use rh coordinate system in 2d

z = 0 is now "farthest back" and z=1000 "farthest forward"

crates/bevy_render/src/camera/projection.rs

@@ -55,7 +55,7 @@ pub struct OrthographicProjection {
 
 impl CameraProjection for OrthographicProjection {
     fn get_projection_matrix(&self) -> Mat4 {
-        Mat4::orthographic_lh(
+        Mat4::orthographic_rh(
             self.left,
             self.right,
             self.bottom,

crates/bevy_render/src/entity.rs

@@ -20,7 +20,7 @@ pub struct MeshComponents {
 }
 
 #[derive(Bundle)]
-pub struct PerspectiveCameraComponents {
+pub struct Camera3dComponents {
     pub camera: Camera,
     pub perspective_projection: PerspectiveProjection,
     pub visible_entities: VisibleEntities,
@@ -30,9 +30,9 @@ pub struct PerspectiveCameraComponents {
     pub scale: Scale,
 }
 
-impl Default for PerspectiveCameraComponents {
+impl Default for Camera3dComponents {
     fn default() -> Self {
-        PerspectiveCameraComponents {
+        Camera3dComponents {
             camera: Camera {
                 name: Some(base::camera::CAMERA3D.to_string()),
                 ..Default::default()
@@ -48,7 +48,7 @@ impl Default for PerspectiveCameraComponents {
 }
 
 #[derive(Bundle)]
-pub struct OrthographicCameraComponents {
+pub struct Camera2dComponents {
     pub camera: Camera,
     pub orthographic_projection: OrthographicProjection,
     pub visible_entities: VisibleEntities,
@@ -58,17 +58,23 @@ pub struct OrthographicCameraComponents {
     pub scale: Scale,
 }
 
-impl Default for OrthographicCameraComponents {
+impl Default for Camera2dComponents {
     fn default() -> Self {
-        OrthographicCameraComponents {
+        // we want 0 to be "closest" and +far to be "farthest" in 2d, so we offset
+        // the camera's translation by far and use a right handed coordinate system   
+        let far = 1000.0;
+        Camera2dComponents {
             camera: Camera {
                 name: Some(base::camera::CAMERA2D.to_string()),
                 ..Default::default()
             },
-            orthographic_projection: Default::default(),
+            orthographic_projection: OrthographicProjection {
+                far,
+                ..Default::default()
+            },
             visible_entities: Default::default(),
             transform: Default::default(),
-            translation: Default::default(),
+            translation: Translation::new(0.0, 0.0, far - 0.1),
             rotation: Default::default(),
             scale: Default::default(),
         }

crates/bevy_ui/src/focus.rs

@@ -106,8 +106,7 @@ pub fn ui_focus_system(
         })
         .collect::<Vec<_>>();
 
-    // TODO: sort by negative when we move back to a right handed coordinate system
-    moused_over_z_sorted_nodes.sort_by_key(|(_, _, _, z)| *z);
+    moused_over_z_sorted_nodes.sort_by_key(|(_, _, _, z)| -*z);
     for (focus_policy, click, hover, _) in moused_over_z_sorted_nodes {
         if mouse_clicked {
             // only consider nodes with ClickState "clickable"

crates/bevy_ui/src/update.rs

@@ -37,7 +37,7 @@ pub fn ui_update_system(
     };
 
     let mut previous_sibling_result = Some(Rect {
-        z: 999.0,
+        z: 0.0,
         size: window_size,
     });
     for entity in orphan_nodes {
@@ -66,8 +66,8 @@ fn update_node_entity(
                 z = previous_rect.z
             };
 
-            z -= UI_Z_STEP;
-            node.update(&mut translation, z - parent_rect.z, parent_rect.size);
+            z += UI_Z_STEP;
+            node.update(&mut translation, z + parent_rect.z, parent_rect.size);
             return Some(Rect { size: node.size, z });
         }
     }

examples/2d/sprite.rs

@@ -14,7 +14,7 @@ fn setup(
 ) {
     let texture_handle = asset_server.load("assets/branding/icon.png").unwrap();
     commands
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         .spawn(SpriteComponents {
             material: materials.add(texture_handle.into()),
             ..Default::default()

examples/2d/sprite_sheet.rs

@@ -37,7 +37,7 @@ fn setup(
     let texture_atlas = TextureAtlas::from_grid(texture_handle, texture.size, 7, 1);
     let texture_atlas_handle = texture_atlases.add(texture_atlas);
     commands
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         .spawn(SpriteSheetComponents {
             texture_atlas: texture_atlas_handle,
             scale: Scale(6.0),

examples/2d/texture_atlas.rs

@@ -27,7 +27,7 @@ fn setup(
     rpg_sprite_handles.handles = asset_server
         .load_asset_folder("assets/textures/rpg")
         .unwrap();
-    commands.spawn(OrthographicCameraComponents::default());
+    commands.spawn(Camera2dComponents::default());
 }
 
 #[derive(Default)]

examples/3d/3d_scene.rs

@@ -48,7 +48,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, 8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/3d/load_model.rs

@@ -37,7 +37,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(-2.0, 2.0, 6.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/3d/parenting.rs

@@ -53,7 +53,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(5.0, 10.0, 10.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/3d/spawner.rs

@@ -62,7 +62,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, -8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/3d/texture.rs

@@ -91,7 +91,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, -8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/3d/z_sort_debug.rs

@@ -84,7 +84,7 @@ fn setup(
                 });
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(5.0, 10.0, 10.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/app/dynamic_plugin_loading/example_plugin/src/lib.rs

@@ -33,7 +33,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, 8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/asset/asset_loading.rs

@@ -70,7 +70,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(0.0, 3.0, 10.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/asset/hot_asset_reloading.rs

@@ -45,7 +45,7 @@ fn setup(
             ..Default::default()
         })
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(2.0, 2.0, 6.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/game/breakout.rs

@@ -40,7 +40,7 @@ fn setup(
     // Add the game's entities to our world
     commands
         // camera
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         // paddle
         .spawn(SpriteComponents {
             material: materials.add(Color::rgb(0.2, 0.2, 0.8).into()),

examples/shader/shader_custom_material.rs

@@ -109,7 +109,7 @@ fn setup(
         })
         .with(material)
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, -8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/shader/shader_defs.rs

@@ -152,7 +152,7 @@ fn setup(
         })
         .with(blue_material)
         // camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(3.0, 5.0, -8.0),
                 Vec3::new(0.0, 0.0, 0.0),

examples/ui/button.rs

@@ -92,7 +92,7 @@ fn setup(
 ) {
     commands
         // ui camera
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         .spawn(ButtonComponents {
             node: Node::new(Anchors::CENTER, Margins::new(-75.0, 75.0, -35.0, 35.0)),
             material: button_materials.normal,

examples/ui/font_atlas_debug.rs

@@ -65,7 +65,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut state: ResM
     state.handle = font_handle;
     commands
         // 2d camera
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         // texture
         .spawn(LabelComponents {
             node: Node::new(Anchors::TOP_LEFT, Margins::new(0.0, 250.0, 0.0, 60.0)),

examples/ui/text.rs

@@ -26,7 +26,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     let font_handle = asset_server.load("assets/fonts/FiraSans-Bold.ttf").unwrap();
     commands
         // 2d camera
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         // texture
         .spawn(LabelComponents {
             node: Node::new(Anchors::TOP_LEFT, Margins::new(0.0, 250.0, 0.0, 60.0)),

examples/ui/ui.rs

@@ -23,7 +23,7 @@ fn setup(
 
     commands
         // ui camera
-        .spawn(OrthographicCameraComponents::default())
+        .spawn(Camera2dComponents::default())
         // root node
         .spawn(NodeComponents {
             node: Node::new(Anchors::FULL, Margins::default()),

examples/ui/ui_bench.rs

@@ -22,7 +22,7 @@ fn placement_system(
 }
 
 fn setup(mut commands: Commands, mut materials: ResMut<Assets<ColorMaterial>>) {
-    commands.spawn(OrthographicCameraComponents::default());
+    commands.spawn(Camera2dComponents::default());
 
     let mut prev = Vec2::default();
     let count = 1000;

examples/window/multiple_windows.rs

@@ -136,7 +136,7 @@ fn setup(
             ..Default::default()
         })
         // main camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             transform: Transform::new_sync_disabled(Mat4::face_toward(
                 Vec3::new(0.0, 0.0, 6.0),
                 Vec3::new(0.0, 0.0, 0.0),
@@ -145,7 +145,7 @@ fn setup(
             ..Default::default()
         })
         // second window camera
-        .spawn(PerspectiveCameraComponents {
+        .spawn(Camera3dComponents {
             camera: Camera {
                 name: Some("Secondary".to_string()),
                 window: WindowReference::Id(window_id),