birches and "Acalok" Trees

assets/world/manifests/birch.ron

@@ -0,0 +1,52 @@
+(
+    [
+        (
+            specifier: "world.tree.birch.1",
+            center: (12, 9, 10)
+        ),
+        (
+            specifier: "world.tree.birch.2",
+            center: (12, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.3",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.4",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.5",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.6",
+            center: (9, 9, 10)
+        ),
+        (
+            specifier: "world.tree.birch.7",
+            center: (10, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.8",
+            center: (9, 9, 10)
+        ),
+        (
+            specifier: "world.tree.birch.9",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.10",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.11",
+            center: (9, 10, 10)
+        ),
+        (
+            specifier: "world.tree.birch.12",
+            center: (9, 10, 10)
+        ),
+    ]
+)

world/src/block/natural.rs

@@ -64,6 +64,7 @@ pub fn structure_gen<'a>(
             ForestKind::Savannah => &ACACIAS,
             ForestKind::Oak if QUIRKY_RAND.get(st_seed) % 16 == 7 => &OAK_STUMPS,
             ForestKind::Oak if QUIRKY_RAND.get(st_seed) % 8 == 7 => &FRUIT_TREES,
+            ForestKind::Oak if QUIRKY_RAND.get(st_seed) % 14 == 7 => &BIRCHES,
             ForestKind::Oak => &OAKS,
             ForestKind::Pine => &PINES,
             ForestKind::SnowPine => &SNOW_PINES,
@@ -119,6 +120,7 @@ lazy_static! {
     pub static ref SNOW_PINES: Vec<Arc<Structure>> = load_structures("snow_pines");
     pub static ref ACACIAS: Vec<Arc<Structure>> = load_structures("acacias");
     pub static ref FRUIT_TREES: Vec<Arc<Structure>> = load_structures("fruit_trees");
+    pub static ref BIRCHES: Vec<Arc<Structure>> = load_structures("birch");
     pub static ref MANGROVE_TREES: Vec<Arc<Structure>> = load_structures("mangrove_trees");
     pub static ref QUIRKY: Vec<Arc<Structure>> = load_structures("quirky");
     pub static ref QUIRKY_DRY: Vec<Arc<Structure>> = load_structures("quirky_dry");