106 lines
3.1 KiB
C++
Executable file
106 lines
3.1 KiB
C++
Executable file
/* Audio Library for Teensy 3.X
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* Copyright (c) 2017, Paul Stoffregen, paul@pjrc.com
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*
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* Development of this audio library was funded by PJRC.COM, LLC by sales of
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* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
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* open source software by purchasing Teensy or other PJRC products.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice, development funding notice, and this permission
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* notice shall be included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <Arduino.h>
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#include "synth_pwm.h"
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#include "utility/dspinst.h"
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#if defined(__ARM_ARCH_7EM__)
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void AudioSynthWaveformPWM::update(void)
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{
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audio_block_t *block, *modinput;
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uint32_t i;
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int32_t out;
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modinput = receiveReadOnly();
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if (magnitude == 0) {
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if (modinput) release(modinput);
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return;
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}
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block = allocate();
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if (!block) {
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// unable to allocate memory, so we'll send nothing
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if (modinput) release(modinput);
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return;
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}
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if (modinput) {
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const uint32_t _duration = duration;
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uint32_t _elapsed = elapsed;
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int32_t _magnitude = magnitude;
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for (i=0; i < AUDIO_BLOCK_SAMPLES; i++) {
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_elapsed += 65536;
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int32_t in = modinput->data[i];
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if (_magnitude < 0) in = -in;
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uint32_t dur = ((uint64_t)(in + 32768) * _duration) >> 15;
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if (_elapsed < dur) {
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out = _magnitude;
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} else {
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int32_t e = _elapsed - dur;
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signed_saturate_rshift(e, 17, 0);
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if (e < 0) e = 0;
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_elapsed = e;
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// elapsed must be 0 to 65535
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// magnitude must be -32767 to +32767
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out = _magnitude - ((_magnitude * _elapsed) >> 15);
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_magnitude = -_magnitude;
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}
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block->data[i] = out;
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}
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elapsed = _elapsed;
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magnitude = _magnitude;
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release(modinput);
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} else {
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for (i=0; i < AUDIO_BLOCK_SAMPLES; i++) {
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elapsed += 65536;
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if (elapsed < duration) {
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out = magnitude;
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} else {
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elapsed -= duration;
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// elapsed must be 0 to 65535
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// magnitude must be -32767 to +32767
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out = magnitude - ((magnitude * elapsed) >> 15);
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magnitude = -magnitude;
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}
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block->data[i] = out;
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}
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}
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transmit(block);
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release(block);
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}
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#elif defined(KINETISL)
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void AudioSynthWaveformPWM::update(void)
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{
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audio_block_t *block = receiveReadOnly();
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if (block) release(block);
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}
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#endif
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