Hello !
I'm creating some games for Android/iPhone devices and I want to know which way is the best to do HUD : - Should I use GUITexture so I can create Atlas and reduce the number of draw calls - Or can I go with OnGUI and use drawTexture ? (can I use an atlas with OnGUI ?)
Thanks !
If you're designing for mobile, OnGUI is plain out. Every single OnGUI call is drawn with every frame, which effectively (in a best case scenario) doubles the load on the system.
If you design anything more complex than a couple of buttons, 20 OnGUI elements prove to be slower than 70-80 animated sprites (actual experience figures). Draw everything with GUITextures (or sprites), and track touches. GUITextures even have events to handle touch, so that should make them sexy once you wrap your head around their transforms.
GUITexture is definitely the way to go on Mobile. OnGUI is not only not as easy to use, but it's way more expensive.
Test Prime31's GUISprite classes. They are all single draw call, and optimized very nicely.
https://github.com/prime31/P31UnityAddOns/tree/master/GUISpriteUI