/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.common.midi.synth;
public abstract class SynthUnit {
private static final double CONCERT_A_PITCH = 69.0;
private static final double CONCERT_A_FREQUENCY = 440.0;
/**
* @param pitch
* MIDI pitch in semitones
* @return frequency
*/
public static double pitchToFrequency(double pitch) {
double semitones = pitch - CONCERT_A_PITCH;
return CONCERT_A_FREQUENCY * Math.pow(2.0, semitones / 12.0);
}
public abstract float render();
}