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_TREMOLOEFFECT_H 18 #define ANDROID_FXLAB_TREMOLOEFFECT_H 19 20 21 #include "utils/SineWave.h" 22 23 class TremoloEffect { 24 public: TremoloEffect(float frequency,float height)25 TremoloEffect(float frequency, float height): 26 kCenter(1 - height), 27 kSignal {SineWave{frequency, height, SAMPLE_RATE}} { } 28 29 template <class numeric_type> operator()30 void operator () (numeric_type &x) { 31 x = x * (kSignal() + kCenter); 32 } 33 template <class iter_type> operator()34 void operator () (iter_type begin, iter_type end) { 35 for (; begin != end; ++begin) { 36 operator()(*begin); 37 } 38 } 39 private: 40 const float kCenter; 41 std::function<float()> kSignal; 42 }; 43 #endif //ANDROID_FXLAB_TREMOLOEFFECT_H 44