From 343ccdd12a5467408ee74dc1e3332ee774143df6 Mon Sep 17 00:00:00 2001
From: Fabien Freling <public@ffreling.com>
Date: Mon, 16 Oct 2017 22:44:58 +0200
Subject: [PATCH] Compute angles for raycaster

---
 src/main.rs | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 5dca0c4..fb3da81 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,7 +14,7 @@ struct Position {
 
 struct Player {
    pos: Position,
-   angle: f64,
+   angle: f64, // radian or degree
 }
 
 
@@ -33,10 +33,10 @@ fn main() {
         Tile::Wall, Tile::Wall, Tile::Wall, Tile::Wall, Tile::Wall,
     ];
 
-    let mut player: Player;
-    player.pos.x = 2.0;
-    player.pos.y = 2.0;
-    player.angle = 0.0;
+    let mut player = Player { pos: Position { x: 2.0, y: 2.0}, angle: 0.0};
+
+    let horiz_fov = 90 as f64;
+    //let height_unit = 64;
 
     while let Some(event) = window.next() {
         let window_size = window.size();
@@ -64,6 +64,20 @@ fn main() {
                       [0.0, h / 2.0, w, h / 2.0],
                       context.transform,
                       graphics);
+
+            // Walls
+            let left = player.angle + (horiz_fov / 2.0);
+            let right = player.angle - (horiz_fov / 2.0);
+            // for every angle (range / w)
+            let step = (left - right) / w;
+            let mut ray_angle = left;
+            for n in 0..(window_size.width - 1) {
+                //   cast a ray
+                //   see what wall it hits
+                //   compute wall height
+                //   draw wall portion
+                ray_angle += step;
+            }
         });
     }
 }