Fix robot viewing direction

1 files changed, 8 insertions, 11 deletions

diff --git a/src/RobotRace.java b/src/RobotRace.java
index 66e2594..e166ad9 100644
--- a/src/RobotRace.java
+++ b/src/RobotRace.java
@@ -506,17 +506,14 @@ public class RobotRace extends Base {
             Vector robotPos = raceTrack.getPointForLane(robot.getTimePos(), i);
             gl.glTranslated(robotPos.x(), robotPos.y(), robotPos.z());
 
-            /* Calculate angle for the robots to look at, multiply by 180/PI
-             * to convert the radions to degrees.
-             * First get the tangent of the robot, that is the real direction
-             * where the robot is looking to.
-             * Then add this vector to the actual position, and from the
-             * resulting vector we can calculate the angle. */
-            Vector robotTangent = raceTrack.getTangent(robot.getTimePos());
-            Vector totalVector = robotTangent.add(robotPos);
-
-            double angle = atan2(totalVector.y(), totalVector.x()) * 180/PI;
-
+            /* While the robot looks in the tangent direction, the position of
+             * the robot on the track is determined by the normal. For cases
+             * where the origin is used to create the track (circles), the
+             * robot position could be used as well (for direction). In the
+             * general case though, the normal is needed.
+             */
+            Vector norm = raceTrack.getNormal(robot.getTimePos());
+            double angle = atan2(norm.y(), norm.x()) * 180 / PI;
             gl.glRotated(angle, 0, 0, 1);
 
             // Draw the current robot