Make looks_like a mandatory entry for in-game objects

[I-am-Erk]

Is your feature request related to a problem? Please describe.
Presently there are thousands of unique objects, ranging from terrain and items to monsters and players, in game. In order to make a tileset that works, it is necessary to make most of these as unique graphics.

Describe the solution you'd like
The looks_like field should be mandatory for all terrain, furnitures, items,etc - anything that has a graphic in game. Note that copy-from counts as looks_like. The only exception should be monsters, as most monsters are better off without an icon if it would lead to confusing something for a weaker version.

Describe alternatives you've considered
Another possibility would be to have a generic fallback graphic for these things by category, eg. all weapons would have a default graphic, all monsters, etc - but that is potentially messy and does not necessarily convey any useful information. Because looks_like is managed by the content creator we can actually pick things that look kind of like what we're aiming for.

Additional context
This is one of several suggestions to make graphical content contribution more accessible.

[KorGgenT]

codewise this isn't hard: the hard part is adding looks_like to all the json entries. so, if someone wants to do the json i'd be happy to do the C++ here

[kevingranade]

Remember to check src == "dda" so we don't break mods, yet.

[Maddremor]

A sort of fallback could be to assign default tiles to abstract objects from which actual items are created using copy-from.

[moxian]

How do you suggest dealing with objects that don't have "look alikes"? What does Mi-Go look like? What does a backpack look like? What does a door look like?

Do you propose assigning looks_like for those to arbitrary other objects (since there's no "good" match for them anyway)?

[Fris0uman]

So for exemple: we have a bunch of different backpacks, so let's say all the backpack variants looks_like backpack then what does backpack looks_like? Does it become the reference and doesn't have a looks_like field or does it looks_like an other backpack variant, and then don't we have a problem with circular reference?

[I-am-Erk]

We probably need a root item abstract for general categories, so backpack would looks_like "wearable" or something, mi-go would looks_like "monster". The trick would be to not let people overuse this, and to have those root categories

[kevingranade]

Implementation wise, there would be a whitelist of items, monsters, terrain, etc that must have a tile.

This would be a whitelist instead of an entity property for several reasons. It makes it easier to enumerate those mandatory tile entities for tileset creators, and it makes it more obvious in code reviews when someone attempts to add a new mandatory tile.

[hexagonrecursion]

I would argue that looks_like should be optional for mobs. One of the reasons I use tiles is that it makes it easier not to confuse one monster for another. C:DDA has an impressive bestiary of monsters many of which are not generic - each may sometimes require unique tactical considerations. I much prefer mobs looking ugly to the game misleading me about the threat I am facing.

[I-am-Erk]

Yes, it's interesting this issue is old enough to still include it, because not long after I changed the tune. I'll update the issue to suit.

[hexagonrecursion]

most monsters are better off without an icon if it would lead to confusing something for a weaker version.

It's not just weaker or stronger. It's not a linear spectrum. Some monsters shoot acid, some zap electricity, some can jump, some can grab you, some can knock you down, some can throw your character several tiles away etc.