XPilot For Windows FAQ (Threaded Draw)

April 28, 1997

An Explanation of Threaded Draw

As you should have read, one of the big problems with XPilotNT is the amount of data drawn. This data is in the form of one big hairy bitmap (the playfield). When i tell Windows to copy the new offscreen bitmap onto the screen, the program sits and waits for (hopefully) the video hardware to copy the data. During this time, the CPU could be doing exciting things, like reading more network packets and preparing another bitmap to be drawn.

The threadedDraw option makes XPilotNT run in 2 threads. The main thread does all the fun stuff. The second thread waits to be notified that a bitmap is ready; and tells Windows to draw it. This second thread is the one that gets stuck waiting for the hardware to finish. Hopefully, the main thread can continue.

On NT, this works great. On Windows 95, this works sometimes (surprise). In fact, it can reduce performance. That's why i made it a user configurable option.

"Why not use DirectX?"
When i last checked, DirectX only supported 640x480. XPilotNT can use a 1024x1024 window. (If you have a smaller screen, then you see less of the game.) Also, DirectX requires big video ram. So if you're running anything bigger than 800x600, think 8 or 16MB video card.

Also, i keep reading horror stories about messing people's computers up with the DirectX auto-installer. I'm not interested.