/* * Copyright 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. */ #include #include #include "SawtoothOscillator.h" SawtoothOscillator::SawtoothOscillator() : OscillatorBase() { } int32_t SawtoothOscillator::onProcess(int32_t numFrames) { const float *frequencies = frequency.getBuffer(); const float *amplitudes = amplitude.getBuffer(); float *buffer = output.getBuffer(); // Use the phase directly as a non-band-limited "sawtooth". // WARNING: This will generate unpleasant aliasing artifacts at higher frequencies. for (int i = 0; i < numFrames; i++) { float phase = incrementPhase(frequencies[i]); // phase ranges from -1 to +1 *buffer++ = phase * amplitudes[i]; } return numFrames; }