fix floor warping

1 files changed, 10 insertions, 2 deletions

diff --git a/src/renderer.rs b/src/renderer.rs
index 3ab67d6..bce3391 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -46,6 +46,14 @@ impl Renderer {
             let rdx = ray_angle.cos();
             let rdy = ray_angle.sin();
 
+            // Floor uses perpendicular distance from the LUT, but needs
+            // Euclidean distance for correct world-position projection.
+            // Scale by 1/cos(angle_diff) so that rdx_floor / rdy_floor
+            // map floor_dist → Euclidean travel along the ray.
+            let cos_diff = (ray_angle - game.player.angle).cos().abs().max(0.001);
+            let rdx_floor = rdx / cos_diff;
+            let rdy_floor = rdy / cos_diff;
+
             // ---- DDA setup -------------------------------------------------
             let mut map_x = game.player.x as isize;
             let mut map_y = game.player.y as isize;
@@ -151,8 +159,8 @@ impl Renderer {
                         let gray = darken_fx(0xFF80_8080, self.floor_bright_lut[py]);
                         buffer[py * self.screen_w + sx] = gray;
                     } else {
-                        let fx = game.player.x + floor_dist * rdx;
-                        let fy = game.player.y + floor_dist * rdy;
+                        let fx = game.player.x + floor_dist * rdx_floor;
+                        let fy = game.player.y + floor_dist * rdy_floor;
 
                         let ftx = ((fx.fract().abs() * TEX_SIZE as f64) as usize).min(TEX_SIZE - 1);
                         let fty = ((fy.fract().abs() * TEX_SIZE as f64) as usize).min(TEX_SIZE - 1);