From 0c42c33b7ecf29ebddcc84978965c2b22cd5c8d3 Mon Sep 17 00:00:00 2001
From: Elijah Voigt <elijah.caine.mv@gmail.com>
Date: Sat, 13 Dec 2025 22:24:59 -0800
Subject: [PATCH] We can draw a shape!

---
 tetris/src/blocks.rs | 74 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 66 insertions(+), 8 deletions(-)

diff --git a/tetris/src/blocks.rs b/tetris/src/blocks.rs
index fd91145..7ca8236 100644
--- a/tetris/src/blocks.rs
+++ b/tetris/src/blocks.rs
@@ -21,10 +21,16 @@ impl Plugin for BlocksPlugin {
                 Update,
                 updated_shape_asset.run_if(on_message::<AssetEvent<ShapeAsset>>),
             )
-            .add_observer(add_shape);
+            .add_observer(add_shape)
+            .add_observer(add_relative_position)
+            .add_observer(add_grid_position);
     }
 }
 
+const SCALE: f32 = 20.0;
+const X_MAX: usize = 10;
+const Y_MAX: usize = 20;
+
 /// Shape asset
 /// Stores shape data in an asset file, likely toml
 #[derive(Asset, TypePath, Debug, Deserialize)]
@@ -44,14 +50,43 @@ fn default_tint() -> String {
 
 impl ShapeAsset {
     fn as_bundle(&self) -> impl Bundle {
+        // Get shape block's relative positions
         let [a, b, c, d] = self.layout.positions();
 
-        related!(ShapeBlocks[
-            (self.mesh.clone(), self.material.clone(), a),
-            (self.mesh.clone(), self.material.clone(), b),
-            (self.mesh.clone(), self.material.clone(), c),
-            (self.mesh.clone(), self.material.clone(), d),
-        ])
+        (
+            GridPosition { x: 5, y: 5 }, // TEMP
+            related!(ShapeBlocks[
+                (self.mesh.clone(), self.material.clone(), a),
+                (self.mesh.clone(), self.material.clone(), b),
+                (self.mesh.clone(), self.material.clone(), c),
+                (self.mesh.clone(), self.material.clone(), d),
+            ])
+        )
+    }
+}
+
+/// The main play area grid coordinates
+#[derive(Component)]
+#[require(Transform)]
+struct GridPosition {
+    pub x: usize,
+    pub y: usize,
+}
+
+impl GridPosition {
+    fn with_relative_offset(&self, other: &RelativePosition) -> GridPosition {
+        GridPosition {
+            x: self.x.checked_add_signed(other.x).unwrap(),
+            y: self.y.checked_add_signed(other.y).unwrap(),
+        }
+    }
+}
+
+impl Into<Vec3> for &GridPosition {
+    fn into(self) -> Vec3 {
+        let x = (self.x as f32 * SCALE) - ((X_MAX / 2) as f32 * SCALE);
+        let y = (self.y as f32 * SCALE) - ((Y_MAX / 2) as f32 * SCALE);
+        Vec3::new(x, y, 0.0)
     }
 }
 
@@ -135,7 +170,7 @@ impl AssetLoader for ShapeAssetLoader {
         let parsed = toml::from_slice::<ShapeAsset>(bytes.as_slice())?;
         let mesh = {
             // https://docs.rs/bevy/latest/bevy/asset/struct.LoadContext.html#method.add_labeled_asset
-            let m: Mesh = Rectangle::new(100.0, 100.0).into();
+            let m: Mesh = Rectangle::new(SCALE, SCALE).into();
             let h: Handle<Mesh> =
                 load_context.add_labeled_asset(format!("{}#mesh", load_context.asset_path()), m);
             Mesh2d(h)
@@ -211,6 +246,7 @@ fn add_shape(
     commands.entity(event.entity).insert(shape.as_bundle());
 }
 
+/// When a shape asset is updated, propogate other required changes
 fn updated_shape_asset(
     mut messages: MessageReader<AssetEvent<ShapeAsset>>,
     query: Query<&AssetComponent<ShapeAsset>>,
@@ -228,3 +264,25 @@ fn updated_shape_asset(
         AssetEvent::LoadedWithDependencies { id } => debug!("Asset lodaed: {id:?}"),
     })
 }
+
+/// What to do when a relative position is added to a block
+fn add_relative_position(
+    event: On<Add, RelativePosition>,
+    relative_positions: Query<&RelativePosition>,
+    blocks: Query<&ShapeBlock>,
+    grid_positions: Query<&GridPosition>,
+    mut commands: Commands,
+) {
+    let parent_shape = blocks.get(event.entity).unwrap();
+    let rp = relative_positions.get(event.entity).unwrap();
+    let gp = grid_positions.get(parent_shape.0).unwrap();
+    commands.entity(event.entity).insert(gp.with_relative_offset(rp));
+}
+
+fn add_grid_position(
+    event: On<Add, GridPosition>,
+    mut query: Query<(&GridPosition, &mut Transform)>,
+) {
+    let (gp, mut t) = query.get_mut(event.entity).unwrap();
+    t.translation = gp.into();
+}