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.
58 lines
1.9 KiB
58 lines
1.9 KiB
/*
|
|
* AudioSynthWaveformSine_F32
|
|
*
|
|
* Created: Chip Audette (OpenAudio) Feb 2017
|
|
* Modeled on: AudioSynthWaveformSine from Teensy Audio Library
|
|
*
|
|
* Purpose: Create sine wave of given amplitude and frequency
|
|
*
|
|
* License: MIT License. Use at your own risk.
|
|
*
|
|
*/
|
|
|
|
#include "synth_sine_f32.h"
|
|
#include "utility/dspinst.h"
|
|
|
|
// data_waveforms.c
|
|
extern "C" {
|
|
extern const int16_t AudioWaveformSine[257];
|
|
}
|
|
|
|
void AudioSynthWaveformSine_F32::update(void) {
|
|
audio_block_f32_t *block;
|
|
uint32_t i, ph, inc, index, scale;
|
|
int32_t val1, val2;
|
|
static uint32_t block_length = 0;
|
|
|
|
if (enabled) {
|
|
if (magnitude) {
|
|
block = allocate_f32();
|
|
if (block) {
|
|
block_length = (uint32_t)block->length;
|
|
ph = phase_accumulator;
|
|
inc = phase_increment;
|
|
for (i=0; i < block_length; i++) {
|
|
index = ph >> 24;
|
|
val1 = AudioWaveformSine[index];
|
|
val2 = AudioWaveformSine[index+1];
|
|
scale = (ph >> 8) & 0xFFFF;
|
|
val2 *= scale;
|
|
val1 *= 0x10000 - scale;
|
|
#if (defined(KINETISK) || defined(__IMXRT1062__) )
|
|
block->data[i] = (float) multiply_32x32_rshift32(val1 + val2, magnitude);
|
|
#elif defined(KINETISL)
|
|
block->data[i] = (float) ((((val1 + val2) >> 16) * magnitude) >> 16);
|
|
#endif
|
|
ph += inc;
|
|
block->data[i] = block->data[i] / 32767.0f; // scale to float
|
|
}
|
|
phase_accumulator = ph;
|
|
|
|
AudioStream_F32::transmit(block);
|
|
AudioStream_F32::release(block);
|
|
return;
|
|
}
|
|
}// end if (magnitude)
|
|
phase_accumulator += phase_increment * block_length; // continue sine wave while magnitude==0
|
|
} // end if (enabled)
|
|
}
|
|
|