ID:113035
 
Not a bug
BYOND Version:481
Operating System:Windows XP Home
Web Browser:Chrome 11.0.696.65
Applies to:Dream Seeker
Status: Not a bug

This is not a bug. It may be an incorrect use of syntax or a limitation in the software. For further discussion on the matter, please consult the BYOND forums.
Descriptive Problem Summary:
Icons seem to randomly disappear as a user moves. This is only occurring on icons or images bigger than 32x32.
Numbered Steps to Reproduce Problem:
1. Create a map
2. Fill the map with a turf(in my case grass)
3. Place a icon or image that is bigger then 32x32 on the map(I have click behavior set to insert instance on click)
Code Snippet (if applicable) to Reproduce Problem:


Expected Results:
The image or icon should appear exactly as how it was placed on the map.
Actual Results:
One tile of the image usually disappears randomly as a user moves towards or away from it. Here are some screenshots showing this behavior in action!
http://imageshack.us/photo/my-images/685/bug2jv.png/


http://imageshack.us/photo/my-images/220/bug1g.png/

Does the problem occur:
Every time? Or how often?Every Time
In other games? No Clue
In other user accounts? Yes
On other computers? Yes

When does the problem NOT occur?
Sometimes when there is no icon under the image or icon.
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.)

Workarounds:
Delete any underlaying icon or image.
I had this problem before with larger icons.

Usually fixed when I set it to a layer that was higher than the turf it's below.
Because if the icon is on the same layer as thee one below it, the extra pieces will clash with the ones below it.

Set the tent's layer to layer=TURF_LAYER+1 or anything that's higher than the grass' layer. Usually worked for me.
Big icons should be pulling themselves in front of icons on the same layer, but it's possible that micro-layer differences are impacting the result. Since I can't reproduce this, can you upload a demo that shows it in action? If you don't have a demo, you can email a .zip of the source to me at [email protected] and just tell me what I need to do to get to the part that shows the bug.
Lummox I sent you a email with the source attached. The emails subject was Runtime Graphics bug.
On further investigation (sorry it took so long to get to this) I have discovered this is not a bug. Your code did show the problem in action, but after stepping through thoroughly I discovered the issue.

The problem you're having is that the big icon you're using is not the turf's main icon; it is an underlay. The main icon is just a simple 32x32. The turf in question is type /turf/Dane, and has the /turf/Tent that should display the big icon as an underlay. Because it isn't the main icon, it doesn't use the "pull forward" behavior that big icons have to try to overcome ambiguous layering situations that arise from giving them the same layer as the surrounding icons.

There is a simple workaround to this that doesn't involve deleting any other underlays: give /turf/Tent a slightly higher layer, such as TURF_LAYER+0.01, which will completely resolve the ambiguity.