mirror of
https://github.com/nishiowo/nishbox
synced 2025-04-21 20:24:39 +00:00
72 lines
1.4 KiB
C
72 lines
1.4 KiB
C
#include <gf_pre.h>
|
|
|
|
/* External library */
|
|
|
|
/* Interface */
|
|
#include <gf_math.h>
|
|
|
|
/* Engine */
|
|
|
|
/* Standard */
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
|
|
double gf_math_log2(double x) { return log(x) / log(2); }
|
|
|
|
void gf_math_normalize(gf_math_vector_t v) {
|
|
double x = v[0];
|
|
double y = v[1];
|
|
double z = v[2];
|
|
double length;
|
|
|
|
x *= x;
|
|
y *= y;
|
|
z *= z;
|
|
|
|
length = sqrt(x + y + z);
|
|
if(length > 0) {
|
|
length = (double)1 / length;
|
|
} else {
|
|
length = 0;
|
|
}
|
|
v[0] *= length;
|
|
v[1] *= length;
|
|
v[2] *= length;
|
|
}
|
|
|
|
void gf_math_normal(gf_math_vector_t r, gf_math_vector_t v0, gf_math_vector_t v1, gf_math_vector_t v2) {
|
|
gf_math_vector_t tmp0;
|
|
gf_math_vector_t tmp1;
|
|
|
|
gf_math_subtract(tmp0, v1, v0);
|
|
gf_math_subtract(tmp1, v2, v0);
|
|
|
|
gf_math_multiply(r, tmp0, tmp1);
|
|
|
|
gf_math_normalize(r);
|
|
}
|
|
|
|
void gf_math_subtract(gf_math_vector_t r, gf_math_vector_t v0, gf_math_vector_t v1) {
|
|
r[0] = v0[0] - v1[0];
|
|
r[1] = v0[1] - v1[1];
|
|
r[2] = v0[2] - v1[2];
|
|
}
|
|
|
|
void gf_math_multiply(gf_math_vector_t r, gf_math_vector_t v0, gf_math_vector_t v1) {
|
|
r[0] = v0[1] * v1[2] - v0[2] * v1[1];
|
|
r[1] = v0[2] * v1[0] - v0[0] * v1[2];
|
|
r[2] = v0[0] * v1[1] - v0[1] * v1[0];
|
|
}
|
|
|
|
double gf_math_cot(double x) { return (double)1 / tan(x); }
|
|
|
|
double gf_math_nearest_2pow(double x) {
|
|
double l = gf_math_log2(x);
|
|
double r = pow(2, (int)l);
|
|
if(x == r) {
|
|
return r;
|
|
}
|
|
return pow(2, 1 + (int)l);
|
|
}
|