smooth material mixing

1 files changed, 67 insertions, 10 deletions

diff --git a/src/content/world/mines.rs b/src/content/world/mines.rs
index d750619..961b068 100644
--- a/src/content/world/mines.rs
+++ b/src/content/world/mines.rs
@@ -1,5 +1,5 @@
 use fastnoise_lite::{FastNoiseLite, FractalType};
-use glam::IVec2;
+use glam::{IVec2, Vec2};
 
 use crate::{
     content::materials::MaterialId,
@@ -7,28 +7,85 @@ use crate::{
     sim::cell::Cell,
 };
 
-const ROUGHNESS: f32 = 0.375;
+const DISPLACEMENT_ROUGHNESS: f32 = 0.375;
+const BOUNDARY_ROUGHNESS: f32 = 0.375;
 
 pub struct MinesBiome {
-    pub edge_roughness: FastNoiseLite,
+    pub dirt_roughness: FastNoiseLite,
+    pub water_roughness: FastNoiseLite,
+    pub wood_roughness: FastNoiseLite,
 }
 
 impl MinesBiome {
+    fn pixel_idx_to_type(idx: u8) -> MinesBiomePixelType {
+        match idx {
+            1 => MinesBiomePixelType::Dirt,
+            12 => MinesBiomePixelType::Water,
+            13 => MinesBiomePixelType::Wood,
+            _ => MinesBiomePixelType::Void,
+        }
+    }
+
+    fn material_roughness(&self, pixel_type: MinesBiomePixelType, world: Vec2) -> f32 {
+        match pixel_type {
+            MinesBiomePixelType::Dirt => self.dirt_roughness.get_noise_2d(world.x, world.y),
+            MinesBiomePixelType::Water => self.water_roughness.get_noise_2d(world.x, world.y),
+            MinesBiomePixelType::Wood => self.wood_roughness.get_noise_2d(world.x, world.y),
+            _ => self.dirt_roughness.get_noise_2d(world.x, world.y),
+        }
+    }
+
     pub fn new() -> Self {
-        let mut edge_roughness = FastNoiseLite::new();
-        edge_roughness.set_fractal_type(Some(FractalType::Ridged));
-        edge_roughness.set_fractal_octaves(Some(2));
-        MinesBiome { edge_roughness }
+        let mut dirt_roughness = FastNoiseLite::with_seed(0);
+        dirt_roughness.set_fractal_type(Some(FractalType::Ridged));
+        dirt_roughness.set_fractal_octaves(Some(2));
+
+        let mut water_roughness = FastNoiseLite::with_seed(100);
+        water_roughness.set_fractal_type(Some(FractalType::FBm));
+        water_roughness.set_frequency(Some(0.005));
+        water_roughness.set_fractal_octaves(Some(2));
+
+        let mut wood_roughness = FastNoiseLite::with_seed(200);
+        wood_roughness.set_fractal_type(Some(FractalType::FBm));
+        wood_roughness.set_frequency(Some(0.02));
+        wood_roughness.set_fractal_octaves(Some(2));
+        MinesBiome {
+            dirt_roughness,
+            water_roughness,
+            wood_roughness,
+        }
     }
 }
 
+enum MinesBiomePixelType {
+    Void,
+    Dirt,
+    Water,
+    Wood,
+}
+
 impl Biome for MinesBiome {
     fn fragment(&self, pixel: InterpolatedPixel, world: IVec2) -> Cell {
         let world = world.as_vec2();
-        let displacement = ROUGHNESS * self.edge_roughness.get_noise_2d(world.x, world.y);
 
-        match pixel.interpolated_pixel_index {
-            0 => {
+        let pixel_idx = pixel
+            .interpolated_pixel_indices
+            .iter()
+            .map(|&(i, s)| {
+                (
+                    i,
+                    s + self.material_roughness(MinesBiome::pixel_idx_to_type(i), world)
+                        * BOUNDARY_ROUGHNESS,
+                )
+            })
+            .max_by(|&(_, s1), &(_, s2)| s1.total_cmp(&s2))
+            .map_or(0, |(i, _)| i);
+
+        let displacement =
+            DISPLACEMENT_ROUGHNESS * self.dirt_roughness.get_noise_2d(world.x, world.y);
+
+        match pixel_idx {
+            1 => {
                 if pixel.interpolated_solidity + displacement <= 0.0 {
                     return Cell::void();
                 }