blockgame/mods/bg_api/util_node.lua
trans_soup 3459e94de8 improve flood_fill api function.
make `flood_fill` able to be interrupted if its callback returns false;
the meaning that was previously indicated by this return value is now
indicated by nil instead.

update code that uses this function to account for this change.
2023-10-17 15:48:57 +02:00

89 lines
2 KiB
Lua

function blockgame.reg_simple_node (name, desc, groups)
local my_modname = minetest.get_current_modname()
return blockgame.register_node(my_modname .. ":" .. name, {
description = desc,
tiles = {
my_modname .. "_" .. name .. ".png",
},
groups = groups,
})
end
function blockgame.air_flows_through (pos, node)
node = node or minetest.get_node(pos)
return blockgame.item_matches(node.name, {
"air",
"group:air_flowable",
})
end
function blockgame.attempt_place (pos, node)
if minetest.get_node(pos).name ~= "air" then return false end
minetest.set_node(pos, node)
return true
end
function blockgame.random_walk (data)
local pos = vector.copy(data.pos)
local min_steps = data.min_steps or 0
local max_steps = data.max_steps or 8
local check = data.check
local neighborhood = data.neighborhood or blockgame.vector.dirs
local steps = math.random(min_steps, max_steps)
local step = 0
while step < steps do
local dir = blockgame.random_element(neighborhood)
local new_pos = pos + dir
if check(new_pos, minetest.get_node(new_pos)) then pos = new_pos end
step = step + 1
end
return pos
end
function blockgame.flood_fill (start, step, max_range)
max_range = max_range or 4
local queue = { { pos = start, range = 0 } }
local visited = {}
local matches = {}
local rejected = {}
local cancel = false
while #queue > 0 and not cancel do
local current = table.remove(queue, 1)
local pos = current.pos
local range = current.range
local hash = minetest.hash_node_position(pos)
if not visited[hash] and range <= max_range and step(pos, range) then
local step_result = step(pos, range)
if step_result then
table.insert(matches, pos)
local neighbors = blockgame.vector.get_neighbors(pos)
for _, p in pairs(neighbors) do
table.insert(queue, { pos = p, range = range + 1 })
end
elseif step_result == nil then
table.insert(rejected, pos)
else cancel = true end
end
visited[hash] = true
end
return matches, rejected
end