fix remote players ghosting
[carveJwlIkooP6JGAAIwe30JlM.git] / camera.h
1 #ifndef CAMERA_H
2 #define CAMERA_H
3
4 #include "skaterift.h"
5
6 typedef struct camera camera;
7 struct camera{
8 /* Input */
9 v3f angles;
10 v3f pos;
11 float fov, nearz, farz;
12
13 /* Output */
14 m4x3f transform,
15 transform_inverse;
16
17 struct camera_mtx{
18 m4x4f p,
19 v,
20 pv;
21 }
22 mtx,
23 mtx_prev;
24 };
25
26 static void camera_lerp_angles( v3f a, v3f b, float t, v3f d ){
27 d[0] = vg_alerpf( a[0], b[0], t );
28 d[1] = vg_lerpf( a[1], b[1], t );
29 d[2] = vg_lerpf( a[2], b[2], t );
30 }
31
32 static void camera_lerp( camera *a, camera *b, float t, camera *d ){
33 v3_lerp( a->pos, b->pos, t, d->pos );
34 d->angles[0] = vg_alerpf( a->angles[0], b->angles[0], t );
35 d->angles[1] = vg_lerpf( a->angles[1], b->angles[1], t );
36 d->angles[2] = vg_lerpf( a->angles[2], b->angles[2], t );
37 d->fov = vg_lerpf( a->fov, b->fov, t );
38 }
39
40 static void camera_copy( camera *a, camera *d ){
41 v3_copy( a->pos, d->pos );
42 v3_copy( a->angles, d->angles );
43 d->fov = a->fov;
44 }
45
46 /*
47 * 1) [angles, pos] -> transform
48 */
49 static void camera_update_transform( camera *cam )
50 {
51 v4f qyaw, qpitch, qcam;
52 q_axis_angle( qyaw, (v3f){ 0.0f, 1.0f, 0.0f }, -cam->angles[0] );
53 q_axis_angle( qpitch, (v3f){ 1.0f, 0.0f, 0.0f }, -cam->angles[1] );
54
55 q_mul( qyaw, qpitch, qcam );
56 q_m3x3( qcam, cam->transform );
57 v3_copy( cam->pos, cam->transform[3] );
58 }
59
60 /*
61 * 2) [transform] -> transform_inverse, view matrix
62 */
63 static void camera_update_view( camera *cam )
64 {
65 m4x4_copy( cam->mtx.v, cam->mtx_prev.v );
66 m4x3_invert_affine( cam->transform, cam->transform_inverse );
67 m4x3_expand( cam->transform_inverse, cam->mtx.v );
68 }
69
70 /*
71 * 3) [fov,nearz,farz] -> projection matrix
72 */
73 static void camera_update_projection( camera *cam )
74 {
75 m4x4_copy( cam->mtx.p, cam->mtx_prev.p );
76 m4x4_projection( cam->mtx.p, cam->fov,
77 (float)vg.window_x / (float)vg.window_y,
78 cam->nearz, cam->farz );
79 }
80
81 /*
82 * 4) [projection matrix, view matrix] -> previous pv, new pv
83 */
84 static void camera_finalize( camera *cam )
85 {
86 m4x4_copy( cam->mtx.pv, cam->mtx_prev.pv );
87 m4x4_mul( cam->mtx.p, cam->mtx.v, cam->mtx.pv );
88 }
89
90 /*
91 * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf
92 */
93 static void m4x4_clip_projection( m4x4f mat, v4f plane )
94 {
95 v4f c =
96 {
97 (vg_signf(plane[0]) + mat[2][0]) / mat[0][0],
98 (vg_signf(plane[1]) + mat[2][1]) / mat[1][1],
99 -1.0f,
100 (1.0f + mat[2][2]) / mat[3][2]
101 };
102
103 v4_muls( plane, 2.0f / v4_dot(plane,c), c );
104
105 mat[0][2] = c[0];
106 mat[1][2] = c[1];
107 mat[2][2] = c[2] + 1.0f;
108 mat[3][2] = c[3];
109 }
110
111 /*
112 * Undoes the above operation
113 */
114 static void m4x4_reset_clipping( m4x4f mat, float ffar, float fnear )
115 {
116 mat[0][2] = 0.0f;
117 mat[1][2] = 0.0f;
118 mat[2][2] = -(ffar + fnear) / (ffar - fnear);
119 mat[3][2] = -2.0f * ffar * fnear / (ffar - fnear);
120 }
121
122 #endif /* CAMERA_H */