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 SkBlurMaskFilter_DEFINED 9 #define SkBlurMaskFilter_DEFINED 10 11 // we include this since our callers will need to at least be able to ref/unref 12 #include "SkMaskFilter.h" 13 #include "SkScalar.h" 14 #include "SkBlurTypes.h" 15 16 class SK_API SkBlurMaskFilter { 17 public: 18 /** 19 * If radius > 0, return the corresponding sigma, else return 0. Use this to convert from the 20 * (legacy) idea of specify the blur "radius" to the standard notion of specifying its sigma. 21 */ 22 static SkScalar ConvertRadiusToSigma(SkScalar radius); 23 24 enum BlurFlags { 25 kNone_BlurFlag = 0x00, 26 /** The blur layer's radius is not affected by transforms */ 27 kIgnoreTransform_BlurFlag = 0x01, 28 /** Use a smother, higher qulity blur algorithm */ 29 kHighQuality_BlurFlag = 0x02, 30 /** mask for all blur flags */ 31 kAll_BlurFlag = 0x03 32 }; 33 34 /** Create a blur maskfilter. 35 * @param style The SkBlurStyle to use 36 * @param sigma Standard deviation of the Gaussian blur to apply. Must be > 0. 37 * @param occluder The rect for which no pixels need be drawn (b.c. it will be overdrawn 38 * with some opaque object. This is just a hint which backends are free to 39 * ignore. 40 * @param flags Flags to use - defaults to none 41 * @return The new blur maskfilter 42 */ 43 static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma, 44 const SkRect& occluder, uint32_t flags = kNone_BlurFlag); 45 46 static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma, 47 uint32_t flags = kNone_BlurFlag) { 48 return Make(style, sigma, SkRect::MakeEmpty(), flags); 49 } 50 51 #ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER 52 /** Create an emboss maskfilter 53 @param blurSigma standard deviation of the Gaussian blur to apply 54 before applying lighting (e.g. 3) 55 @param direction array of 3 scalars [x, y, z] specifying the direction of the light source 56 @param ambient 0...1 amount of ambient light 57 @param specular coefficient for specular highlights (e.g. 8) 58 @return the emboss maskfilter 59 */ 60 static sk_sp<SkMaskFilter> MakeEmboss(SkScalar blurSigma, const SkScalar direction[3], 61 SkScalar ambient, SkScalar specular); 62 #endif 63 64 static const int kMaxDivisions = 6; 65 66 // This method computes all the parameters for drawing a partially occluded nine-patched 67 // blurred rrect mask: 68 // rrectToDraw - the integerized rrect to draw in the mask 69 // widthHeight - how large to make the mask (rrectToDraw will be centered in this coord sys) 70 // rectXs, rectYs - the x & y coordinates of the covering geometry lattice 71 // texXs, texYs - the texture coordinate at each point in rectXs & rectYs 72 // numXs, numYs - number of coordinates in the x & y directions 73 // skipMask - bit mask that contains a 1-bit whenever one of the cells is occluded 74 // It returns true if 'devRRect' is nine-patchable 75 static bool ComputeBlurredRRectParams(const SkRRect& srcRRect, const SkRRect& devRRect, 76 const SkRect& occluder, 77 SkScalar sigma, SkScalar xformedSigma, 78 SkRRect* rrectToDraw, 79 SkISize* widthHeight, 80 SkScalar rectXs[kMaxDivisions], 81 SkScalar rectYs[kMaxDivisions], 82 SkScalar texXs[kMaxDivisions], 83 SkScalar texYs[kMaxDivisions], 84 int* numXs, int* numYs, uint32_t* skipMask); 85 86 SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() 87 88 private: 89 SkBlurMaskFilter(); // can't be instantiated 90 }; 91 92 #endif 93
