1 /* 2 * Copyright 2017 Google Inc. 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 SkMaskBlurFilter_DEFINED 9 #define SkMaskBlurFilter_DEFINED 10 11 #include <algorithm> 12 #include <memory> 13 #include <tuple> 14 15 #include "include/core/SkTypes.h" 16 #include "src/core/SkMask.h" 17 18 // Implement a single channel Gaussian blur. The specifics for implementation are taken from: 19 // https://drafts.fxtf.org/filters/#feGaussianBlurElement 20 class SkMaskBlurFilter { 21 public: 22 // Create an object suitable for filtering an SkMask using a filter with width sigmaW and 23 // height sigmaH. 24 SkMaskBlurFilter(double sigmaW, double sigmaH); 25 26 // returns true iff the sigmas will result in an identity mask (no blurring) 27 bool hasNoBlur() const; 28 29 // Given a src SkMask, generate dst SkMask returning the border width and height. 30 SkIPoint blur(const SkMask& src, SkMaskBuilder* dst) const; 31 32 private: 33 const double fSigmaW; 34 const double fSigmaH; 35 }; 36 37 #endif // SkBlurMaskFilter_DEFINED 38