Add swimable property to node

[SnoutBug]

Problem

Currently nodes support various properties such as

• climbable
• walkable
  etc.

Wether you can swim in a node is defined by the liquid type, however.
Something like swimable quicksand is not possible to code with ease. Sand is not a liquid.

Solutions

Add swimable as a property to a node, and detach it from the liquid property.

Alternatives

Using climbable, but this does not behave like swimming

Additional context

No response

[grorp]

There already is a liquid_move_physics node definition field.

[SnoutBug]

If I'm not mistaken, this requires for the node to still be a liquid.
This did not work in minetest game when creating a nodebox and copying the definition from default:water_source.

[SmallJoker]

How about
https://github.com/minetest/minetest/blob/d15214af522387c118010c24c391d785a3985c3f/doc/lua_api.md?plain=1#L9844-L9849
?
Your issue does not state what exactly you'd like to have. I assume it's to slow down the player movement in quicksand, which is what this NodeDef field does.

[grorp]

If I'm not mistaken, this requires for the node to still be a liquid.

See #10810 which decoupled these and introduced the mentioned liquid_move_physics and move_resistance fields. ("Liquid" node is ambiguous, I assume you refer to liquidtype. Nice comment on the same PR: #10810 (comment))

[SnoutBug]

To answer the usecase:

I originally intended to create a node which behaves like a liquid, e.g. allows for swimming, reduces movement etc. But without it's spreading.

When I originally created this issue, it was not clear to me how to stop liquid spreading, which was solved in #15647.

However: swimming is still coupled to liquidtype = "source" or "flowing". This is what I noticed in my tests anyways.

This is why I suggested that liquid_move_physics is not contributing to my usecase - which is still unclear if it does to be honest.

Can you provide an example how liquid_move_physics works on a node with liquidtype = ""?