CCovell Stretch demo

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CCovell Stretch demo
by hap on 2005-06-15 (#2464)

http://nesdev.com/Stretch.zip

What causes emulators to show garbage inside and to the right of the wave ?
... cause mine doesn't, it shows black lines instead, and I think that's a bad thing :p

by tepples on 2005-06-15 (#2466)

It has something to do with how the NES prefetches the first two tiles of the next scanline.

by hap on 2005-06-15 (#2470)

Hmm, it updates the ppu address mid-scanline. I was filling the background scanline buffer using the x tile offset from the ppu address, and that's why this demo didn't look messy in my emulator. But, it's plain wrong handling it that way, so I've fixed it and it looks alright now (meaning: lots of garbage). Plus, it fixed Rad Racer, maybe some other stuff too.