From d57e41a27653cc6e7bfa234a5caeec3a7618e513 Mon Sep 17 00:00:00 2001
From: Fabien Freling <public@ffreling.com>
Date: Sun, 22 Oct 2017 22:22:49 +0200
Subject: [PATCH] Add engine module

---
 src/engine.rs | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/main.rs   | 56 +++---------------------------------------
 2 files changed, 71 insertions(+), 53 deletions(-)
 create mode 100644 src/engine.rs

diff --git a/src/engine.rs b/src/engine.rs
new file mode 100644
index 0000000..a8f46bf
--- /dev/null
+++ b/src/engine.rs
@@ -0,0 +1,68 @@
+extern crate piston_window;
+
+use piston_window::*;
+
+struct Position {
+    x: f64,
+    y: f64,
+}
+
+struct Player {
+   pos: Position,
+   angle: f64, // radian or degree
+}
+
+pub struct Engine {
+    w: f64,
+    h: f64,
+    horiz_fov: f64,
+    player: Player,
+}
+
+impl Engine {
+    pub fn new(size: Size) -> Engine {
+        Engine {
+            w: size.width as f64,
+            h: size.height as f64,
+            horiz_fov: 90.,
+            player: Player {
+                pos: Position { x: 2., y: 2. },
+                angle: 0.,
+            }
+        }
+    }
+
+    pub fn render(&mut self, context: Context, graphics: &mut G2d) {
+
+        clear([1.0; 4], graphics);
+
+        // Ceiling
+        let ceiling_color = [0.3, 0.3, 0.3, 1.0];
+        rectangle(ceiling_color,
+                  [0.0, 0.0, self.w, self.h / 2.0],
+                  context.transform,
+                  graphics);
+
+        // Floor
+        let floor_color = [0.5, 0.5, 0.5, 1.0];
+        rectangle(floor_color,
+                  [0.0, self.h / 2.0, self.w, self.h / 2.0],
+                  context.transform,
+                  graphics);
+
+        // Walls
+        let left = self.player.angle + (self.horiz_fov / 2.0);
+        let right = self.player.angle - (self.horiz_fov / 2.0);
+        // for every angle (range / w)
+        let step = (left - right) / self.w;
+        let mut ray_angle = left;
+        let width = self.w as i32;
+        for n in 0..width {
+            //   cast a ray
+            //   see what wall it hits
+            //   compute wall height
+            //   draw wall portion
+            ray_angle += step;
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index fb3da81..12f1159 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,23 +1,13 @@
 extern crate piston_window;
 
 use piston_window::*;
+mod engine;
 
 enum Tile {
     Empty,
     Wall,
 }
 
-struct Position {
-    x: f64,
-    y: f64,
-}
-
-struct Player {
-   pos: Position,
-   angle: f64, // radian or degree
-}
-
-
 fn main() {
     let mut window: PistonWindow =
         WindowSettings::new("Rustenstein", [640, 480])
@@ -33,51 +23,11 @@ fn main() {
         Tile::Wall, Tile::Wall, Tile::Wall, Tile::Wall, Tile::Wall,
     ];
 
-    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;
+    let mut engine = engine::Engine::new(window.size());
 
     while let Some(event) = window.next() {
-        let window_size = window.size();
-        let w = window_size.width as f64;
-        let h = window_size.height as f64;
-
         window.draw_2d(&event, |context, graphics| {
-            clear([1.0; 4], graphics);
-
-            rectangle([1.0, 0.0, 0.0, 1.0], // red
-                      [0.0, 0.0, 100.0, 100.0],
-                      context.transform,
-                      graphics);
-
-            // Ceiling
-            let ceiling_color = [0.3, 0.3, 0.3, 1.0];
-            rectangle(ceiling_color,
-                      [0.0, 0.0, w, h / 2.0],
-                      context.transform,
-                      graphics);
-
-            // Floor
-            let floor_color = [0.5, 0.5, 0.5, 1.0];
-            rectangle(floor_color,
-                      [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;
-            }
+            engine.render(context, graphics);
         });
     }
 }