collision works

pkg/breakout/ball.go

@@ -43,8 +43,18 @@ func (self *Ball) HandlePaddleCollision(paddle *Paddle) {
 	intersects := aabb.Intersects(p)
 
 	if intersects {
-		// Bounce off of things
-		self.Box.Velocity = self.Box.Velocity.Mul(-1)
+		newVelocity := self.Box.Velocity
+		if aabb.HorizontalCollision(p) {
+			newVelocity[0] = -1 * newVelocity[0]
+		}
+
+		if aabb.VerticalCollision(p) {
+			// Change differently based on which part of the paddle we hit
+			// TODO
+			newVelocity[1] = -1 * newVelocity[1]
+		}
+
+		self.Box.Velocity = newVelocity
 	}
 }
 
@@ -58,10 +68,10 @@ func (self *Ball) HandleTargetCollisions(targets *Targets) {
 			intersects = aabb.Intersects(b)
 
 			if intersects {
+				// TODO points
 				brick.Break()
 
-				// Bounce off of things
-				self.Box.Velocity = self.Box.Velocity.Mul(-1)
+				self.UpdateVelocityFromCollision(aabb, b)
 			}
 		}
 	}
@@ -73,11 +83,25 @@ func (self *Ball) HandleSideWallsCollisions(sidewalls *SideWalls) {
 	aabb := self.GetAABB()
 	boxes := sidewalls.Boxes
 	for _, box := range boxes {
-		intersects = aabb.Intersects(box.GetAABB())
+		b := box.GetAABB()
+		intersects = aabb.Intersects(b)
 
 		if intersects {
-			// Bounce off of things
-			//self.Box.Velocity = self.Box.Velocity.Mul(-1)
+			self.UpdateVelocityFromCollision(aabb, b)
 		}
 	}
 }
+
+func (self *Ball) UpdateVelocityFromCollision(us, them *globjects.AABB) {
+	newVelocity := self.Box.Velocity
+
+	if us.HorizontalCollision(them) {
+		newVelocity[0] = -1 * newVelocity[0]
+	}
+
+	if us.VerticalCollision(them) {
+		newVelocity[1] = -1 * newVelocity[1]
+	}
+
+	self.Box.Velocity = newVelocity
+}

pkg/breakout/gamewindow.go

@@ -32,7 +32,6 @@ type GameWindow struct {
 	mouseMoved bool
 	running    bool
 	fullscreen bool
-	wireframe  bool
 	freelook   bool
 }
 
@@ -40,7 +39,6 @@ func NewGameWindow(title string) (*GameWindow, error) {
 	gameWindow := GameWindow{
 		running:    true,
 		fullscreen: false,
-		wireframe:  false,
 		freelook:   false,
 		keystates:  make(map[sdl.Keycode]bool),
 	}
@@ -164,11 +162,6 @@ func (w *GameWindow) ToggleWireframe() {
 	for _, o := range w.GLObjects {
 		o.ToggleWireframe()
 	}
-
-	w.Paddle.ToggleWireframe()
-	w.Ball.ToggleWireframe()
-
-	w.wireframe = !w.wireframe
 }
 
 func (w *GameWindow) GLDraw() {

pkg/globjects/aabb.go

@@ -41,15 +41,15 @@ func NewAABBFromBox(box *Box) *AABB {
 
 	// Then get the axis-align version of this box using min/max
 	max := mgl32.Vec3{
-		mathhelpers.Max32f(topRight.X(), bottomLeft.X()),
-		mathhelpers.Max32f(topRight.Y(), bottomLeft.Y()),
-		mathhelpers.Max32f(topRight.Z(), bottomLeft.Z()),
+		mathhelpers.Maxf32(topRight.X(), bottomLeft.X()),
+		mathhelpers.Maxf32(topRight.Y(), bottomLeft.Y()),
+		mathhelpers.Maxf32(topRight.Z(), bottomLeft.Z()),
 	}
 
 	min := mgl32.Vec3{
-		mathhelpers.Min32f(topRight.X(), bottomLeft.X()),
-		mathhelpers.Min32f(topRight.Y(), bottomLeft.Y()),
-		mathhelpers.Min32f(topRight.Z(), bottomLeft.Z()),
+		mathhelpers.Minf32(topRight.X(), bottomLeft.X()),
+		mathhelpers.Minf32(topRight.Y(), bottomLeft.Y()),
+		mathhelpers.Minf32(topRight.Z(), bottomLeft.Z()),
 	}
 
 	// Then move it into position based on the translation
@@ -78,3 +78,32 @@ func (self *AABB) IntersectsArray(other *AABB) []bool {
 
 	return boolArray
 }
+
+// HorizontalCollisions returns true if the our box hit the 'other' box on the X axis.
+// This is expected to be called after checking for a general intersection with Intersects()
+func (self *AABB) HorizontalCollision(other *AABB) bool {
+
+	right := self.TopRight.X() - other.BottomLeft.X()
+	left := self.BottomLeft.X() - other.TopRight.X()
+
+	right = mathhelpers.Absf32(right)
+	left = mathhelpers.Absf32(left)
+
+	min := mathhelpers.Minf32(right, left)
+
+	return mathhelpers.Absf32(min) < 0.1
+
+}
+
+func (self *AABB) VerticalCollision(other *AABB) bool {
+	top := self.TopRight.Y() - other.BottomLeft.Y()
+	bottom := self.BottomLeft.Y() - other.TopRight.Y()
+
+	top = mathhelpers.Absf32(top)
+	bottom = mathhelpers.Absf32(bottom)
+
+	min := mathhelpers.Minf32(top, bottom)
+
+	return mathhelpers.Absf32(min) < 0.1
+
+}

pkg/mathhelpers/mathhelpers.go

@@ -28,7 +28,7 @@ func AngleBetweenVectors(v1, v2 mgl32.Vec3) (float32, error) {
 	return float32(angle), nil
 }
 
-func Max32f(a, b float32) float32 {
+func Maxf32(a, b float32) float32 {
 	if a >= b {
 		return a
 	} else {
@@ -36,10 +36,18 @@ func Max32f(a, b float32) float32 {
 	}
 }
 
-func Min32f(a, b float32) float32 {
+func Minf32(a, b float32) float32 {
 	if a <= b {
 		return a
 	} else {
 		return b
 	}
 }
+
+func Absf32(a float32) float32 {
+	if a < 0 {
+		a = a * -1
+	}
+
+	return a
+}