See Quartz 2D PG: Transparency Layers
Using CGContextBeginTransparencyLayer/CGContextEndTransparencyLayer may be a solution to avoid doing a 2-step rendering (first tinting, then do the final rendering), by using layers instead of generating a first UIImage then using it to generate the second, final image.
This is only a hypothesis and some stuff to experiment — maybe that won't do it, but it's worth testing and digging a bit to check if that may be interesting.
See Quartz 2D PG: Transparency Layers
Using
CGContextBeginTransparencyLayer/CGContextEndTransparencyLayermay be a solution to avoid doing a 2-step rendering (first tinting, then do the final rendering), by using layers instead of generating a firstUIImagethen using it to generate the second, final image.This is only a hypothesis and some stuff to experiment — maybe that won't do it, but it's worth testing and digging a bit to check if that may be interesting.