Two quick questions...

FatalCrest

Um, Why is it important that all exported sprites pixel dimensions be divisible by 4?

Anddd what happens if we don't design a game to fit the 960x480 iPhone resolution?

synthesis

The power of 4 rule is simply a doubling of the power of 2 rule. It is necessary if using Resolution Independence. This is because when GS reduces the larger images is half...you want to have an even number for the width and height...so that when GS places the image...it doesn't center its placement on a half pixel...but rather it places it between pixels with an equal number of pixels on each side of the center point. If its an odd number...it can cause blurring.

There are tons of posts already on this subject in the forum...do a search if you need more details.

Resolution Independence is an option. You don't have to use it. A game will still play on the iPhone 4...however the lower quality of image resolution will be noticeable on the sharper screen of the new device.

FatalCrest

Thanks!
I've been worried about my game lately haha

StusApps

also the power of 2 (2,4,8,16,32,64,128,256,512,1024) relates to memory usage in your game.

Example as I understand it:

A graphic that is 60 pixels by 60 pixels will use the same memory as one that is 64x64.

Therefore if you use a 66x66 then it will use the same memory as a 128x128 graphic, resizing it down to 64x64 will result in a memory saving in game. Imagine it as rounding up to the nearest number on the list at the top.

To a large degree this might be unavoidable as graphic sizes at these resolutions might not work well for your game. But on some graphics it could save you a little ram.