41 lines
1.2 KiB
C++
41 lines
1.2 KiB
C++
#ifndef MENGA_FAST_MATH
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#define MENGA_FAST_MATH
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#include "mengumath.h"
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#include <cmath>
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namespace Mengu {
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namespace dsp {
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// PADE approximations. Only accurate on certain ranges
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// use between -pi to +pi
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template<typename FloatType>
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FloatType sin(FloatType x) {
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x = std::fmod(x + MATH_PI, MATH_TAU) - MATH_PI;
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FloatType x2 = x * x;
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FloatType numerator = x * ((11 * x2) * x2 + 2520);
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FloatType denominator = 60 * x2 + 2520;
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return numerator / denominator;
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}
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// use between -pi to +pi
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template<typename FloatType>
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FloatType cos(FloatType x) {
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x = std::fmod(x + MATH_PI, MATH_TAU) - MATH_PI;
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FloatType x2 = x * x;
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FloatType numerator = 131040 + x2 * (62160 + x2 * (3814 - x2 * 59));
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FloatType denominator = 131040 + x2 * (3360 + x2 * 34);
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return numerator / denominator;
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}
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template<typename FloatType>
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FloatType tan(FloatType x) {
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x = std::fmod(x + MATH_PI, MATH_TAU) - MATH_PI;
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FloatType x2 = x * x;
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FloatType numerator = x * (-135135 + x2 * (17325 + x2 * (-378 + x2)));
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FloatType denominator = -135135 + x2 * (62370 + x2 * (-3150 + 28 * x2));
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return numerator / denominator;
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}
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} // namespace dsp
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} // namespace Mengu
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#endif |