Map Editor Not Drawing Objects in the correct Order [conditions applied]

ID:871845
 
Jul 15 2012, 10:34 am
Keywords: drawing, layer, same
BYOND Version:496
Operating System:Windows 7 Pro
Web Browser:Chrome 20.0.1132.57
Applies to:Dream Maker
Status: Open
Issue hasn't been assigned a status value.
Descriptive Problem Summary:
Usually in the Map Editor, Objects(atoms) of the same layer are drawn in the order they are placed on the Map.(Pretty neat and logical)

However, when atoms have a pixel_x or pixel_y (maybe pixel_z also?) components, this is not found to be always true..

This image should explain more clearly.


Numbered Steps to Reproduce Problem:
1.Download the Project
2.Follow the instructions inside the LayerTest.dm


Basically use the Map Editor and see the results based on the objects I have defined there.

Expected Results:
The Atoms if having the same layer should be drawn in the order of their placement on the map.


Actual Results:
Some tiles are drawn under the atoms placed previously..

Does the problem occur:
Every time? Or how often?
Every time when the conditions are true..

When does the problem NOT occur?
Avoid Using pixel_x,pixel_y and maybe pixel_z.


Workarounds:
None known yet... (even though I do have a Hypothesis, =P)
Jul 15 2012, 12:20 pm
I'd also like to point out something similar exists in Dream Seeker. Overlapping big atoms have their sprites swap layers depending on their position in relation to the player.
Jul 15 2012, 12:43 pm
Yes of course.When I say there is such a problem in Dream Maker I also mean that naturally there is the same problem in Dream Seeker.
Jul 15 2012, 1:07 pm
It's probably worth noting that you're using the depreciated TILED_ICON_MAP format in your example.

However, I am still seeing the "swapping" effect at runtime that SuperAntx mentioned, even after switching to the TOPDOWN_MAP format.
Jul 15 2012, 2:48 pm
If it makes any difference (although I mentioned it in its own bug report), SIDE_MAP had some pretty bad swapping and unexpected effects. After a fix or two, it still isn't perfect. Sometimes moving south against the north face of a tall object shows you over it instead of the expected perspective result.
Jul 15 2012, 4:39 pm
A big part of the problem is that the layering engine is not able to fully resolve all cases where objects are on the same layer. TOPDOWN_MAP will not fix this.

The ultimate solution is probably a topological sort, but this has been fairly iffy in implementation. It's something I do plan to revisit.
Jul 15 2012, 11:49 pm
In response to Lummox JR
Lummox JR wrote:
The ultimate solution is probably a topological sort, but this has been fairly iffy in implementation. It's something I do plan to revisit.

I hope you revisit soon.