You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
71 lines
2.2 KiB
71 lines
2.2 KiB
/*
|
|
Extended to F32
|
|
Created: Chip Audette, OpenAudio, Feb 2017
|
|
Extended to Teensy 4.x Bob larkn June 2020
|
|
|
|
License: MIT License. Use at your own risk.
|
|
*/
|
|
|
|
/* Audio Library for Teensy 3.X
|
|
* Copyright (c) 2014, 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 "synth_whitenoise_f32.h"
|
|
|
|
// Algorithm from Pure data [noise~] object
|
|
// https://github.com/pure-data/pure-data/blob/master/src/d_osc.c
|
|
|
|
void AudioSynthNoiseWhite_F32::update(void)
|
|
{
|
|
float gain = level;
|
|
if (gain == 0) {
|
|
return;
|
|
}
|
|
|
|
audio_block_f32_t *block = AudioStream_F32::allocate_f32();
|
|
if (!block) {
|
|
return;
|
|
}
|
|
|
|
float *p = block->data;
|
|
|
|
uint32_t val = seed;
|
|
|
|
gain *= (float)(1.0 / 0x40000000);
|
|
|
|
for(int i = 0; i < block->length; ++i) {
|
|
p[i] = (float)((val & 0x7fffffff) - 0x40000000) * gain;
|
|
val = val * 435898247 + 382842987;
|
|
}
|
|
|
|
seed = val;
|
|
|
|
AudioStream_F32::transmit(block);
|
|
AudioStream_F32::release(block);
|
|
}
|
|
|
|
uint16_t AudioSynthNoiseWhite_F32::instance_count = 0;
|
|
|
|
|
|
|