1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
#ifndef _V3F_H
#define _V3F_H
#include <math.h>
typedef struct v3f_t {
float x, y, z;
} v3f_t;
#define v3f_set(_v3f, _x, _y, _z) \
(_v3f)->x = _x; \
(_v3f)->y = _y; \
(_v3f)->z = _z;
#define v3f_init(_x, _y, _z) \
{ \
.x = _x, \
.y = _y, \
.z = _z, \
}
/* return if a and b are equal */
static inline int v3f_equal(const v3f_t *a, const v3f_t *b)
{
return (a->x == b->x && a->y == b->y && a->z == b->z);
}
/* return the result of (a + b) */
static inline v3f_t v3f_add(const v3f_t *a, const v3f_t *b)
{
v3f_t res = v3f_init(a->x + b->x, a->y + b->y, a->z + b->z);
return res;
}
/* return the result of (a - b) */
static inline v3f_t v3f_sub(const v3f_t *a, const v3f_t *b)
{
v3f_t res = v3f_init(a->x - b->x, a->y - b->y, a->z - b->z);
return res;
}
/* return the result of (-v) */
static inline v3f_t v3f_negate(const v3f_t *v)
{
v3f_t res = v3f_init(-v->x, -v->y, -v->z);
return res;
}
/* return the result of (a * b) */
static inline v3f_t v3f_mult(const v3f_t *a, const v3f_t *b)
{
v3f_t res = v3f_init(a->x * b->x, a->y * b->y, a->z * b->z);
return res;
}
/* return the result of (v * scalar) */
static inline v3f_t v3f_mult_scalar(const v3f_t *v, float scalar)
{
v3f_t res = v3f_init( v->x * scalar, v->y * scalar, v->z * scalar);
return res;
}
/* return the result of (uv / scalar) */
static inline v3f_t v3f_div_scalar(const v3f_t *v, float scalar)
{
v3f_t res = v3f_init(v->x / scalar, v->y / scalar, v->z / scalar);
return res;
}
/* return the result of (a . b) */
static inline float v3f_dot(const v3f_t *a, const v3f_t *b)
{
return a->x * b->x + a->y * b->y + a->z * b->z;
}
/* return the length of the supplied vector */
static inline float v3f_length(const v3f_t *v)
{
return sqrtf(v3f_dot(v, v));
}
/* return the normalized form of the supplied vector */
static inline v3f_t v3f_normalize(const v3f_t *v)
{
v3f_t nv;
float f;
f = 1.0f / v3f_length(v);
v3f_set(&nv, f * v->x, f * v->y, f * v->z);
return nv;
}
/* return the distance squared between two arbitrary points */
static inline float v3f_distance_sq(const v3f_t *a, const v3f_t *b)
{
return powf(a->x - b->x, 2) + powf(a->y - b->y, 2) + powf(a->z - b->z, 2);
}
/* return the distance between two arbitrary points */
/* (consider using v3f_distance_sq() instead if possible, sqrtf() is slow) */
static inline float v3f_distance(const v3f_t *a, const v3f_t *b)
{
return sqrtf(v3f_distance_sq(a, b));
}
/* return the cross product of two unit vectors */
static inline v3f_t v3f_cross(const v3f_t *a, const v3f_t *b)
{
v3f_t product = v3f_init(a->y * b->z - a->z * b->y, a->z * b->x - a->x * b->z, a->x * b->y - a->y * b->x);
return product;
}
/* return the linearly interpolated vector between the two vectors at point alpha (0-1.0) */
static inline v3f_t v3f_lerp(const v3f_t *a, const v3f_t *b, float alpha)
{
v3f_t lerp_a, lerp_b;
lerp_a = v3f_mult_scalar(a, 1.0f - alpha);
lerp_b = v3f_mult_scalar(b, alpha);
return v3f_add(&lerp_a, &lerp_b);
}
/* return the normalized linearly interpolated vector between the two vectors at point alpha (0-1.0) */
static inline v3f_t v3f_nlerp(const v3f_t *a, const v3f_t *b, float alpha)
{
v3f_t lerp;
lerp = v3f_lerp(a, b, alpha);
return v3f_normalize(&lerp);
}
#endif
|
