Railway Time: Basic time counter and utility functions

3 files changed, 146 insertions, 2 deletions

diff --git a/advtrains/init.lua b/advtrains/init.lua
index 4e5ae90..3fc0de0 100644
--- a/advtrains/init.lua
+++ b/advtrains/init.lua
@@ -68,6 +68,8 @@ function atdump(t, intend)
 			str=minetest.pos_to_string(t)
 		elseif t.p and t.s then -- interlocking sigd
 			str="S["..minetest.pos_to_string(t.p).."/"..t.s.."]"
+		elseif advtrains.lines and t.s and t.m then -- RwT
+			str=advtrains.lines.rwt.to_string(t)
 		else
 			str="{"
 			local intd = (intend or "") .. "  "
@@ -417,7 +419,9 @@ minetest.register_globalstep(function(dtime_mt)
 			atlatc.mainloop_stepcode(dtime)
 			atlatc.interrupt.mainloop(dtime)
 		end
-		
+		if advtrains.lines then
+			advtrains.lines.step(dtime)
+		end
 		
 		--trigger a save when necessary
 		save_timer=save_timer-dtime
diff --git a/advtrains_line_automation/init.lua b/advtrains_line_automation/init.lua
index 5609524..eba288f 100644
--- a/advtrains_line_automation/init.lua
+++ b/advtrains_line_automation/init.lua
@@ -18,6 +18,7 @@ advtrains.lines = {
 
 local modpath = minetest.get_modpath(minetest.get_current_modname()) .. DIR_DELIM
 
+dofile(modpath.."railwaytime.lua")
 dofile(modpath.."stoprail.lua")
 
 
@@ -25,12 +26,19 @@ function advtrains.lines.load(data)
 	if data then
 		advtrains.lines.stations = data.stations or {}
 		advtrains.lines.stops = data.stops or {}
+		advtrains.lines.rwt.set_time(data.rwt_time)
 	end
 end
 
 function advtrains.lines.save()
 	return {
 		stations = advtrains.lines.stations,
-		stops = advtrains.lines.stops
+		stops = advtrains.lines.stops,
+		rwt_time = advtrains.lines.rwt.get_time()
 	}
 end
+
+function advtrains.lines.step(dtime)
+	advtrains.lines.rwt.step(dtime)
+	atdebug(advtrains.lines.rwt.now())
+end
diff --git a/advtrains_line_automation/railwaytime.lua b/advtrains_line_automation/railwaytime.lua
new file mode 100644
index 0000000..d117af1
--- /dev/null
+++ b/advtrains_line_automation/railwaytime.lua
@@ -0,0 +1,132 @@
+-- railwaytime.lua
+-- Advtrains uses a desynchronized time for train movement. Everything is counted relative to this time counter.
+-- The advtrains-internal time is in no way synchronized to the real-life time, due to:
+-- - Lag
+-- - Server stops/restarts
+-- However, this means that implementing a "timetable" system using the "real time" is not practical. Therefore,
+-- we introduce a custom time system, the RWT(Railway Time), which has nothing to do with RLT(Real-Life Time)
+-- RWT has a time cycle of 1 hour. This should be sufficient for most train lines that will ever be built in Minetest.
+-- A RWT looks like this:    37;25
+-- The ; is to distinguish it from a normal RLT (which has colons e.g. 12:34:56). Left number is minutes, right number is seconds.
+-- The minimum RWT is 00;00, the maximum is 59;59.
+-- It is OK to leave one places out at either end, esp. when writing relative times, such as:
+-- 43;3   22;0   2;30   0;10  ;10
+-- Those places are then filled with zeroes. Indeed, ";" would be valid for 00;00 .
+
+--[[
+1;23;45 = {
+	s=45,
+	m=23,
+	c=1, -- Cycle(~hour), not displayed most time
+}
+
+]]
+
+local rwt = {}
+
+--Time Stamp (Seconds since start of world)
+local e_time = 0
+
+-- Current rw time, cached and updated each step
+local crwtime
+
+function rwt.set_time(t)
+	e_time = t or 0
+end
+
+function rwt.get_time()
+	return e_time
+end
+
+function rwt.step(dt)
+	e_time = e_time + dt
+end
+
+function rwt.now()
+	return rwt.from_sec(e_time)
+end
+
+function rwt.new(c, m, s)
+	return {
+		c = c or 0,
+		m = m or 0,
+		s = s or 0
+	}
+end
+function rwt.copy(rwtime)
+	return {
+		c = rwtime.c or 0,
+		m = rwtime.m or 0,
+		s = rwtime.s or 0
+	}
+end
+
+function rwt.from_sec(stime)
+	local res = {}
+	local seconds = atfloor(stime)
+	res.s = seconds % 60
+	local minutes = atfloor(seconds/60)
+	res.m = minutes % 60
+	res.c = atfloor(minutes/60)
+	return res
+end
+
+function rwt.to_sec(rwtime, c_over)
+	return (c_over or rwtime.c)*60*60 + rwtime.m*60 + rwtime.s
+end
+
+function rwt.add(t1, t2)
+	local t1s = rwt.to_sec(t1)
+	local t2s = rwt.to_sec(t1)
+	return rwt.from_sec(t1s + t2s)
+end
+
+function rwt.sub(t1, t2)
+	local t1s = rwt.to_sec(t1)
+	local t2s = rwt.to_sec(t1)
+	return rwt.from_sec(t1s - t2s)
+end
+
+-- Threshold values
+-- "reftime" is the time to which this is made relative and defaults to now.
+rwt.CA_FUTURE	= 60*60 - 1		-- Selected so that time lies at or in the future of reftime (at nearest point in time)
+rwt.CA_FUTURES	= 60*60 		-- Same, except when times are equal, advances one full cycle
+rwt.CA_PAST		= 0				-- Selected so that time lies at or in the past of reftime
+rwt.CA_PASTS	= -1	 		-- Same, except when times are equal, goes back one full cycle
+rwt.CA_CENTER	= 30*60			-- If time is within past 30 minutes of reftime, selected as past, else selected as future.
+
+-- Adjusts the "cycle" value of a railway time to be in some relation to reftime.
+-- Modifies rwtime in-place
+function rwt.adjust(rwtime, reftime_p, thresh)
+	local reftime = reftime_p or rwt.now()
+	
+	local reftimes = rwt.to_sec(reftime)
+	
+	local rwtimes = rwt.to_sec(rwtime, 0)
+	local timeres = reftimes + thresh - rwtimes
+	local cycles = atfloor(timeres / (60*60))
+
+	rwtime.c = cycles
+end
+
+function rwt.get_adjust(rwtime, reftime, thresh)
+	local res = rwt.copy(rwtime)
+	rwt.adjust(res, reftime, thresh)
+	return res
+end
+
+function rwt.to_string(rwtime, places)
+	local pl = places or 2
+	if rwtime.c~=0 or pl>=3 then
+		return string.format("%d;%02d;%02d", rwtime.c, rwtime.m, rwtime.s)
+	elseif rwtime.m~=0 or pl>=2 then
+		return string.format("%02d;%02d", rwtime.m, rwtime.s)
+	else
+		return string.format(";%02d",rwtime.s)
+	end
+	return str
+end
+
+
+
+advtrains.lines.rwt = rwt