ChristopherBiscardi · August 27, 2024 23:43 · Aug 27, 2024
diff --git a/changes.diff b/changes.diff
@@ -0,0 +1,42 @@
+diff --git a/examples/mouse_to_tile.rs b/examples/mouse_to_tile.rs
+index 9ea13ec..3b03fc0 100644
+--- a/examples/mouse_to_tile.rs
++++ b/examples/mouse_to_tile.rs
+@@ -1,4 +1,8 @@
+-use bevy::{color::palettes, math::Vec4Swizzles};
++use bevy::{
++    color::palettes::{self, tailwind::GREEN_400},
++    math::Vec4Swizzles,
++    sprite::MaterialMesh2dBundle,
++};
+ use bevy::{ecs::system::Resource, prelude::*};
+ use bevy_ecs_tilemap::prelude::*;
+ mod helpers;
+@@ -325,6 +329,9 @@ fn highlight_tile_labels(
+     highlighted_tiles_q: Query<Entity, With<HighlightedLabel>>,
+     tile_label_q: Query<&TileLabel>,
+     mut text_q: Query<&mut Text>,
++    input: Res<ButtonInput<MouseButton>>,
++    mut meshes: ResMut<Assets<Mesh>>,
++    mut materials: ResMut<Assets<ColorMaterial>>,
+ ) {
+     // Un-highlight any previously highlighted tile labels.
+     for highlighted_tile_entity in highlighted_tiles_q.iter() {
+@@ -357,6 +364,17 @@ fn highlight_tile_labels(
+         {
+             // Highlight the relevant tile's label
+             if let Some(tile_entity) = tile_storage.get(&tile_pos) {
++                if input.just_pressed(MouseButton::Left) {
++                    dbg!(cursor_in_map_pos, cursor_pos, tile_pos);
++                    let pos = tile_pos.center_in_world(grid_size, map_type);
++                    let pos = map_transform.compute_matrix() * Vec4::from((pos, 0., 1.));
++                    commands.spawn(MaterialMesh2dBundle {
++                        mesh: meshes.add(Circle { radius: 2.0 }).into(),
++                        material: materials.add(Color::from(GREEN_400)),
++                        transform: Transform::from_xyz(pos.x, pos.y, 2.0),
++                        ..default()
++                    });
++                }
+                 if let Ok(label) = tile_label_q.get(tile_entity) {
+                     if let Ok(mut tile_text) = text_q.get_mut(label.0) {
+                         for section in tile_text.sections.iter_mut() {
diff --git a/main.rs b/main.rs
@@ -0,0 +1,428 @@
+use bevy::{
+    color::palettes::{self, tailwind::GREEN_400},
+    math::Vec4Swizzles,
+    sprite::MaterialMesh2dBundle,
+};
+use bevy::{ecs::system::Resource, prelude::*};
+use bevy_ecs_tilemap::prelude::*;
+mod helpers;
+use helpers::camera::movement as camera_movement;
+
+// Press SPACE to change map type. Hover over mouse tiles to highlight their labels.
+//
+// The most important function here is the `highlight_tile_labels` systems, which shows how to
+// convert a mouse cursor position into a tile position.
+
+// You can increase the MAP_SIDE_LENGTH, in order to test that mouse picking works for larger maps,
+// but just make sure that you run in release mode (`cargo run --release --example mouse_to_tile`)
+// otherwise things might be too slow.
+const MAP_SIDE_LENGTH_X: u32 = 4;
+const MAP_SIDE_LENGTH_Y: u32 = 4;
+
+const TILE_SIZE_SQUARE: TilemapTileSize = TilemapTileSize { x: 50.0, y: 50.0 };
+const TILE_SIZE_ISO: TilemapTileSize = TilemapTileSize { x: 100.0, y: 50.0 };
+const TILE_SIZE_HEX_ROW: TilemapTileSize = TilemapTileSize { x: 50.0, y: 58.0 };
+const TILE_SIZE_HEX_COL: TilemapTileSize = TilemapTileSize { x: 58.0, y: 50.0 };
+const GRID_SIZE_SQUARE: TilemapGridSize = TilemapGridSize { x: 50.0, y: 50.0 };
+const GRID_SIZE_HEX_ROW: TilemapGridSize = TilemapGridSize { x: 50.0, y: 58.0 };
+const GRID_SIZE_HEX_COL: TilemapGridSize = TilemapGridSize { x: 58.0, y: 50.0 };
+const GRID_SIZE_ISO: TilemapGridSize = TilemapGridSize { x: 100.0, y: 50.0 };
+
+#[derive(Deref, Resource)]
+pub struct TileHandleHexRow(Handle<Image>);
+
+#[derive(Deref, Resource)]
+pub struct TileHandleHexCol(Handle<Image>);
+
+#[derive(Deref, Resource)]
+pub struct TileHandleSquare(Handle<Image>);
+
+#[derive(Deref, Resource)]
+pub struct TileHandleIso(Handle<Image>);
+
+#[derive(Deref, Resource)]
+pub struct FontHandle(Handle<Font>);
+
+impl FromWorld for TileHandleHexCol {
+    fn from_world(world: &mut World) -> Self {
+        let asset_server = world.resource::<AssetServer>();
+        Self(asset_server.load("bw-tile-hex-col.png"))
+    }
+}
+impl FromWorld for TileHandleHexRow {
+    fn from_world(world: &mut World) -> Self {
+        let asset_server = world.resource::<AssetServer>();
+        Self(asset_server.load("bw-tile-hex-row.png"))
+    }
+}
+impl FromWorld for TileHandleIso {
+    fn from_world(world: &mut World) -> Self {
+        let asset_server = world.resource::<AssetServer>();
+        Self(asset_server.load("bw-tile-iso.png"))
+    }
+}
+impl FromWorld for TileHandleSquare {
+    fn from_world(world: &mut World) -> Self {
+        let asset_server = world.resource::<AssetServer>();
+        Self(asset_server.load("bw-tile-square.png"))
+    }
+}
+impl FromWorld for FontHandle {
+    fn from_world(world: &mut World) -> Self {
+        let asset_server = world.resource::<AssetServer>();
+        Self(asset_server.load("fonts/FiraSans-Bold.ttf"))
+    }
+}
+
+// Generates the initial tilemap, which is a square grid.
+fn spawn_tilemap(mut commands: Commands, tile_handle_square: Res<TileHandleSquare>) {
+    commands.spawn(Camera2dBundle::default());
+
+    let map_size = TilemapSize {
+        x: MAP_SIDE_LENGTH_X,
+        y: MAP_SIDE_LENGTH_Y,
+    };
+
+    let mut tile_storage = TileStorage::empty(map_size);
+    let tilemap_entity = commands.spawn_empty().id();
+    let tilemap_id = TilemapId(tilemap_entity);
+
+    fill_tilemap(
+        TileTextureIndex(0),
+        map_size,
+        tilemap_id,
+        &mut commands,
+        &mut tile_storage,
+    );
+
+    let tile_size = TILE_SIZE_SQUARE;
+    let grid_size = GRID_SIZE_SQUARE;
+    let map_type = TilemapType::Square;
+
+    commands.entity(tilemap_entity).insert(TilemapBundle {
+        grid_size,
+        size: map_size,
+        storage: tile_storage,
+        texture: TilemapTexture::Single(tile_handle_square.clone()),
+        tile_size,
+        map_type,
+        transform: get_tilemap_center_transform(&map_size, &grid_size, &map_type, 0.0),
+        ..Default::default()
+    });
+}
+
+#[derive(Component)]
+struct TileLabel(Entity);
+
+// Generates tile position labels of the form: `(tile_pos.x, tile_pos.y)`
+fn spawn_tile_labels(
+    mut commands: Commands,
+    tilemap_q: Query<(&Transform, &TilemapType, &TilemapGridSize, &TileStorage)>,
+    tile_q: Query<&mut TilePos>,
+    font_handle: Res<FontHandle>,
+) {
+    let text_style = TextStyle {
+        font: font_handle.clone(),
+        font_size: 20.0,
+        color: Color::BLACK,
+    };
+    let text_justify = JustifyText::Center;
+    for (map_transform, map_type, grid_size, tilemap_storage) in tilemap_q.iter() {
+        for tile_entity in tilemap_storage.iter().flatten() {
+            let tile_pos = tile_q.get(*tile_entity).unwrap();
+            let tile_center = tile_pos.center_in_world(grid_size, map_type).extend(1.0);
+            let transform = *map_transform * Transform::from_translation(tile_center);
+
+            let label_entity = commands
+                .spawn(Text2dBundle {
+                    text: Text::from_section(
+                        format!("{}, {}", tile_pos.x, tile_pos.y),
+                        text_style.clone(),
+                    )
+                    .with_justify(text_justify),
+                    transform,
+                    ..default()
+                })
+                .id();
+            commands
+                .entity(*tile_entity)
+                .insert(TileLabel(label_entity));
+        }
+    }
+}
+
+#[derive(Component)]
+pub struct MapTypeLabel;
+
+// Generates the map type label: e.g. `Square { diagonal_neighbors: false }`
+fn spawn_map_type_label(
+    mut commands: Commands,
+    font_handle: Res<FontHandle>,
+    windows: Query<&Window>,
+    map_type_q: Query<&TilemapType>,
+) {
+    let text_style = TextStyle {
+        font: font_handle.clone(),
+        font_size: 20.0,
+        color: Color::BLACK,
+    };
+    let text_alignment = JustifyText::Center;
+
+    for window in windows.iter() {
+        for map_type in map_type_q.iter() {
+            // Place the map type label somewhere in the top left side of the screen
+            let transform = Transform {
+                translation: Vec2::new(-0.5 * window.width() / 2.0, 0.8 * window.height() / 2.0)
+                    .extend(1.0),
+                ..Default::default()
+            };
+            commands.spawn((
+                Text2dBundle {
+                    text: Text::from_section(format!("{map_type:?}"), text_style.clone())
+                        .with_justify(text_alignment),
+                    transform,
+                    ..default()
+                },
+                MapTypeLabel,
+            ));
+        }
+    }
+}
+
+// Swaps the map type, when user presses SPACE
+#[allow(clippy::too_many_arguments)]
+fn swap_map_type(
+    mut tilemap_query: Query<(
+        &mut Transform,
+        &TilemapSize,
+        &mut TilemapType,
+        &mut TilemapGridSize,
+        &mut TilemapTexture,
+        &mut TilemapTileSize,
+    )>,
+    keyboard_input: Res<ButtonInput<KeyCode>>,
+    tile_label_q: Query<
+        (&TileLabel, &TilePos),
+        (With<TileLabel>, Without<MapTypeLabel>, Without<TilemapType>),
+    >,
+    mut map_type_label_q: Query<&mut Text, With<MapTypeLabel>>,
+    mut transform_q: Query<&mut Transform, Without<TilemapType>>,
+    tile_handle_square: Res<TileHandleSquare>,
+    tile_handle_hex_row: Res<TileHandleHexRow>,
+    tile_handle_hex_col: Res<TileHandleHexCol>,
+    tile_handle_iso: Res<TileHandleIso>,
+) {
+    if keyboard_input.just_pressed(KeyCode::Space) {
+        for (
+            mut map_transform,
+            map_size,
+            mut map_type,
+            mut grid_size,
+            mut map_texture,
+            mut tile_size,
+        ) in tilemap_query.iter_mut()
+        {
+            match map_type.as_ref() {
+                TilemapType::Square { .. } => {
+                    *map_type = TilemapType::Isometric(IsoCoordSystem::Diamond);
+                    *map_texture = TilemapTexture::Single((*tile_handle_iso).clone());
+                    *tile_size = TILE_SIZE_ISO;
+                    *grid_size = GRID_SIZE_ISO;
+                }
+                TilemapType::Isometric(IsoCoordSystem::Diamond) => {
+                    *map_type = TilemapType::Isometric(IsoCoordSystem::Staggered);
+                    *map_texture = TilemapTexture::Single((*tile_handle_iso).clone());
+                    *tile_size = TILE_SIZE_ISO;
+                    *grid_size = GRID_SIZE_ISO;
+                }
+                TilemapType::Isometric(IsoCoordSystem::Staggered) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::Row);
+                    *map_texture = TilemapTexture::Single((*tile_handle_hex_row).clone());
+                    *tile_size = TILE_SIZE_HEX_ROW;
+                    *grid_size = GRID_SIZE_HEX_ROW;
+                }
+                TilemapType::Hexagon(HexCoordSystem::Row) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::RowEven);
+                }
+                TilemapType::Hexagon(HexCoordSystem::RowEven) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::RowOdd);
+                }
+                TilemapType::Hexagon(HexCoordSystem::RowOdd) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::Column);
+                    *map_texture = TilemapTexture::Single((*tile_handle_hex_col).clone());
+                    *tile_size = TILE_SIZE_HEX_COL;
+                    *grid_size = GRID_SIZE_HEX_COL;
+                }
+                TilemapType::Hexagon(HexCoordSystem::Column) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::ColumnEven);
+                }
+                TilemapType::Hexagon(HexCoordSystem::ColumnEven) => {
+                    *map_type = TilemapType::Hexagon(HexCoordSystem::ColumnOdd);
+                }
+                TilemapType::Hexagon(HexCoordSystem::ColumnOdd) => {
+                    *map_type = TilemapType::Square;
+                    *map_texture = TilemapTexture::Single((*tile_handle_square).clone());
+                    *tile_size = TILE_SIZE_SQUARE;
+                    *grid_size = GRID_SIZE_SQUARE;
+                }
+            }
+
+            *map_transform = get_tilemap_center_transform(map_size, &grid_size, &map_type, 0.0);
+
+            for (label, tile_pos) in tile_label_q.iter() {
+                if let Ok(mut tile_label_transform) = transform_q.get_mut(label.0) {
+                    let tile_center = tile_pos.center_in_world(&grid_size, &map_type).extend(1.0);
+                    *tile_label_transform =
+                        *map_transform * Transform::from_translation(tile_center);
+                }
+            }
+
+            for mut label_text in map_type_label_q.iter_mut() {
+                label_text.sections[0].value = format!("{:?}", map_type.as_ref());
+            }
+        }
+    }
+}
+
+#[derive(Component)]
+struct HighlightedLabel;
+
+#[derive(Resource)]
+pub struct CursorPos(Vec2);
+impl Default for CursorPos {
+    fn default() -> Self {
+        // Initialize the cursor pos at some far away place. It will get updated
+        // correctly when the cursor moves.
+        Self(Vec2::new(-1000.0, -1000.0))
+    }
+}
+
+// We need to keep the cursor position updated based on any `CursorMoved` events.
+pub fn update_cursor_pos(
+    camera_q: Query<(&GlobalTransform, &Camera)>,
+    mut cursor_moved_events: EventReader<CursorMoved>,
+    mut cursor_pos: ResMut<CursorPos>,
+) {
+    for cursor_moved in cursor_moved_events.read() {
+        // To get the mouse's world position, we have to transform its window position by
+        // any transforms on the camera. This is done by projecting the cursor position into
+        // camera space (world space).
+        for (cam_t, cam) in camera_q.iter() {
+            if let Some(pos) = cam.viewport_to_world_2d(cam_t, cursor_moved.position) {
+                *cursor_pos = CursorPos(pos);
+            }
+        }
+    }
+}
+
+// This is where we check which tile the cursor is hovered over.
+fn highlight_tile_labels(
+    mut commands: Commands,
+    cursor_pos: Res<CursorPos>,
+    tilemap_q: Query<(
+        &TilemapSize,
+        &TilemapGridSize,
+        &TilemapType,
+        &TileStorage,
+        &Transform,
+    )>,
+    highlighted_tiles_q: Query<Entity, With<HighlightedLabel>>,
+    tile_label_q: Query<&TileLabel>,
+    mut text_q: Query<&mut Text>,
+    input: Res<ButtonInput<MouseButton>>,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<ColorMaterial>>,
+) {
+    // Un-highlight any previously highlighted tile labels.
+    for highlighted_tile_entity in highlighted_tiles_q.iter() {
+        if let Ok(label) = tile_label_q.get(highlighted_tile_entity) {
+            if let Ok(mut tile_text) = text_q.get_mut(label.0) {
+                for section in tile_text.sections.iter_mut() {
+                    section.style.color = Color::BLACK;
+                }
+                commands
+                    .entity(highlighted_tile_entity)
+                    .remove::<HighlightedLabel>();
+            }
+        }
+    }
+
+    for (map_size, grid_size, map_type, tile_storage, map_transform) in tilemap_q.iter() {
+        // Grab the cursor position from the `Res<CursorPos>`
+        let cursor_pos: Vec2 = cursor_pos.0;
+        // We need to make sure that the cursor's world position is correct relative to the map
+        // due to any map transformation.
+        let cursor_in_map_pos: Vec2 = {
+            // Extend the cursor_pos vec3 by 0.0 and 1.0
+            let cursor_pos = Vec4::from((cursor_pos, 0.0, 1.0));
+            let cursor_in_map_pos = map_transform.compute_matrix().inverse() * cursor_pos;
+            cursor_in_map_pos.xy()
+        };
+        // Once we have a world position we can transform it into a possible tile position.
+        if let Some(tile_pos) =
+            TilePos::from_world_pos(&cursor_in_map_pos, map_size, grid_size, map_type)
+        {
+            // Highlight the relevant tile's label
+            if let Some(tile_entity) = tile_storage.get(&tile_pos) {
+                if input.just_pressed(MouseButton::Left) {
+                    dbg!(cursor_in_map_pos, cursor_pos, tile_pos);
+                    let pos = tile_pos.center_in_world(grid_size, map_type);
+                    let pos = map_transform.compute_matrix() * Vec4::from((pos, 0., 1.));
+                    commands.spawn(MaterialMesh2dBundle {
+                        mesh: meshes.add(Circle { radius: 2.0 }).into(),
+                        material: materials.add(Color::from(GREEN_400)),
+                        transform: Transform::from_xyz(pos.x, pos.y, 2.0),
+                        ..default()
+                    });
+                }
+                if let Ok(label) = tile_label_q.get(tile_entity) {
+                    if let Ok(mut tile_text) = text_q.get_mut(label.0) {
+                        for section in tile_text.sections.iter_mut() {
+                            section.style.color = palettes::tailwind::RED_600.into();
+                        }
+                        commands.entity(tile_entity).insert(HighlightedLabel);
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[derive(SystemSet, Clone, Copy, Hash, PartialEq, Eq, Debug)]
+pub struct SpawnTilemapSet;
+
+fn main() {
+    App::new()
+        .add_plugins(
+            DefaultPlugins
+                .set(WindowPlugin {
+                    primary_window: Some(Window {
+                        title: String::from("Mouse Position to Tile Position"),
+                        ..Default::default()
+                    }),
+                    ..default()
+                })
+                .set(ImagePlugin::default_nearest()),
+        )
+        .init_resource::<CursorPos>()
+        .init_resource::<TileHandleIso>()
+        .init_resource::<TileHandleHexCol>()
+        .init_resource::<TileHandleHexRow>()
+        .init_resource::<TileHandleSquare>()
+        .init_resource::<FontHandle>()
+        .add_plugins(TilemapPlugin)
+        .add_systems(
+            Startup,
+            (spawn_tilemap, apply_deferred)
+                .chain()
+                .in_set(SpawnTilemapSet),
+        )
+        .add_systems(
+            Startup,
+            (spawn_tile_labels, spawn_map_type_label).after(SpawnTilemapSet),
+        )
+        .add_systems(First, (camera_movement, update_cursor_pos).chain())
+        .add_systems(Update, swap_map_type)
+        .add_systems(Update, highlight_tile_labels.after(swap_map_type))
+        .run();
+}