macOS NSView and drawing background only once

[kamy]

Hi guys,

Am back with more drawing fun!

So am drawing images and animating them on an NsView which is on a
Window.

Here is what i do

    - (void)drawRect:(NSRect)rect
    {
            [self animateFrame:rect];
    }

In the animateFrame method - i do
a) Set background image
b) Do the animations

- (void)animateFrame: (CGRect) rect
{
              //backgroundImage is NSImage
               [backgroundImage drawInRect:rect
                                   fromRect:NSMakeRect(0, 0,    
                                   backgroundImage.size.width, 
                                   backgroundImage.size.height)
                                  operation:NSCompositeCopy
                                   fraction:1.0f];

               //Do more crazy animations
           
}

So far so good.
But i feel i can draw the background image only once instead of doing it every 0.2 seconds - Just to optimise things.

So when i take that line out and place it somewhere else. It draws the background for the first time and when 'drawRect' is fired again by timer - The background is gone - am assuming repainted.

So my question is - Is there a way to preserve the background drawing even as drawRect is invoked repeatedly?

Am scrounging through the Apple docs but i though i will ask the Guru's here!

Thanks!
KamyFC