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