What algorithm are you using to speed up your collision checks? Do you use a grid?
And as to the backbuffer thing, yes I know what double buffering is and how it works. Also there is no SetBuffer BackBuffer in BlitzMax. You should look at the OpenGL documentation. When you Flip() your backbuffer to make it visible on the display, you are NOT guaranteed what the contents of that buffer will be when you flip again. It *might* be the content that it had when you last flipped, OR it might be garbage, OR it might be some entirely new buffer which you haven't used yet, OR you might get a cycling sequence of several backbuffers.
The whole `mouse lag` issue is directly the result of the way that the graphics drivers sometimes allocate multiple back buffers and cycle through them so that the one you rendered to might not even be displayed until several frames later. I'm not saying that when you Flip() you would be several frames behind (especially if you have a fix for the lag issue), but I am saying that you cannot 100% trust that your buffer contents will be preserved after a flip. It would be GREAT if that were the case, and you could actually keep the buffer content, because that would make things like tilemap scrollers much easier - you could do things like dirty overlapping rectangles and all that. But you can't reliably do that.
I can tell you that on my iBook your game flashes and flickers like crazy because it uses multiple backbuffers and by the time your front buffer becomes your next used backbuffer it's several frames behind.
And as to the backbuffer thing, yes I know what double buffering is and how it works. Also there is no SetBuffer BackBuffer in BlitzMax. You should look at the OpenGL documentation. When you Flip() your backbuffer to make it visible on the display, you are NOT guaranteed what the contents of that buffer will be when you flip again. It *might* be the content that it had when you last flipped, OR it might be garbage, OR it might be some entirely new buffer which you haven't used yet, OR you might get a cycling sequence of several backbuffers.
The whole `mouse lag` issue is directly the result of the way that the graphics drivers sometimes allocate multiple back buffers and cycle through them so that the one you rendered to might not even be displayed until several frames later. I'm not saying that when you Flip() you would be several frames behind (especially if you have a fix for the lag issue), but I am saying that you cannot 100% trust that your buffer contents will be preserved after a flip. It would be GREAT if that were the case, and you could actually keep the buffer content, because that would make things like tilemap scrollers much easier - you could do things like dirty overlapping rectangles and all that. But you can't reliably do that.
I can tell you that on my iBook your game flashes and flickers like crazy because it uses multiple backbuffers and by the time your front buffer becomes your next used backbuffer it's several frames behind.