From eb1a4830ca902bf5cf27d30f92f6da2027e40f62 Mon Sep 17 00:00:00 2001
From: Levi Pearson <levi.pearson@harman.com>
Date: Sat, 30 Jul 2016 19:55:30 -0600
Subject: [PATCH] Misc cleanup

---
 src/game/map.rs  |  6 ++++++
 src/game/mod.rs  |  7 ++++---
 src/game/ship.rs | 33 +++++++++++----------------------
 3 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/src/game/map.rs b/src/game/map.rs
index 8ac967f..b844eed 100644
--- a/src/game/map.rs
+++ b/src/game/map.rs
@@ -18,6 +18,12 @@ impl Map {
         [self.width / 2.0, self.height / 2.0]
     }
 
+    pub fn clamp(&self, other: Vec2d) -> Vec2d {
+        let x = other[0].max(0.0).min(self.width);
+        let y = other[1].max(0.0).min(self.height);
+        [x, y]
+    }
+
     pub fn draw_grid<G>(&self,
                         cam_pos: Vec2d,
                         cam_size: Vec2d,
diff --git a/src/game/mod.rs b/src/game/mod.rs
index a7cdb2c..26b345e 100644
--- a/src/game/mod.rs
+++ b/src/game/mod.rs
@@ -67,16 +67,17 @@ impl Game {
 
             let ds = context.draw_state.blend(Blend::Alpha);
 
+            /* Make the camera coordinate origin the center of the window */
             let ct = context.transform.trans((args.width / 2) as Scalar,
                                              (args.height / 2) as Scalar);
 
             let cam_pos = self.camera.position;
-            let cam_width = self.camera.width;
-            let cam_height = self.camera.height;
+            let cam_size= [self.camera.width, self.camera.height];
 
+            /* Transform world coordinates to camera-relative coordinates */
             let cam_trans = ct.append_transform(translate(mul_scalar(cam_pos, -1.0)));
 
-            self.map.draw_grid(cam_pos, [cam_width, cam_height], &ds, cam_trans, gl);
+            self.map.draw_grid(cam_pos, cam_size, &ds, cam_trans, gl);
 
             for bullet in self.bullets.iter() {
                 draw_bullet(&bullet, &ds, cam_trans, gl);
diff --git a/src/game/ship.rs b/src/game/ship.rs
index 4e2e155..6b01335 100644
--- a/src/game/ship.rs
+++ b/src/game/ship.rs
@@ -29,31 +29,20 @@ impl Ship {
         }
     }
 
-    pub fn update(&mut self, thr: Scalar, rot: Scalar, dt: Scalar, map: &Map) {
-        let thrust = thr * THRUST_RATE * dt;
-        let dv = [self.rotation.cos() * thrust, self.rotation.sin() * thrust];
-        let dr = rot * TURN_RATE * dt;
+    pub fn update(&mut self, thr: Scalar, rot: Scalar, d_t: Scalar, map: &Map) {
+        let thrust = thr * THRUST_RATE * d_t;
+        let d_vel = [self.rotation.cos() * thrust, self.rotation.sin() * thrust];
+        let d_rot = rot * TURN_RATE * d_t;
 
-        self.rotation += dr;
-        self.velocity = add(self.velocity, dv);
+        self.rotation += d_rot;
+        self.velocity = add(self.velocity, d_vel);
         self.position = add(self.position, self.velocity);
 
-        if self.position[0] > map.width {
-            self.velocity[0] = 0.0;
-            self.position[0] = map.width;
-        }
-        if self.position[0] < 0.0 {
-            self.velocity[0] = 0.0;
-            self.position[0] = 0.0;
-        }
-        if self.position[1] > map.height {
-            self.velocity[1] = 0.0;
-            self.position[1] = map.height;
-        }
-        if self.position[1] < 0.0 {
-            self.velocity[1] = 0.0;
-            self.position[1] = 0.0;
-        }
+        let oldpos = self.position;
+        self.position = map.clamp(oldpos);
+
+        if self.position[0] != oldpos[0] { self.velocity[0] = 0.0; }
+        if self.position[1] != oldpos[1] { self.velocity[1] = 0.0; }
     }
 
     pub fn trajectory(&self) -> (Vec2d, Vec2d, Vec2d) {