skia2/modules/particles/include/SkParticleBinding.h
Brian Osman 6104ba0dca Particles: Do a cleanup/standardization pass on the API
For clients not using JSON, the factories were inconsistent.

Change-Id: Ifd920fa1e18f5edffa12de238af8488406951e5b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/257683
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2019-12-03 20:06:18 +00:00

86 lines
2.8 KiB
C++

/*
* Copyright 2019 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkParticleBinding_DEFINED
#define SkParticleBinding_DEFINED
#include "include/core/SkString.h"
#include "modules/particles/include/SkReflected.h"
#include "src/sksl/SkSLExternalValue.h"
#include <memory>
class SkParticleEffect;
class SkParticleEffectParams;
class SkRandom;
namespace skresources {
class ResourceProvider;
}
namespace SkSL {
class Compiler;
}
class SkParticleExternalValue : public SkSL::ExternalValue {
public:
SkParticleExternalValue(const char* name, SkSL::Compiler& compiler, const SkSL::Type& type)
: SkSL::ExternalValue(name, type)
, fCompiler(compiler)
, fRandom(nullptr)
, fEffect(nullptr) {}
void setRandom(SkRandom* random) { fRandom = random; }
void setEffect(SkParticleEffect* effect) { fEffect = effect; }
protected:
SkSL::Compiler& fCompiler;
SkRandom* fRandom;
SkParticleEffect* fEffect;
};
class SkParticleBinding : public SkReflected {
public:
SkParticleBinding(const char* name = "name") : fName(name) {}
REFLECTED_ABSTRACT(SkParticleBinding, SkReflected)
void visitFields(SkFieldVisitor* v) override;
virtual std::unique_ptr<SkParticleExternalValue> toValue(SkSL::Compiler&) = 0;
virtual void prepare(const skresources::ResourceProvider*) = 0;
static void RegisterBindingTypes();
/*
* All SkParticleBinding objects expose a particular native object to an effect's SkSL code.
* In all cases, the 'name' is the symbol that will be used to access the object from the SkSL.
* Each binding is a callable object, so the SkSL name behaves like a function. The behavior of
* each kind of binding is described below.
*/
// void name(loop) -- Creates an effect instance. Effect will loop if 'loop' is true, otherwise
// it's a one-shot. The new effect inherits all properties from the calling effect or particle.
static sk_sp<SkParticleBinding> MakeEffect(const char* name,
sk_sp<SkParticleEffectParams> effect);
// float4 name(xy) -- Fetches RGBA data from an image. 'xy' are normalized image coordinates.
static sk_sp<SkParticleBinding> MakeImage(const char* name,
const char* imagePath, const char* imageName);
// float4 name(t) -- Fetches position and normal from an SkPath. 't' is the normalized distance
// along the path. The return value contains position in .xy and normal in .zw.
static sk_sp<SkParticleBinding> MakePath(const char* name,
const char* pathPath, const char* pathName);
protected:
SkString fName;
};
#endif // SkParticleBinding_DEFINED