Texture performance

[JPvdB]

Hello,

I am new to iPhone development. Currently, I am thinking about writing a game that is rather graphics heavy.

I have not yet signed up to the iPhone Developer Program, as I am not sure whether I will get a reasonable performance. I am, being a student, a bit short of money and it would be a kind of a waste if I enroll only to discover that my idea is, performance-wise, too ambitious. I have googled a lot on the subject, but I keep hearing different stories about the performance that would apply to my situation.

It would be great if you guys could shed some light on the subject. The situation is as follows: there are only few polygons and basically, the game consists of lots of 2D sprites in a 3D environment. I won't be using lighting, but I will make some heavy use of alpha blending. You could see the game as a 2D game with sprites, but with the difference that it will be 3D (with perspective).
I can stuff my sprites in a large texture map (maybe two, not sure yet), but still - how fast does OpenGL ES handle lots of textures with alpha blending?

I am very sorry if similar questions have been asked before.

Thanks a lot,
JPvdB

[warmi]

Originally Posted by JPvdB

Hello,

I am new to iPhone development. Currently, I am thinking about writing a game that is rather graphics heavy.

I have not yet signed up to the iPhone Developer Program, as I am not sure whether I will get a reasonable performance. I am, being a student, a bit short of money and it would be a kind of a waste if I enroll only to discover that my idea is, performance-wise, too ambitious. I have googled a lot on the subject, but I keep hearing different stories about the performance that would apply to my situation.

It would be great if you guys could shed some light on the subject. The situation is as follows: there are only few polygons and basically, the game consists of lots of 2D sprites in a 3D environment. I won't be using lighting, but I will make some heavy use of alpha blending. You could see the game as a 2D game with sprites, but with the difference that it will be 3D (with perspective).
I can stuff my sprites in a large texture map (maybe two, not sure yet), but still - how fast does OpenGL ES handle lots of textures with alpha blending?

I am very sorry if similar questions have been asked before.

Thanks a lot,
JPvdB

On the older model (3g) I was able to pump out about 350 32x32 alpha blended sprites + full screen dual blended background ( 2 textures blended with combiners ) while maintaining around 32 fps.

On the 3gs , the number went up to around 1750.

[mlfarrell]

I think you'll be fine. My game is 3D and does well over 20,000 texture mapped polygons with frame rates in the 30-60 range. On the non-3gs I need to cut that down some.

2D performance should be fine. The trick is to merge all of your drawing into as few of opengl calls as much as possible. Say if you have 100 images to render, instead of calling glDrawArrays 100 times with 100 state & texture changes, do fewer calls using 1 big collage texture containing multiple subimages.