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 SkPathEffect_DEFINED 9 #define SkPathEffect_DEFINED 10 11 #include "include/core/SkFlattenable.h" 12 #include "include/core/SkScalar.h" 13 // not needed, but some of our clients need it (they don't IWYU) 14 #include "include/core/SkPath.h" 15 16 class SkPath; 17 struct SkRect; 18 class SkStrokeRec; 19 20 /** \class SkPathEffect 21 22 SkPathEffect is the base class for objects in the SkPaint that affect 23 the geometry of a drawing primitive before it is transformed by the 24 canvas' matrix and drawn. 25 26 Dashing is implemented as a subclass of SkPathEffect. 27 */ 28 class SK_API SkPathEffect : public SkFlattenable { 29 public: 30 /** 31 * Returns a patheffect that apples each effect (first and second) to the original path, 32 * and returns a path with the sum of these. 33 * 34 * result = first(path) + second(path) 35 * 36 */ 37 static sk_sp<SkPathEffect> MakeSum(sk_sp<SkPathEffect> first, sk_sp<SkPathEffect> second); 38 39 /** 40 * Returns a patheffect that applies the inner effect to the path, and then applies the 41 * outer effect to the result of the inner's. 42 * 43 * result = outer(inner(path)) 44 */ 45 static sk_sp<SkPathEffect> MakeCompose(sk_sp<SkPathEffect> outer, sk_sp<SkPathEffect> inner); 46 GetFlattenableType()47 static SkFlattenable::Type GetFlattenableType() { 48 return kSkPathEffect_Type; 49 } 50 51 // move to base? 52 53 enum DashType { 54 kNone_DashType, //!< ignores the info parameter 55 kDash_DashType, //!< fills in all of the info parameter 56 }; 57 58 struct DashInfo { DashInfoDashInfo59 DashInfo() : fIntervals(nullptr), fCount(0), fPhase(0) {} DashInfoDashInfo60 DashInfo(SkScalar* intervals, int32_t count, SkScalar phase) 61 : fIntervals(intervals), fCount(count), fPhase(phase) {} 62 63 SkScalar* fIntervals; //!< Length of on/off intervals for dashed lines 64 // Even values represent ons, and odds offs 65 int32_t fCount; //!< Number of intervals in the dash. Should be even number 66 SkScalar fPhase; //!< Offset into the dashed interval pattern 67 // mod the sum of all intervals 68 }; 69 70 DashType asADash(DashInfo* info) const; 71 72 /** 73 * Given a src path (input) and a stroke-rec (input and output), apply 74 * this effect to the src path, returning the new path in dst, and return 75 * true. If this effect cannot be applied, return false and ignore dst 76 * and stroke-rec. 77 * 78 * The stroke-rec specifies the initial request for stroking (if any). 79 * The effect can treat this as input only, or it can choose to change 80 * the rec as well. For example, the effect can decide to change the 81 * stroke's width or join, or the effect can change the rec from stroke 82 * to fill (or fill to stroke) in addition to returning a new (dst) path. 83 * 84 * If this method returns true, the caller will apply (as needed) the 85 * resulting stroke-rec to dst and then draw. 86 */ 87 bool filterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect* cullR) const; 88 89 /** Version of filterPath that can be called when the CTM is known. */ 90 bool filterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect* cullR, 91 const SkMatrix& ctm) const; 92 93 /** True if this path effect requires a valid CTM */ 94 bool needsCTM() const; 95 96 static sk_sp<SkPathEffect> Deserialize(const void* data, size_t size, 97 const SkDeserialProcs* procs = nullptr); 98 99 private: 100 SkPathEffect() = default; 101 friend class SkPathEffectBase; 102 103 using INHERITED = SkFlattenable; 104 }; 105 106 #endif 107