1 files changed, 48 insertions, 1 deletions

diff --git a/src/texture.rs b/src/texture.rs
index bdbb15c..e5720c0 100644
--- a/src/texture.rs
+++ b/src/texture.rs
@@ -60,6 +60,49 @@ pub fn generate_wall_texture(rng: &mut impl Rng) -> Vec<u32> {
     tex
 }
 
+/// Gray stone-tile floor with a dark hole in the centre — the exit staircase.
+pub fn generate_exit_texture(rng: &mut impl Rng) -> Vec<u32> {
+    let mut tex = generate_floor_texture(rng);
+
+    let cx = TEX_SIZE as f64 / 2.0;
+    let cy = TEX_SIZE as f64 / 2.0;
+    let hole_radius = TEX_SIZE as f64 * 0.35;
+    let fade_zone = TEX_SIZE as f64 * 0.08;
+
+    for y in 0..TEX_SIZE {
+        for x in 0..TEX_SIZE {
+            let dx = x as f64 - cx;
+            let dy = y as f64 - cy;
+            let dist = (dx * dx + dy * dy).sqrt();
+
+            if dist < hole_radius {
+                // Deep black void.
+                let edge = (dist / hole_radius).clamp(0.0, 1.0);
+                // Slight blueish tint near the edge for depth.
+                let r = (8.0 * (1.0 - edge)) as u8;
+                let g = (6.0 * (1.0 - edge)) as u8;
+                let b = (12.0 * edge + 4.0 * (1.0 - edge)) as u8;
+                tex[y * TEX_SIZE + x] =
+                    0xFF00_0000 | ((r as u32) << 16) | ((g as u32) << 8) | (b as u32);
+            } else if dist < hole_radius + fade_zone {
+                // Fade zone: blend from floor to darkness.
+                let t = ((dist - hole_radius) / fade_zone).clamp(0.0, 1.0);
+                let floor_color = tex[y * TEX_SIZE + x];
+                let fr = ((floor_color >> 16) & 0xFF) as f64;
+                let fg = ((floor_color >> 8) & 0xFF) as f64;
+                let fb = (floor_color & 0xFF) as f64;
+
+                let r = (fr * t + 8.0 * (1.0 - t)) as u8;
+                let g = (fg * t + 6.0 * (1.0 - t)) as u8;
+                let b = (fb * t + 12.0 * (1.0 - t)) as u8;
+                tex[y * TEX_SIZE + x] =
+                    0xFF00_0000 | ((r as u32) << 16) | ((g as u32) << 8) | (b as u32);
+            }
+        }
+    }
+    tex
+}
+
 /// Gray stone-tile floor — 64×64, checkerboard with grout and subtle colour tint.
 pub fn generate_floor_texture(rng: &mut impl Rng) -> Vec<u32> {
     let seed = rng.gen::<u64>();
@@ -68,7 +111,11 @@ pub fn generate_floor_texture(rng: &mut impl Rng) -> Vec<u32> {
     for y in 0..TEX_SIZE {
         for x in 0..TEX_SIZE {
             let h = hash(x as u32, y as u32, seed);
-            let h2 = hash(x.wrapping_add(2000) as u32, y.wrapping_add(2000) as u32, seed);
+            let h2 = hash(
+                x.wrapping_add(2000) as u32,
+                y.wrapping_add(2000) as u32,
+                seed,
+            );
 
             let tile_x = x / 16;
             let tile_y = y / 16;