ID:2086681
 
Resolved
Image updates didn't appear on the correct map tick, and in some environments they didn't appear until a fresh map draw.
BYOND Version:510.1344
Operating System:Windows 10 Home 64-bit
Web Browser:Chrome 50.0.2661.102
Applies to:Dream Seeker
Status: Resolved (510.1345)

This issue has been resolved.
Descriptive Problem Summary:
When applying an image to a /turf via MouseEntered() or MouseExited(), it lags behind by a tile. The location is set to the correct /turf, but the image is drawn on the tile I had moved my mouse over from.

Numbered Steps to Reproduce Problem:
see Code Snippet

Code Snippet (if applicable) to Reproduce Problem:
mob/player
var/tmp/image/move_indicator

turf/MouseEntered(location,control,params)
if(istype(usr, /mob/player))
var/mob/player/p = usr
if(!p.move_indicator)
p.move_indicator = image('indicator.dmi',src,"Red",FLY_LAYER,null)
p << p.move_indicator
else
world << "[src.x] [src.y]" //outputs the turf's x/y
p.move_indicator.loc = src //set to turf I entered before this /turf
world << "[p.move_indicator.x] [p.move_indicator.y]" //outputs the turf's x/y, they match


Expected Results:
Image to be drawn on the correct turf.

Actual Results:
Image is drawn on the turf I moved my mouse from.

Does the problem occur:
Every time? Or how often? yes
In other games? dont know
In other user accounts? dont know
On other computers? dont know

When does the problem NOT occur?

When I revert to 510.1339

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.)

510.1339 was the last version this worked. From 510.1340 and up, it stopped functioning properly.

Workarounds:

Revert to 510.1339
I can't reproduce this. I'll need a test case.

I tried your code in a test project and didn't see the problem. I thought maybe the fact that there are screen objects being animated might be relevant, so I tried on a more vanilla project. Same thing: The image was always on the correct square in 510.1344.
Lummox JR changed status to 'Unverified'
Lummox JR resolved issue with message:
Image updates didn't appear on the correct map tick, and in some environments they didn't appear until a fresh map draw.