Anyone here to iphone programming?

sorry mods, i know this probably isn’t the appropriate place for this question, but i wasn’t sure where else to put it (and it kind of relates to AS3)

I want to make an iphone game, using some bitmap generating algorithms i’ve developed and used in AS3. the thing is, i’m new to xcode/objective-c and programming on a (ugh) mac, and can’t find out how to do certain things. in actionscript, what i would do is create a bitmapdata object, and use the setpixel function to shade each pixel according to an algorithm, to make some pretty looking gradients. is anyone here familiar with obj-c, and know what the equivelents to flash’s bitmapdata object (and it’s setpixel function) would be? if so, if you could point me in the right direction here i’d really appreciate it, thanks!