/* * Copyright 2017 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkGaussFilter_DEFINED #define SkGaussFilter_DEFINED #include // Define gaussian filters for values of sigma < 2. Produce values good to 1 part in 1,000,000. // Produces values as defined in "Scale-Space for Discrete Signals" by Tony Lindeberg. class SkGaussFilter { public: static constexpr int kGaussArrayMax = 6; explicit SkGaussFilter(double sigma); size_t size() const { return fN; } int radius() const { return fN - 1; } int width() const { return 2 * this->radius() + 1; } // Allow a filter to be used in a C++ ranged-for loop. const double* begin() const { return &fBasis[0]; } const double* end() const { return &fBasis[fN]; } private: double fBasis[kGaussArrayMax]; int fN; }; #endif // SkGaussFilter_DEFINED