grid system basics

src/grid.rs

@@ -1,3 +1,70 @@
 use bevy::prelude::*;
 
+use crate::{animation::transform::AnimatedTransform, card::drag::MousePosition};
+
 pub struct GridPlugin;
+
+impl Plugin for GridPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, setup_grid)
+            .add_systems(Update, snap_grid_elements);
+    }
+}
+
+#[derive(Component)]
+struct Grid {
+    bounds: Rect,
+    columns: usize,
+    rows: usize,
+    elements: Vec<Option<Entity>>,
+}
+
+impl Grid {
+    pub fn square(start: Vec2, side: f32, cells: usize) -> Self {
+        let mut elements: Vec<Option<Entity>> = Vec::new();
+        elements.resize(cells * cells, None);
+        Grid {
+            bounds: Rect {
+                min: start,
+                max: start + Vec2::new(side * (cells as f32), side * (cells as f32)),
+            },
+            columns: cells,
+            rows: cells,
+            elements: elements,
+        }
+    }
+
+    pub fn get_position(&self, index: usize) -> Vec3 {
+        let x = index % self.columns;
+        let y = (index / self.columns).clamp(0, self.rows - 1);
+
+        (self.bounds.min + self.cell_size() / 2. + vec2(x as f32, y as f32) * self.cell_size())
+            .extend(0.)
+    }
+
+    fn cell_size(&self) -> Vec2 {
+        self.bounds.size() / vec2(self.columns as f32, -(self.rows as f32))
+    }
+}
+
+fn setup_grid(mut commands: Commands) {
+    commands.spawn(Grid::square(vec2(-244., 192.), 80., 5));
+}
+
+fn snap_grid_elements(
+    mut transform_query: Query<&mut AnimatedTransform>,
+    grid_query: Query<&Grid>,
+) {
+    for grid in grid_query {
+        for (index, el) in grid.elements.iter().enumerate() {
+            let Some(entity) = el else {
+                continue;
+            };
+            let Ok(mut transform) = transform_query.get_mut(entity.clone()) else {
+                continue;
+            };
+
+            transform.translation = grid.get_position(index);
+        }
+    }
+}

src/main.rs

@@ -15,6 +15,7 @@ fn main() {
             card::CardPlugin,
             DefaultPlugins,
             dev_tools::DevToolsPlugin,
+            grid::GridPlugin,
             turns::TurnSystemPlugin,
         ))
         .add_systems(Startup, setup)