optimize chunk meshing data

engine/world_generation/src/lib.rs

@@ -15,6 +15,7 @@ pub mod prelude {
 	use bevy::render::mesh::MeshVertexAttribute;
 	use bevy::render::render_resource::VertexFormat;
 	use bevy_inspector_egui::InspectorOptions;
+	use rayon::iter::{IntoParallelIterator, IntoParallelRefIterator, ParallelIterator};
 	pub const TEX_MULTI: Vec2 = Vec2::new(1000., 1.);
 
 	pub const HEX_CORNERS: [Vec3; 6] = [
@@ -70,20 +71,20 @@ pub mod prelude {
 
 	#[derive(Clone)]
 	pub struct Chunk {
-		pub heights: [f32; Chunk::SIZE * Chunk::SIZE],
-		pub textures: [[u32; 2]; Chunk::SIZE * Chunk::SIZE],
-		pub moisture: [f32; Chunk::SIZE * Chunk::SIZE],
-		pub temperature: [f32; Chunk::SIZE * Chunk::SIZE],
+		pub heights: [f32; Chunk::AREA],
+		pub textures: [[u32; 2]; Chunk::AREA],
+		pub moisture: [f32; Chunk::AREA],
+		pub temperature: [f32; Chunk::AREA],
 		pub chunk_offset: IVec2,
 	}
 
 	impl Default for Chunk {
 		fn default() -> Self {
 			Self {
-				heights: [0.; Chunk::SIZE * Chunk::SIZE],
-				textures: [[0; 2]; Chunk::SIZE * Chunk::SIZE],
-				moisture: [0.; Chunk::SIZE * Chunk::SIZE],
-				temperature: [0.; Chunk::SIZE * Chunk::SIZE],
+				heights: [0.; Chunk::AREA],
+				textures: [[0; 2]; Chunk::AREA],
+				moisture: [0.; Chunk::AREA],
+				temperature: [0.; Chunk::AREA],
 				chunk_offset: Default::default(),
 			}
 		}
@@ -91,9 +92,74 @@ pub mod prelude {
 
 	impl Chunk {
 		pub const SIZE: usize = 64;
+		pub const AREA: usize = Chunk::SIZE * Chunk::SIZE;
 		pub const WORLD_WIDTH: f32 = Chunk::SIZE as f32 * SHORT_DIAGONAL;
 		pub const WORLD_HEIGHT: f32 = Chunk::SIZE as f32 * 1.5;
 		pub const WORLD_SIZE: Vec2 = Vec2::new(Chunk::WORLD_WIDTH, Chunk::WORLD_HEIGHT);
+
+		pub fn get_pos_z_edge(&self) -> [f32; Chunk::SIZE] {
+			let mut data = [0.; Chunk::SIZE];
+
+			for x in 0..Chunk::SIZE {
+				let idx = x + (Chunk::SIZE - 1) * Chunk::SIZE;
+				data[x] = self.heights[idx];
+			}
+
+			return data;
+		}
+
+		pub fn get_neg_z_edge(&self) -> [f32; Chunk::SIZE] {
+			let mut data = [0.; Chunk::SIZE];
+
+			for x in 0..Chunk::SIZE {
+				data[x] = self.heights[x];
+			}
+
+			return data;
+		}
+
+		pub fn get_pos_x_edge(&self) -> [f32; Chunk::SIZE] {
+			let mut data = [0.; Chunk::SIZE];
+
+			for z in 0..Chunk::SIZE {
+				let idx = (Chunk::SIZE - 1) + z * Chunk::SIZE;
+				data[z] = self.heights[idx];
+			}
+
+			return data;
+		}
+
+		pub fn get_neg_x_edge(&self) -> [f32; Chunk::SIZE] {
+			let mut data = [0.; Chunk::SIZE];
+
+			for z in 0..Chunk::SIZE {
+				let idx = z * Chunk::SIZE;
+				data[z] = self.heights[idx];
+			}
+
+			return data;
+		}
+	}
+
+	pub struct MeshChunkData {
+		pub heights: [f32; Chunk::AREA],
+		pub textures: [[u32; 2]; Chunk::AREA],
+	}
+
+	impl MeshChunkData {
+		pub fn get_neighbors(&self, coord: &HexCoord) -> [f32; 6] {
+			let mut data = [0.; 6];
+			let n_tiles = coord.get_neighbors();
+			for i in 0..6 {
+				let n = n_tiles[i];
+				if !n.is_in_bounds(Chunk::SIZE, Chunk::SIZE) {
+					continue;
+				}
+				data[i] = self.heights[n.to_index(Chunk::SIZE)];
+			}
+
+			return data;
+		}
 	}
 
 	#[derive(Resource, Clone)]
@@ -105,6 +171,17 @@ pub mod prelude {
 	}
 
 	impl Map {
+		pub fn get_chunk_mesh_data(&self, chunk_index: usize) -> MeshChunkData {
+			#[cfg(feature = "tracing")]
+			let _spawn_span = info_span!("Chunk Mesh Data").entered();
+			let chunk = &self.chunks[chunk_index];
+
+			return MeshChunkData {
+				heights: chunk.heights.clone(),
+				textures: chunk.textures.clone(),
+			};
+		}
+
 		pub fn get_neighbors(&self, pos: &HexCoord) -> [Option<f32>; 6] {
 			let mut results: [Option<f32>; 6] = [None; 6];
 			let w = self.width * Chunk::SIZE;