From 2edc7c61af0d390c1e2e84d775f3d88b8ba34f40 Mon Sep 17 00:00:00 2001
From: Fraser Graham <frasergraham@me.com>
Date: Fri, 18 Oct 2013 20:40:09 -0700
Subject: [PATCH] fixing bug where heading can be 0

---
 player.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/player.go b/player.go
index dc6d931..dc43e26 100644
--- a/player.go
+++ b/player.go
@@ -95,13 +95,18 @@ func (p *player) nudge(g *game) {
 		// We may have been stopped before this and had no heading
 		current_heading = p.Robot.MoveTo.Sub(p.Robot.Position).Normalize()
 	}
+
+	// Where do we WANT to be heading?
 	new_heading := p.Robot.MoveTo.Sub(p.Robot.Position).Normalize()
+
 	// Is our direction change too much? Hard coding to 5 degrees/s for now
 	angle := v.Angle(current_heading, new_heading) * v.Rad2deg
 	dir := 1.0
 	if angle < 0 {
 		dir = -1.0
 	}
+
+	// Max turn radius in this case is 100 degrees per second
 	if math.Abs(angle) > (100 * delta) {
 		// New heading should be a little less, take current heading and
 		// rotate by the max turn radius per frame.
@@ -120,7 +125,11 @@ func (p *player) nudge(g *game) {
 		p.Robot.Heading = v.Vector2d{X: 0, Y: 0}
 	} else {
 		p.Robot.Position = p.Robot.Position.Add(move_vector)
-		p.Robot.Heading = new_heading
+		if new_heading.Mag() > 0 {
+			p.Robot.Heading = new_heading
+		} else {
+			log.Printf("Zero Heading %v", new_heading)
+		}
 	}
 }