1 /* 2 * Copyright 2019 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * https://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_FXLAB_DELAYLINE_H 18 #define ANDROID_FXLAB_DELAYLINE_H 19 20 #include <vector> 21 22 23 template<class T> 24 class DelayLine { 25 public: DelayLine(std::size_t size)26 DelayLine(std::size_t size): N(size), mArr(N, 0) { } push(const T & value)27 void push(const T& value) { 28 mArr[mfront++] = value; 29 if (mfront == N) mfront = 0; 30 } 31 // indexed from last value written backwards 32 // i.e T-1 to T-N 33 const T& operator[](int i) { 34 int index = mfront - i; 35 if (index < 0) index += N; 36 return mArr[index]; 37 } 38 39 private: 40 const int N; 41 int mfront = 0; 42 std::vector<T> mArr; 43 }; 44 #endif //ANDROID_FXLAB_DELAYLINE_H 45