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Tag: optimizations

iOS Performance tips (I): Drawing shadows

Angel G. Olloqui 06 September, 2013


It is very common to see shadows in different apps. In many occasions shadows are just rendered by using an image with the shadow predrawn, which basically performs as any other UIImageView. However, sometimes you may need to draw the shadow from code. When this time comes you will face performance problems that in case of heavy use (especially in iPad in combination with table or collection views) it can slow down you UI. 
It might seem negligible, but if your view is a composition of multiple views applying shadows then you will actually experience a very big UI performance degradation. For example, in my latest project where I had a grid view with shaded cells like this:

Tags: ios, performance, optimizations, shadows


ARC (III) - ARC Optimizations

Angel G. Olloqui 02 November, 2012

In my previous two posts about ARC (post I and post II) I have talked about the optimizations and how ARC can perform as fast (or even faster) as manual memory management. This is quite clear when working with simple alloc/retain/release examples because it is exactly equivalent to manual memory management but using C calls (which are faster). However, I haven’t explain how it does it when dealing with methods that return autoreleased memory. So, it is time to have some fun.
First, lets copy again the resulting ARC compiled code seen in the first post:

Tags: arc, memory management, objective-c, xcode, optimizations