Improve biome color handling

src/model/mod.rs

@@ -926,13 +926,15 @@ fn calculate_biome(snapshot: &world::Snapshot, x: i32, z: i32, img: &image::Dyna
     for xx in -1 .. 2 {
         for zz in -1 .. 2 {
             let bi = snapshot.get_biome(x+xx, z+zz);
-            let ix = bi.color_index & 0xFF;
-            let iy = bi.color_index >> 8;
+            let color_index = bi.get_color_index();
+            let ix = color_index & 0xFF;
+            let iy = color_index >> 8;
 
             let ix = min(max(ix, 0), 255);
             let iy = min(max(iy, 0), 255);
 
             let col = img.get_pixel(ix as u32, iy as u32);
+            let col = bi.process_color(col);
             r += col.data[0] as u32;
             g += col.data[1] as u32;
             b += col.data[2] as u32;

src/world/biome.rs

@@ -1,25 +1,46 @@
 
+use image::Rgba;
+
 #[derive(Clone, Copy)]
 pub struct Biome {
     pub id: usize,
     pub temperature: f64,
     pub moisture: f64,
-    pub color_index: usize,
 }
 
 impl Biome {
-    const fn new(id: usize, t: f64, m: f64) -> Biome{
+    const fn new(id: usize, t: f64, m: f64) -> Biome {
         Biome {
             id: id,
             temperature: t,
             moisture: m*t,
-            color_index: (((1.0 - t) * 255.0) as usize) | ((((1.0 - (m*t)) * 255.0) as usize) << 8),
         }
     }
 
     pub fn by_id(id: usize) -> Biome {
         *BY_ID.get(id).unwrap_or(&INVALID)
     }
+
+    pub fn get_color_index(self) -> usize {
+        let t = self.temperature.min(1.0).max(0.0);
+        let m = self.moisture.min(1.0).max(0.0);
+        (((1.0 - t) * 255.0) as usize) | ((((1.0 - (m*t)) * 255.0) as usize) << 8)
+    }
+
+    pub fn process_color(self, col: Rgba<u8>) -> Rgba<u8> {
+        if self.id == ROOFED_FOREST.id || self.id == ROOFED_FOREST_MOUNTAINS.id {
+            Rgba {
+                data: [
+                    ((col.data[0] as u32 + 0x28) / 2) as u8,
+                    ((col.data[1] as u32 + 0x34) / 2) as u8,
+                    ((col.data[2] as u32 + 0x0A) / 2) as u8,
+                    255
+                ]
+            }
+        } else {
+            col
+        }
+    }
 }
 
 macro_rules! define_biomes {