/*
|
* 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 <cstddef>
|
|
// 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
|
