSTRACT(SkParticleBinding, SkReflected)
48
49 void visitFields(SkFieldVisitor* v) override;
50
51 virtual std::unique_ptr<SkParticleExternalValue> toValue(SkSL::Compiler&) = 0;
52 virtual void prepare(const skresources::ResourceProvider*) = 0;
53
54 static void RegisterBindingTypes();
55
56 /*
57 * All SkParticleBinding objects expose a particular native object to an effect's SkSL code.
58 * In all cases, the 'name' is the symbol that will be used to access the object from the SkSL.
59 * Each binding is a callable object, so the SkSL name behaves like a function. The behavior of
60 * each kind of binding is described below.
61 */
62
63 // void name(loop) -- Creates an effect instance. Effect will loop if 'loop' is true, otherwise
64 // it's a one-shot. The new effect inherits all properties from the calling effect or particle.
65 static sk_sp<SkParticleBinding> MakeEffect(const char* name,
66 sk_sp<SkParticleEffectParams> effect);
67
68 // float4 name(xy) -- Fetches RGBA data from an image. 'xy' are normalized image coordinates.
69 static sk_sp<SkParticleBinding> MakeImage(const char* name,
70 const char* imagePath, const char* imageName);
71
72 // float4 name(t) -- Fetches position and normal from an SkPath. 't' is the normalized distance
73 // along the path. The return value contains position in .xy and normal in .zw.
74 static sk_sp<SkParticleBinding> MakePath(const char* name,
75 const char* pathPath, const char* pathName);
76
77protected:
78 SkString fName;
79};
80
81#endif // SkParticleBinding_DEFINED
82