skia2/include/effects/SkLayerRasterizer.h
reed 9fa60daad4 Simplify flattening to just write enough to call the factory/public-constructor for the class. We want to *not* rely on private constructors, and not rely on calling through the inheritance hierarchy for either flattening or unflattening(CreateProc).
Refactoring pattern:

1. guard the existing constructor(readbuffer) with the legacy build-flag
2. If you are a instancable subclass, implement CreateProc(readbuffer) to create a new instances from the buffer params (or return NULL).

If you're a shader subclass
1. You must read/write the local matrix if your class accepts that in its factory/constructor, else ignore it.

R=robertphillips@google.com, mtklein@google.com, senorblanco@google.com, senorblanco@chromium.org, sugoi@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/395603002
2014-08-21 07:59:51 -07:00

93 lines
3.0 KiB
C++

/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkLayerRasterizer_DEFINED
#define SkLayerRasterizer_DEFINED
#include "SkRasterizer.h"
#include "SkDeque.h"
#include "SkScalar.h"
class SkPaint;
class SK_API SkLayerRasterizer : public SkRasterizer {
public:
virtual ~SkLayerRasterizer();
class SK_API Builder {
public:
Builder();
~Builder();
void addLayer(const SkPaint& paint) {
this->addLayer(paint, 0, 0);
}
/**
* Add a new layer (above any previous layers) to the rasterizer.
* The layer will extract those fields that affect the mask from
* the specified paint, but will not retain a reference to the paint
* object itself, so it may be reused without danger of side-effects.
*/
void addLayer(const SkPaint& paint, SkScalar dx, SkScalar dy);
/**
* Pass queue of layers on to newly created layer rasterizer and return it. The builder
* *cannot* be used any more after calling this function. If no layers have been added,
* returns NULL.
*
* The caller is responsible for calling unref() on the returned object, if non NULL.
*/
SkLayerRasterizer* detachRasterizer();
/**
* Create and return a new immutable SkLayerRasterizer that contains a shapshot of the
* layers that were added to the Builder, without modifying the Builder. The Builder
* *may* be used after calling this function. It will continue to hold any layers
* previously added, so consecutive calls to this function will return identical objects,
* and objects returned by future calls to this function contain all the layers in
* previously returned objects. If no layers have been added, returns NULL.
*
* Future calls to addLayer will not affect rasterizers previously returned by this call.
*
* The caller is responsible for calling unref() on the returned object, if non NULL.
*/
SkLayerRasterizer* snapshotRasterizer() const;
private:
SkDeque* fLayers;
};
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLayerRasterizer)
protected:
SkLayerRasterizer();
SkLayerRasterizer(SkDeque* layers);
#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
SkLayerRasterizer(SkReadBuffer&);
#endif
virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
// override from SkRasterizer
virtual bool onRasterize(const SkPath& path, const SkMatrix& matrix,
const SkIRect* clipBounds,
SkMask* mask, SkMask::CreateMode mode) const;
private:
const SkDeque* const fLayers;
static SkDeque* ReadLayers(SkReadBuffer& buffer);
friend class LayerRasterizerTester;
typedef SkRasterizer INHERITED;
};
#endif