1 /******************************************************************************* 2 * Copyright 2009-2016 Jörg Müller 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 #pragma once 18 19 /** 20 * @file Threshold.h 21 * @ingroup fx 22 * The Threshold class. 23 */ 24 25 #include "fx/Effect.h" 26 27 AUD_NAMESPACE_BEGIN 28 29 class CallbackIIRFilterReader; 30 31 /** 32 * This sound Transforms any signal to a square signal by thresholding. 33 */ 34 class AUD_API Threshold : public Effect 35 { 36 private: 37 /** 38 * The threshold. 39 */ 40 const float m_threshold; 41 42 // delete copy constructor and operator= 43 Threshold(const Threshold&) = delete; 44 Threshold& operator=(const Threshold&) = delete; 45 46 public: 47 /** 48 * Creates a new threshold sound. 49 * \param sound The input sound. 50 * \param threshold The threshold. 51 */ 52 Threshold(std::shared_ptr<ISound> sound, float threshold = 0.0f); 53 54 /** 55 * Returns the threshold. 56 */ 57 float getThreshold() const; 58 59 virtual std::shared_ptr<IReader> createReader(); 60 61 /** 62 * The thresholdFilter function implements the doFilterIIR callback 63 * for the callback IIR filter. 64 * @param reader The CallbackIIRFilterReader that executes the callback. 65 * @param threshold The threshold value. 66 * @return The filtered sample. 67 */ 68 static sample_t AUD_LOCAL thresholdFilter(CallbackIIRFilterReader* reader, float* threshold); 69 70 /** 71 * The endThresholdFilter function implements the endFilterIIR callback 72 * for the callback IIR filter. 73 * @param threshold The threshold value. 74 */ 75 static void AUD_LOCAL endThresholdFilter(float* threshold); 76 }; 77 78 AUD_NAMESPACE_END 79