#ifndef CAMERA_H
#define CAMERA_H
-#include "common.h"
+#include "skaterift.h"
-VG_STATIC v2f camera_angles;
-VG_STATIC v3f camera_pos;
+typedef struct camera camera;
+struct camera{
+ /* Input */
+ v3f angles;
+ v3f pos;
+ float fov, nearz, farz;
-VG_STATIC m4x3f camera_mtx,
- camera_mtx_inverse;
+ /* Output */
+ m4x3f transform,
+ transform_inverse;
-VG_STATIC void camera_update(void)
+ struct camera_mtx{
+ m4x4f p,
+ v,
+ pv;
+ }
+ mtx,
+ mtx_prev;
+};
+
+static void camera_lerp_angles( v3f a, v3f b, float t, v3f d ){
+ d[0] = vg_alerpf( a[0], b[0], t );
+ d[1] = vg_lerpf( a[1], b[1], t );
+ d[2] = vg_lerpf( a[2], b[2], t );
+}
+
+/* lerp position, fov, and angles */
+static void camera_lerp( camera *a, camera *b, float t, camera *d ){
+ v3_lerp( a->pos, b->pos, t, d->pos );
+ camera_lerp_angles( a->angles, b->angles, t, d->angles );
+ d->fov = vg_lerpf( a->fov, b->fov, t );
+}
+
+static void camera_copy( camera *a, camera *d ){
+ v3_copy( a->pos, d->pos );
+ v3_copy( a->angles, d->angles );
+ d->fov = a->fov;
+}
+
+static void m4x3_transform_camera( m4x3f m, camera *cam ){
+ m4x3_mulv( m, cam->pos, cam->pos );
+
+ v3f v0;
+ v3_angles_vector( cam->angles, v0 );
+ m3x3_mulv( m, v0, v0 );
+ v3_normalize( v0 );
+ v3_angles( v0, cam->angles );
+}
+
+/*
+ * 1) [angles, pos] -> transform
+ */
+static void camera_update_transform( camera *cam )
{
- /* Update camera matrices */
v4f qyaw, qpitch, qcam;
- q_axis_angle( qyaw, (v3f){ 0.0f, 1.0f, 0.0f }, -camera_angles[0] );
- q_axis_angle( qpitch, (v3f){ 1.0f, 0.0f, 0.0f }, -camera_angles[1] );
+ q_axis_angle( qyaw, (v3f){ 0.0f, 1.0f, 0.0f }, -cam->angles[0] );
+ q_axis_angle( qpitch, (v3f){ 1.0f, 0.0f, 0.0f }, -cam->angles[1] );
q_mul( qyaw, qpitch, qcam );
- q_m3x3( qcam, camera_mtx );
- v3_copy( camera_pos, camera_mtx[3] );
+ q_m3x3( qcam, cam->transform );
+ v3_copy( cam->pos, cam->transform[3] );
+}
+
+/*
+ * 2) [transform] -> transform_inverse, view matrix
+ */
+static void camera_update_view( camera *cam )
+{
+ m4x4_copy( cam->mtx.v, cam->mtx_prev.v );
+ m4x3_invert_affine( cam->transform, cam->transform_inverse );
+ m4x3_expand( cam->transform_inverse, cam->mtx.v );
+}
+
+/*
+ * 3) [fov,nearz,farz] -> projection matrix
+ */
+static void camera_update_projection( camera *cam )
+{
+ m4x4_copy( cam->mtx.p, cam->mtx_prev.p );
+ m4x4_projection( cam->mtx.p, cam->fov,
+ (float)vg.window_x / (float)vg.window_y,
+ cam->nearz, cam->farz );
+}
+
+/*
+ * 4) [projection matrix, view matrix] -> previous pv, new pv
+ */
+static void camera_finalize( camera *cam )
+{
+ m4x4_copy( cam->mtx.pv, cam->mtx_prev.pv );
+ m4x4_mul( cam->mtx.p, cam->mtx.v, cam->mtx.pv );
+}
- m4x3_invert_affine( camera_mtx, camera_mtx_inverse );
+/*
+ * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf
+ */
+static void m4x4_clip_projection( m4x4f mat, v4f plane )
+{
+ v4f c =
+ {
+ (vg_signf(plane[0]) + mat[2][0]) / mat[0][0],
+ (vg_signf(plane[1]) + mat[2][1]) / mat[1][1],
+ -1.0f,
+ (1.0f + mat[2][2]) / mat[3][2]
+ };
+
+ v4_muls( plane, 2.0f / v4_dot(plane,c), c );
+
+ mat[0][2] = c[0];
+ mat[1][2] = c[1];
+ mat[2][2] = c[2] + 1.0f;
+ mat[3][2] = c[3];
+}
+
+/*
+ * Undoes the above operation
+ */
+static void m4x4_reset_clipping( m4x4f mat, float ffar, float fnear )
+{
+ mat[0][2] = 0.0f;
+ mat[1][2] = 0.0f;
+ mat[2][2] = -(ffar + fnear) / (ffar - fnear);
+ mat[3][2] = -2.0f * ffar * fnear / (ffar - fnear);
}
#endif /* CAMERA_H */