76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
#include "vec3.h"
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#include "utils.h"
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#include <math.h>
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Vec3 vec3_neg(Vec3 v) { return (Vec3){-v.x, -v.y, -v.z}; }
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Vec3 vec3_add(Vec3 v1, Vec3 v2) {
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return (Vec3){v1.x + v2.x, v1.y + v2.y, v1.z + v2.z};
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}
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Vec3 vec3_sub(Vec3 v1, Vec3 v2) {
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return (Vec3){v1.x - v2.x, v1.y - v2.y, v1.z - v2.z};
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}
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Vec3 vec3_mul(double c, Vec3 v) { return (Vec3){c * v.x, c * v.y, c * v.z}; }
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Vec3 vec3_div(Vec3 v, double c) { return (Vec3){v.x / c, v.y / c, v.z / c}; }
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double vec3_length(Vec3 v) { return sqrt(vec3_length2(v)); }
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double vec3_length2(Vec3 v) { return v.x * v.x + v.y * v.y + v.z * v.z; }
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Vec3 vec3_normalize(Vec3 v) { return vec3_div(v, vec3_length(v)); }
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double vec3_dot(Vec3 v1, Vec3 v2) {
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return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z;
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}
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Vec3 vec3_cross(Vec3 v1, Vec3 v2) {
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return (Vec3){
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v1.y * v2.z - v1.z * v2.y,
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v1.z * v2.x - v1.x * v2.z,
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v1.x * v2.y - v1.y * v2.x,
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};
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}
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Vec3 vec3_random(void) {
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return (Vec3){
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random_double(),
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random_double(),
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random_double(),
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};
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}
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Vec3 vec3_random_in_range(double min, double max) {
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return (Vec3){
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random_double_in_range(min, max),
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random_double_in_range(min, max),
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random_double_in_range(min, max),
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};
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}
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Vec3 vec3_random_in_unit_sphere(void) {
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while (1) {
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Vec3 result = vec3_random_in_range(-1, 1);
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if (vec3_length2(result) >= 1)
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continue;
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return result;
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}
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}
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Vec3 vec3_random_unit_vector(void) {
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return vec3_normalize(vec3_random_in_unit_sphere());
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}
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bool vec3_is_near_zero(Vec3 v) {
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static const double threshold = 1e-8;
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return (fabs(v.x) < threshold) && (fabs(v.y) < threshold) &&
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(fabs(v.z) < threshold);
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}
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Vec3 vec3_reflect(Vec3 v, Vec3 n) {
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return vec3_sub(v, vec3_mul(2 * vec3_dot(v, n), n));
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}
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