11.Touches

11. Touches

-- test

-- Use this function to perform your initial setup
function setup()
    if backup then Backup("pinch") end
    img=readImage("Small World:Mine Medium")
    p=pinch()
end

function draw()
    background(0)
    p:processTouches()
    sprite(img,WIDTH/2,HEIGHT/2,500*p.zoom)
end

function touched(touch)
    p:touched(touch)
end


pinch=class()

function pinch:init()
    self.tb={}
    self.zoom=1
end

function pinch:touched(touch)
    if touch.state==ENDED then self.tb={} self.d1=nil self.d2=nil
    else table.insert(self.tb,{x=touch.x,y=touch.y}) end
end

function pinch:processTouches()  
    if #self.tb==2 then 
        local v1,v2=vec2(self.tb[1].x,self.tb[1].y), vec2(self.tb[2].x,self.tb[2].y)
        self.d1=v1:dist(v2)
    end
    if self.d2~=nil then self.zoom=self.zoom*self.d1/self.d2 end
    self.d2=self.d1  self.tb={}
end