2020-10-08 20:29:39 +02:00
|
|
|
-- Use the movement gravity for the downwards acceleration.
|
|
|
|
-- The setting may change in-game but for simplicity we don't support this.
|
|
|
|
local movement_gravity = tonumber(core.settings:get("movement_gravity")) or 9.81
|
2014-08-31 14:44:42 +02:00
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2020-10-08 20:29:39 +02:00
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|
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-- get_flow_target_raw determines position to which the water flows, or returns
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|
|
-- nothing if no target position was found
|
2020-10-08 19:35:12 +02:00
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|
|
local neighbour_offsets = {
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|
|
{x=-1, y=0, z=0},
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|
|
{x=1, y=0, z=0},
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{x=0, y=0, z=-1},
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{x=0, y=0, z=1}
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|
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|
}
|
2020-10-08 20:29:39 +02:00
|
|
|
local function get_flow_target_raw(pos)
|
|
|
|
local param2 = minetest.get_node(pos).param2
|
|
|
|
if param2 > 7 then
|
|
|
|
-- The liquid flows downwards
|
|
|
|
return
|
2020-10-08 19:35:12 +02:00
|
|
|
end
|
|
|
|
local neighbours = {}
|
|
|
|
for n = 1, 4 do
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|
|
|
local p = vector.add(pos, neighbour_offsets[n])
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|
|
neighbours[n] = p
|
|
|
|
neighbours[n + 4] = minetest.get_node(p)
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|
|
|
end
|
|
|
|
for i = 1, 4 do
|
|
|
|
-- If a neighbour has a lower height, flow to it
|
|
|
|
local node = neighbours[i + 4]
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|
|
|
if node.name == "default:water_flowing"
|
|
|
|
and node.param2 < param2 then
|
|
|
|
return neighbours[i]
|
2012-09-25 16:29:37 +02:00
|
|
|
end
|
2014-08-31 14:12:32 +02:00
|
|
|
end
|
2020-10-08 19:35:12 +02:00
|
|
|
for i = 1, 4 do
|
2020-10-08 20:29:39 +02:00
|
|
|
-- Flow to a downwards-flowing neighbour if its height is not too small
|
2020-10-08 19:35:12 +02:00
|
|
|
local node = neighbours[i + 4]
|
|
|
|
if node.name == "default:water_flowing"
|
|
|
|
and node.param2 >= 11 then
|
|
|
|
return neighbours[i]
|
2012-09-25 16:29:37 +02:00
|
|
|
end
|
2014-08-31 14:12:32 +02:00
|
|
|
end
|
2020-10-08 19:35:12 +02:00
|
|
|
for i = 1, 4 do
|
2020-10-08 20:29:39 +02:00
|
|
|
-- Flow to a neighbouring unsolid node
|
2020-10-08 19:35:12 +02:00
|
|
|
local node = neighbours[i + 4]
|
|
|
|
if node.name ~= "default:water_flowing" then
|
|
|
|
local def = minetest.registered_nodes[node.name]
|
|
|
|
if def and not def.walkable then
|
|
|
|
return neighbours[i]
|
|
|
|
end
|
2012-09-25 16:29:37 +02:00
|
|
|
end
|
2014-08-31 14:12:32 +02:00
|
|
|
end
|
2020-10-08 20:29:39 +02:00
|
|
|
-- No neighbour found
|
|
|
|
end
|
|
|
|
|
|
|
|
-- get_flow_target caches the results from get_flow_target_raw for 10 s
|
|
|
|
local flow_target_cache = {}
|
|
|
|
setmetatable(flow_target_cache, {__mode = "kv"})
|
|
|
|
local function get_flow_target(pos)
|
|
|
|
local vi = minetest.hash_node_position(pos)
|
|
|
|
local t = minetest.get_us_time()
|
|
|
|
if flow_target_cache[vi]
|
|
|
|
and t - flow_target_cache[vi][1] < 10 * 1000000 then
|
|
|
|
return flow_target_cache[vi][2]
|
|
|
|
end
|
|
|
|
local flow_target = get_flow_target_raw(pos)
|
|
|
|
flow_target_cache[vi] = {t, flow_target}
|
|
|
|
return flow_target
|
2014-08-31 14:12:32 +02:00
|
|
|
end
|
2012-09-25 16:29:37 +02:00
|
|
|
|
2014-08-31 14:12:32 +02:00
|
|
|
local item_entity = minetest.registered_entities["__builtin:item"]
|
2020-10-08 20:29:39 +02:00
|
|
|
local old_on_step = item_entity.on_step
|
2012-09-25 16:29:37 +02:00
|
|
|
|
2016-02-18 18:45:59 +01:00
|
|
|
item_entity.makes_footstep_sound = true
|
2020-10-08 20:29:39 +02:00
|
|
|
-- The "bt_" prefix shows that the value comes from builtin_item
|
2016-02-21 12:31:33 +01:00
|
|
|
item_entity.bt_timer = 0
|
2020-05-09 17:42:51 +02:00
|
|
|
item_entity.on_step = function(self, dtime, ...)
|
2020-10-08 20:29:39 +02:00
|
|
|
-- Remember the velocity before an original on_step can change it
|
|
|
|
local vel_desired
|
|
|
|
if self.bt_reset_velocity then
|
|
|
|
vel_desired = self.object:get_velocity()
|
|
|
|
end
|
2015-06-05 11:30:34 +02:00
|
|
|
|
2020-10-08 20:29:39 +02:00
|
|
|
old_on_step(self, dtime, ...)
|
2020-10-08 19:35:12 +02:00
|
|
|
|
2020-10-08 20:29:39 +02:00
|
|
|
-- Ignore the item if it should not interact with physics
|
|
|
|
if not self.physical_state then
|
|
|
|
return
|
2016-05-26 12:17:00 +02:00
|
|
|
end
|
2020-10-08 19:35:12 +02:00
|
|
|
|
2020-10-08 20:29:39 +02:00
|
|
|
-- Reset the velocity if needed
|
|
|
|
if vel_desired
|
|
|
|
and not vector.equals(self.object:get_velocity(), vel_desired) then
|
|
|
|
self.object:set_velocity(vel_desired)
|
2016-05-26 12:17:00 +02:00
|
|
|
end
|
|
|
|
|
2020-10-08 20:29:39 +02:00
|
|
|
-- For performance reasons, skip the remaining code in frequent steps
|
2020-10-08 19:35:12 +02:00
|
|
|
self.bt_timer = self.bt_timer + dtime
|
2020-10-08 20:29:39 +02:00
|
|
|
if self.bt_timer < 0.1 then
|
2016-02-21 12:31:33 +01:00
|
|
|
return
|
|
|
|
end
|
|
|
|
self.bt_timer = 0
|
|
|
|
|
2020-08-01 21:12:24 +02:00
|
|
|
local p = self.object:get_pos()
|
2016-05-26 12:17:00 +02:00
|
|
|
local pos = vector.round(p)
|
2020-10-08 20:29:39 +02:00
|
|
|
local nodename = minetest.get_node(pos).name
|
2015-06-05 11:30:34 +02:00
|
|
|
|
2020-10-08 20:29:39 +02:00
|
|
|
if self.bt_reset_velocity then
|
|
|
|
-- Set the item acceleration to its default (changed again below)
|
|
|
|
self.object:set_acceleration({x=0, y=-movement_gravity, z=0})
|
|
|
|
self.bt_reset_velocity = nil
|
2016-05-26 12:17:00 +02:00
|
|
|
end
|
2020-10-08 20:29:39 +02:00
|
|
|
local def = minetest.registered_nodes[nodename]
|
|
|
|
if not def or not def.liquidtype or def.liquidtype ~= "flowing" then
|
2020-10-08 19:35:12 +02:00
|
|
|
return
|
|
|
|
end
|
2020-10-08 20:29:39 +02:00
|
|
|
local pos_next = get_flow_target(pos)
|
|
|
|
if not pos_next then
|
2020-10-08 19:35:12 +02:00
|
|
|
return
|
|
|
|
end
|
2020-10-08 20:29:39 +02:00
|
|
|
local vel_current = vel_desired or self.object:get_velocity()
|
|
|
|
local acc = vector.multiply(vector.subtract(pos_next, pos), 2.0)
|
|
|
|
if math.abs(vel_current.x) > 1.0 then
|
|
|
|
acc.x = 0
|
|
|
|
end
|
|
|
|
if math.abs(vel_current.z) > 1.0 then
|
|
|
|
acc.z = 0
|
|
|
|
end
|
|
|
|
acc.y = -movement_gravity
|
|
|
|
self.object:set_acceleration(acc)
|
|
|
|
self.bt_reset_velocity = true
|
2014-08-31 14:12:32 +02:00
|
|
|
end
|
|
|
|
|
|
|
|
minetest.register_entity(":__builtin:item", item_entity)
|