When inside of an /area with the PLANE_MASTER appearance flag set the client will start using an extra 5-10% CPU power and visibly slowdown while moving through the area, standing still lets CPU settle back down.
Numbered Steps to Reproduce Problem:
1) Create project.
2) Add any area with PLANE_MASTER set to the map.
3) Walk into said area.
4) Walk around inside of said area a bit.
Code Snippet (if applicable) to Reproduce Problem:
area/bad_area
appearance_flags = PLANE_MASTER
Expected Results:
I didn't really expect it to do anything, I actually set the value accidentally and couldn't figure out why things were running so slowly. Using a ton of CPU probably isn't expected though.
Actual Results:
Sluggish movement, client lag, high CPU usage.
Does the problem occur:
Every time? Or how often? Every time
In other games? Every project I've tested
In other user accounts? Yep
On other computers? Yep
When does the problem NOT occur? When not inside of the area in question.
Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)
Definitely didn't exist in 510 ;)
Workarounds:
Not using PLANE_MASTER inside of /area, slowdown happens in both software and hardware mode.
I'm guessing that it's trying to process each tile as a separate PLANE_MASTER rather than as a single entity.