Draw materials in tile atlas view

[KoBeWi]

Fixes #77672

godot.windows.editor.dev.x86_64_jduJMJS1OT.mp4

Test TileSet:
Shaderset.tres.txt
(requires icon.png)

There is also a separate (and unreported?) issue where the "ghost" tiles (i.e. when drawing on TileMap) are not using their material.

[groud]

Soooo. I've been thinking about it a bit and I am a bit worried this cached materials pool could become big as it is only cleaned when changing sources. While most of the edits only trigger queue_redraw.

I would be more confident if the cache was cleaned dynamically in the drawing functions. The idea would be, when drawing, to keep track of the materials in the cache that were not used by any tile, then free the corresponding CanvasItems at the end of the drawing function.

Also, this needs to be implemented for _draw_alternatives, which means you probably need two HashMaps to store the CanvasItems.

[KoBeWi]

Soooo. I've been thinking about it a bit and I am a bit worried this cached materials pool could become big as it is only cleaned when changing sources. While most of the edits only trigger queue_redraw.

I implemented what you said and then discovered that material change always results in set_atlas_source(), so removing unused materials is useless 🙄

[KoBeWi]

Ok pushed fix for alternate tiles. I did not add removing unused materials for the reason described above.

[groud]

I implemented what you said and then discovered that material change always results in set_atlas_source(), so removing unused materials is useless roll_eyes

hmm, that sounds like a bug though. I don't really understand why that would be triggered.
I guess it can be merged as is anyway, it's not a big deal.

[akien-mga]

Thanks!

[vmedea]

Can confirm this solves #77672. This is so much better thank u!!!

[YuriSizov]

Cherry-picked for 4.0.4.