One of my main game features (visually) is the overlay texture I'm using. This overlay texture is full screen, and covers the entire screen which gives it a nice transparent pattern. On my PC and Mac builds, the impact to my framerates are minimal at best. On my iPad, I lose 15fps automatically.
I did some google searching, but didn't quite find a solution yet. The overlay image is 1024x768 and fits the entire iPad screen nicely. At first I assumed it was because the texture wasn't POT. So I tried splitting it into two textures: 1024x512 and 1024x256. Still to slow. So I tried googling some more. It turns out that the fill rate for mobile devices (especially a 1st Gen iPad) isn't nearly as fast as a PC or Mac video card. That's understandable because the entire quad uses alpha blending and the entire screen has to be processed by the fragment program, but I still haven't quite found a solution yet.
One idea I had was to render a few rows of 32x32 textured quads. The other idea is to get a new iPad. Tbh, I was trying to hold off on getting a new iPad because I'm saving for other hardware as well as licenses (fortunately for me, I can save up more than $1000 USD per month easily). On top of that, I want my game to work at proper speeds on an iPad2. When my game is ready, I will likely make it iOS7 exclusive anyway. And lastly, I plan on presenting this game at a public event in Seattle in early April, so I have to get the frame rates working acceptably before then (nobody wants to spend too much time on fixing a minuscule problem when there are other features that need to be finished).
I'm sure someone else has had the same problem here, but I still haven't managed to google any solutions. This sucks. Any ideas? Thanks.