starting procedural generation

src/main.rs

@@ -1,3 +1,80 @@
-fn main() {
-    println!("Hello, world!");
+// Example Code
+
+use noise::{NoiseFn, Perlin};
+#[derive(Debug, Clone, Copy)]
+enum BlockType {
+    Air,
+    Grass,
+    Dirt,
+    Stone,
+    Water,
+}
+const CHUNK_SIZE: usize = 16;
+const CHUNK_HEIGHT: usize = 128;
+
+type Chunk = Vec<Vec<Vec<BlockType>>>;
+
+fn main() {
+    let perlin = Perlin::new(42);
+    let scale = 0.1;
+    let x = 10.0 * scale;
+    let y = 20.0 * scale;
+    let noise_value = perlin.get([x, y]);
+    println!("Noise value: {}", noise_value);
+}
+fn fbm(perlin: &Perlin, x: f64, y: f64, octaves: u32, persistence: f64) -> f64 {
+    let mut total = 0.0;
+    let mut amplitude = 1.0;
+    let mut frequency = 1.0;
+    let mut max_value = 0.0;
+
+    for _ in 0..octaves {
+        total += perlin.get([x * frequency, y * frequency]) * amplitude;
+        max_value += amplitude;
+        amplitude *= persistence;
+        frequency *= 2.0;
+    }
+    total / max_value
+}
+
+fn map_noise_to_height(noise_value: f64) -> usize {
+    let normalized = (noise_value + 1.0) / 2.0; // map from [-1, 1] to [0, 1]
+    let max_height = 128;
+    (normalized * max_height as f64) as usize
+}
+fn generate_chunk(perlin: &Perlin, chunk_x: i32, chunk_z: i32) -> Chunk {
+    let mut chunk = vec![vec![vec![BlockType::Air; CHUNK_HEIGHT]; CHUNK_SIZE]; CHUNK_SIZE];
+    let scale = 0.1;
+
+    for local_x in 0..CHUNK_SIZE {
+        for local_z in 0..CHUNK_SIZE {
+            let world_x = chunk_x * CHUNK_SIZE as i32 + local_x as i32;
+            let world_z = chunk_z * CHUNK_SIZE as i32 + local_z as i32;
+            let noise_value = fbm(
+                perlin,
+                world_x as f64 * scale,
+                world_z as f64 * scale,
+                4,
+                0.5,
+            );
+            let height = map_noise_to_height(noise_value);
+
+            for y in 0..CHUNK_HEIGHT {
+                if y > height {
+                    chunk[local_x][local_z][y] = if y < 64 {
+                        BlockType::Water
+                    } else {
+                        BlockType::Air
+                    };
+                } else if y == height {
+                    chunk[local_x][local_z][y] = BlockType::Grass;
+                } else if y > height.saturating_sub(3) {
+                    chunk[local_x][local_z][y] = BlockType::Dirt;
+                } else {
+                    chunk[local_x][local_z][y] = BlockType::Stone;
+                }
+            }
+        }
+    }
+    chunk
 }