From 33d978de06b9f98da26e72dafe7a8708850f0fb4 Mon Sep 17 00:00:00 2001
From: Wuzzy <almikes@aol.com>
Date: Sat, 20 Jan 2018 19:04:53 +0100
Subject: [PATCH] Propagate redstone power through opaque blocks

---
 mods/ITEMS/REDSTONE/mesecons/init.lua     | 20 ---------------
 mods/ITEMS/REDSTONE/mesecons/internal.lua | 31 +++++++++++++++++++----
 mods/ITEMS/REDSTONE/mesecons/util.lua     |  7 ++++-
 3 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/mods/ITEMS/REDSTONE/mesecons/init.lua b/mods/ITEMS/REDSTONE/mesecons/init.lua
index 4ef690b8de..3286c0cef4 100644
--- a/mods/ITEMS/REDSTONE/mesecons/init.lua
+++ b/mods/ITEMS/REDSTONE/mesecons/init.lua
@@ -81,13 +81,6 @@ mesecon.queue:add_function("receptor_on", function (pos, rules)
 		for _, rulename in ipairs(rulenames) do
 			mesecon.turnon(np, rulename)
 		end
-		if rule.spread then
-			if minetest.get_item_group(minetest.get_node(np).name, "opaque") == 1 then
-				for _, neighbor in ipairs(mesecon.mcl_get_neighbors(np)) do
-					mesecon.turnon(neighbor.pos, vector.add(rule, neighbor.link))
-				end
-			end
-		end
 	end
 
 	mesecon.vm_commit()
@@ -117,19 +110,6 @@ mesecon.queue:add_function("receptor_off", function (pos, rules)
 				mesecon.vm_abort()
 			end
 		end
-		if rule.spread then
-			if minetest.get_item_group(minetest.get_node(np).name, "opaque") == 1 then
-				for _, neighbor in ipairs(mesecon.mcl_get_neighbors(np)) do
-					mesecon.vm_begin()
-					mesecon.changesignal(neighbor.pos, minetest.get_node(neighbor.pos), vector.add(rule, neighbor.link), mesecon.state.off, 2)
-					if (mesecon.turnoff(neighbor.pos, vector.add(rule, neighbor.link))) then
-						mesecon.vm_commit()
-					else
-						mesecon.vm_abort()
-					end
-				end
-			end
-		end
 	end
 end)
 
diff --git a/mods/ITEMS/REDSTONE/mesecons/internal.lua b/mods/ITEMS/REDSTONE/mesecons/internal.lua
index 3a75a23f60..0158467219 100644
--- a/mods/ITEMS/REDSTONE/mesecons/internal.lua
+++ b/mods/ITEMS/REDSTONE/mesecons/internal.lua
@@ -403,12 +403,24 @@ function mesecon.turnon(pos, link)
 				mesecon.activate(f.pos, node, f.link, depth)
 			end
 		end
+		if node and f.link.spread and minetest.get_item_group(node.name, "opaque") == 1 then
+			-- Call turnon on neighbors
+			-- Warning: A LOT of nodes need to be looked at for this to work
+			for _, r in ipairs(mesecon.rule2meta(f.link, mesecon.rules.mcl_alldirs_spread)) do
+				local np = vector.add(f.pos, r)
+				for _, l in ipairs(mesecon.rules_link_rule_all(f.pos, r)) do
+					local nlink = table.copy(l)
+					nlink.spread = false
+					table.insert(frontiers, {pos = np, link = nlink})
+				end
+			end
+		end
 
 		depth = depth + 1
 	end
 end
 
--- Turn on an equipotential section starting at `pos`, which outputs in the direction of `link`.
+-- Turn off an equipotential section starting at `pos`, which outputs in the direction of `link`.
 -- Breadth-first search. Map is abstracted away in a voxelmanip.
 -- Follow all all conductor paths replacing conductors that were already
 -- looked at, deactivating / changing all effectors along the way.
@@ -464,6 +476,10 @@ function mesecon.turnoff(pos, link)
 				depth = depth
 			})
 		end
+		if node and f.link.spread and minetest.get_item_group(node.name, "opaque") == 1 then
+			-- TODO: Call turnoff on neighbors
+		end
+
 		depth = depth + 1
 	end
 
@@ -490,8 +506,10 @@ function mesecon.rules_link_rule_all(output, rule)
 
 	for _, inputrule in ipairs(mesecon.flattenrules(inputrules)) do
 		-- Check if input accepts from output
-		if  vector.equals(vector.add(input, inputrule), output) then
-			table.insert(rules, inputrule)
+		if vector.equals(vector.add(input, inputrule), output) then
+			local newrule = table.copy(inputrule)
+			newrule.spread = rule.spread
+			table.insert(rules, newrule)
 		end
 	end
 
@@ -510,8 +528,11 @@ function mesecon.rules_link_rule_all_inverted(input, rule)
 	local rules = {}
 
 	for _, outputrule in ipairs(mesecon.flattenrules(outputrules)) do
-		if  vector.equals(vector.add(output, outputrule), input) then
-			table.insert(rules, mesecon.invertRule(outputrule))
+		if vector.equals(vector.add(output, outputrule), input) then
+			local newrule = table.copy(outputrule)
+			newrule = mesecon.invertRule(newrule)
+			newrule.spread = rule.spread
+			table.insert(rules, newrule)
 		end
 	end
 	return rules
diff --git a/mods/ITEMS/REDSTONE/mesecons/util.lua b/mods/ITEMS/REDSTONE/mesecons/util.lua
index c848b9d3e8..7fd1f6fd31 100644
--- a/mods/ITEMS/REDSTONE/mesecons/util.lua
+++ b/mods/ITEMS/REDSTONE/mesecons/util.lua
@@ -198,7 +198,12 @@ function mesecon.set_bit(binary,bit,value)
 end
 
 function mesecon.invertRule(r)
-	return vector.multiply(r, -1)
+	local spread = r.spread
+	r = vector.multiply(r, -1)
+	if spread then
+		r.spread = true
+	end
+	return r
 end
 
 function mesecon.tablecopy(table) -- deep table copy