Add 2d camera

src/ecs/components/camera.rs

@@ -20,7 +20,13 @@ impl Default for CameraComponent {
 }
 
 impl CameraComponent {
-    pub fn new() -> Self {
+    pub fn new_3d() -> Self {
         Self::default()
     }
+
+    pub fn new_2d() -> Self {
+        let mut s = Self::default();
+        s.mode = CameraProjectionMode::Orthographic;
+        s
+    }
 }

src/render/camera.rs

@@ -40,6 +40,7 @@ impl Projection {
 pub struct RenderCamera {
     view_proj: glam::Mat4,
     
+    size: PhysicalSize<u32>,
     aspect: f32,
     znear: f32,
     zfar: f32,
@@ -50,6 +51,7 @@ impl RenderCamera {
         Self {
             view_proj: glam::Mat4::IDENTITY,
 
+            size,
             aspect: size.width as f32 / size.height as f32,
             znear: 0.1,
             zfar: 100.0,
@@ -61,14 +63,12 @@ impl RenderCamera {
     }
 
     pub fn update_view_projection(&mut self, camera: &CameraComponent) -> &glam::Mat4 {
+        match camera.mode {
+            CameraProjectionMode::Perspective => {
                 let position = camera.transform.translation;
                 let target = camera.transform.rotation * glam::Vec3::new(0.0, 0.0, -1.0);
                 let target = target.normalize();
 
-        /* debug!("Camera rotation: {:?}", rotation);
-        debug!("Camera position: {:?}", position);
-        debug!("Camera target: {:?}", target); */
-
                 let view = glam::Mat4::look_to_rh(
                     position,
                     target,
@@ -79,9 +79,23 @@ impl RenderCamera {
 
                 self.view_proj = OPENGL_TO_WGPU_MATRIX * proj * view;
                 &self.view_proj
-    }
+            },
+            CameraProjectionMode::Orthographic => {
+                let position = camera.transform.translation;
+                let target = camera.transform.rotation * glam::Vec3::new(0.0, 0.0, -1.0);
+                let target = target.normalize();
 
-    pub fn view_proj(&self) -> &glam::Mat4 {
+                let ratio_size_per_depth = ((camera.fov.to_radians() / 2.0) * 2.0).atan();
+                let distance = (target - position).length();
+
+                let size_y = ratio_size_per_depth * distance;
+                let size_x = ratio_size_per_depth * distance * self.aspect;
+
+                let proj = glam::Mat4::orthographic_rh_gl(-size_x, size_x, -size_y, size_y, self.znear, self.zfar);
+
+                self.view_proj = OPENGL_TO_WGPU_MATRIX * proj;
                 &self.view_proj
+            },
+        }
     }
 }