ios - execute drawRect on every frame? -

i'm trying implement custom view visualizes value changing in real time (like example volume of audio output), , achieve have drawrect execute every animation frame render correct view state value.

the solution can think of set timer execute 60 times per second, , call view.setneedsdisplay() i'm sure not best way behavior , guarantee smooth performance.

edit give slightly more concrete example

so situation have this:

//there variable changing continuously var dynamicfoo : double!  //i want create view class renders foo in real-time class foovisualizerview : uiview {     //i have drawing code renders foo @ given value    override func drawrect(rect: cgrect) {        valuedependantdrawfunction(dynamicfoo)    }  } 

ideally foovisualizerview redraw on every animation frame.

a cadisplaylink sounds want - timer called every time screen updated. can call setneedsdisplay display link method.

note though code needs complete in 1/60 of second method or terrible.