wip: engine enhancements and fixes

platform/src/camera.rs

@@ -0,0 +1,24 @@
+use glam::{Mat4, Vec3};
+
+#[derive(Copy, Clone)]
+pub struct Camera {
+    pub eye:    Vec3,
+    pub center: Vec3,
+    pub up:     Vec3,
+    pub fovy:   f32,
+    pub aspect: f32,
+    pub znear:  f32,
+    pub zfar:   f32,
+}
+
+impl Camera {
+    pub fn view(&self) -> Mat4 {
+        Mat4::look_at_rh(self.eye, self.center, self.up)
+    }
+    pub fn projection(&self) -> Mat4 {
+        Mat4::perspective_rh(self.fovy, self.aspect, self.znear, self.zfar)
+    }
+    pub fn view_proj(&self) -> Mat4 {
+        self.projection() * self.view()
+    }
+}