Make tubes opaque when entities are not used (#29)

* Make tubes opaque when entities are not used

decorative_tubes.lua

@@ -49,12 +49,13 @@ minetest.register_node("pipeworks:steel_pane_embedded_tube", {
 	drawtype = "nodebox",
 	description = S("Airtight panel embedded tube"),
 	tiles = {
-		"pipeworks_pane_embedded_tube_sides.png^[transformR90",
-		"pipeworks_pane_embedded_tube_sides.png^[transformR90",
-		"pipeworks_pane_embedded_tube_sides.png",
-		"pipeworks_pane_embedded_tube_sides.png",
-		"pipeworks_pane_embedded_tube_ends.png", "pipeworks_pane_embedded_tube_ends.png",
-		},
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_sides.png^[transformR90"),
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_sides.png^[transformR90"),
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_sides.png"),
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_sides.png"),
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_ends.png"),
+		pipeworks.make_tube_tile("pipeworks_pane_embedded_tube_ends.png"),
+	},
 	use_texture_alpha = texture_alpha_mode,
 	node_box = pane_box,
 	selection_box = pane_box,

init.lua

@@ -69,6 +69,29 @@ function pipeworks.fix_image_names(table, replacement)
 	return outtable
 end
 
+local function overlay_tube_texture(texture)
+	-- The texture appears the first time to be colorized as the opaque background.
+	return ("(%s)^[noalpha^[colorize:#dadada^(%s)"):format(texture, texture)
+end
+
+function pipeworks.make_tube_tile(tile)
+	if pipeworks.use_real_entities then
+		return tile
+	elseif type(tile) == "string" then
+		return overlay_tube_texture(tile)
+	else
+		tile = table.copy(tile)
+		if tile.color then
+			-- Won't work 100% of the time, but good enough.
+			tile.name = tile.name .. "^[multiply:" .. minetest.colorspec_to_colorstring(tile.color)
+			tile.color = nil
+		end
+		tile.name = overlay_tube_texture(tile.name)
+		tile.backface_culling = nil -- The texture is opaque
+		return tile
+	end
+end
+
 function pipeworks.add_node_box(t, b)
 	if not t or not b then return end
 	for i in ipairs(b)

routing_tubes.lua

@@ -143,10 +143,14 @@ local texture_alpha_mode = minetest.features.use_texture_alpha_string_modes
 	and "clip" or true
 
 if pipeworks.enable_one_way_tube then
+	local tiles = {"pipeworks_one_way_tube_top.png", "pipeworks_one_way_tube_top.png", "pipeworks_one_way_tube_output.png",
+		"pipeworks_one_way_tube_input.png", "pipeworks_one_way_tube_side.png", "pipeworks_one_way_tube_top.png"}
+	for i, tile in ipairs(tiles) do
+		tiles[i] = pipeworks.make_tube_tile(tile)
+	end
 	minetest.register_node("pipeworks:one_way_tube", {
 		description = S("One way tube"),
-		tiles = {"pipeworks_one_way_tube_top.png", "pipeworks_one_way_tube_top.png", "pipeworks_one_way_tube_output.png",
-			"pipeworks_one_way_tube_input.png", "pipeworks_one_way_tube_side.png", "pipeworks_one_way_tube_top.png"},
+		tiles = tiles,
 		use_texture_alpha = texture_alpha_mode,
 		paramtype2 = "facedir",
 		drawtype = "nodebox",

settingtypes.txt

@@ -77,4 +77,5 @@ pipeworks_drop_on_routing_fail (Drop On Routing Fail) bool false
 pipeworks_delete_item_on_clearobject (Delete Item On Clearobject) bool true
 
 #Use real visible entities in tubes within active areas.
+#When disabled, tubes are made opaque.
 pipeworks_use_real_entities (Use real entities) bool true

tube_registration.lua

@@ -80,6 +80,10 @@ local register_one_tube = function(name, tname, dropname, desc, plain, noctrs, e
 		wscale = {x = 1, y = 1, z = 0.01}
 	end
 
+	for i, tile in ipairs(outimgs) do
+		outimgs[i] = pipeworks.make_tube_tile(tile)
+	end
+
 	local rname = string.format("%s_%s", name, tname)
 	table.insert(tubenodes, rname)