Feature: add coordinates

packages/engine/src/lib.rs

@@ -1 +1,2 @@
 pub mod core;
+pub mod world;

packages/engine/src/world/coordinate.rs

@@ -0,0 +1,190 @@
+use super::{ChunkPosition, CHUNK_SIZE};
+
+pub type WorldUnit = i64;
+pub type ChunkUnit = usize;
+pub type IndexUnit = usize;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Coordinate {
+    /// Coordinates for the entire world.
+    World(WorldUnit, WorldUnit, WorldUnit),
+    /// Coordinates inside of a chunk.
+    Chunk(usize, usize, usize),
+    /// Coordiantes inside of a chunk's index.
+    Index(IndexUnit),
+}
+
+impl Coordinate {
+    pub fn world_to_chunk(
+        x: WorldUnit,
+        y: WorldUnit,
+        z: WorldUnit,
+    ) -> (ChunkUnit, ChunkUnit, ChunkUnit) {
+        let adjust = |value: WorldUnit| {
+            let remainder = value % CHUNK_SIZE as WorldUnit;
+            if remainder < 0 {
+                (remainder + CHUNK_SIZE as WorldUnit) as ChunkUnit
+            } else {
+                remainder as ChunkUnit
+            }
+        };
+
+        (adjust(x), adjust(y), adjust(z))
+    }
+
+    pub fn chunk_to_world(
+        x: ChunkUnit,
+        y: ChunkUnit,
+        z: ChunkUnit,
+        chunk_position: &ChunkPosition,
+    ) -> (WorldUnit, WorldUnit, WorldUnit) {
+        let x = (chunk_position.x * CHUNK_SIZE as i32) as WorldUnit
+            + x as WorldUnit;
+        let y = (chunk_position.y * CHUNK_SIZE as i32) as WorldUnit
+            + y as WorldUnit;
+        let z = (chunk_position.z * CHUNK_SIZE as i32) as WorldUnit
+            + z as WorldUnit;
+
+        (x, y, z)
+    }
+
+    pub fn chunk_to_index(x: ChunkUnit, y: ChunkUnit, z: ChunkUnit) -> usize {
+        x + (y * CHUNK_SIZE) + (z * CHUNK_SIZE * CHUNK_SIZE)
+    }
+
+    pub fn index_to_chunk(index: usize) -> (ChunkUnit, ChunkUnit, ChunkUnit) {
+        let x = index % CHUNK_SIZE;
+        let y = (index / CHUNK_SIZE) % CHUNK_SIZE;
+        let z = index / (CHUNK_SIZE * CHUNK_SIZE);
+        (x, y, z)
+    }
+
+    pub fn to_world(&self, chunk_position: &ChunkPosition) -> Self {
+        match self {
+            Coordinate::World(_, _, _) => *self,
+            Coordinate::Chunk(x, y, z) => {
+                let world_coordinates =
+                    Self::chunk_to_world(*x, *y, *z, chunk_position);
+                Coordinate::World(
+                    world_coordinates.0,
+                    world_coordinates.1,
+                    world_coordinates.2,
+                )
+            }
+            Coordinate::Index(index) => {
+                let chunk_coordinates = Self::index_to_chunk(*index);
+                let world_coordinates = Self::chunk_to_world(
+                    chunk_coordinates.0,
+                    chunk_coordinates.1,
+                    chunk_coordinates.2,
+                    chunk_position,
+                );
+                Coordinate::World(
+                    world_coordinates.0,
+                    world_coordinates.1,
+                    world_coordinates.2,
+                )
+            }
+        }
+    }
+
+    pub fn to_chunk(&self) -> Self {
+        match self {
+            Coordinate::World(x, y, z) => {
+                let chunk_coordinates = Self::world_to_chunk(*x, *y, *z);
+                Coordinate::Chunk(
+                    chunk_coordinates.0,
+                    chunk_coordinates.1,
+                    chunk_coordinates.2,
+                )
+            }
+            Coordinate::Chunk(_, _, _) => *self,
+            Coordinate::Index(index) => {
+                let chunk_coordinates = Self::index_to_chunk(*index);
+                Coordinate::Chunk(
+                    chunk_coordinates.0,
+                    chunk_coordinates.1,
+                    chunk_coordinates.2,
+                )
+            }
+        }
+    }
+
+    pub fn to_index(&self) -> Self {
+        match self {
+            Coordinate::World(x, y, z) => {
+                let chunk_coordinates = Self::world_to_chunk(*x, *y, *z);
+                let index_coordinates = Self::chunk_to_index(
+                    chunk_coordinates.0,
+                    chunk_coordinates.1,
+                    chunk_coordinates.2,
+                );
+                Coordinate::Index(index_coordinates)
+            }
+            Coordinate::Chunk(x, y, z) => {
+                let index_coordinates = Self::chunk_to_index(*x, *y, *z);
+                Coordinate::Index(index_coordinates)
+            }
+            Coordinate::Index(_) => *self,
+        }
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    #[test]
+    fn world_to_chunk() {
+        let world_coord = Coordinate::World(324, 6, -452);
+        let chunk_coord = world_coord.to_chunk();
+
+        assert_eq!(chunk_coord, Coordinate::Chunk(4, 6, 28));
+    }
+
+    #[test]
+    fn world_to_index() {
+        let world_coord = Coordinate::World(-324, 140, 9420);
+        let index_coord = world_coord.to_index();
+
+        assert_eq!(index_coord, Coordinate::Index(12700))
+    }
+
+    #[test]
+    fn chunk_to_world() {
+        let chunk_coord = Coordinate::Chunk(0, 12, 4);
+        let chunk_position = ChunkPosition { x: 0, y: -2, z: 32 };
+        let world_coord = chunk_coord.to_world(&chunk_position);
+
+        assert_eq!(world_coord, Coordinate::World(0, -52, 1028));
+    }
+
+    #[test]
+    fn chunk_to_index() {
+        let chunk_coord = Coordinate::Chunk(4, 15, 31);
+        let index_coord = chunk_coord.to_index();
+
+        assert_eq!(index_coord, Coordinate::Index(32228));
+    }
+
+    #[test]
+    fn index_to_world() {
+        let index_coord = Coordinate::Index(19008);
+        let chunk_position = ChunkPosition {
+            x: -452,
+            y: 17,
+            z: -4,
+        };
+        let world_coord = index_coord.to_world(&chunk_position);
+
+        assert_eq!(world_coord, Coordinate::World(-14464, 562, -110));
+    }
+
+    #[test]
+    fn index_to_chunk() {
+        let index_coord = Coordinate::Index(6473);
+        let chunk_coord = index_coord.to_chunk();
+
+        assert_eq!(chunk_coord, Coordinate::Chunk(9, 10, 6))
+    }
+}

packages/engine/src/world/mod.rs

@@ -0,0 +1,9 @@
+pub mod coordinate;
+
+pub const CHUNK_SIZE: usize = 32;
+
+pub struct ChunkPosition {
+    pub x: i32,
+    pub y: i32,
+    pub z: i32,
+}