From f0558a20c1674459bbd46a965672983fc91a7278 Mon Sep 17 00:00:00 2001
From: Peter Wu <lekensteyn@gmail.com>
Date: Fri, 20 Dec 2013 12:44:28 +0100
Subject: Attempt to implement First Person viewing mode

---
 src/Camera.java | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/Camera.java b/src/Camera.java
index 57c6d70..694633d 100644
--- a/src/Camera.java
+++ b/src/Camera.java
@@ -146,7 +146,21 @@ class Camera {
      * on the first person mode.
      */
     private void setFirstPersonMode() {
-        // code goes here ...
+        /**
+         * First person mode: look from the slowest robot forward.
+         */
+        Robot focus = getSlowestRobot();
+
+        // trivial: looks from the robot POV.
+        eye = track.getPointForLane(focus.getTimePos(), focus.getLane());
+
+        // The question is similar to question 2b of the intermediate test
+        // http://www.win.tue.nl/~vanwijk/2IV60/2IV60_test_exam_161213_answers.pdf
+        // C(t) = E(t) + P'(t) (P'(t) is the tangent vector).
+        center = center.add(track.getTangent(focus.getTimePos()));
+
+        // trivial: look forward, so up vector points up.
+        up = Vector.Z;
     }
 
     /**
@@ -163,4 +177,17 @@ class Camera {
         }
         return selected;
     }
+
+    /**
+     * Returns the robots which has the lowest Global State Time position.
+     */
+    private Robot getSlowestRobot() {
+        Robot slowest = robots[0];
+        for (Robot robot : robots) {
+            if (robot.getTimePos() < slowest.getTimePos()) {
+                slowest = robot;
+            }
+        }
+        return slowest;
+    }
 }
-- 
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