Subtracting a string from inside a CALayer. Like an cut out mask in Photoshop.

example.m

CALayer *myLayer = [CALayer layer];
[myLayer setFrame:rect];
	
[myLayer setBackgroundColor:[myColour CGColor]];
[myLayer setCornerRadius:radius];

UIGraphicsBeginImageContext([myLayer frame].size);
	
CGContextRef context = UIGraphicsGetCurrentContext();
	
CGContextSaveGState(context);
[myLayer renderInContext:context];
CGContextRestoreGState(context);
	
CGContextSetBlendMode(context, kCGBlendModeClear);
	
[myString drawInRect:myStringsBounds withFont:[UIFont boldSystemFontOfSize: 11]];
	
CGContextSetBlendMode(context, kCGBlendModeNormal);
	
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
	
UIGraphicsEndImageContext();
	
[outputImage drawInRect:rect];

gistfile1.c

CALayer *myLayer = [CALayer layer];
[myLayer setFrame:rect];
	
[myLayer setBackgroundColor:[myColour CGColor]];
[myLayer setCornerRadius:radius];

UIGraphicsBeginImageContext([myLayer frame].size);
	
CGContextRef context = UIGraphicsGetCurrentContext();
	
CGContextSaveGState(context);
[myLayer renderInContext:context];
CGContextRestoreGState(context);
	
CGContextSetBlendMode(context, kCGBlendModeClear);
	
[myString drawInRect:myStringsBounds withFont:[UIFont boldSystemFontOfSize: 11]];
	
CGContextSetBlendMode(context, kCGBlendModeNormal);
	
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
	
UIGraphicsEndImageContext();
	
[outputImage drawInRect:rect];

gistfile1.m

CALayer *myLayer = [CALayer layer];
[myLayer setFrame:rect];
	
[myLayer setBackgroundColor:[myColour CGColor]];
[myLayer setCornerRadius:radius];

UIGraphicsBeginImageContext([myLayer frame].size);
	
CGContextRef context = UIGraphicsGetCurrentContext();
	
CGContextSaveGState(context);
[myLayer renderInContext:context];
CGContextRestoreGState(context);
	
CGContextSetBlendMode(context, kCGBlendModeClear);
	
[myString drawInRect:myStringsBounds withFont:[UIFont boldSystemFontOfSize: 11]];
	
CGContextSetBlendMode(context, kCGBlendModeNormal);
	
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
	
UIGraphicsEndImageContext();
	
[outputImage drawInRect:rect];