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 "SkRect.h" 14 #include "SkScalar.h" 15 #include "SkBlurTypes.h" 16 17 class SkRRect; 18 19 class SK_API SkBlurMaskFilter { 20 public: 21 /** 22 * If radius > 0, return the corresponding sigma, else return 0. Use this to convert from the 23 * (legacy) idea of specify the blur "radius" to the standard notion of specifying its sigma. 24 */ 25 static SkScalar ConvertRadiusToSigma(SkScalar radius); 26 27 enum BlurFlags { 28 kNone_BlurFlag = 0x00, 29 /** The blur layer's radius is not affected by transforms */ 30 kIgnoreTransform_BlurFlag = 0x01, 31 /** Use a smother, higher qulity blur algorithm */ 32 kHighQuality_BlurFlag = 0x02, 33 /** mask for all blur flags */ 34 kAll_BlurFlag = 0x03 35 }; 36 37 /** Create a blur maskfilter. 38 * @param style The SkBlurStyle to use 39 * @param sigma Standard deviation of the Gaussian blur to apply. Must be > 0. 40 * @param occluder The rect for which no pixels need be drawn (b.c. it will be overdrawn 41 * with some opaque object. This is just a hint which backends are free to 42 * ignore. 43 * @param flags Flags to use - defaults to none 44 * @return The new blur maskfilter 45 */ 46 static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma, 47 const SkRect& occluder, uint32_t flags = kNone_BlurFlag); 48 49 static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma, 50 uint32_t flags = kNone_BlurFlag) { 51 return Make(style, sigma, SkRect::MakeEmpty(), flags); 52 } 53 54 #ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER 55 /** Create an emboss maskfilter 56 @param blurSigma standard deviation of the Gaussian blur to apply 57 before applying lighting (e.g. 3) 58 @param direction array of 3 scalars [x, y, z] specifying the direction of the light source 59 @param ambient 0...1 amount of ambient light 60 @param specular coefficient for specular highlights (e.g. 8) 61 @return the emboss maskfilter 62 */ 63 static sk_sp<SkMaskFilter> MakeEmboss(SkScalar blurSigma, const SkScalar direction[3], 64 SkScalar ambient, SkScalar specular); 65 #endif 66 67 static const int kMaxDivisions = 6; 68 69 // This method computes all the parameters for drawing a partially occluded nine-patched 70 // blurred rrect mask: 71 // rrectToDraw - the integerized rrect to draw in the mask 72 // widthHeight - how large to make the mask (rrectToDraw will be centered in this coord sys) 73 // rectXs, rectYs - the x & y coordinates of the covering geometry lattice 74 // texXs, texYs - the texture coordinate at each point in rectXs & rectYs 75 // numXs, numYs - number of coordinates in the x & y directions 76 // skipMask - bit mask that contains a 1-bit whenever one of the cells is occluded 77 // It returns true if 'devRRect' is nine-patchable 78 static bool ComputeBlurredRRectParams(const SkRRect& srcRRect, const SkRRect& devRRect, 79 const SkRect& occluder, 80 SkScalar sigma, SkScalar xformedSigma, 81 SkRRect* rrectToDraw, 82 SkISize* widthHeight, 83 SkScalar rectXs[kMaxDivisions], 84 SkScalar rectYs[kMaxDivisions], 85 SkScalar texXs[kMaxDivisions], 86 SkScalar texYs[kMaxDivisions], 87 int* numXs, int* numYs, uint32_t* skipMask); 88 89 SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() 90 91 private: 92 SkBlurMaskFilter(); // can't be instantiated 93 }; 94 95 #endif 96