X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;ds=sidebyside;f=camera.h;h=596409937ceb3cf2f532c7d22f2c999533bd9fa7;hb=f7db507815e2822d971031c30f25e02b45e9c914;hp=1c265a7515dd3bdf3209c9b9e5f1e9f791940e3f;hpb=75703291fbf045008a3b1ebb20fc46a2617b6b3b;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/camera.h b/camera.h
index 1c265a7..5964099 100644
--- a/camera.h
+++ b/camera.h
@@ -3,24 +3,104 @@
 
 #include "common.h"
 
-VG_STATIC v2f camera_angles;
-VG_STATIC v3f camera_pos;
+typedef struct camera camera;
 
-VG_STATIC m4x3f camera_mtx,
-                camera_mtx_inverse;
+struct camera
+{
+   /* Input */
+   v2f angles;
+   v3f pos;
+   float fov, nearz, farz;
+
+   /* Output */
+   m4x3f transform,
+         transform_inverse;
 
-VG_STATIC void camera_update(void)
+   struct camera_mtx
+   {
+      m4x4f p,
+            v,
+            pv;
+   }
+   mtx,
+   mtx_prev;
+}
+VG_STATIC main_camera;
+
+/*
+ * 1) [angles, pos] -> transform 
+ */
+VG_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
+ */
+VG_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
+ */
+VG_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 
+ */
+VG_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 );
+}
+
+/* 
+ * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf 
+ */
+VG_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 );
 
-   m4x3_invert_affine( camera_mtx, camera_mtx_inverse );
+   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
+ */
+VG_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 */