| /* |
| * 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 <math.h> |
| #include <unistd.h> |
| |
| #include "SawtoothOscillator.h" |
| |
| SawtoothOscillator::SawtoothOscillator() |
| : OscillatorBase() { |
| } |
| |
| int32_t SawtoothOscillator::onProcess(int 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". |
| // 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; |
| } |