Biomes with param2 for their nodes

[kno10]

Problem

param2 can be used for coloring nodes, such as grass, per biome; but the current biome API does not allow the specification of param2 values for nodes, only node names.
I saw that earlier proposals #6441 were rejected, but maybe just because they were too complicated.

Solutions

A biome definition currently contains node names, but no param2 values. E.g., from the current documentation:

{
    name = "tundra",
    node_dust = "default:snow",
    node_top = "default:dirt_with_snow",
    node_filler = "default:permafrost",

Adding fields param2_dust, param2_top, param2_filler etc. would be simple and consistent with the decoration API.
Alternatively, node_dust could accept a table with name and param2.

Because the decoration API has support for param2:

    param2 = 0,
    -- Param2 value of decoration nodes.
    -- If param2_max is not 0, this is the lower limit of a randomly
    -- selected param2.

    param2_max = 0,
    -- Upper limit of the randomly selected param2.
    -- If absent, the parameter 'param2' is used as a constant.

Alternatives

• add a separate node type for each color (suggested in Per-biome grass and foliage colors, using hardware coloring #6441)
• use a costly postprocessing step to set the param2 values (as currently done in Voxelibre and Mineclonia)
• abuse the decoration mechanism with fill_ratio=10, place_offset_y=-1 to replace nodes (untested)

Additional context

No response

[sfence]

It can also be useful with #13811.

[cx384]

I suggest to not use param2 and to instead add a biome dependent node tiles feature (similar to what I wrote about in #15203).
This way the nodes are the same, but only look different to the client depending on where they are placed.
But I'm not completely sure what your exact use case is, so I don't know if it could be solved this way.

[kno10]

@cx384 biome-specific hardware-accelerated coloring, not more complex textures. paramtype2="color" in particular.

[cx384]

Then biome dependent node tile (not texture) modifiers (like align_style) would be a good solution, since you don't have to pollute pram2 (you can still use it for something else) and you don't have to manually update things, but the nodes will be exactly the same on server-side, besides their map position.

[sfence]

@cx384 Biome depend node tile does not sound good to me. In that case, the node you place will be able to look different depending on the biome. The builders will not be happy with that.

[cx384]

, the node you place will be able to look different depending on the biome.

Yeah, this is something I previously meant with the use case.

[kno10]

I also do not think this will work well for my use cases.
Consider a tree is generated, it should have all its leaves set to the same param2 color, even if some of the leaves reach into another biome.