28 lines
698 B
C++
28 lines
698 B
C++
#include <math.h>
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#include <stdint.h>
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template<uint32_t period, int16_t max_val>
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int16_t sine(uint32_t t) {
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// 0 <= t < period is 0 <= t_2pi < 2 pi
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float t_2pi = 2 * M_PI / static_cast<float>(period) * t;
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return static_cast<int16_t>(sinf(t_2pi) * max_val);
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}
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template<uint32_t period, int16_t max_val>
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int16_t square(uint32_t t) {
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if (t <= period / 2) {
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return -max_val;
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} else {
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return max_val;
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}
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}
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template<uint32_t period, int16_t max_val>
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int16_t sawtooth(uint32_t t) {
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// f(t) = a t + y
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// f(0) = -max_val = y
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// f(period) = a * period - max_val = max_val
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// a = 2 * max_val / period
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return 2 * max_val * t / period - max_val;
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}
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