1 /* 2 * Copyright 2006 The Android Open Source Project 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 SkMaskFilter_DEFINED 9 #define SkMaskFilter_DEFINED 10 11 #include "SkBlurTypes.h" 12 #include "SkCoverageMode.h" 13 #include "SkFlattenable.h" 14 #include "SkScalar.h" 15 16 class SkMatrix; 17 struct SkRect; 18 class SkString; 19 20 /** \class SkMaskFilter 21 22 SkMaskFilter is the base class for object that perform transformations on 23 the mask before drawing it. An example subclass is Blur. 24 */ 25 class SK_API SkMaskFilter : public SkFlattenable { 26 public: 27 /** Create a blur maskfilter. 28 * @param style The SkBlurStyle to use 29 * @param sigma Standard deviation of the Gaussian blur to apply. Must be > 0. 30 * @param respectCTM if true the blur's sigma is modified by the CTM. 31 * @return The new blur maskfilter 32 */ 33 static sk_sp<SkMaskFilter> MakeBlur(SkBlurStyle style, SkScalar sigma, 34 bool respectCTM = true); 35 36 /** 37 * Construct a maskfilter whose effect is to first apply the inner filter and then apply 38 * the outer filter to the result of the inner's. Returns nullptr on failure. 39 */ 40 static sk_sp<SkMaskFilter> MakeCompose(sk_sp<SkMaskFilter> outer, sk_sp<SkMaskFilter> inner); 41 42 /** 43 * Compose two maskfilters together using a coverage mode. Returns nullptr on failure. 44 */ 45 static sk_sp<SkMaskFilter> MakeCombine(sk_sp<SkMaskFilter> filterA, sk_sp<SkMaskFilter> filterB, 46 SkCoverageMode mode); 47 48 /** 49 * Construct a maskfilter with an additional transform. 50 * 51 * Note: unlike shader local matrices, this transform composes next to the CTM. 52 * 53 * TotalMatrix = CTM x MaskFilterMatrix x (optional/downstream) ShaderLocalMatrix 54 */ 55 sk_sp<SkMaskFilter> makeWithMatrix(const SkMatrix&) const; 56 57 static SkFlattenable::Type GetFlattenableType() { 58 return kSkMaskFilter_Type; 59 } 60 61 SkFlattenable::Type getFlattenableType() const override { 62 return kSkMaskFilter_Type; 63 } 64 65 static sk_sp<SkMaskFilter> Deserialize(const void* data, size_t size, 66 const SkDeserialProcs* procs = nullptr) { 67 return sk_sp<SkMaskFilter>(static_cast<SkMaskFilter*>( 68 SkFlattenable::Deserialize( 69 kSkMaskFilter_Type, data, size, procs).release())); 70 } 71 72 private: 73 static void RegisterFlattenables(); 74 friend class SkFlattenable; 75 }; 76 77 #endif 78
