abstract the particle spawner start/stop functions

homedecor/bathroom_sanitation.lua

@@ -168,33 +168,12 @@ homedecor.register("shower_tray", {
 	sounds = default.node_sound_stone_defaults(),
 	on_destruct = function(pos)
 		headpos = {x=pos.x, y=pos.y+2, z=pos.z}
-		local above_spawner_meta = minetest.get_meta(headpos)
+		homedecor.stop_particle_spawner(headpos)
-
-		local id = above_spawner_meta:get_int("active")
-		local s_handle = above_spawner_meta:get_int("sound")
-
-		if id ~= 0 then
-			minetest.delete_particlespawner(id)
-		end
-
-		if s_handle then
-			minetest.after(0, function(s_handle)
-				minetest.sound_stop(s_handle)
-			end, s_handle)
-		end
-
-		above_spawner_meta:set_int("active", nil)
-		above_spawner_meta:set_int("sound", nil)
 	end
 })
 
 --Shower Head
 
-local fdir_to_flowpos = {
-	minx = { 0.15, 0.05, -0.15, -0.05 }, maxx = { -0.15, -0.3, 0.15, 0.3 },
-	minz = { 0.05, 0.15, -0.05, -0.15 }, maxz = { -0.3, -0.15, 0.3, 0.15 },
-	velx = { 0, -0.2, 0, 0.2 }, velz = { -0.2, 0, 0.2, 0 }
-}
 
 local sh_cbox = {
 	type = "fixed",
@@ -214,69 +193,21 @@ homedecor.register("shower_head", {
 	selection_box = sh_cbox,
 	walkable = false,
 	on_rightclick = function (pos, node, clicker)
-		local below = minetest.get_node({x=pos.x, y=pos.y-2.0, z=pos.z})
+		local below = minetest.get_node_or_nil({x=pos.x, y=pos.y-2.0, z=pos.z})
-		local is_tray = string.find(below.name, "homedecor:shower_tray")
+		if below and string.find(below.name, "homedecor:shower_tray") then
-		local fdir = node.param2
+			local particledef = {
-		local minx = fdir_to_flowpos.minx[fdir + 1]
+				outlet_x    = 0,
-		local maxx = fdir_to_flowpos.maxx[fdir + 1]
+				outlet_y    = -0.42,
-		local minz = fdir_to_flowpos.minz[fdir + 1]
+				outlet_z    = 0.1,
-		local maxz = fdir_to_flowpos.maxz[fdir + 1]
+				velocity_x  = { min = -0.15, max = 0.15 },
-		local velx = fdir_to_flowpos.velx[fdir + 1]
+				velocity_z  = { min = -0.3,  max = 0.1 },
-		local velz = fdir_to_flowpos.velz[fdir + 1]
+				spread      = 0.12
-
+			}
-		local this_spawner_meta = minetest.get_meta(pos)
+			homedecor.start_particle_spawner(pos, node, particledef, "homedecor_shower")
-		local id = this_spawner_meta:get_int("active")
-		local s_handle = this_spawner_meta:get_int("sound")
-
-		if id ~= 0 then
-			if s_handle then
-				minetest.after(0, function(s_handle)
-					minetest.sound_stop(s_handle)
-				end, s_handle)
-			end
-			minetest.delete_particlespawner(id)
-			this_spawner_meta:set_int("active", nil)
-			this_spawner_meta:set_int("sound", nil)
-			return
-		end
-
-		if fdir and fdir < 4 and is_tray and (not id or id == 0) then
-			id = minetest.add_particlespawner({
-				amount = 60, time = 0, collisiondetection = true,
-				minpos = {x=pos.x - minx, y=pos.y-0.45, z=pos.z - minz},
-				maxpos = {x=pos.x - maxx, y=pos.y-0.45, z=pos.z - maxz},
-				minvel = {x=velx, y=-2, z=velz}, maxvel = {x=velx, y=-2, z=velz},
-				minacc = {x=0, y=0, z=0}, maxacc = {x=0, y=-0.05, z=0},
-				minexptime = 2, maxexptime = 4, minsize = 0.5, maxsize = 1,
-				texture = "homedecor_water_particle.png",
-			})
-			s_handle = minetest.sound_play("homedecor_shower", {
-				pos = pos,
-				max_hear_distance = 5,
-				loop = true 
-			})
-			this_spawner_meta:set_int("active", id)
-			this_spawner_meta:set_int("sound", s_handle)
-			return
 		end
 	end,
 	on_destruct = function(pos)
-		local this_spawner_meta = minetest.get_meta(pos)
+		homedecor.stop_particle_spawner(pos)
-		local id = this_spawner_meta:get_int("active")
-		local s_handle = this_spawner_meta:get_int("sound")
-
-		if id ~= 0 then
-			minetest.delete_particlespawner(id)
-		end
-
-		if s_handle then
-			minetest.after(0, function(s_handle)
-				minetest.sound_stop(s_handle)
-			end, s_handle)
-		end
-
-		this_spawner_meta:set_int("active", nil)
-		this_spawner_meta:set_int("sound", nil)
 	end
 })
 

homedecor/handlers/water_particles.lua

@@ -0,0 +1,113 @@
+-- variables taken by the start... function
+--
+-- pos and node are as usual, from e.g. on_rightclick.
+--
+-- in the { particledef } table:
+--
+-- outletx/y/z are the exact coords of the starting point
+--     for the spawner, relative to the center of the node
+--
+-- velocityx/y are the speed of the particles,
+--     relative to a node placed while looking north (facedir 0)
+--
+-- spread is the radius from the starting point,
+-- along X and Z only, to randomly spawn particles.
+--
+-- soundname is the filename (without .ogg) of the sound file
+-- to be played along with the particle stream
+
+function homedecor.start_particle_spawner(pos, node, particledef, soundname)
+
+	local this_spawner_meta = minetest.get_meta(pos)
+	local id = this_spawner_meta:get_int("active")
+	local s_handle = this_spawner_meta:get_int("sound")
+
+	if id ~= 0 then
+		if s_handle then
+			minetest.after(0, function(s_handle)
+				minetest.sound_stop(s_handle)
+			end, s_handle)
+		end
+		minetest.delete_particlespawner(id)
+		this_spawner_meta:set_int("active", nil)
+		this_spawner_meta:set_int("sound", nil)
+		return
+	end
+
+	local fdir = node.param2
+
+	if fdir and fdir < 4 and (not id or id == 0) then
+
+		local outletx    = particledef.outlet_x
+		local outlety    = particledef.outlet_y
+		local outletz    = particledef.outlet_z
+		local velocityx  = particledef.velocity_x
+		local velocityz  = particledef.velocity_z
+		local spread     = particledef.spread
+
+		local minx_t = {  outletx - spread, -outletz - spread, outletx - spread, outletz - spread }
+		local maxx_t = {  outletx + spread, -outletz + spread, outletx + spread, outletz + spread }
+		local minz_t = { -outletz - spread,  outletx - spread, outletz - spread, outletx - spread }
+		local maxz_t = { -outletz + spread,  outletx + spread, outletz + spread, outletx + spread }
+
+		local minvelx_t = { velocityx.min, velocityz.min, -velocityx.max, -velocityz.max }
+		local maxvelx_t = { velocityx.max, velocityz.max, -velocityx.min, -velocityz.min }
+		local minvelz_t = { velocityz.min, velocityx.min, -velocityz.max,  velocityx.min }
+		local maxvelz_t = { velocityz.max, velocityx.max, -velocityz.min,  velocityx.max }
+
+		local minx = minx_t[fdir + 1]
+		local maxx = maxx_t[fdir + 1]
+		local minz = minz_t[fdir + 1]
+		local maxz = maxz_t[fdir + 1]
+
+		local minvelx = minvelx_t[fdir + 1]
+		local minvelz = minvelz_t[fdir + 1]
+		local maxvelx = maxvelx_t[fdir + 1]
+		local maxvelz = maxvelz_t[fdir + 1]
+
+		id = minetest.add_particlespawner({
+			amount = 60,
+			time = 0,
+			collisiondetection = true,
+			minpos = {x=pos.x - minx, y=pos.y + outlety, z=pos.z - minz},
+			maxpos = {x=pos.x - maxx, y=pos.y + outlety, z=pos.z - maxz},
+			minvel = {x = minvelx, y=-2, z = minvelz},
+			maxvel = {x = maxvelx, y=-2, z = maxvelz},
+			minacc = {x=0, y=0, z=0},
+			maxacc = {x=0, y=-0.05, z=0},
+			minexptime = 2,
+			maxexptime = 4,
+			minsize = 0.5,
+			maxsize = 1,
+			texture = "homedecor_water_particle.png",
+		})
+		s_handle = minetest.sound_play(soundname, {
+			pos = pos,
+			max_hear_distance = 5,
+			loop = true
+		})
+		this_spawner_meta:set_int("active", id)
+		this_spawner_meta:set_int("sound", s_handle)
+		return
+	end
+end
+
+function homedecor.stop_particle_spawner(pos)
+	local this_spawner_meta = minetest.get_meta(pos)
+	local id = this_spawner_meta:get_int("active")
+	local s_handle = this_spawner_meta:get_int("sound")
+
+	if id ~= 0 then
+		minetest.delete_particlespawner(id)
+	end
+
+	if s_handle then
+		minetest.after(0, function(s_handle)
+			minetest.sound_stop(s_handle)
+		end, s_handle)
+	end
+
+	this_spawner_meta:set_int("active", nil)
+	this_spawner_meta:set_int("sound", nil)
+end
+

homedecor/init.lua

@@ -120,6 +120,8 @@ dofile(homedecor.modpath.."/handlers/expansion.lua")
 dofile(homedecor.modpath.."/handlers/furnaces.lua")
 -- glue it all together into a registration function
 dofile(homedecor.modpath.."/handlers/registration.lua")
+-- some nodes have particle spawners
+dofile(homedecor.modpath.."/handlers/water_particles.lua")
 
 -- load various other components
 dofile(homedecor.modpath.."/misc-nodes.lua")					-- the catch-all for all misc nodes