ID:2124286
 
Resolved
Certain large view sizes could cause tiles near a corner of the viewing area to disappear.
BYOND Version:511.1350
Operating System:Windows 7 Ultimate 64-bit
Web Browser:Chrome 51.0.2704.103
Applies to:Dream Seeker
Status: Resolved (511.1351)

This issue has been resolved.
Descriptive Problem Summary:

http://files.byondhome.com/Ter13/PixelBender_src.zip

I can't describe this. Something is wrong. Run the demo. It has to be seen.

WTF is going on?
Well, it looks like the floober flabber is connecting to the jibber jabber, which in turn makes the dilly dadler react violently.

No, but srs. I just see a navy and (REALLY LIGHT) cyan pixel being drawn in a striped pattern across the screen.
Look at the top-right corner. That black space shouldn't be there. The viewport is ditching tiles, but in a really, really strange way.
Okay, I saw that. I just wasn't sure if it was intentional.
This has been a thing since forever, iirc. Also, if you move northeast, it disappears (is filled in).
I'll take a look Monday and see what's going on.
I'm a little late getting to this, but it appears to be (as I suspected) an overflow issue. 80+60 > 127, hence the trouble.

Switching several of the 1-byte values in view calculations to 2-byte values fixes it.
Lummox JR resolved issue with message:
Certain large view sizes could cause tiles near a corner of the viewing area to disappear.