1 /* gph-cmath - C graphics math library
2 * Copyright (C) 2018 John Tsiombikas <nuclear@member.fsf.org>
4 * This program is free software. Feel free to use, modify, and/or redistribute
5 * it under the terms of the MIT/X11 license. See LICENSE for details.
6 * If you intend to redistribute parts of the code without the LICENSE file
7 * replace this paragraph with the full contents of the LICENSE file.
9 static inline void cgm_vcons(cgm_vec3 *v, float x, float y, float z)
16 static inline void cgm_vadd(cgm_vec3 *a, const cgm_vec3 *b)
23 static inline void cgm_vsub(cgm_vec3 *a, const cgm_vec3 *b)
30 static inline void cgm_vmul(cgm_vec3 *a, const cgm_vec3 *b)
37 static inline void cgm_vscale(cgm_vec3 *v, float s)
44 static inline void cgm_vmul_m4v3(cgm_vec3 *v, const float *m)
46 float x = v->x * m[0] + v->y * m[4] + v->z * m[8] + m[12];
47 float y = v->x * m[1] + v->y * m[5] + v->z * m[9] + m[13];
48 v->z = v->x * m[2] + v->y * m[6] + v->z * m[10] + m[14];
53 static inline void cgm_vmul_v3m4(cgm_vec3 *v, const float *m)
55 float x = v->x * m[0] + v->y * m[1] + v->z * m[2] + m[3];
56 float y = v->x * m[4] + v->y * m[5] + v->z * m[6] + m[7];
57 v->z = v->x * m[8] + v->y * m[9] + v->z * m[10] + m[11];
62 static inline void cgm_vmul_m3v3(cgm_vec3 *v, const float *m)
64 float x = v->x * m[0] + v->y * m[4] + v->z * m[8];
65 float y = v->x * m[1] + v->y * m[5] + v->z * m[9];
66 v->z = v->x * m[2] + v->y * m[6] + v->z * m[10];
71 static inline void cgm_vmul_v3m3(cgm_vec3 *v, const float *m)
73 float x = v->x * m[0] + v->y * m[1] + v->z * m[2];
74 float y = v->x * m[4] + v->y * m[5] + v->z * m[6];
75 v->z = v->x * m[8] + v->y * m[9] + v->z * m[10];
80 static inline float cgm_vdot(const cgm_vec3 *a, const cgm_vec3 *b)
82 return a->x * b->x + a->y * b->y + a->z * b->z;
85 static inline void cgm_vcross(cgm_vec3 *res, const cgm_vec3 *a, const cgm_vec3 *b)
87 res->x = a->y * b->z - a->z * b->y;
88 res->y = a->z * b->x - a->x * b->z;
89 res->z = a->x * b->y - a->y * b->x;
92 static inline float cgm_vlength(const cgm_vec3 *v)
94 return sqrt(v->x * v->x + v->y * v->y + v->z * v->z);
97 static inline float cgm_vlength_sq(const cgm_vec3 *v)
99 return v->x * v->x + v->y * v->y + v->z * v->z;
102 static inline float cgm_vdist(const cgm_vec3 *a, const cgm_vec3 *b)
104 float dx = a->x - b->x;
105 float dy = a->y - b->y;
106 float dz = a->z - b->z;
107 return sqrt(dx * dx + dy * dy + dz * dz);
110 static inline float cgm_vdist_sq(const cgm_vec3 *a, const cgm_vec3 *b)
112 float dx = a->x - b->x;
113 float dy = a->y - b->y;
114 float dz = a->z - b->z;
115 return dx * dx + dy * dy + dz * dz;
118 static inline void cgm_vnormalize(cgm_vec3 *v)
120 float len = cgm_vlength(v);
122 float s = 1.0f / len;
129 static inline void cgm_vreflect(cgm_vec3 *v, const cgm_vec3 *n)
131 float ndotv2 = cgm_vdot(v, n) * 2.0f;
132 v->x -= n->x * ndotv2;
133 v->y -= n->y * ndotv2;
134 v->z -= n->z * ndotv2;
137 static inline void cgm_vrefract(cgm_vec3 *v, const cgm_vec3 *n, float ior)
139 float ndotv = cgm_vdot(v, n);
140 float k = 1.0f - ior * ior * (1.0f - ndotv * ndotv);
142 cgm_vreflect(v, n); /* TIR */
144 float sqrt_k = sqrt(k);
145 v->x = ior * v->x - (ior * ndotv + sqrt_k) * n->x;
146 v->y = ior * v->y - (ior * ndotv + sqrt_k) * n->y;
147 v->z = ior * v->z - (ior * ndotv + sqrt_k) * n->z;
151 static inline void cgm_vrotate_quat(cgm_vec3 *v, const cgm_quat *q)
153 cgm_quat vq, inv_q = *q, tmp_q = *q;
155 cgm_qcons(&vq, v->x, v->y, v->z, 0.0f);
157 cgm_qmul(&tmp_q, &vq);
158 cgm_qmul(&vq, &inv_q);
159 cgm_vcons(v, vq.x, vq.y, vq.z);
162 static inline void cgm_vrotate_axis(cgm_vec3 *v, int axis, float angle)
165 cgm_mrotation_axis(m, axis, angle);
169 static inline void cgm_vrotate(cgm_vec3 *v, float angle, float x, float y, float z)
172 cgm_mrotation(m, angle, x, y, z);
176 static inline void cgm_vrotate_euler(cgm_vec3 *v, float a, float b, float c, enum cgm_euler_mode mode)
179 cgm_mrotation_euler(m, a, b, c, mode);
183 static inline void cgm_vlerp(cgm_vec3 *res, const cgm_vec3 *a, const cgm_vec3 *b, float t)
185 res->x = a->x + (b->x - a->x) * t;
186 res->y = a->y + (b->y - a->y) * t;
187 res->z = a->z + (b->z - a->z) * t;