67 lines
2.3 KiB
C++
67 lines
2.3 KiB
C++
/* Audio Library for Teensy 3.X
|
|
* Copyright (c) 2016, 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.
|
|
*/
|
|
|
|
#ifndef synth_karplusstrong_h_
|
|
#define synth_karplusstrong_h_
|
|
#include "Arduino.h"
|
|
#include "AudioStream.h"
|
|
#include "utility/dspinst.h"
|
|
|
|
class AudioSynthKarplusStrong : public AudioStream
|
|
{
|
|
public:
|
|
AudioSynthKarplusStrong() : AudioStream(0, NULL) {
|
|
state = 0;
|
|
}
|
|
void noteOn(float frequency, float velocity) {
|
|
if (velocity > 1.0f) {
|
|
velocity = 0.0f;
|
|
} else if (velocity <= 0.0f) {
|
|
noteOff(1.0f);
|
|
return;
|
|
}
|
|
magnitude = velocity * 65535.0f;
|
|
int len = (AUDIO_SAMPLE_RATE_EXACT / frequency) + 0.5f;
|
|
if (len > 536) len = 536;
|
|
bufferLen = len;
|
|
bufferIndex = 0;
|
|
state = 1;
|
|
}
|
|
void noteOff(float velocity) {
|
|
state = 0;
|
|
}
|
|
virtual void update(void);
|
|
private:
|
|
uint8_t state; // 0=steady output, 1=begin on next update, 2=playing
|
|
uint16_t bufferLen;
|
|
uint16_t bufferIndex;
|
|
int32_t magnitude; // current output
|
|
static uint32_t seed; // must start at 1
|
|
int16_t buffer[536]; // TODO: dynamically use audio memory blocks
|
|
};
|
|
|
|
#endif
|