sns: filter resize should reset internal state

code/espurna/filters/LastFilter.h

@@ -18,14 +18,22 @@ class LastFilter : public BaseFilter {
  }
 
  void reset() override {
- _value = 0;
+ _reset();
+ }
+
+ void resize(size_t) override {
+ _reset();
  }
 
  double value() const override {
  return _value;
  }
 
 private:
+ void _reset() {
+ _value = 0;
+ }
+
  double _value = 0;
  bool _status = false;
 };

code/espurna/filters/MaxFilter.h

@@ -19,14 +19,22 @@ class MaxFilter : public BaseFilter {
  return 1;
  }
 
+ void resize(size_t) override {
+ _reset();
+ }
+
  void reset() override {
- _value = 0;
+ _reset();
  }
 
  double value() const {
  return _value;
  }
 
 private:
+ void _reset() {
+ _value = 0;
+ }
+
  double _value = 0;
 };

code/espurna/filters/MedianFilter.h

@@ -19,12 +19,7 @@ class MedianFilter : public BaseFilter {
  }
 
  void reset() override {
- if (_values.size() > 2) {
- _values[0] = _values.back();
- _values.resize(1);
- } else {
- _values.clear();
- }
+ _reset();
  }
 
  double value() const override {
@@ -66,14 +61,20 @@ class MedianFilter : public BaseFilter {
  }
 
  void resize(size_t capacity) override {
- if (_capacity != capacity) {
- _capacity = capacity;
- _values.clear();
- _values.reserve(_capacity + 1);
- }
+ _values.reserve(capacity + 1);
+ _reset();
  }
 
 private:
+ void _reset() {
+ auto previous = _values.size()
+ ? _values.back()
+ : 0.0;
+ _values.clear();
+ _values.push_back(previous);
+
+ }
+
  std::vector<double> _values;
  size_t _capacity = 0;
 };

code/espurna/filters/MovingAverageFilter.h

@@ -36,14 +36,22 @@ class MovingAverageFilter : public BaseFilter {
  }
 
  void resize(size_t size) override {
- _values.clear();
  _values.reserve(size);
+ _reset();
  }
 
  void reset() override {
- _values.clear();
+ _reset();
  }
 
 private:
+ void _reset() {
+ if (_values.size()) {
+ _values.erase(_values.begin(), _values.end() - 1);
+ } else {
+ _values.clear();
+ }
+ }
+
  std::vector<double> _values{};
 };

code/espurna/filters/SumFilter.h

@@ -17,14 +17,22 @@ class SumFilter : public BaseFilter {
  return 1;
  }
 
+ void resize(size_t) override {
+ _reset();
+ }
+
  void reset() override {
- _value = 0.0;
+ _reset();
  }
 
  double value() const override {
  return _value;
  }
 
 private:
+ void _reset() {
+ _value = 0.0;
+ }
+
  double _value = 0.0;
 };