1 /* 2 * Copyright 2019 The Android Open Source Project 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 * http://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 18 #ifndef OBOETESTER_EXPONENTIAL_SHAPE_H 19 #define OBOETESTER_EXPONENTIAL_SHAPE_H 20 21 #include "flowgraph/FlowGraphNode.h" 22 23 /** 24 * Generate a exponential sweep between min and max. 25 * 26 * The waveform is not band-limited so it will have aliasing artifacts at higher frequencies. 27 */ 28 class ExponentialShape : public oboe::flowgraph::FlowGraphFilter { 29 public: 30 ExponentialShape(); 31 32 int32_t onProcess(int32_t numFrames) override; 33 getMinimum()34 float getMinimum() const { 35 return mMinimum; 36 } 37 38 /** 39 * The minimum and maximum should not span zero. 40 * They should both be positive or both negative. 41 * 42 * @param minimum 43 */ setMinimum(float minimum)44 void setMinimum(float minimum) { 45 mMinimum = minimum; 46 mRatio = mMaximum / mMinimum; 47 } 48 getMaximum()49 float getMaximum() const { 50 return mMaximum; 51 } 52 53 /** 54 * The minimum and maximum should not span zero. 55 * They should both be positive or both negative. 56 * 57 * @param maximum 58 */ setMaximum(float maximum)59 void setMaximum(float maximum) { 60 mMaximum = maximum; 61 mRatio = mMaximum / mMinimum; 62 } 63 64 private: 65 float mMinimum = 0.0; 66 float mMaximum = 1.0; 67 float mRatio = 1.0; 68 }; 69 70 #endif //OBOETESTER_EXPONENTIAL_SHAPE_H 71