units testing

game/main/src/utlis/tile_selection_plugin.rs

@@ -0,0 +1,62 @@
+use bevy::{prelude::*, window::PrimaryWindow};
+use bevy_rapier3d::{plugin::RapierContext, prelude::QueryFilter};
+use shared::{
+	resources::{TileContact, TileUnderCursor},
+	tags::MainCamera,
+};
+use world_generation::{hex_utils::HexCoord, prelude::Map, states::GeneratorState};
+pub struct TileSelectionPlugin;
+
+impl Plugin for TileSelectionPlugin {
+	fn build(&self, app: &mut App) {
+		app.init_resource::<TileUnderCursor>();
+		app.add_systems(
+			PreUpdate,
+			update_tile_under_cursor.run_if(in_state(GeneratorState::Idle)),
+		);
+	}
+}
+
+fn update_tile_under_cursor(
+	cam_query: Query<(&GlobalTransform, &Camera), With<MainCamera>>,
+	window: Query<&Window, With<PrimaryWindow>>,
+	rapier_context: Res<RapierContext>,
+	map: Res<Map>,
+	mut tile_under_cursor: ResMut<TileUnderCursor>,
+) {
+	let win = window.single();
+	let (cam_transform, camera) = cam_query.single();
+	let Some(cursor_pos) = win.cursor_position() else {
+		return;
+	};
+
+	let Some(cam_ray) = camera.viewport_to_world(cam_transform, cursor_pos) else {
+		return;
+	};
+
+	let collision = rapier_context.cast_ray(
+		cam_ray.origin,
+		cam_ray.direction.into(),
+		500.,
+		true,
+		QueryFilter::only_fixed(),
+	);
+
+	if let Some((_e, dist)) = collision {
+		let contact_point = cam_ray.get_point(dist);
+		let contact_coord = HexCoord::from_world_pos(contact_point);
+		//todo: handle correct tile detection when contacting a tile from the side
+		if !map.is_in_bounds(&contact_coord) {
+			tile_under_cursor.0 = None;
+			return;
+		}
+		let surface = map.sample_height(&contact_coord);
+		tile_under_cursor.0 = Some(TileContact::new(
+			contact_coord,
+			contact_point,
+			contact_coord.to_world(surface),
+		));
+	} else {
+		tile_under_cursor.0 = None;
+	}
+}