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switch to int32_t and add modulo period for input values

master
loooph 2021-09-05 22:26:28 +02:00
parent 4e0097be1c
commit b60e0a6c46
1 changed files with 11 additions and 8 deletions
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19
include/generators.hpp
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@ -1,15 +1,17 @@
#include <math.h> #include <math.h>
#include <stdint.h> #include <stdint.h>
template<uint32_t period, int16_t max_val> template<int32_t period, int32_t max_val>
int16_t sine(uint32_t t) { int32_t sine(int32_t t) {
// 0 <= t < period is 0 <= t_2pi < 2 pi // 0 <= t < period is 0 <= t_2pi < 2 pi
float t_2pi = 2 * M_PI / static_cast<float>(period) * t; t %= period;
return static_cast<int16_t>(sinf(t_2pi) * max_val); float t_2pi = 2 * M_PI / static_cast<float>(period) * t;
return static_cast<int32_t>(sinf(t_2pi) * max_val);
} }
template<uint32_t period, int16_t max_val> template<int32_t period, int32_t max_val>
int16_t square(uint32_t t) { int32_t square(int32_t t) {
t %= period;
if (t <= period / 2) { if (t <= period / 2) {
return -max_val; return -max_val;
} else { } else {
@ -17,11 +19,12 @@ int16_t square(uint32_t t) {
} }
} }
template<uint32_t period, int16_t max_val> template<int32_t period, int32_t max_val>
int16_t sawtooth(uint32_t t) { int32_t sawtooth(int32_t t) {
// f(t) = a t + y // f(t) = a t + y
// f(0) = -max_val = y // f(0) = -max_val = y
// f(period) = a * period - max_val = max_val // f(period) = a * period - max_val = max_val
// a = 2 * max_val / period // a = 2 * max_val / period
t %= period;
return 2 * max_val * t / period - max_val; return 2 * max_val * t / period - max_val;
} }