32 lines
910 B
C
32 lines
910 B
C
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#include <math.h>
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#include "config.h"
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struct stfu_phaser stfu_pump_phaser(struct stfu_phaser phaser);
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struct stfu_phaser stfu_set_phaser_frequency(struct stfu_phaser phaser,
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float frequency);
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/* Useful for feeding into phase parameters of oscillators and such.
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* Repeats over [-PI, PI)
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*/
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struct stfu_phaser {
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float v, a;
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} stfu_init_phaser(float frequency) {
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struct stfu_phaser r = {0};
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r = stfu_set_phaser_frequency(r, frequency);
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return r;
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}
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struct stfu_phaser stfu_pump_phaser(struct stfu_phaser phaser) {
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phaser.v += phaser.a;
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if (phaser.v >= (float)M_PI)
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phaser.v -= (float)M_PI * 2.0f;
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return phaser;
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}
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struct stfu_phaser stfu_set_phaser_frequency(struct stfu_phaser phaser,
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float frequency) {
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phaser.a = 2 * ((float)M_PI / (float)STFU_AUDIO_FRAME_RATE) * frequency;
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return phaser;
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}
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