Fixing previous commit.

world/src/lib.rs

@@ -65,7 +65,8 @@ impl World {
         BlockGen::new(self, ColumnGen::new(&self.sim))
     }
 
-    pub fn generate_chunk(&self, chunk_pos: Vec2<i32>) -> (TerrainChunk, ChunkSupplement) {
+    pub fn generate_chunk(&self, chunk_pos: Vec2<i32>,
+                          flag: &AtomicBool) -> Result<(TerrainChunk, ChunkSupplement), ()> {
         let air = Block::empty();
         let stone = Block::new(BlockKind::Dense, Rgb::new(200, 220, 255));
         let water = Block::new(BlockKind::Water, Rgb::new(60, 90, 190));
@@ -81,7 +82,7 @@ impl World {
         {
             Some((base_z, sim_chunk)) => (base_z as i32, sim_chunk),
             None => {
-                return (
+                return Ok((
                     TerrainChunk::new(
                         CONFIG.sea_level as i32,
                         water,
@@ -89,7 +90,7 @@ impl World {
                         TerrainChunkMeta::void(),
                     ),
                     ChunkSupplement::default(),
-                )
+                ))
             }
         };
 
@@ -101,6 +102,7 @@ impl World {
         let mut chunk = TerrainChunk::new(base_z, stone, air, meta);
         for x in 0..TerrainChunkSize::RECT_SIZE.x as i32 {
             for y in 0..TerrainChunkSize::RECT_SIZE.y as i32 {
+                if flag.load(Ordering::Relaxed) { return Err(()) };
                 let wpos2d = Vec2::new(x, y)
                     + Vec2::from(chunk_pos) * TerrainChunkSize::RECT_SIZE.map(|e| e as i32);
 
@@ -151,7 +153,7 @@ impl World {
             },
         };
 
-        (chunk, supplement)
+        Ok((chunk, supplement))
     }
 }