1 files changed, 66 insertions, 0 deletions
diff --git a/src/sim/world.rs b/src/sim/world.rs
new file mode 100644
index 0000000..3c7b05b
--- /dev/null
+++ b/src/sim/world.rs
@@ -0,0 +1,66 @@
+use std::collections::HashMap;
+
+use crate::{
+    config::CHUNK_SIZE,
+    sim::{cell::Cell, chunk::Chunk},
+};
+
+pub struct World {
+    pub chunks: Vec<Chunk>,
+    // TODO FxHashMap?
+    pub chunk_position_to_chunk_idx: HashMap<(i32, i32), usize>,
+}
+
+impl World {
+    #[inline]
+    pub fn split_game_position(x: i32, y: i32) -> ((i32, i32), (u8, u8)) {
+        (
+            (
+                // TODO is this cast expensive?
+                x.div_euclid(CHUNK_SIZE as i32),
+                y.div_euclid(CHUNK_SIZE as i32),
+            ),
+            (
+                x.rem_euclid(CHUNK_SIZE as i32) as u8,
+                y.rem_euclid(CHUNK_SIZE as i32) as u8,
+            ),
+        )
+    }
+
+    // VERY EXPENSIVE
+    pub fn get_cell_from_game_position(&self, x: i32, y: i32) -> Option<Cell> {
+        let ((cx, cy), (dx, dy)) = World::split_game_position(x, y);
+        self.chunk_position_to_chunk_idx
+            .get(&(cx, cy))
+            .map(|&idx| self.chunks[idx].get_cell_at_local_position(dx, dy))
+    }
+
+    // VERY EXPENSIVE
+    pub fn set_cell_from_game_position(&mut self, x: i32, y: i32, cell: Cell) -> () {
+        let ((cx, cy), (dx, dy)) = World::split_game_position(x, y);
+        if let Some(&idx) = self.chunk_position_to_chunk_idx.get(&(cx, cy)) {
+            self.chunks[idx].set_cell_at_local_position(dx, dy, cell);
+        }
+    }
+
+    pub fn insert(&mut self, x: i32, y: i32, chunk: Chunk) -> () {
+        self.chunk_position_to_chunk_idx
+            .insert((x, y), self.chunks.len());
+        self.chunks.push(chunk);
+    }
+
+    pub fn from_default_size() -> Self {
+        let mut world = World {
+            chunks: Vec::new(),
+            chunk_position_to_chunk_idx: HashMap::new(),
+        };
+
+        for y in -10..10 {
+            for x in -10..10 {
+                world.insert(x, y, Chunk::void());
+            }
+        }
+
+        world
+    }
+}