Add signal safety control override, restructure control system

10 files changed, 315 insertions, 57 deletions

diff --git a/advtrains/atc.lua b/advtrains/atc.lua
index 22de4ca..b00849d 100644
--- a/advtrains/atc.lua
+++ b/advtrains/atc.lua
@@ -20,10 +20,11 @@ end
 --contents: {command="...", arrowconn=0-15 where arrow points}
 
 --general
-function atc.train_set_command(train_id, command, arrow)
-	atc.train_reset_command(train_id)
-	advtrains.trains[train_id].atc_arrow = arrow
-	advtrains.trains[train_id].atc_command = command
+function atc.train_set_command(train, command, arrow)
+	atc.train_reset_command(train)
+	train.atc_delay = 0
+	train.atc_arrow = arrow
+	train.atc_command = command
 end
 
 function atc.send_command(pos, par_tid)
@@ -49,7 +50,7 @@ function atc.send_command(pos, par_tid)
 					atwarn("ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
 				end
 				
-				atc.train_set_command(train_id, atc.controllers[pts].command, iconnid==1)
+				atc.train_set_command(train, atc.controllers[pts].command, iconnid==1)
 				atprint("Sending ATC Command to", train_id, ":", atc.controllers[pts].command, "iconnid=",iconnid)
 				return true
 				
@@ -66,12 +67,13 @@ function atc.send_command(pos, par_tid)
 	return false
 end
 
-function atc.train_reset_command(train_id)
-	advtrains.trains[train_id].atc_command=nil
-	advtrains.trains[train_id].atc_delay=0
-	advtrains.trains[train_id].atc_brake_target=nil
-	advtrains.trains[train_id].atc_wait_finish=nil
-	advtrains.trains[train_id].atc_arrow=nil
+function atc.train_reset_command(train)
+	train.atc_command=nil
+	train.atc_delay=nil
+	train.atc_brake_target=nil
+	train.atc_wait_finish=nil
+	train.atc_arrow=nil
+	train.tarvelocity=nil
 end
 
 --nodes
@@ -179,7 +181,7 @@ local matchptn={
 			train.tarvelocity = 0
 		elseif train.velocity>tonumber(match) then
 			train.atc_brake_target=tonumber(match)
-			if train.tarvelocity>train.atc_brake_target then
+			if not train.tarvelocity or train.tarvelocity>train.atc_brake_target then
 				train.tarvelocity=train.atc_brake_target
 			end
 		end
@@ -258,7 +260,7 @@ function atc.execute_atc_command(id, train)
 		while nest>=0 do
 			if pos>#rest then
 				atwarn(sid(id), attrans("ATC command syntax error: I statement not closed: @1",command))
-				atc.train_reset_command(id)
+				atc.train_reset_command(train)
 				return
 			end
 			local char=string.sub(rest, pos, pos)
@@ -301,7 +303,7 @@ function atc.execute_atc_command(id, train)
 		end
 	end
 	atwarn(sid(id), attrans("ATC command parse error: Unknown command: @1", command))
-	atc.train_reset_command(id)
+	atc.train_reset_command(train)
 end
 
 
diff --git a/advtrains/init.lua b/advtrains/init.lua
index 46a73d4..c1f280d 100644
--- a/advtrains/init.lua
+++ b/advtrains/init.lua
@@ -45,6 +45,7 @@ function advtrains.pcall(fun)
 			atwarn(debug.traceback())
 			if advtrains.atprint_context_tid then
 				advtrains.path_print(advtrains.trains[advtrains.atprint_context_tid], atdebug)
+				atwarn(advtrains.trains[advtrains.atprint_context_tid].debug)
 			end
 		end)
 	if not succ then
diff --git a/advtrains/path.lua b/advtrains/path.lua
index 19b4e78..5c3db94 100644
--- a/advtrains/path.lua
+++ b/advtrains/path.lua
@@ -260,7 +260,7 @@ function advtrains.path_get_index_by_offset(train, index, offset)
 	--atdebug("pibo: 2 off=",off,"idx=",idx)
 	-- then walk the path forward until we would overshoot
 	while off - train.path_dist[idx] >= 0 do
-		idx = idx - 1
+		idx = idx + 1
 		advtrains.path_get_adjacent(train, idx)
 		if not train.path_dist[idx] then
 			for i=-5,5 do
diff --git a/advtrains/trainhud.lua b/advtrains/trainhud.lua
index 60ef5d1..f326427 100644
--- a/advtrains/trainhud.lua
+++ b/advtrains/trainhud.lua
@@ -44,19 +44,19 @@ function advtrains.on_control_change(pc, train, flip)
 	else
 		local act=false
 		if pc.up then
-		   train.lever=4
+		   train.ctrl.user=4
 		   act=true
 		end
 		if pc.jump then
-			train.lever = 1
+			train.ctrl.user = 1
 			act=true
 		end
 		if pc.down then
 			if train.velocity>0 then
 				if pc.jump then
-					train.lever = 0
+					train.ctrl.user = 0
 				else
-					train.lever = 2
+					train.ctrl.user = 2
 				end
 				act=true
 			else
@@ -77,7 +77,9 @@ function advtrains.on_control_change(pc, train, flip)
 				train.door_open = 1
 			end
 		end
-		train.active_control = act
+		if not act then
+			train.ctrl.user = nil
+		end
 		if pc.aux1 then
 			--horn
 		end
@@ -161,9 +163,7 @@ function advtrains.hud_train_format(train, flip)
 	
 	local max=train.max_speed or 10
 	local vel=advtrains.abs_ceil(train.velocity)
-	local tvel=advtrains.abs_ceil(train.tarvelocity)
 	local vel_kmh=advtrains.abs_ceil(advtrains.ms_to_kmh(train.velocity))
-	local tvel_kmh=advtrains.abs_ceil(advtrains.ms_to_kmh(train.tarvelocity))
 	
 	local levers = "B - o +"
 	local tlev=train.lever
@@ -174,11 +174,28 @@ function advtrains.hud_train_format(train, flip)
 	if tlev == 3 then levers = "B - >o< +" end
 	if tlev == 4 then levers = "B - o >+<" end
 	
-	local topLine, firstLine, secondLine
+	local topLine, firstLine
+	
+	local secondLine
+	if train.tarvelocity then
+		local b="   "
+		local tvel=advtrains.abs_ceil(train.tarvelocity)
+		local tvel_kmh=advtrains.abs_ceil(advtrains.ms_to_kmh(train.tarvelocity))
+		if train.atc_brake_target then
+			b="-B-"
+		end
+		secondLine="ATC"..b..": |"..string.rep("+", tvel)..string.rep("_", max-tvel).."> "..tvel_kmh.." km/h"
+	elseif train.atc_delay then
+		secondLine = "ATC waiting "..advtrains.abs_ceil(train.atc_delay).."s"
+	else
+		secondLine = "Manual operation"
+	end
+	if train.ctrl.lzb then
+		secondLine = "-!- Safety override -!-"
+	end
 	
 	topLine="  ["..mletter[fct].."]  {"..levers.."} "..doorstr[(train.door_open or 0) * fct]
 	firstLine=attrans("Speed:").." |"..string.rep("+", vel)..string.rep("_", max-vel).."> "..vel_kmh.." km/h"
-	secondLine=attrans("Target:").." |"..string.rep("+", tvel)..string.rep("_", max-tvel).."> "..tvel_kmh.." km/h"
 	
-	return topLine.."\n"..firstLine.."\n"..secondLine
+	return (train.debug or "").."\n"..topLine.."\n"..firstLine.."\n"..secondLine
 end
diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua
index 861c042..f26f7da 100644
--- a/advtrains/trainlogic.lua
+++ b/advtrains/trainlogic.lua
@@ -181,6 +181,13 @@ local function assertdef(tbl, var, def)
 	end
 end
 
+function advtrains.get_acceleration(train, lever)
+	local acc_all = t_accel_all[lever]
+	local acc_eng = t_accel_eng[lever]
+	local nwagons = #train.trainparts
+	local acc = acc_all + (acc_eng*train.locomotives_in_train)/nwagons
+	return acc
+end
 
 -- Small local util function to recalculate train's end index
 local function recalc_end_index(train)
@@ -219,9 +226,10 @@ function advtrains.train_ensure_init(id, train)
 	if train.no_step then return end
 
 	assertdef(train, "velocity", 0)
-	assertdef(train, "tarvelocity", 0)
+	--assertdef(train, "tarvelocity", 0)
 	assertdef(train, "acceleration", 0)
 	assertdef(train, "id", id)
+	assertdef(train, "ctrl", {})
 	
 	
 	if not train.drives_on or not train.max_speed then
@@ -275,11 +283,10 @@ function advtrains.train_step_b(id, train, dtime)
 	
 	--- 3. handle velocity influences ---
 	local train_moves=(train.velocity~=0)
-	local tarvel_cap
+	local tarvel_cap = train.speed_restriction
 	
 	if train.recently_collided_with_env then
 		tarvel_cap=0
-		train.active_control=false
 		if not train_moves then
 			train.recently_collided_with_env=nil--reset status when stopped
 		end
@@ -307,11 +314,24 @@ function advtrains.train_step_b(id, train, dtime)
 		tarvel_cap=1
 	end
 	
+	-- Driving control rework:
+	--[[
+	Items are only defined when something is controlling them.
+	In order of precedence.
+	train.ctrl = {
+		lzb  = restrictive override from LZB
+		user = User input from driverstand
+		atc  = ATC command override (determined here)
+	}
+	The code here determines the precedence and writes the final control into train.lever
+	]]
+	
 	--interpret ATC command and apply auto-lever control when not actively controlled
 	local trainvelocity = train.velocity
-	if not train.lever then train.lever=3 end
-	if train.active_control then
-		advtrains.atc.train_reset_command(id)
+	
+	
+	if train.ctrl.user then
+		advtrains.atc.train_reset_command(train)
 	else
 		local braketar = train.atc_brake_target
 		local emerg = false -- atc_brake_target==-1 means emergency brake (BB command)
@@ -323,8 +343,11 @@ function advtrains.train_step_b(id, train, dtime)
 			train.atc_brake_target=nil
 			braketar = nil
 		end
+		if train.tarvelocity and train.velocity==train.tarvelocity then
+			train.tarvelocity = nil
+		end
 		if train.atc_wait_finish then
-			if not train.atc_brake_target and train.velocity==train.tarvelocity then
+			if not train.atc_brake_target and not train.tarvelocity then
 				train.atc_wait_finish=nil
 			end
 		end
@@ -334,42 +357,62 @@ function advtrains.train_step_b(id, train, dtime)
 			else
 				train.atc_delay=train.atc_delay-dtime
 			end
+		elseif train.atc_delay then
+			train.atc_delay = nil
 		end
 		
-		train.lever = 3
-		if train.tarvelocity>trainvelocity then train.lever=4 end
-		if train.tarvelocity<trainvelocity then
+		train.ctrl.atc = nil
+		if train.tarvelocity and train.tarvelocity>trainvelocity then
+			train.ctrl.atc=4
+		end
+		if train.tarvelocity and train.tarvelocity<trainvelocity then
 			if (braketar and braketar<trainvelocity) then
 				if emerg then
-					train.lever = 0
+					train.ctrl.atc = 0
 				else
-					train.lever=1
+					train.ctrl.atc=1
 				end
 			else
-				train.lever=2
+				train.ctrl.atc=2
 			end
 		end
 	end
 	
-	if tarvel_cap and tarvel_cap<train.tarvelocity then
+	if tarvel_cap and train.tarvelocity and tarvel_cap<train.tarvelocity then
 		train.tarvelocity=tarvel_cap
 	end
-	local tmp_lever = train.lever
+	
+	local tmp_lever
+	
+	for _, lev in pairs(train.ctrl) do
+		-- use the most restrictive of all control overrides
+		tmp_lever = math.min(tmp_lever or 4, lev)
+	end
+	
+	if not tmp_lever then
+		-- if there was no control at all, default to 3
+		tmp_lever = 3
+	end
+	
 	if tarvel_cap and trainvelocity>tarvel_cap then
 		tmp_lever = 0
 	end
 	
+	train.lever = tmp_lever
+	
 	--- 3a. actually calculate new velocity ---
 	if tmp_lever~=3 then
-		local acc_all = t_accel_all[tmp_lever]
-		local acc_eng = t_accel_eng[tmp_lever]
-		local nwagons = #train.trainparts
-		local accel = acc_all + (acc_eng*train.locomotives_in_train)/nwagons
+		local accel = advtrains.get_acceleration(train, tmp_lever)
 		local vdiff = accel*dtime
-		if not train.active_control then
+		
+		-- ATC control exception: don't cross tarvelocity if
+		-- atc provided a target_vel
+		if train.tarvelocity then
 			local tvdiff = train.tarvelocity - trainvelocity
-			if math.abs(vdiff) > math.abs(tvdiff) then
+			if tvdiff~=0 and math.abs(vdiff) > math.abs(tvdiff) then
 				--applying this change would cross tarvelocity
+				--atdebug("In Tvdiff condition, clipping",vdiff,"to",tvdiff)
+				--atdebug("vel=",trainvelocity,"tvel=",train.tarvelocity)
 				vdiff=tvdiff
 			end
 		end
@@ -385,9 +428,9 @@ function advtrains.train_step_b(id, train, dtime)
 		end
 		train.acceleration=vdiff
 		train.velocity=train.velocity+vdiff
-		if train.active_control then
-			train.tarvelocity = train.velocity
-		end
+		--if train.ctrl.user then
+		--	train.tarvelocity = train.velocity
+		--end
 	else
 		train.acceleration = 0
 	end
@@ -443,7 +486,7 @@ if train.no_step or train.wait_for_path then return end
 					if not collided and advtrains.occ.check_collision(testpos, id) then
 						--collides
 						train.velocity = 0
-						train.tarvelocity = 0
+						advtrains.atc.train_reset_command(train)
 						collided = true
 					end
 					--- 8b damage players ---
@@ -622,7 +665,7 @@ function advtrains.create_new_train_at(pos, connid, ioff, trainparts)
 	t.last_connid=connid
 	t.last_frac=ioff
 	
-	t.tarvelocity=0
+	--t.tarvelocity=0
 	t.velocity=0
 	t.trainparts=trainparts
 	
diff --git a/advtrains_interlocking/database.lua b/advtrains_interlocking/database.lua
index 030a5e0..af90880 100644
--- a/advtrains_interlocking/database.lua
+++ b/advtrains_interlocking/database.lua
@@ -485,7 +485,7 @@ function ildb.get_ip_signal_asp(pts, connid)
 			ildb.clear_ip_signal(pts, connid)
 			return nil
 		end
-		return asp
+		return asp, p
 	end
 	return nil
 end
diff --git a/advtrains_interlocking/init.lua b/advtrains_interlocking/init.lua
index 19501b6..d6625eb 100644
--- a/advtrains_interlocking/init.lua
+++ b/advtrains_interlocking/init.lua
@@ -8,9 +8,12 @@ local modpath = minetest.get_modpath(minetest.get_current_modname()) .. DIR_DELI
 dofile(modpath.."database.lua")
 dofile(modpath.."signal_api.lua")
 dofile(modpath.."demosignals.lua")
-dofile(modpath.."train_related.lua")
+dofile(modpath.."train_sections.lua")
 dofile(modpath.."route_prog.lua")
 dofile(modpath.."routesetting.lua")
 dofile(modpath.."tcb_ts_ui.lua")
 
+dofile(modpath.."lzb.lua")
+
+
 minetest.register_privilege("interlocking", {description = "Can set up track sections, routes and signals.", give_to_singleplayer = true})
diff --git a/advtrains_interlocking/lzb.lua b/advtrains_interlocking/lzb.lua
new file mode 100644
index 0000000..c9e40ab
--- /dev/null
+++ b/advtrains_interlocking/lzb.lua
@@ -0,0 +1,194 @@
+-- lzb.lua
+-- Enforced and/or automatic train override control, obeying signals
+
+--[[
+Documentation of train.lzb table
+train.lzb = {
+	trav = Current index that the traverser has advanced so far
+	travsht = boolean indicating whether the train will be a shunt move at "trav"
+	travspd = speed restriction at end of traverser
+	travwspd = warning speed res.
+	oncoming = table containing oncoming signals, in order of appearance on the path
+		{
+			pos = position of the signal (not the IP!)
+			idx = where this is on the path
+			spd = speed allowed to pass (determined dynamically)
+		}
+}
+each step, for every item in "oncoming", we need to determine the location to start braking (+ some safety margin)
+and, if we passed this point for at least one of the items, initiate brake.
+When speed has dropped below, say 3, decrease the margin to zero, so that trains actually stop at the signal IP.
+The spd variable and travsht need to be updated on every aspect change. it's probably best to reset everything when any aspect changes
+
+The traverser stops at signals that result in spd==0, because changes beyond there are likely.
+]]
+
+local il = advtrains.interlocking
+
+local BRAKE_SPACE = 10
+local AWARE_ZONE  = 50
+
+local ADD_STAND  =  2
+local ADD_SLOW   =  1
+local ADD_FAST   =  10
+
+local SHUNT_SPEED_MAX = 4
+
+local function look_ahead(id, train)
+	
+	local acc = advtrains.get_acceleration(train, 1)
+	local vel = train.velocity
+	local brakedst = -(vel*vel) / (2*acc)
+	
+	local brake_i = advtrains.path_get_index_by_offset(train, train.index, brakedst + BRAKE_SPACE)
+	--local aware_i = advtrains.path_get_index_by_offset(train, brake_i, AWARE_ZONE)
+	
+	local lzb = train.lzb
+	local trav = lzb.trav
+	local travspd = lzb.travspd
+	local travwspd = lzb.travwspd
+	local lspd
+	
+	train.debug = lspd
+	
+	while trav <= brake_i and (not lspd or lspd>0) do
+		trav = trav + 1
+		local pos = advtrains.path_get(train, trav)
+		local pts = advtrains.roundfloorpts(pos)
+		local cn  = train.path_cn[trav]
+		-- check offtrack
+		if trav > train.path_trk_f then
+			lspd = 0
+			table.insert(lzb.oncoming, {
+				idx = trav-1,
+				spd = 0,
+			})
+		else
+			-- check for signal
+			local asp, spos = il.db.get_ip_signal_asp(pts, cn)
+			--atdebug("trav: ",pos, cn, asp, spos, "travsht=", lzb.travsht)
+			if asp then
+				local nspd = 0
+				--interpreting aspect and determining speed to proceed
+				if lzb.travsht then
+					--shunt move
+					if asp.shunt.free then
+						nspd = SHUNT_SPEED_MAX
+					elseif asp.shunt.proceed_as_main and asp.main.free then
+						nspd = asp.main.speed
+						lzb.travsht = false
+					end
+				else
+					--train move
+					if asp.main.free then
+						nspd = asp.main.speed
+					elseif asp.shunt.free then
+						nspd = SHUNT_SPEED_MAX
+						lzb.travsht = true
+					end
+				end
+				-- nspd can now be: 1. !=0: new speed restriction, 2. =0: stop here or 3. nil: keep travspd
+				if nspd then
+					if nspd == -1 then
+						travspd = nil
+					else
+						travspd = nspd
+					end
+				end
+				
+				local nwspd = asp.info.w_speed
+				if nwspd then
+					if nwspd == -1 then
+						travwspd = nil
+					else
+						travwspd = nwspd
+					end
+				end
+				--atdebug("ns,wns,ts,wts", nspd, nwspd, travspd, travwspd)
+				lspd = travspd
+				if travwspd and (not lspd or lspd>travwspd) then
+					lspd = travwspd
+				end
+				
+				table.insert(lzb.oncoming, {
+					pos = spos,
+					idx = trav,
+					spd = lspd,
+				})
+				-- TODO register aspect change callback!
+			end
+		end
+	end
+	
+	lzb.trav = trav
+	lzb.travspd = travspd
+	lzb.travwspd = travwspd
+	
+end
+
+--[[
+Distance needed to accelerate from v0 to v1 with constant acceleration a:
+
+         v1 - v0     a   / v1 - v0 \ 2
+s = v0 * -------  +  - * | ------- |
+            a        2   \    a    /
+]]
+
+local function apply_control(id, train)
+	local lzb = train.lzb
+	
+	local i = 1
+	while i<#lzb.oncoming do
+		if lzb.oncoming[i].idx < train.index then
+			train.speed_restriction = lzb.oncoming[i].spd
+			table.remove(lzb.oncoming, i)
+		else
+			i = i + 1
+		end
+	end
+	
+	for i, it in ipairs(lzb.oncoming) do
+		local a = advtrains.get_acceleration(train, 1) --should be negative
+		local v0 = train.velocity
+		local v1 = it.spd
+		if v1 and v1 <= v0 then
+			local f = (v1-v0) / a
+			local s = v0*f + a*f*f/2
+			
+			local st = s + ADD_SLOW
+			if v0 > 3 then
+				st = s + ADD_FAST
+			end
+			if v0<=0 then
+				st = s + ADD_STAND
+			end
+			
+			local i = advtrains.path_get_index_by_offset(train, it.idx, -st)
+			
+			--train.debug = dump({v0f=v0*f, aff=a*f*f,v0=v0, v1=v1, f=f, a=a, s=s, st=st, i=i, idx=train.index})
+			if i <= train.index then
+				-- Gotcha! Braking...
+				train.ctrl.lzb = 1
+				--train.debug = train.debug .. "BRAKE!!!"
+				return
+			end
+		end
+	end
+	train.ctrl.lzb = nil
+end
+
+
+advtrains.te_register_on_new_path(function(id, train)
+	train.lzb = {
+		trav = atfloor(train.index),
+		travsht = train.is_shunt,
+		oncoming = {}
+	}
+	train.ctrl.lzb = nil
+	look_ahead(id, train)
+end)
+
+advtrains.te_register_on_update(function(id, train)
+	look_ahead(id, train)
+	apply_control(id, train)
+end)
diff --git a/advtrains_interlocking/train_related.lua b/advtrains_interlocking/train_sections.lua
index 8bc9716..8bc9716 100644
--- a/advtrains_interlocking/train_related.lua
+++ b/advtrains_interlocking/train_sections.lua
diff --git a/advtrains_luaautomation/atc_rail.lua b/advtrains_luaautomation/atc_rail.lua
index d001d88..1fab620 100644
--- a/advtrains_luaautomation/atc_rail.lua
+++ b/advtrains_luaautomation/atc_rail.lua
@@ -50,9 +50,7 @@ function r.fire_event(pos, evtdata)
 		atc_send = function(cmd)
 			if not train_id then return false end
 			assertt(cmd, "string")
-			advtrains.atc.train_reset_command(train_id)
-			train.atc_command=cmd
-			train.atc_arrow=atc_arrow
+			advtrains.atc.train_set_command(train, cmd, atc_arrow)
 			return true
 		end,
 		set_line = function(line)
@@ -62,7 +60,7 @@ function r.fire_event(pos, evtdata)
 		atc_reset = function(cmd)
 			if not train_id then return false end
 			assertt(cmd, "string")
-			advtrains.atc.train_reset_command(train_id)
+			advtrains.atc.train_reset_command(train)
 			return true
 		end,
 		atc_arrow = atc_arrow,