function painting(){
    canvas.addEventListener('mousedown', down)
    canvas.addEventListener('mouseup', toggledraw)
    canvas.addEventListener('mousemove',
    function(evt){
        var mosuePos = getMousePos(canvas, evt)
        var posx =mosuePos.x
        var posy =mosuePos.y
        var tryb = "kółko" //1
        draw(canvas, posx, posy, tryb) //2
    })

    function down(){
        md = true
    }
    function toggledraw(){
        md = false
    }
    function getMousePos(canvas, evt){
        var rect = canvas.getBoundingClientRect()
        return{
            x:evt.clientX - rect.left,
            y:evt.clientY - rect.top
        }
    }
    function draw(canvas, posx, posy, tryb){ //3
        var context = canvas.getContext('2d')
        if(md){
            if (tryb == "kwadrat") //4
                context.fillRect(posx, posy, 10, 10)
            else if (tryb == "kółko")
                alert("rysowanie koła")
        }
    }
}