Virtual Joystick Ghosting

Monkey Targets Forums/Android/Virtual Joystick Ghosting

Sam	(Posted 2012) [#1]

I'm trying to write a virtual joystick library, and I've gotten it working with one joystick at a time, but when I try to interact with more than that, it gets weird. If I place a thumb on both, then move one up or down, the other one moves slightly, then jumps back into place. I would really appreciate some input.

Import mojo

Global touchArr:Bool[32]

Class vJoy
	Private
	Field joyX:Float,joyY:Float
	Field x:Float,y:Float
	Field angle:Float
	Field innerRadius:Float,outerRadius:Float
	Field touching:Bool
	Field touch:Int
	Field radius:Float
	
	Method dist:Float(x1:Float,y1:Float,x2:Float,y2:Float)
		Return Sqrt(Pow(y2-y1,2) + Pow(x2-x1,2))
	End	
	
	Method testTouches:Int()
		For Local i = 0 Until 32
			If Not touchArr[i]
				If TouchDown(i)
					Return i
				Else
					touchArr[i] = False
				Endif
			Endif
		Next
		Return -1
	End
	
	Public
	Method New(radius:Float,x:Float,y:Float)
		outerRadius = radius
		innerRadius = radius/3
		
		radius = (outerRadius - innerRadius)
		
		Self.x = x
		Self.y = y
				
		joyX = x
		joyY = y
		angle = 0
		
		touching = False
	End
	
	Method update:Void()
		If Not touching
			touch = testTouches()
		Endif
		
		If touch > -1
			If Not TouchDown(touch)
				touching = False
				touchArr[touch] = False
				joyX = x
				joyY = y
				
				Return
			Endif
		
			If dist(TouchX(touch),TouchY(touch),x,y) < (outerRadius-innerRadius)
				touching = True
				touchArr[touch] = True
				joyX = TouchX(touch)
				joyY = TouchY(touch)
			Else
				If touching
					'angle = 90 + ATan2(TouchX(touch) - x,TouchY(touch) - y)
					'joyX = (outerRadius - innerRadius)*Cos(angle) + x
					'joyY = (outerRadius - innerRadius)*-Sin(angle) + y
				Endif
			Endif
		Endif
	End	
	
	Method getX:Float()
		Return 100*(joyX - x)/(outerRadius-innerRadius)
	End
	
	Method getY:Float()
		Return 100*(y - joyY)/(outerRadius-innerRadius)
	End
	
	Method getTouch:Int()
		Return touch
	End
	
	Method draw:Void()
		SetColor(255,255,255)
		DrawCircle x,y,outerRadius
		SetColor(0,0,0)
		DrawCircle x,y,outerRadius-2
		
		SetColor(255,255,255)
		DrawCircle joyX,joyY,innerRadius
		
		'set the color back to white, to not mess with user drawings
		SetColor(255,255,255)
		'DrawText angle,0,24
	End
End

Class MyApp Extends App

	Field joy1:vJoy
	Field joy2:vJoy
	
	Method OnCreate()
		joy1 = New vJoy(150,150,DeviceHeight()-150)
		joy2 = New vJoy(150,DeviceWidth()-150,DeviceHeight()-150)
		
		For Local i:Int = 0 Until 32
			touchArr[i] = False
		Next
		
		SetUpdateRate 60
	End
	
	Method OnUpdate()
		joy1.update()
		joy2.update()
	End
	
	Method OnRender()
		Cls
		joy1.draw()
		joy2.draw()
		DrawText "Touch 1: " + joy1.getTouch(),0,0
		DrawText "Touch 2: " + joy2.getTouch(),0,12
	End
End

Function Main()
	New MyApp
End

therevills

(Posted 2012) [#2]

What device are you testing on? It could be that the device does not really support multiple touches...

Fryman

(Posted 2012) [#3]

Some devices get confused if the joysticks are both placed on the bottom of the screen. My old San Francisco used to suffer from this.

Sam	(Posted 2012) [#4]

I'm testing on my Motorola Triumph. I know it supports multiple touches.

Fryman

(Posted 2012) [#5]

Try setting one joystick to appear in the top left of the screen and the other in the bottom right, and see if you have the same problem.

You can also test how accurate the multitouch is by using multitouch tester from the market

If you look on the Motorola Triumph on the XDA forums it is a phone which suffers from Multitouch snapping

Sam	(Posted 2012) [#6]

Thanks. I tried it on my Notion Ink, and it seems to work, there's still just a little bit of jumping.