Refactor: move Camera outside RobotRace

Extra changes include reordering comments around conditions and
adding the GlobalState parameter to the constructor.

2 files changed, 106 insertions, 103 deletions

diff --git a/src/Camera.java b/src/Camera.java
new file mode 100644
index 0000000..e865bc7
--- /dev/null
+++ b/src/Camera.java
@@ -0,0 +1,105 @@
+
+import robotrace.Vector;
+import static java.lang.Math.*;
+import robotrace.GlobalState;
+
+/**
+ * Implementation of a camera with a position and orientation.
+ */
+class Camera {
+
+    /** The position of the camera. */
+    public Vector eye = new Vector(3f, 6f, 5f);
+
+    /** The point to which the camera is looking. */
+    public Vector center = Vector.O;
+
+    /** The up vector. */
+    public Vector up = Vector.Z;
+
+    /**
+     * A reference to the global game state from RobotRace.
+     */
+    private final GlobalState gs;
+
+    public Camera(GlobalState gs) {
+        this.gs = gs;
+    }
+
+    /**
+     * Updates the camera viewpoint and direction based on the
+     * selected camera mode.
+     */
+    public void update(int mode) {
+        if (1 == mode) { // Helicopter mode
+            setHelicopterMode();
+        } else if (2 == mode) { // Motor cycle mode
+            setMotorCycleMode();
+        } else if (3 == mode) { // First person mode
+            setFirstPersonMode();
+        } else if (4 == mode) { // Auto mode
+            // code goes here...
+        } else { // Default mode
+            setDefaultMode();
+        }
+    }
+
+    /**
+     * Computes {@code eye}, {@code center}, and {@code up}, based
+     * on the camera's default mode.
+     */
+    private void setDefaultMode() {
+        /*        z |
+         *          |   vDist %
+         *          |    %    * Ez
+         *          |%________*________ y
+         *      Ex /    %     *
+         *      /        s %  *
+         * x /  - - - - - - - *
+         *           Ey
+         * phi is angle between vDist and XY plane (Z direction)
+         * theta is angle between X-axis and s (XY plane)
+         * E = (Ex, Ey, Ez)
+         * sin phi  = Ez / vDist => Ez = vDist * sin phi
+         * cos phi = s / vDist => s = vDist * cos phi
+         * Ex = s * sin theta
+         * Ey = s * cos theta
+         */
+        float Ex, Ey, Ez, s;
+        Ez = gs.vDist * (float) sin(gs.phi);
+        s = gs.vDist * (float) cos(gs.phi);
+        Ex = s * (float) sin(gs.theta);
+        Ey = s * (float) cos(gs.theta);
+
+        // change center point with WASD
+        Ex += gs.cnt.x();
+        Ey += gs.cnt.y();
+        Ez += gs.cnt.z();
+
+        eye = new Vector(Ex, Ey, Ez);
+    }
+
+    /**
+     * Computes {@code eye}, {@code center}, and {@code up}, based
+     * on the helicopter mode.
+     */
+    private void setHelicopterMode() {
+        // code goes here ...
+    }
+
+    /**
+     * Computes {@code eye}, {@code center}, and {@code up}, based
+     * on the motorcycle mode.
+     */
+    private void setMotorCycleMode() {
+        // code goes here ...
+    }
+
+    /**
+     * Computes {@code eye}, {@code center}, and {@code up}, based
+     * on the first person mode.
+     */
+    private void setFirstPersonMode() {
+        // code goes here ...
+    }
+}
diff --git a/src/RobotRace.java b/src/RobotRace.java
index 6495285..6919422 100644
--- a/src/RobotRace.java
+++ b/src/RobotRace.java
@@ -106,7 +106,7 @@ public class RobotRace extends Base {
             /* add other parameters that characterize this robot */);
         
         // Initialize the camera
-        camera = new Camera();
+        camera = new Camera(gs);
         
         // Initialize the race track
         raceTrack = new RaceTrack();
@@ -286,108 +286,6 @@ public class RobotRace extends Base {
     }
     
     /**
-     * Implementation of a camera with a position and orientation. 
-     */
-    private class Camera {
-        
-        /** The position of the camera. */
-        public Vector eye = new Vector(3f, 6f, 5f);
-        
-        /** The point to which the camera is looking. */
-        public Vector center = Vector.O;
-        
-        /** The up vector. */
-        public Vector up = Vector.Z;
-        
-        /**
-         * Updates the camera viewpoint and direction based on the
-         * selected camera mode.
-         */
-        public void update(int mode) {
-            // Helicopter mode
-            if (1 == mode) {  
-                setHelicopterMode();
-                
-            // Motor cycle mode
-            } else if (2 == mode) { 
-                setMotorCycleMode();
-                
-            // First person mode
-            } else if (3 == mode) { 
-                setFirstPersonMode();
-                
-            // Auto mode
-            } else if (4 == mode) { 
-                // code goes here...
-                
-            // Default mode
-            } else {
-                setDefaultMode();
-            }
-        }
-        
-        /**
-         * Computes {@code eye}, {@code center}, and {@code up}, based
-         * on the camera's default mode.
-         */
-        private void setDefaultMode() {
-            /*        z |
-             *          |   vDist %
-             *          |    %    * Ez
-             *          |%________*________ y
-             *      Ex /    %     *
-             *      /        s %  *
-             * x /  - - - - - - - *
-             *           Ey
-             * phi is angle between vDist and XY plane (Z direction)
-             * theta is angle between X-axis and s (XY plane)
-             * E = (Ex, Ey, Ez)
-             * sin phi  = Ez / vDist => Ez = vDist * sin phi
-             * cos phi = s / vDist => s = vDist * cos phi
-             * Ex = s * sin theta
-             * Ey = s * cos theta
-             */
-            float Ex, Ey, Ez, s;
-            Ez = gs.vDist * (float) sin(gs.phi);
-            s = gs.vDist * (float) cos(gs.phi);
-            Ex = s * (float) sin(gs.theta);
-            Ey = s * (float) cos(gs.theta);
-
-            // change center point with WASD
-            Ex += gs.cnt.x();
-            Ey += gs.cnt.y();
-            Ez += gs.cnt.z();
-
-            eye = new Vector(Ex, Ey, Ez);
-        }
-        
-        /**
-         * Computes {@code eye}, {@code center}, and {@code up}, based
-         * on the helicopter mode.
-         */
-        private void setHelicopterMode() {
-            // code goes here ...
-        }
-        
-        /**
-         * Computes {@code eye}, {@code center}, and {@code up}, based
-         * on the motorcycle mode.
-         */
-        private void setMotorCycleMode() {
-            // code goes here ...
-        }
-        
-        /**
-         * Computes {@code eye}, {@code center}, and {@code up}, based
-         * on the first person mode.
-         */
-        private void setFirstPersonMode() {
-            // code goes here ...
-        }
-        
-    }
-    
-    /**
      * Main program execution body, delegates to an instance of
      * the RobotRace implementation.
      */