1 files changed, 105 insertions, 0 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 ...
+    }
+}