Add "New From Route" function into route editing form

This patch allows creating new routes based on what was done on another route. This can be useful to fix minor mistakes on a route, or to create similar routes. Note that the route buffer created "steps back" one section, but with turnouts kept.

The new button is placed above the "Save ARS" button - I know it is ugly, so please suggest a better place for it.

1 files changed, 20 insertions, 7 deletions

diff --git a/advtrains_interlocking/route_prog.lua b/advtrains_interlocking/route_prog.lua
index 6abe431..e8f5e8e 100644
--- a/advtrains_interlocking/route_prog.lua
+++ b/advtrains_interlocking/route_prog.lua
@@ -214,19 +214,32 @@ end
 
 local player_rte_prog = {}
 
-function advtrains.interlocking.init_route_prog(pname, sigd)
+function advtrains.interlocking.init_route_prog(pname, sigd, default_route)
 	if not minetest.check_player_privs(pname, "interlocking") then
 		minetest.chat_send_player(pname, "Insufficient privileges to use this!")
 		return
 	end
-	player_rte_prog[pname] = {
+	local rp = {
 		origin = sigd,
-		route = {
-			name = "PROG["..pname.."]",
-		},
-		tmp_lcks = {},
 	}
-	advtrains.interlocking.visualize_route(sigd, player_rte_prog[pname].route, "prog_"..pname, player_rte_prog[pname].tmp_lcks, pname)
+	if default_route then
+		rp.route = table.copy(default_route)
+
+		-- "Step back one section", but keeping turnouts
+		local last_route = rp.route[#rp.route]
+		if last_route then
+			rp.tmp_lcks = last_route.locks
+			rp.route[#rp.route] = nil
+		end
+		rp.route.name = "PROG["..pname.."]"
+	else
+		rp.route = {
+			name = "PROG["..pname.."]"
+		}
+		rp.tmp_lcks = {}
+	end
+	player_rte_prog[pname] = rp
+	advtrains.interlocking.visualize_route(sigd, rp.route, "prog_"..pname, rp.tmp_lcks, pname)
 	minetest.chat_send_player(pname, "Route programming mode active. Punch TCBs to add route segments, punch turnouts to lock them.")
 end