I have a Quartz Drawing problem

Alex1987 · 10-24-2009, 06:17 PM

Hi guys,

I have a view (MKMapView) and on it I've a transparent view on which I draw different things. Now I would like to give the user the option to erase things so that the "background view" (the mapView) will be seen in the erased places. Do you think it's possible?

Thanks

Alex1987 · 10-25-2009, 01:02 PM

There are apps that do something of the sort, so I know it can be done. Sumthing with layers or stencil buffer perhaps. Nobody knows?

mkzero · 10-25-2009, 01:18 PM

I think you can simply use the drawRect method in your UIView. You can pass a rectangle that should be drawn and if you get the touches and calculate a rect around them you should be able to "erase" the rect the user touches.
Not sure if this is too much effort though ;-)

Alex1987 · 10-25-2009, 02:02 PM

Quote:

Originally Posted by mkzero

I think you can simply use the drawRect method in your UIView. You can pass a rectangle that should be drawn and if you get the touches and calculate a rect around them you should be able to "erase" the rect the user touches.
Not sure if this is too much effort though ;-)

Well it's not that easy. What if a user draws a circle and then erases part of it (let's just say that the erased area is not a rectangle) - what then?