From 3e827c23b9a9df72f55150ac38214444edd697f3 Mon Sep 17 00:00:00 2001
From: thetaepsilon-gamedev <thetaepsilon-gamedev@noreply.users.github.com>
Date: Wed, 27 Sep 2017 17:49:49 +0100
Subject: flowing_logic.lua: separate out new logic into seperate file

---
 new_flow_logic.lua | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 new_flow_logic.lua

(limited to 'new_flow_logic.lua')

diff --git a/new_flow_logic.lua b/new_flow_logic.lua
new file mode 100644
index 0000000..3fd1bb6
--- /dev/null
+++ b/new_flow_logic.lua
@@ -0,0 +1,121 @@
+-- reimplementation of new_flow_logic branch: processing functions
+-- written 2017 by thetaepsilon
+
+
+
+-- global values and thresholds for water behaviour
+-- TODO: add some way of setting this per-world
+local thresholds = {}
+-- limit on pump pressure - will not absorb more than can be taken
+thresholds.pump_pressure = 2
+
+
+
+-- borrowed from above: might be useable to replace the above coords tables
+local make_coords_offsets = function(pos, include_base)
+	local coords = {
+		{x=pos.x,y=pos.y-1,z=pos.z},
+		{x=pos.x,y=pos.y+1,z=pos.z},
+		{x=pos.x-1,y=pos.y,z=pos.z},
+		{x=pos.x+1,y=pos.y,z=pos.z},
+		{x=pos.x,y=pos.y,z=pos.z-1},
+		{x=pos.x,y=pos.y,z=pos.z+1},
+	}
+	if include_base then table.insert(coords, pos) end
+	return coords
+end
+
+
+
+-- local debuglog = function(msg) print("## "..msg) end
+
+
+
+-- new version of liquid check
+-- accepts a limit parameter to only delete water blocks that the receptacle can accept,
+-- and returns it so that the receptacle can update it's pressure values.
+-- this should ensure that water blocks aren't vanished from existance.
+-- will take care of zero or negative-valued limits.
+pipeworks.check_for_liquids_v2 = function(pos, limit)
+	if not limit then
+		limit = 6
+	end
+	local coords = make_coords_offsets(pos, false)
+	local total = 0
+	for index, tpos in ipairs(coords) do
+		if total >= limit then break end
+		local name = minetest.get_node(tpos).name
+		if name == "default:water_source" then
+			minetest.remove_node(tpos)
+			total = total + 1
+		end
+	end
+	return total
+end
+
+
+
+
+local label_pressure = "pipeworks.water_pressure"
+local label_haspressure = "pipeworks.is_pressure_node"
+pipeworks.balance_pressure = function(pos, node)
+	-- debuglog("balance_pressure() "..node.name.." at "..pos.x.." "..pos.y.." "..pos.z)
+	-- check the pressure of all nearby nodes, and average it out.
+	-- for the moment, only balance neighbour nodes if it already has a pressure value.
+	-- XXX: maybe this could be used to add fluid behaviour to other mod's nodes too?
+
+	-- unconditionally include self in nodes to average over
+	local meta = minetest.get_meta(pos)
+	local currentpressure = meta:get_float(label_pressure)
+	meta:set_int(label_haspressure, 1)
+	local connections = { meta }
+	local totalv = currentpressure
+	local totalc = 1
+
+	-- then handle neighbours, but if not a pressure node don't consider them at all
+	for _, npos in ipairs(make_coords_offsets(pos, false)) do
+		local neighbour = minetest.get_meta(npos)
+		local haspressure = (neighbour:get_int(label_haspressure) ~= 0)
+		if haspressure then
+			local n = neighbour:get_float(label_pressure)
+			table.insert(connections, neighbour)
+			totalv = totalv + n
+			totalc = totalc + 1
+		end
+	end
+
+	local average = totalv / totalc
+	for _, targetmeta in ipairs(connections) do
+		targetmeta:set_float(label_pressure, average)
+	end
+end
+
+
+
+pipeworks.run_pump_intake = function(pos, node)
+	-- try to absorb nearby water nodes, but only up to limit.
+	-- NB: check_for_liquids_v2 handles zero or negative from the following subtraction
+	local meta = minetest.get_meta(pos)
+	local currentpressure = meta:get_float(label_pressure)
+	local intake_limit = thresholds.pump_pressure - currentpressure
+	local actual_intake = pipeworks.check_for_liquids_v2(pos, intake_limit)
+	local newpressure = actual_intake + currentpressure
+	-- debuglog("oldpressure "..currentpressure.." intake_limit "..intake_limit.." actual_intake "..actual_intake.." newpressure "..newpressure)
+	meta:set_float(label_pressure, newpressure)
+end
+
+
+
+pipeworks.run_spigot_output = function(pos, node)
+	-- try to output a water source node if there's enough pressure and space below.
+	local meta = minetest.get_meta(pos)
+	local currentpressure = meta:get_float(label_pressure)
+	if currentpressure > 1 then
+		local below = {x=pos.x, y=pos.y-1, z=pos.z}
+		local name = minetest.get_node(below).name
+		if (name == "air") or (name == "default:water_flowing") then
+			minetest.set_node(below, {name="default:water_source"})
+			meta:set_float(label_pressure, currentpressure - 1)
+		end
+	end
+end
-- 
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