Hi!
How can we run a OpenGL applications (say a games) in higher frame rate like 500 - 800 FPS ?
For a example AOE 2 is running with more than 700 FPS (I know it is about DirectX). Eventhough I just clear buffers and swap buffers within the game loop, I can only get about 200 (max) FPS. I know that FPS isn't a good messurenment (and also depend on the hardware), but I feel I missed some concepts in OpenGL. Did I ? Pls anyone can give me a hint ?
AOE 2 is a DirectDraw application, not Direct3D. There is no way to compare OpenGL and DirectDraw.
Also, check the method you're using for swapping buffers. In Direct3D there are flip method, copy method, and discard method. The best one is discard, which means that you don't care about previous contents in the buffer, and allow the driver to manage them efficiently.
One of the things you seem to miss (judging from your answer/comments, so correct me if I'm wrong) is that you need to determine what to render.
For example as you said you have multiple layers and such, well the first thing you need to do is not render anything that is off screen (which is possible and is sometimes done). What you should also do is not render things that you are certain are not visible, for example if some area of the top layer is not transparent (or filled up) you should not render the layers below it.
In general what I'm trying to say is that it is in most cases better to eliminate invisible things in the logic than to render all things and just let the things on top end up in the rendered image.
I'm getting roughly 5.600 FPS with an empty display loop (GeForce 260 GTX, 1920x1080). Adding glClear lowers it to 4.000 FPS which is still way over 200... A simple graphics engine (AoE2 style) should run at about 100-200 FPS (GeForce 8 or similar). Probably more if it's multi-threaded and fully optimized.
I don't know what exactly you do in your loop or what hardware that is running on, but 200 FPS sounds like you are doing something else besides drawing nothing (sleep? game logic stuff? greedy framework? Aero?). The swapbuffer function should not take 5ms even if both framebuffers have to be copied. You can use a profile to check where the most CPU time is spent (timing results from gl* functions are mostly useless though)
If you are doing something with OpenGL (drawing stuff, creating textures, etc.) there is a nice extension to measure times called GL_EXT_timer_query.
Some general optimization tips:
And another thing, I wont use any fancy 3D, only drawing tons (tons == 3000) of 2D textures. So, is it possible to gain much performance by using VBO ?
If your textures are small, try to combine them in one bigger texture and address them via texture coordinates. That will save you a lot of state changes. If your textures are e.g. 128x128, you can put 16 of them in one 512x512 texture, bringing your texture related state changes down by a factor of 16.