From 64a452da244877496bc18378cfcb35f76d950feb Mon Sep 17 00:00:00 2001
From: Anthony Zhang <azhang9@gmail.com>
Date: Wed, 18 Jul 2012 23:38:59 -0400
Subject: Fix piston duplication bug, simplify piston handling, limit piston
 push distance to 15 blocks. Remove deprecated object:get_entity_name() call,
 and some obselete settings.

---
 mesecons_pistons/init.lua | 287 +++++++++++++++++-----------------------------
 1 file changed, 106 insertions(+), 181 deletions(-)

(limited to 'mesecons_pistons/init.lua')

diff --git a/mesecons_pistons/init.lua b/mesecons_pistons/init.lua
index 3175170..c199fbe 100644
--- a/mesecons_pistons/init.lua
+++ b/mesecons_pistons/init.lua
@@ -41,208 +41,133 @@ minetest.register_node("mesecons_pistons:piston_sticky", {
 })
 
 minetest.register_craft({
-	output = '"mesecons_pistons:piston_sticky" 1',
+	output = "mesecons_pistons:piston_sticky",
 	recipe = {
-		{'"mesecons_materials:glue"'},
-		{'"mesecons_pistons:piston_normal"'},
+		{"mesecons_materials:glue"},
+		{"mesecons_pistons:piston_normal"},
 	}
 })
 
--- get push direction normal
+-- get push direction
 function mesecon:piston_get_direction(pos)
-	local direction = {x=0, y=0, z=0}
-	if OLD_PISTON_DIRECTION==1 then
-		getactivated=0
-		local lpos={x=pos.x, y=pos.y, z=pos.z}
-		local getactivated=0
-		local rules=mesecon:get_rules("piston")
-	
-		getactivated=getactivated+mesecon:is_power_on(pos, rules[1].x, rules[1].y, rules[1].z)
-		if getactivated>0 then direction.y=-1 return direction end
-		getactivated=getactivated+mesecon:is_power_on(pos, rules[2].x, rules[2].y, rules[2].z)
-		if getactivated>0 then direction.y=1 return direction end
-		for k=3, 5 do
-			getactivated=getactivated+mesecon:is_power_on(pos, rules[k].x, rules[k].y, rules[k].z)
-		end
-		if getactivated>0 then direction.z=1 return direction end
-	
-		for n=6, 8 do
-			getactivated=getactivated+mesecon:is_power_on(pos, rules[n].x, rules[n].y, rules[n].z)
-		end
-
-		if getactivated>0 then direction.z=-1 return direction end
-	
-		for j=9, 11 do
-			getactivated=getactivated+mesecon:is_power_on(pos, rules[j].x, rules[j].y, rules[j].z)
-		end
-
-		if getactivated>0 then direction.x=-1 return direction end
-
-		for l=12, 14 do
-			getactivated=getactivated+mesecon:is_power_on(pos, rules[l].x, rules[l].y, rules[l].z)
-		end
-		if getactivated>0 then direction.x=1 return direction end
-	else
-		local node=minetest.env:get_node(pos)
-		if node.param2==3 then
-			return {x=1, y=0, z=0}
-		end
-		if node.param2==2 then
-			return {x=0, y=0, z=1}
-		end
-		if node.param2==1 then
-			return {x=-1, y=0, z=0}
-		end
-		if node.param2==0 then
-			return {x=0, y=0, z=-1}
-		end
+	local param2 = minetest.env:get_node(pos).param2
+	if param2 == 3 then
+		return {x=1, y=0, z=0}
+	elseif param2 == 2 then
+		return {x=0, y=0, z=1}
+	elseif param2 == 1 then
+		return {x=-1, y=0, z=0}
+	else --param2 == 0
+		return {x=0, y=0, z=-1}
 	end
-	return direction
 end
 
--- get pull/push direction sticky
-function mesecon:sticky_piston_get_direction(pos)
-	if OLD_PISTON_DIRECTION==1 then
-		getactivated=0
-		local direction = {x=0, y=0, z=0}
-		local lpos={x=pos.x, y=pos.y, z=pos.z}
-		local getactivated=0
-		local rules=mesecon:get_rules("piston")
-
-		getactivated=getactivated+mesecon:is_power_off(pos, rules[1].x, rules[1].y, rules[1].z)
-		if getactivated>0 then direction.y=-1 return direction end
-		getactivated=getactivated+mesecon:is_power_off(pos, rules[2].x, rules[2].y, rules[2].z)
-		if getactivated>0 then direction.y=1 return direction end
-
-		for k=3, 5 do
-			getactivated=getactivated+mesecon:is_power_off(pos, rules[k].x, rules[k].y, rules[k].z)
-		end
-		if getactivated>0 then direction.z=1 return direction end
+-- Push action
+mesecon:register_on_signal_on(function (pos, node)
+	if node.name ~= "mesecons_pistons:piston_normal" and node.name ~= "mesecons_pistons:piston_sticky" then
+		return
+	end
 
-		for n=6, 8 do
-			getactivated=getactivated+mesecon:is_power_off(pos, rules[n].x, rules[n].y, rules[n].z)
+	local dir = mesecon:piston_get_direction(pos)
+
+	--determine the number of nodes that need to be pushed
+	local count = 0
+	local checkpos = {x=pos.x + dir.x, y=pos.y + dir.y, z=pos.z + dir.z} --first node being pushed
+	local checknode = minetest.env:get_node(checkpos)
+	while checknode.name ~= "air"
+	and checknode.name ~= "ignore"
+	and checknode.name ~= "default:water_source"
+	and checknode.name ~= "default:water_flowing"
+	and checknode.name ~= "default:lava_source"
+	and checknode.name ~= "default:lava_flowing" do
+		--limit piston pushing capacity
+		count = count + 1
+		if count > 15 then
+			return
+		end
+
+		--check for collision with stopper
+		checkpos.x, checkpos.y, checkpos.z = checkpos.x + dir.x, checkpos.y + dir.y, checkpos.z + dir.z
+		checknode = minetest.env:get_node(checkpos)
+		if mesecon:is_mvps_stopper(checknode.name) then 
+			return
 		end
+	end
 
-		if getactivated>0 then direction.z=-1 return direction end
-	
-		for j=9, 11 do
-			getactivated=getactivated+mesecon:is_power_off(pos, rules[j].x, rules[j].y, rules[j].z)
-		end
+	--add pusher entity
+	local object
+	if node.name == "mesecons_pistons:piston_normal" then --normal piston
+		object = minetest.env:add_entity(pos, "mesecons_pistons:piston_pusher_normal")
+	else --sticky piston
+		object = minetest.env:add_entity(pos, "mesecons_pistons:piston_pusher_sticky")
+	end
 
-		if getactivated>0 then direction.x=-1 return direction end
-	
-		for l=12, 14 do
-			getactivated=getactivated+mesecon:is_power_off(pos, rules[l].x, rules[l].y, rules[l].z)
-		end
-		if getactivated>0 then direction.x=1 return direction end
+	--move pusher forward
+	if ENABLE_PISTON_ANIMATION then
+		object:setvelocity({x=dir.x * 4, y=dir.y * 4, z=dir.z * 4})
 	else
-		local node=minetest.env:get_node(pos)
-		if node.param2==3 then
-			return {x=1, y=0, z=0}
-		end
-		if node.param2==2 then
-			return {x=0, y=0, z=1}
-		end
-		if node.param2==1 then
-			return {x=-1, y=0, z=0}
-		end
-		if node.param2==0 then
-			return {x=0, y=0, z=-1}
-		end
+		object:moveto(pos, false)
 	end
-	return direction
-end
-
--- Push action
-mesecon:register_on_signal_on(function (pos, node)
-	if (node.name=="mesecons_pistons:piston_normal" or node.name=="mesecons_pistons:piston_sticky") then
-		local direction=mesecon:piston_get_direction(pos)
-
-		local checknode={}
-		local checkpos={x=pos.x, y=pos.y, z=pos.z}
-		repeat -- Check if it collides with a stopper
-			checkpos={x=checkpos.x+direction.x, y=checkpos.y+direction.y, z=checkpos.z+direction.z}
-			checknode=minetest.env:get_node(checkpos)
-			if mesecon:is_mvps_stopper(checknode.name) then 
-				return 
-			end
-		until checknode.name=="air"
-		or checknode.name=="ignore" 
-		or checknode.name=="default:water" 
-		or checknode.name=="default:water_flowing" 
-
-		local obj={}
-		if node.name=="mesecons_pistons:piston_normal" then
-			obj=minetest.env:add_entity(pos, "mesecons_pistons:piston_pusher_normal")
-		elseif node.name=="mesecons_pistons:piston_sticky" then
-			obj=minetest.env:add_entity(pos, "mesecons_pistons:piston_pusher_sticky")
-		end
-		
-		if ENABLE_PISTON_ANIMATION==1 then		
-			obj:setvelocity({x=direction.x*4, y=direction.y*4, z=direction.z*4})
-		else
-			obj:moveto({x=pos.x+direction.x, y=pos.y+direction.y, z=pos.z+direction.z}, false)
-		end
-		
-		local np = {x=pos.x+direction.x, y=pos.y+direction.y, z=pos.z+direction.z}	
-		local coln = minetest.env:get_node(np)
-		
-		or checknode.name=="ignore" 
-		or checknode.name=="default:water" 
-		or checknode.name=="default:water_flowing" 
 
-		if coln.name ~= "air" and coln.name ~="water" then
-			local thisp= {x=np.x, y=np.y, z=np.z}
-			local thisnode=minetest.env:get_node(thisp)
-			local nextnode={}
-			minetest.env:dig_node(thisp)
-			repeat
-				thisp.x=thisp.x+direction.x
-				thisp.y=thisp.y+direction.y
-				thisp.z=thisp.z+direction.z
-				nextnode=minetest.env:get_node(thisp)
-				minetest.env:place_node(thisp, {name=thisnode.name})
-				nodeupdate(thisp)
-				thisnode=nextnode
-			until thisnode.name=="air" 
-			or thisnode.name=="ignore" 
-			or thisnode.name=="default:water" 
-			or thisnode.name=="default:water_flowing" 
-		end
+	--move nodes forward
+	pos.x, pos.y, pos.z = pos.x + dir.x, pos.y + dir.y, pos.z + dir.z --move to first node being pushed
+	checknode = minetest.env:get_node(pos)
+	minetest.env:dig_node(pos) --remove the first node
+	for i = 1, count do
+		--move to the next node
+		pos.x, pos.y, pos.z = pos.x + dir.x, pos.y + dir.y, pos.z + dir.z
+
+		--move the node forward
+		local nextnode = minetest.env:get_node(pos)
+		minetest.env:place_node(pos, checknode)
+		checknode = nextnode
 	end
 end)
 
 --Pull action (sticky only)
-mesecon:register_on_signal_off(function (pos, node)
-	if node.name=="mesecons_pistons:piston_sticky" or node.name=="mesecons_pistons:piston_normal" then
-		local objs = minetest.env:get_objects_inside_radius(pos, 2)
-		for k, obj in pairs(objs) do
-			local obj_name = obj:get_entity_name()
-			if obj_name == "mesecons_pistons:piston_pusher_normal" or obj_name == "mesecons_pistons:piston_pusher_sticky" then
-				obj:remove()
-			end
+mesecon:register_on_signal_off(function(pos, node)
+	if node.name ~= "mesecons_pistons:piston_sticky" and node.name ~= "mesecons_pistons:piston_normal" then
+		return
+	end
+
+	--remove piston pusher
+	local found = false --whether or not the piston was extended
+	local objects = minetest.env:get_objects_inside_radius(pos, 2)
+	for k, object in pairs(objects) do
+		local name = object:get_luaentity().name
+		if name == "mesecons_pistons:piston_pusher_normal" or name == "mesecons_pistons:piston_pusher_sticky" then
+			found = true
+			object:remove()
 		end
+	end
 
-		if node.name=="mesecons_pistons:piston_sticky" then
-			local direction=mesecon:sticky_piston_get_direction(pos)
-			local np = {x=pos.x+direction.x, y=pos.y+direction.y, z=pos.z+direction.z}	
-			local coln = minetest.env:get_node(np)
-			if coln.name == "air" or coln.name =="water" then
-				local thisp= {x=np.x+direction.x, y=np.y+direction.y, z=np.z+direction.z}
-				local thisnode=minetest.env:get_node(thisp)
-				if thisnode.name~="air" and thisnode.name~="water" and not mesecon:is_mvps_stopper(thisnode.name) then
-					local newpos={}
-					local oldpos={}
-					minetest.env:place_node(np, {name=thisnode.name})
-					minetest.env:dig_node(thisp)
-				end		
-			end
+	--retract piston
+	if found and node.name == "mesecons_pistons:piston_sticky" then
+		local dir = mesecon:piston_get_direction(pos)
+		pos.x, pos.y, pos.z = pos.x + dir.x, pos.y + dir.y, pos.z + dir.z --move to the node to be replaced
+		local checknode = minetest.env:get_node(pos)
+		if checknode.name == "air"
+		or checknode.name == "default:water_source"
+		or checknode.name == "default:water_flowing"
+		or checknode.name == "default:lava_source"
+		or checknode.name == "default:lava_flowing" then
+			local checkpos = {x=pos.x + dir.x, y=pos.y + dir.y, z=pos.z + dir.z} --move to the node to be retracted
+			local checknode = minetest.env:get_node(checkpos)
+			if checknode.name ~= "air"
+			and checknode.name ~= "ignore"
+			and checknode.name ~= "default:water_source"
+			and checknode.name ~= "default:water_flowing"
+			and checknode.name ~= "default:lava_source"
+			and checknode.name ~= "default:lava_flowing" then
+				minetest.env:place_node(pos, checknode)
+				minetest.env:dig_node(checkpos)
+			end		
 		end
 	end
 end)
 
 --Piston Animation
-local PISTON_PUSHER_NORMAL={
+local PISTON_PUSHER_NORMAL = {
 	physical = false,
 	visual = "sprite",
 	textures = {"default_wood.png", "default_wood.png", "jeija_piston_pusher_normal.png", "jeija_piston_pusher_normal.png", "jeija_piston_pusher_normal.png", "jeija_piston_pusher_normal.png"},
@@ -252,24 +177,24 @@ local PISTON_PUSHER_NORMAL={
 }
 
 function PISTON_PUSHER_NORMAL:on_step(dtime)
-	self.timer=self.timer+dtime
-	if self.timer>=0.24 then
+	self.timer = self.timer+dtime
+	if self.timer >= 0.24 then
 		self.object:setvelocity({x=0, y=0, z=0})
 	end
 end
 
-local PISTON_PUSHER_STICKY={
+local PISTON_PUSHER_STICKY = {
 	physical = false,
 	visual = "sprite",
 	textures = {"default_wood.png", "default_wood.png", "jeija_piston_pusher_sticky.png", "jeija_piston_pusher_sticky.png", "jeija_piston_pusher_sticky.png", "jeija_piston_pusher_sticky.png"},
 	collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
 	visual = "cube",
-	timer=0,
+	timer = 0,
 }
 
 function PISTON_PUSHER_STICKY:on_step(dtime)
 	self.timer=self.timer+dtime
-	if self.timer>=0.24 then
+	if self.timer >= 0.24 then
 		self.object:setvelocity({x=0, y=0, z=0})
 	end
 end
-- 
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