test if a chunk is generated?

[i1abnrk]

Hi everyone. I'm working on a mapgen mod that adapts genmud (old text-based rpg) code to lua. I'm looking for a way to test if a chunk has generated. Is there a null or something if I try to get a node that hasn't been generated yet? Some of the features I'm adapting (such as connecting roads) will be easier a simple test like this for edge-finding.
Thanks for any ideas.

[PilzAdam]

You cant test if it has generated, but you can test if its loaded by using minetest.get_node_or_nil().

[Casimir]

Here "pos" is one position in the area you want to check.

Code: Select all

if minetest.registered_nodes[minetest.get_node(pos).name] then
    -- succes
end

[PilzAdam]

Here "pos" is one position in the area you want to check.

Code: Select all

if minetest.registered_nodes[minetest.get_node(pos).name] then
    -- succes
end

This will always jump to "succes"; get_node() returns ignore for unloaded areas, and ignore is in the registered_nodes table.

[Casimir]

Then...

Code: Select all

if minetest.get_node(pos).name ~= "ignore" then
    -- succes
end

[i1abnrk]

Code: Select all

local c_nil = minetest.get_content_id("ignore") 
if minetest.get_node(pos)==c_nil then
    --true
end

This looks valid. These are good ideas. get_node_or_nil is undocumented in wiki.
So am I right in assuming only asynchronous sqlite transactions are available to lua? (vm:get_data() and vm:write_to_map()) Using async means the edge-finding technique requires a full rewrite of voxeldata every time a client accesses a chunk. Synchronous writeback from client this way could strain the server so I'd best write genmud on server-side in C++ as a patch I think.
These are assumptions, does it sound right?
Genmud generates the full map and minetest uses event-based chunk generation. Using perlin prediction is possible in lua instead of server code. The logic switches would be more tedious and slow in lua, though.

[sfan5]

get_node returns a table, you can't compare that to a node id
Do it like this:

Then...

Code: Select all

if minetest.get_node(pos).name ~= "ignore" then
    -- success
end

[PilzAdam]

Then...

Code: Select all

if minetest.get_node(pos).name ~= "ignore" then
    -- succes
end

Thats like exaclty the same thing as I posted as first answer to this topic...

[i1abnrk]

~='ignore' works for me. I think testing 'if loaded' the closest solution I'll get with the current lua API. I'll have to pick through github to see if I can expose a sqlite query to lua to test 'if generated'.