camera handling

src/main.rs

@@ -1,40 +1,95 @@
-use crate::shape_follow::ShapeFollowPlugin;
-use crate::utils::get_cursor_world_pos;
-use bevy::color::palettes::basic::{RED, WHITE};
+use crate::camera::CameraPlugin;
+use crate::logic_sim::LogicSimPlugin;
 use bevy::prelude::*;
 
 mod fps_counter;
+mod logic_sim;
 mod shape_follow;
 mod utils;
 fn main() {
     App::new()
         .add_plugins((
             DefaultPlugins,
-            fps_counter::FpsCounterPlugin,
-            ShapeFollowPlugin,
+            CameraPlugin,
+            // fps_counter::FpsCounterPlugin,
+            // ShapeFollowPlugin,
+            LogicSimPlugin,
         ))
-        .add_systems(Startup, (setup_camera, change_window_mode))
-        .add_systems(Update, draw_cursor)
         .run();
 }
 
-const CURSOR_SIZE: f32 = 10.0;
-fn change_window_mode(mut windows: Query<&mut Window>) {
-    let mut window = windows.single_mut();
-    // window.mode = WindowMode::Fullscreen(MonitorSelection::Current);
-    window.present_mode = bevy::window::PresentMode::AutoNoVsync;
-}
-fn setup_camera(mut commands: Commands) {
-    commands.spawn(Camera2d);
-}
-fn draw_cursor(
-    camera_query: Single<(&Camera, &GlobalTransform)>,
-    windows: Query<&Window>,
-    mut gizmos: Gizmos,
-) {
-    let Some(point) = get_cursor_world_pos(camera_query, windows) else {
-        return;
-    };
+mod camera {
+    use crate::utils::get_cursor_world_pos;
+    use bevy::color::palettes::basic::WHITE;
+    use bevy::input::common_conditions::input_pressed;
+    use bevy::input::mouse::{AccumulatedMouseMotion, AccumulatedMouseScroll};
+    use bevy::prelude::*;
 
-    gizmos.circle_2d(point, CURSOR_SIZE, WHITE);
+    const CURSOR_SIZE: f32 = 10.0;
+    fn change_window_mode(mut windows: Query<&mut Window>) {
+        let mut window = windows.single_mut();
+        // window.mode = WindowMode::Fullscreen(MonitorSelection::Current);
+        window.present_mode = bevy::window::PresentMode::AutoNoVsync;
+    }
+
+    pub struct CameraPlugin;
+    impl Plugin for CameraPlugin {
+        fn build(&self, app: &mut App) {
+            app.insert_resource(CameraSettings {
+                zoom_speed: 0.05,
+                orthographic_zoom_range: 0.01..1000.0,
+            })
+            .add_systems(Startup, (change_window_mode, setup_camera))
+            .add_systems(Update, draw_cursor)
+            .add_systems(Update, zoom)
+            .add_systems(Update, handle_pan.run_if(input_pressed(MouseButton::Right)));
+        }
+    }
+    fn setup_camera(mut commands: Commands) {
+        commands.spawn(Camera2d);
+    }
+    fn draw_cursor(
+        camera_query: Single<(&Camera, &GlobalTransform)>,
+        windows: Query<&Window>,
+        mut gizmos: Gizmos,
+    ) {
+        let Some(point) = get_cursor_world_pos(camera_query, windows) else {
+            return;
+        };
+
+        gizmos.circle_2d(point, CURSOR_SIZE, WHITE);
+    }
+
+    fn handle_pan(
+        mut camera: Single<(&mut Transform, &OrthographicProjection), With<Camera2d>>,
+        move_event: Res<AccumulatedMouseMotion>,
+    ) {
+        let (camera, camera_projection) = &mut *camera;
+        camera.translation.x -= move_event.delta.x * camera_projection.scale;
+        camera.translation.y += move_event.delta.y * camera_projection.scale;
+        println!("{:?} {:?}", camera_projection.scale, move_event.delta);
+    }
+    fn zoom(
+        mut camera: Single<&mut OrthographicProjection, With<Camera2d>>,
+        camera_settings: Res<CameraSettings>,
+        mouse_wheel_input: Res<AccumulatedMouseScroll>,
+    ) {
+        // We want scrolling up to zoom in, decreasing the scale, so we negate the delta.
+        let delta_zoom = -mouse_wheel_input.delta.y * camera_settings.zoom_speed;
+        // When changing scales, logarithmic changes are more intuitive.
+        // To get this effect, we add 1 to the delta, so that a delta of 0
+        // results in no multiplicative effect, positive values result in a multiplicative increase,
+        // and negative values result in multiplicative decreases.
+        let multiplicative_zoom = 1. + delta_zoom;
+
+        camera.scale = (camera.scale * multiplicative_zoom).clamp(
+            camera_settings.orthographic_zoom_range.start,
+            camera_settings.orthographic_zoom_range.end,
+        );
+    }
+    #[derive(Resource)]
+    pub struct CameraSettings {
+        zoom_speed: f32,
+        orthographic_zoom_range: std::ops::Range<f32>,
+    }
 }