CodeaTuts Joystick Help

CodeaTutsJoystick.lua

--# Joystick
Joystick=class()

function Joystick:init(x,y,id,type)
    self.id=id
    self.type=type
    self.ox=x
    self.oy=y
    self.cx=x    
    self.cy=y
    self.dx=0
    self.dy=0

    self.c=20
    self.bSpeed = 2
end

function Joystick:draw()
    stroke(255)
    strokeWidth(2)
    fill(255,255,255,100)
    ellipse(self.ox,self.oy,150)
    if self.type=="move" then
        heroX=heroX+(self.cx-self.ox)/10
        heroY=heroY+(self.cy-self.oy)/10
    end
    if self.type=="shoot" then
        bDirection=vec2(self.cx-self.ox,self.cy-self.oy)
        bDirection=bDirection:normalize()
        if math.abs(bDirection.x+bDirection.y)>0 then
            self.dx=bDirection.x*self.bSpeed
            self.dy=bDirection.y*self.bSpeed
            self.c=self.c+1
            if self.c>12 then
                table.insert(bTable,vec4(heroX,heroY,self.dx,self.dy)) 
                self.c=0
            end  
        end        
    end
end

function Joystick:touched(touch)
    for jsKey,jsInstance in pairs(jsTable) do
        if touch.id==jsInstance.id then
            if touch.state==MOVING then
                jsInstance.cx=touch.x
                jsInstance.cy=touch.y
            end
            if touch.state==ENDED then
                table.remove(jsTable,jsKey)
            end
        end
    end    
end
--# Main
--displayMode(FULLSCREEN)

function setup()
    heroX,heroY=WIDTH/2,HEIGHT/2
    jsTable,bTable={},{}
    
    parameter.watch("screenX")
    parameter.watch("screenY")
end

function draw()
    background(40, 40, 50)
    for jsIndex,jsInstance in pairs(jsTable) do
        jsInstance:draw()
    end
    fill(255)
    for bIndex,bInstance in pairs(bTable) do
        ellipse(bInstance.x,bInstance.y,10)
        bInstance.x=bInstance.x+bInstance.z
        bInstance.y=bInstance.y+bInstance.w
        if bInstance.x<0 or bInstance.x>WIDTH or bInstance.y<0 or bInstance.y>HEIGHT then
            table.remove(bTable,bIndex)
        end
    end
    sprite("Platformer Art:Guy Standing",heroX,heroY,25)
end

function touched(touch)
    if touch.state==BEGAN then
        if touch.x<WIDTH/2 then
            for a,b in pairs(jsTable) do
                --if b.type=="move" then
                --    return  -- limit 1 move joystick
                --end
            end
            table.insert(jsTable,Joystick(touch.x,touch.y,touch.id,"move"))
        else
            table.insert(jsTable,Joystick(touch.x,touch.y,touch.id,"shoot"))    -- allow multiple shoot
        end
    end
    for jsIndex,jsInstance in pairs(jsTable) do
        jsInstance:touched(touch)
    end
end