Re: Core Animation geometry, layer hosting, and resolution independence

FROM : Jens Alfke
DATE : Wed Mar 12 23:35:35 2008

On 12 Mar '08, at 2:49 PM, Nathan Vander Wilt wrote:

> I don't understand what this "base" coordinate system
> is (not the window's, otherwise the conversions would
> likely be offset by the view's position therein,
> right?). But whatever it is, it seems to be shared by
> the CALayer.



The Cocoa Drawing Guide, under "Pixel-Exact Drawing", says:
"These convenience methods make it possible to convert values to and 
from the base (device) coordinate system. They take into account the 
current backing store configuration for the view, including whether it 
is backed by a layer."

In a layer-backed NSView, it seems that the 'device', aka backing 
store, is the view's CALayer; so these methods will convert to/from 
the layer's coordinates.

I'll go update GeekGameBoard now...

—Jens