Add wildlife density modifier to features.ron

assets/world/features.ron

@@ -10,4 +10,5 @@
     paths: true,
     spots: true,
     site2: false,
+    wildlife_density: 1.0,
 )

world/src/config.rs

@@ -87,6 +87,8 @@ pub struct Features {
     pub paths: bool,
     pub spots: bool,
     pub site2: bool,
+    // 1.0 is the default wildlife density
+    pub wildlife_density: f32,
 }
 
 impl assets::Asset for Features {

world/src/index.rs

@@ -119,6 +119,7 @@ impl IndexOwned {
             // Reload the fields from the asset handle, which is updated automatically
             self.colors = self.index.colors.cloned();
             self.features = self.index.features.cloned();
+            // Update wildlife spawns which is based on base_density in features
             reload(self)
         })
     }

world/src/layer/wildlife.rs

@@ -21,8 +21,6 @@ fn close(x: f32, tgt: f32, falloff: f32) -> f32 {
     (1.0 - (x - tgt).abs() / falloff).max(0.0).powf(0.125)
 }
 
-const BASE_DENSITY: f32 = 1.0e-5; // Base wildlife density
-
 #[derive(Clone, Debug, Deserialize)]
 pub struct SpawnEntry {
     /// User-facing info for wiki, statistical tools, etc.
@@ -131,6 +129,7 @@ impl Pack {
 pub type DensityFn = fn(&SimChunk, &ColumnSample) -> f32;
 
 pub fn spawn_manifest() -> Vec<(&'static str, DensityFn)> {
+    const BASE_DENSITY: f32 = 1.0e-5; // Base wildlife density
     // NOTE: Order matters.
     // Entries with more specific requirements
     // and overall scarcity should come first, where possible.
@@ -317,6 +316,8 @@ pub fn apply_wildlife_supplement<'a, R: Rng>(
     time: Option<&(TimeOfDay, Calendar)>,
 ) {
     let scatter = &index.wildlife_spawns;
+    // Configurable density multiplier
+    let wildlife_density_modifier = index.features.wildlife_density;
 
     for y in 0..vol.size_xy().y as i32 {
         for x in 0..vol.size_xy().x as i32 {
@@ -342,7 +343,7 @@ pub fn apply_wildlife_supplement<'a, R: Rng>(
                 .iter()
                 .enumerate()
                 .find_map(|(_i, (entry, get_density))| {
-                    let density = get_density(chunk, col_sample);
+                    let density = get_density(chunk, col_sample) * wildlife_density_modifier;
                     (density > 0.0)
                         .then(|| {
                             entry