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[carveJwlIkooP6JGAAIwe30JlM.git] / camera.h

diff --git a/camera.h b/camera.h
index 1c265a7515dd3bdf3209c9b9e5f1e9f791940e3f..7bd14e64e6c0eefd4db4d71d6d79cbb4fe8d2558 100644 (file)
--- a/camera.h
+++ b/camera.h
@@ -1,26 +1,131 @@
 #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 */