1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkLayerRasterizer_DEFINED 11 #define SkLayerRasterizer_DEFINED 12 13 #include "SkRasterizer.h" 14 #include "SkDeque.h" 15 #include "SkScalar.h" 16 17 class SkPaint; 18 19 class SK_API SkLayerRasterizer : public SkRasterizer { 20 public: 21 virtual ~SkLayerRasterizer(); 22 23 class SK_API Builder { 24 public: 25 Builder(); 26 ~Builder(); 27 addLayer(const SkPaint & paint)28 void addLayer(const SkPaint& paint) { 29 this->addLayer(paint, 0, 0); 30 } 31 32 /** 33 * Add a new layer (above any previous layers) to the rasterizer. 34 * The layer will extract those fields that affect the mask from 35 * the specified paint, but will not retain a reference to the paint 36 * object itself, so it may be reused without danger of side-effects. 37 */ 38 void addLayer(const SkPaint& paint, SkScalar dx, SkScalar dy); 39 40 /** 41 * Pass queue of layers on to newly created layer rasterizer and return it. The builder 42 * *cannot* be used any more after calling this function. If no layers have been added, 43 * returns NULL. 44 * 45 * The caller is responsible for calling unref() on the returned object, if non NULL. 46 */ 47 SkLayerRasterizer* detachRasterizer(); 48 49 /** 50 * Create and return a new immutable SkLayerRasterizer that contains a shapshot of the 51 * layers that were added to the Builder, without modifying the Builder. The Builder 52 * *may* be used after calling this function. It will continue to hold any layers 53 * previously added, so consecutive calls to this function will return identical objects, 54 * and objects returned by future calls to this function contain all the layers in 55 * previously returned objects. If no layers have been added, returns NULL. 56 * 57 * Future calls to addLayer will not affect rasterizers previously returned by this call. 58 * 59 * The caller is responsible for calling unref() on the returned object, if non NULL. 60 */ 61 SkLayerRasterizer* snapshotRasterizer() const; 62 63 private: 64 SkDeque* fLayers; 65 }; 66 67 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLayerRasterizer) 68 69 protected: 70 SkLayerRasterizer(); 71 SkLayerRasterizer(SkDeque* layers); 72 void flatten(SkWriteBuffer&) const override; 73 74 // override from SkRasterizer 75 virtual bool onRasterize(const SkPath& path, const SkMatrix& matrix, 76 const SkIRect* clipBounds, 77 SkMask* mask, SkMask::CreateMode mode) const override; 78 79 private: 80 const SkDeque* const fLayers; 81 82 static SkDeque* ReadLayers(SkReadBuffer& buffer); 83 84 friend class LayerRasterizerTester; 85 86 typedef SkRasterizer INHERITED; 87 }; 88 89 #endif 90