working version of the frustum based calculation for the perspective matrix

src/viewer.rs

@@ -1,22 +1,41 @@
 use bevy::{prelude::*, window::PresentMode, render::camera::CameraProjectionPlugin};
-use offaxis::{offaxis_camera_setup, OffAxisProjection};
+// use offaxis::{offaxis_camera_setup, OffAxisProjection};
 
 
-#[derive(Component)]
-struct Viewer;
-
-#[derive(Component)]
+#[derive(Component,Default)]
 pub struct Viewer {
-    position: Vec3,
-    orientation: Quat,
-}
+    pub position: Vec3,
+    pub orientation: Quat,
 
+    pub alpha: f32,
+}
 
 impl Viewer {
 
-    fn default() -> Self {
+    pub fn new(position: Vec3) ->Self {
         Self {
-            position: Vec3::ZERO,
+            position,
+            orientation: Quat::IDENTITY,
+            alpha: 0.0,
+
         }
     }
+
+    pub fn default() -> Self {
+        Self {
+            position: Vec3::ZERO,
+            orientation: Quat::IDENTITY,
+            alpha: 0.0
+        }
+    }
+}
+
+pub fn simulate_viewer(mut query: Query<&mut Viewer>)
+{
+    for mut v  in query.iter_mut() {
+        //v.position += Vec3::Y * 0.005;
+        v.alpha += 0.01;
+        let radius = 0.5;
+        v.position = Vec3::new(v.alpha.sin()*radius,v.alpha.cos()*radius,5.0);
+    }
 }