bgc-c/basic-geometry/tangent.c

37 lines
1 KiB
C

#include "tangent.h"
const BgcTangentFP32 BGC_IDLE_TANGENT_FP32 = { 1.0f, 0.0f };
const BgcTangentFP64 BGC_IDLE_TANGENT_FP64 = { 1.0, 0.0 };
void _bgc_tangent_normalize_fp32(const float square_modulus, _BgcDarkTwinTangentFP32* twin)
{
// (square_modulus != square_modulus) is true when square_modulus is NaN
if (square_modulus <= BGC_SQUARE_EPSYLON_FP32 || square_modulus != square_modulus) {
twin->cos = 1.0f;
twin->sin = 0.0f;
return;
}
const float multiplier = sqrtf(1.0f / square_modulus);
twin->cos *= multiplier;
twin->sin *= multiplier;
}
void _bgc_tangent_normalize_fp64(const double square_modulus, _BgcDarkTwinTangentFP64* twin)
{
// (square_modulus != square_modulus) is true when square_modulus is NaN
if (square_modulus <= BGC_SQUARE_EPSYLON_FP64 || square_modulus != square_modulus) {
twin->cos = 1.0;
twin->sin = 0.0;
return;
}
const double multiplier = sqrt(1.0 / square_modulus);
twin->cos *= multiplier;
twin->sin *= multiplier;
}