Fix frustum culling w/ sprite transform scaling

Cargo.toml

@@ -99,6 +99,10 @@ name = "hello_world"
 path = "examples/hello_world.rs"
 
 # 2D Rendering
+[[example]]
+name = "frustum"
+path = "examples/2d/frustum.rs"
+
 [[example]]
 name = "contributors"
 path = "examples/2d/contributors.rs"

crates/bevy_sprite/src/frustum_culling.rs

@@ -46,18 +46,18 @@ pub fn sprite_frustum_culling_system(
         if let Ok(camera_transform) = camera_transforms.get(active_camera_entity) {
             let camera_size = window_size * camera_transform.scale.truncate();
 
-            let rect = Rect {
+            let camera_rect = Rect {
                 position: camera_transform.translation.truncate(),
                 size: camera_size,
             };
 
             for (entity, drawable_transform, sprite) in sprites.iter() {
                 let sprite_rect = Rect {
                     position: drawable_transform.translation.truncate(),
-                    size: sprite.size,
+                    size: sprite.size * drawable_transform.scale.truncate(),
                 };
 
-                if rect.is_intersecting(sprite_rect) {
+                if camera_rect.is_intersecting(sprite_rect) {
                     if culled_sprites.get(entity).is_ok() {
                         commands.entity(entity).remove::<OutsideFrustum>();
                     }
@@ -90,7 +90,7 @@ pub fn atlas_frustum_culling_system(
         if let Ok(camera_transform) = camera_transforms.get(active_camera_entity) {
             let camera_size = window_size * camera_transform.scale.truncate();
 
-            let rect = Rect {
+            let camera_rect = Rect {
                 position: camera_transform.translation.truncate(),
                 size: camera_size,
             };
@@ -102,10 +102,10 @@ pub fn atlas_frustum_culling_system(
 
                         let sprite_rect = Rect {
                             position: drawable_transform.translation.truncate(),
-                            size,
+                            size: size * drawable_transform.scale.truncate(),
                         };
 
-                        if rect.is_intersecting(sprite_rect) {
+                        if camera_rect.is_intersecting(sprite_rect) {
                             if culled_sprites.get(entity).is_ok() {
                                 commands.entity(entity).remove::<OutsideFrustum>();
                             }

examples/2d/frustum.rs

@@ -0,0 +1,96 @@
+use bevy::render::camera::OrthographicProjection;
+use bevy::{prelude::*, render::draw::OutsideFrustum, sprite::SpriteSettings};
+
+struct Bar;
+struct PrintTimer(Timer);
+
+fn setup(mut commands: Commands, mut materials: ResMut<Assets<ColorMaterial>>) {
+    commands.spawn_bundle(OrthographicCameraBundle::new_2d());
+
+    let mut transform = Transform::from_xyz(-400.0, 0.0, 0.0);
+    transform.scale = Vec3::new(1.0, 20.0, 1.0);
+
+    commands
+        .spawn_bundle(SpriteBundle {
+            material: materials.add(Color::rgb(0.5, 0.5, 1.0).into()),
+            transform,
+            sprite: Sprite::new(Vec2::new(30.0, 30.0)),
+            ..Default::default()
+        })
+        .insert(Bar);
+}
+
+fn rotate(mut query: Query<&mut Transform, With<Bar>>, time: Res<Time>) {
+    let speed = 5f32;
+    for mut t in query.iter_mut() {
+        t.rotation *= Quat::from_rotation_z(time.delta_seconds() * speed);
+    }
+}
+
+fn travel_camera(
+    keys: Res<Input<KeyCode>>,
+    mut query: Query<&mut Transform, With<OrthographicProjection>>,
+    time: Res<Time>,
+) {
+    let speed = 2f32;
+    for mut t in query.iter_mut() {
+        if keys.pressed(KeyCode::S) {
+            t.scale += time.delta_seconds() * speed;
+        }
+        if keys.pressed(KeyCode::W) {
+            t.scale -= time.delta_seconds() * speed;
+        }
+    }
+}
+
+fn travel(keys: Res<Input<KeyCode>>, mut query: Query<&mut Transform, With<Bar>>, time: Res<Time>) {
+    let speed = 500f32;
+    for mut t in query.iter_mut() {
+        if keys.pressed(KeyCode::Right) {
+            t.translation.x += time.delta_seconds() * speed;
+        }
+        if keys.pressed(KeyCode::Left) {
+            t.translation.x -= time.delta_seconds() * speed;
+        }
+        if keys.pressed(KeyCode::Up) {
+            t.translation.y += time.delta_seconds() * speed;
+        }
+        if keys.pressed(KeyCode::Down) {
+            t.translation.y -= time.delta_seconds() * speed;
+        }
+    }
+}
+
+fn info(
+    time: Res<Time>,
+    mut timer: ResMut<PrintTimer>,
+    query: Query<&Bar, Without<OutsideFrustum>>,
+) {
+    let mut count = 0;
+    for _ in query.iter() {
+        count += 1;
+    }
+    if timer.0.tick(time.delta()).just_finished() {
+        info!("{} sprites on screen", count);
+    }
+}
+
+fn startup() {
+    info!("use the arrow keys to move the bar, 'W' & 'S' to scale the camera");
+}
+
+fn main() {
+    App::new()
+        .insert_resource(SpriteSettings {
+            frustum_culling_enabled: true,
+        })
+        .insert_resource(PrintTimer(Timer::from_seconds(1.0, true)))
+        .add_plugins(DefaultPlugins)
+        .add_startup_system(setup.system())
+        .add_startup_system(startup.system())
+        .add_system(rotate.system())
+        .add_system(travel.system())
+        .add_system(travel_camera.system())
+        .add_system(info.system())
+        .run();
+}

examples/README.md

@@ -83,6 +83,7 @@ Example | File | Description
 Example | File | Description
 --- | --- | ---
 `contributors` | [`2d/contributors.rs`](./2d/contributors.rs) | Displays each contributor as a bouncy bevy-ball!
+`frustum` | [`2d/frustum.rs`](./2d/frustum.rs) | Tests the frustum culling system (only draws sprites on-screen)
 `many_sprites` | [`2d/many_sprites.rs`](./2d/many_sprites.rs) | Displays many sprites in a grid arragement! Used for performance testing.
 `mesh` | [`2d/mesh.rs`](./2d/mesh.rs) | Renders a custom mesh
 `sprite` | [`2d/sprite.rs`](./2d/sprite.rs) | Renders a sprite