should be all working now

Cargo.toml

@@ -10,3 +10,4 @@ log = "0.4"
 env_logger = "0.10"
 strum = { version = "0.24", features = ["derive"] }
 glam = { version = "0.22", features = ["debug-glam-assert", "mint", "fast-math"] }
+hashbrown = "0.13"

src/game/world.rs

@@ -1,6 +1,6 @@
 use glam::{Vec2, IVec2};
 use glium::Display;
-use std::collections::HashMap;
+use hashbrown::HashMap;
 use crate::game::options::GameOptions;
 
 mod chunk;
@@ -50,16 +50,20 @@ impl World {
         if !self.chunks.contains_key(&position) {
           self.chunks.insert(position, Chunk::new(position));
         }
+        {
+          //we only need mutable reference here:
           let chunk = self.chunks.get_mut(&position).unwrap();
           if x == 0 || z == 0 || x == render_dist || z == render_dist {
             chunk.desired = ChunkState::Loaded;
           } else {
             chunk.desired = ChunkState::Rendered;
           } 
-        if matches!(chunk.state, ChunkState::Nothing) {
-          self.thread.queue_load(position);
         }
-        if matches!(chunk.state, ChunkState::Loaded) && matches!(chunk.desired, ChunkState::Rendered) {
+        //borrow chunk immutably
+        let chunk = self.chunks.get(&position).unwrap();
+        if matches!(chunk.state, ChunkState::Nothing) && matches!(chunk.desired, ChunkState::Loaded | ChunkState::Rendered) {
+          self.thread.queue_load(position);
+        } else if matches!(chunk.state, ChunkState::Loaded) && matches!(chunk.desired, ChunkState::Rendered) {
           fn all_some<'a>(x: [Option<&'a Chunk>; 4]) -> Option<[&'a Chunk; 4]> {
             Some([x[0]?, x[1]?, x[2]?, x[3]?])
           }
@@ -70,33 +74,43 @@ impl World {
               neighbors[2].block_data.is_some() &&
               neighbors[3].block_data.is_some()
             } {
-              self.thread.queue_mesh(chunk, neighbors);
+              self.thread.queue_mesh(
+                position,
+                chunk.block_data.clone().unwrap(), 
+                [
+                  neighbors[0].block_data.clone().unwrap(),
+                  neighbors[1].block_data.clone().unwrap(),
+                  neighbors[2].block_data.clone().unwrap(),
+                  neighbors[3].block_data.clone().unwrap(),
+                ]
+              );
             }
           }
         }
       }
     }
 
-    //Handle Unload
-    self.chunks.retain(|_, chunk| !matches!(chunk.desired, ChunkState::Unload));
-    
-    //State downgrades
-    for (_, chunk) in &mut self.chunks {
+    //Unloads and state downgrades
+    self.chunks.retain(|_, chunk| {
       match chunk.desired {
+        // Chunk unload
+        ChunkState::Unload => false,
         // Any => Nothing downgrade
         ChunkState::Nothing => {
           chunk.block_data = None;
           chunk.mesh = None;
           chunk.state = ChunkState::Nothing;
+          true
         },
         //Render => Loaded downgrade
         ChunkState::Loaded if matches!(chunk.state, ChunkState::Rendering | ChunkState::Rendered) => {
           chunk.mesh = None;
           chunk.state = ChunkState::Loaded;
+          true
         },
-        _ => ()
-      }
+        _ => true
       }
+    });
     //Apply changes from threads
     self.thread.apply_tasks(&mut self.chunks, display);
   }

src/game/world/chunk.rs

@@ -17,7 +17,7 @@ pub enum ChunkState {
   Rendered,
 }
 
-pub type ChunkData = [[[Block; CHUNK_SIZE]; CHUNK_HEIGHT]; CHUNK_SIZE];
+pub type ChunkData = Box<[[[Block; CHUNK_SIZE]; CHUNK_HEIGHT]; CHUNK_SIZE]>;
 
 pub struct Chunk {
   pub position: IVec2,

src/game/world/thread.rs

@@ -1,10 +1,7 @@
 use glam::IVec2;
 use glium::{Display, VertexBuffer, IndexBuffer, index::PrimitiveType};
-use std::{
-  thread::{self, JoinHandle}, 
-  collections::HashMap,
-  mem
-};
+use std::{mem, thread::{self, JoinHandle}};
+use hashbrown::HashMap;
 use super::chunk::{Chunk, ChunkData, ChunkState};
 use crate::game::shaders::chunk::Vertex as ChunkVertex;
 
@@ -38,20 +35,12 @@ impl WorldThreading {
       log::warn!("load: discarded {}, reason: new task started", position);
     }
   }
-  pub fn queue_mesh(&mut self, chunk: &Chunk, neighbors: [&Chunk; 4]) {
-    let position = chunk.position;
-    let data = chunk.block_data.expect("Chunk has no mesh!");
-    let neighbor_data = [
-      neighbors[0].block_data.expect("Chunk has no mesh!"),
-      neighbors[1].block_data.expect("Chunk has no mesh!"),
-      neighbors[2].block_data.expect("Chunk has no mesh!"),
-      neighbors[3].block_data.expect("Chunk has no mesh!"),
-    ];
+  pub fn queue_mesh(&mut self, position: IVec2, chunk: ChunkData, neighbor_data: [ChunkData; 4]) {
     let handle = thread::spawn(move || {
-      mesh_gen::generate_mesh(position, data, neighbor_data)
+      mesh_gen::generate_mesh(position, chunk, neighbor_data)
     });
-    if self.mesh_tasks.insert(chunk.position, Some(handle)).is_some() {
-      log::warn!("mesh: discarded {}, reason: new task started", chunk.position);
+    if self.mesh_tasks.insert(position, Some(handle)).is_some() {
+      log::warn!("mesh: discarded {}, reason: new task started", position);
     }
   }
   pub fn apply_tasks(&mut self, chunks: &mut HashMap<IVec2, Chunk>, display: &Display) {

src/game/world/thread/world_gen.rs

@@ -4,5 +4,5 @@ use crate::game::{
 };
 
 pub fn generate_chunk() -> ChunkData {
-  [[[Block::Stone; CHUNK_SIZE]; CHUNK_HEIGHT]; CHUNK_SIZE]
+  Box::new([[[Block::Stone; CHUNK_SIZE]; CHUNK_HEIGHT]; CHUNK_SIZE])
 }