From af418f1e6f617e4ca39abf7e142c27c8ea4e2e5c Mon Sep 17 00:00:00 2001
From: Fraser Graham <frasergraham@me.com>
Date: Sat, 26 Apr 2014 23:05:33 -0600
Subject: [PATCH] Fixing reversing and wall collisions

---
 robot.go | 60 +++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 40 insertions(+), 20 deletions(-)

diff --git a/robot.go b/robot.go
index 20f71ee..928d764 100644
--- a/robot.go
+++ b/robot.go
@@ -186,7 +186,6 @@ type Instruction struct {
 // collided, if this happened.
 func (r *Robot) checkCollisions(g *Game, probe v.Vector2d) (bool, *v.Point2d, *Robot) {
 	finalCollision := false
-	collision := false
 	closest := math.Inf(1)
 	var intersection *v.Point2d
 	var finalRobot *Robot
@@ -195,19 +194,29 @@ func (r *Robot) checkCollisions(g *Game, probe v.Vector2d) (bool, *v.Point2d, *R
 	botSize := 5.0
 	botPolygon := v.OrientedSquare(r.Position, r.Heading, botSize)
 
-	// Check Walls
-	r_walls := v.AABB2d{A: v.Point2d{X: botSize, Y: botSize}, B: v.Point2d{X: g.width - botSize, Y: g.height - botSize}}
-	collision, _, wallIntersect := v.RectIntersection(r_walls, r.Position, probe)
-	if collision && wallIntersect != nil {
-		finalCollision = true
-		if dist := r.Position.Sub(*wallIntersect).Mag(); dist < closest {
-			intersection = wallIntersect
-			closest = dist
-		}
+	bounds := []Obstacle{
+		Obstacle{
+			Bounds: v.AABB2d{A: v.Point2d{0, 0}, B: v.Point2d{0, g.width}},
+			Hp: 0,
+		},
+		Obstacle{
+			Bounds: v.AABB2d{A: v.Point2d{0, 0}, B: v.Point2d{0, g.height}},
+			Hp: 0,
+		},
+		Obstacle{
+			Bounds: v.AABB2d{A: v.Point2d{g.width, g.height}, B: v.Point2d{0, g.height}},
+			Hp: 0,
+		},
+		Obstacle{
+			Bounds: v.AABB2d{A: v.Point2d{g.width, g.height}, B: v.Point2d{g.width, 0}},
+			Hp: 0,
+		},
 	}
 
+	obstacles := append(g.obstacles, bounds...)
+
 	// Check Obstacles
-	for _, obj := range g.obstacles {
+	for _, obj := range obstacles {
 		// collision due to motion:
 		collision, move_collision, translation := v.PolyPolyIntersection(
 			botPolygon, probe, obj.Bounds.ToPolygon())
@@ -262,7 +271,7 @@ func (r *Robot) Tick(g *Game) {
 	r.Hit = false
 	r.scan(g)
 
-	// Adjust Speed
+	// Cap Target Speed
 	if r.TargetSpeed > r.Stats.Speed {
 		r.TargetSpeed = r.Stats.Speed
 	}
@@ -271,19 +280,30 @@ func (r *Robot) Tick(g *Game) {
 		r.TargetSpeed = -1.0 * r.Stats.Speed
 	}
 
-	if r.Speed < r.TargetSpeed {
+	// Are we speeding up or slowing down?
+	increase := true
+	if float32(math.Abs(float64(r.Speed-r.TargetSpeed))) > v.Epsilon {
+		increase = false
+	}
+
+	if increase {
 		r.Speed += (r.Stats.Acceleration * r.Delta)
+		// Stop us from going too far
 		if r.Speed > r.TargetSpeed {
 			r.Speed = r.TargetSpeed
 		}
-	} else if float32(math.Abs(float64(r.Speed-r.TargetSpeed))) > v.Epsilon {
-		r.Speed -= (r.Stats.Acceleration * r.Delta)
-		// Cap reverse to 1/2 speed
-		if r.Speed < (-0.5 * r.TargetSpeed) {
-			r.Speed = (-0.5 * r.TargetSpeed)
-		}
 	} else {
-		r.Speed = r.TargetSpeed
+		r.Speed -= (r.Stats.Acceleration * r.Delta)
+
+		// Dont go too far
+		if r.Speed < r.TargetSpeed {
+			r.Speed = r.TargetSpeed
+		}
+
+		// Cap reverse at 1/4 top speed
+		if r.Speed < (-0.25 * r.Stats.Speed) {
+			r.Speed = (-0.25 * r.Stats.Speed)
+		}
 	}
 
 	// Adjust Heading