From 5c8962b39bd4f6871ec87a988ac43d7bfad04d2b Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Mon, 11 Apr 2022 16:55:50 +0200
Subject: Implement basic route signaling with Japanese signals for demo

---
 advtrains_interlocking/signal_api.lua | 146 ++++------------------------------
 1 file changed, 17 insertions(+), 129 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 83fae4a..0a9e6ea 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -220,8 +220,17 @@ function advtrains.interlocking.signal_set_aspect(pos, asp)
 	local node=advtrains.ndb.get_node(pos)
 	local ndef=minetest.registered_nodes[node.name]
 	if ndef and ndef.advtrains and ndef.advtrains.set_aspect then
+		local oldasp = advtrains.interlocking.signal_get_aspect(pos) or DANGER
+		local suppasp = advtrains.interlocking.signal_get_supported_aspects(pos) or {}
+		if suppasp.type == 2 then
+			asp = advtrains.interlocking.aspects.type1_to_type2main(asp, suppasp.group)
+		end
 		ndef.advtrains.set_aspect(pos, node, asp)
-		advtrains.interlocking.signal_on_aspect_changed(pos)
+		local actualasp = advtrains.interlocking.signal_get_aspect(pos) or DANGER
+		local aspect_changed = advtrains.interlocking.aspects.not_equalp(oldasp, actualasp)
+		if aspect_changed then
+			advtrains.interlocking.signal_on_aspect_changed(pos)
+		end
 	end
 end
 
@@ -252,7 +261,7 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 			local function callback(pname, aspect)
 				advtrains.interlocking.signal_set_aspect(pos, aspect)
 			end
-			local isasp = ndef.advtrains.get_aspect(pos, node)
+			local isasp = advtrains.interlocking.signal_get_aspect(pos, node)
 			
 			advtrains.interlocking.show_signal_aspect_selector(
 				pname,
@@ -285,8 +294,13 @@ function advtrains.interlocking.signal_get_aspect(pos)
 	local ndef=minetest.registered_nodes[node.name]
 	if ndef and ndef.advtrains and ndef.advtrains.get_aspect then
 		local asp = ndef.advtrains.get_aspect(pos, node)
+		local suppasp = advtrains.interlocking.signal_get_supported_aspects(pos) or {}
+		if suppasp.type == 2 then
+			asp = advtrains.interlocking.aspects.type2main_to_type1(suppasp.group, asp)
+		end
 		if not asp then asp = DANGER end
-		return convert_aspect_if_necessary(asp)
+		asp = convert_aspect_if_necessary(asp)
+		return asp
 	end
 	return nil
 end
@@ -411,129 +425,3 @@ minetest.register_on_punchnode(function(pos, node, player, pointed_thing)
 		players_assign_ip[pname] = nil
 	end
 end)
-
-
---== aspect selector ==--
-
-local players_aspsel = {}
-
---[[
-suppasp: "supported_aspects" table
-purpose: form title string
-callback: func(pname, aspect) called on form submit
-isasp: aspect currently set
-]]
-function advtrains.interlocking.show_signal_aspect_selector(pname, p_suppasp, p_purpose, callback, isasp)
-	local suppasp = p_suppasp or {
-		main = {0, -1}, dst = {false}, shunt = false, info = {},
-	}
-	local purpose = p_purpose or ""
-	
-	local form = "size[7,7]label[0.5,0.5;Select Signal Aspect:]"
-	form = form.."label[0.5,1;"..purpose.."]"
-	
-	form = form.."label[0.5,1.5;== Main Signal ==]"
-	local selid = 1
-	local entries = {}
-	for idx, spv in ipairs(suppasp.main) do
-		local entry
-		if spv == 0 then
-			entry = "Halt"
-		elseif spv == -1 then
-			entry = "Continue at maximum speed"
-		elseif not spv then
-			entry = "Continue\\, speed limit unchanged (no info)"
-		else
-			entry = "Continue at speed of "..spv				
-		end
-		-- hack: the crappy formspec system returns the label, not the index. save the index in it.
-		entries[idx] = idx.."| "..entry
-		if isasp and spv == (isasp.main or false) then
-			selid = idx
-		end
-	end
-	form = form.."dropdown[0.5,2;6;main;"..table.concat(entries, ",")..";"..selid.."]"
-
-	
-	form = form.."label[0.5,3;== Shunting ==]"
-	if suppasp.shunt == nil then
-		local st = 1
-		if isasp and isasp.shunt then st=2 end
-		form = form.."dropdown[0.5,3.5;6;shunt_free;---,allowed;"..st.."]"
-	end
-
-	form = form.."label[0.5,4.5;== Distant Signal ==]"
-	local selid = 1
-	local entries = {}
-	for idx, spv in ipairs(suppasp.dst) do
-		local entry
-		if spv == 0 then
-			entry = "Expect to stop at the next signal"
-		elseif spv == -1 then
-			entry = "Expect to pass the next signal at maximum speed"
-		elseif not spv then
-			entry = "No info"
-		else
-			entry = string.format("Expect to pass the next signal at speed of %d", spv)
-		end
-		entries[idx] = idx.."| "..entry
-		if isasp and spv == (isasp.dst or false) then
-			selid = idx
-		end
-	end
-	form = form.."dropdown[0.5,5;6;dst;"..table.concat(entries, ",")..";"..selid.."]"
-
-	form = form.."button_exit[0.5,6;5,1;save;Save signal aspect]"
-	
-	local token = advtrains.random_id()
-	
-	minetest.show_formspec(pname, "at_il_sigaspdia_"..token, form)
-	
-	minetest.after(1, function()
-	players_aspsel[pname] = {
-		suppasp = suppasp,
-		callback = callback,
-		token = token,
-	}
-	end)
-end
-
-local function usebool(sup, val, free)
-	if sup == nil then
-		return val==free
-	else
-		return sup
-	end
-end
-
--- other side of hack: extract the index
-local function ddindex(val)
-	return tonumber(string.match(val, "^(%d+)|"))
-end
-
--- TODO use non-hacky way to parse outputs
-
-minetest.register_on_player_receive_fields(function(player, formname, fields)
-	local pname = player:get_player_name()
-	local psl = players_aspsel[pname]
-	if psl then
-		if formname == "at_il_sigaspdia_"..psl.token then
-			if fields.save then
-				local maini = ddindex(fields.main)
-				if not maini then return end
-				local dsti = ddindex(fields.dst)
-				if not dsti then return end
-				local asp = {
-					main = psl.suppasp.main[maini],
-					dst = psl.suppasp.dst[dsti],
-					shunt = usebool(psl.suppasp.shunt, fields.shunt_free, "allowed"),
-					info = {}
-				}
-				psl.callback(pname, asp)
-			end
-		else
-			players_aspsel[pname] = nil
-		end
-	end
-	
-end)
-- 
cgit v1.2.3


From 220563012d2aa2c753c791fa9faa38346f1355a5 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Fri, 6 May 2022 21:36:21 +0200
Subject: Record signal aspect to avoid excessive get_aspect calls; report
 testing coverage

---
 advtrains_interlocking/signal_api.lua | 38 ++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 0a9e6ea..a25e1f6 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -178,6 +178,8 @@ advtrains.interlocking.GENERIC_FREE = {
 	dst = false,
 }
 
+local supposed_aspects = {}
+
 local function convert_aspect_if_necessary(asp)
 	if type(asp.main) == "table" then
 		local newasp = {} 
@@ -199,6 +201,24 @@ local function convert_aspect_if_necessary(asp)
 	return asp
 end
 
+function advtrains.interlocking.load_supposed_aspects(tbl)
+	if tbl then
+		supposed_aspects = tbl
+	end
+end
+
+function advtrains.interlocking.save_supposed_aspects()
+	return supposed_aspects
+end
+
+local function set_supposed_aspect(pos, asp)
+	supposed_aspects[advtrains.roundfloorpts(pos)] = asp
+end
+
+local function get_supposed_aspect(pos)
+	return supposed_aspects[advtrains.roundfloorpts(pos)]
+end
+
 function advtrains.interlocking.update_signal_aspect(tcbs)
 	if tcbs.signal then
 		local asp = tcbs.aspect or DANGER
@@ -213,6 +233,7 @@ end
 function advtrains.interlocking.signal_after_dig(pos)
 	-- clear influence point
 	advtrains.interlocking.db.clear_ip_by_signalpos(pos)
+	set_supposed_aspect(pos, nil)
 end
 
 function advtrains.interlocking.signal_set_aspect(pos, asp)
@@ -222,12 +243,13 @@ function advtrains.interlocking.signal_set_aspect(pos, asp)
 	if ndef and ndef.advtrains and ndef.advtrains.set_aspect then
 		local oldasp = advtrains.interlocking.signal_get_aspect(pos) or DANGER
 		local suppasp = advtrains.interlocking.signal_get_supported_aspects(pos) or {}
+		local newasp = asp
 		if suppasp.type == 2 then
 			asp = advtrains.interlocking.aspects.type1_to_type2main(asp, suppasp.group)
 		end
+		set_supposed_aspect(pos, newasp)
 		ndef.advtrains.set_aspect(pos, node, asp)
-		local actualasp = advtrains.interlocking.signal_get_aspect(pos) or DANGER
-		local aspect_changed = advtrains.interlocking.aspects.not_equalp(oldasp, actualasp)
+		local aspect_changed = advtrains.interlocking.aspects.not_equalp(oldasp, newasp)
 		if aspect_changed then
 			advtrains.interlocking.signal_on_aspect_changed(pos)
 		end
@@ -289,7 +311,7 @@ end
 
 -- Returns the actual aspect of the signal at position, as returned by the nodedef.
 -- returns nil when there's no signal at the position
-function advtrains.interlocking.signal_get_aspect(pos)
+function advtrains.interlocking.signal_get_real_aspect(pos)
 	local node=advtrains.ndb.get_node(pos)
 	local ndef=minetest.registered_nodes[node.name]
 	if ndef and ndef.advtrains and ndef.advtrains.get_aspect then
@@ -305,6 +327,16 @@ function advtrains.interlocking.signal_get_aspect(pos)
 	return nil
 end
 
+-- Returns the signal aspect as reported in the suppasp table.
+function advtrains.interlocking.signal_get_aspect(pos)
+	local asp = get_supposed_aspect(pos)
+	if not asp then
+		asp = advtrains.interlocking.signal_get_real_aspect(pos)
+		set_supposed_aspect(pos)
+	end
+	return asp
+end
+
 -- Returns the "supported_aspects" of the signal at position, as returned by the nodedef.
 -- returns nil when there's no signal at the position
 function advtrains.interlocking.signal_get_supported_aspects(pos)
-- 
cgit v1.2.3


From d1a0d8f2654d6ee64c1a43de7958b1eadfaff6b0 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Fri, 10 Jun 2022 22:21:54 +0200
Subject: Use tabs to switch between signaling and IP forms

---
 advtrains_interlocking/signal_api.lua | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index a25e1f6..5b3baf8 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -272,7 +272,10 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 		advtrains.interlocking.show_ip_form(pos, pname)
 		return
 	end
+	advtrains.interlocking.show_signal_form(pos, node, pname)
+end
 	
+function advtrains.interlocking.show_signal_form(pos, node, pname)
 	local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
 	if sigd then
 		advtrains.interlocking.show_signalling_form(sigd, pname)
@@ -288,7 +291,7 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 			advtrains.interlocking.show_signal_aspect_selector(
 				pname,
 				ndef.advtrains.supported_aspects,
-				"Set aspect manually", callback,
+				pos, callback,
 				isasp)
 		else
 			--static signal - only IP
@@ -332,7 +335,7 @@ function advtrains.interlocking.signal_get_aspect(pos)
 	local asp = get_supposed_aspect(pos)
 	if not asp then
 		asp = advtrains.interlocking.signal_get_real_aspect(pos)
-		set_supposed_aspect(pos)
+		set_supposed_aspect(pos, asp)
 	end
 	return asp
 end
@@ -372,6 +375,7 @@ function advtrains.interlocking.show_ip_form(pos, pname, only_notset)
 		return
 	end
 	local form = "size[7,5]label[0.5,0.5;Signal at "..minetest.pos_to_string(pos).."]"
+	form = form .. advtrains.interlocking.make_signal_formspec_tabheader(pname, pos, 7, 2)
 	advtrains.interlocking.db.check_for_duplicate_ip(pos)
 	local pts, connid = advtrains.interlocking.db.get_ip_by_signalpos(pos)
 	if pts then
@@ -394,6 +398,9 @@ end
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	local pname = player:get_player_name()
+	if advtrains.interlocking.handle_signal_formspec_tabheader_fields(pname, fields) then
+		return true
+	end
 	if not minetest.check_player_privs(pname, {train_operator=true, interlocking=true}) then
 		return
 	end
-- 
cgit v1.2.3


From 98c37108762c6d7c9f1d691b84f49bfa65b81b28 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sat, 11 Jun 2022 18:07:00 +0200
Subject: Implement primitive distant signaling

---
 advtrains_interlocking/signal_api.lua | 85 ++---------------------------------
 1 file changed, 3 insertions(+), 82 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 5b3baf8..1fd4e34 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -167,7 +167,6 @@ This function will query get_aspect to retrieve the new aspect.
 
 local DANGER = {
 	main = 0,
-	dst = false,
 	shunt = false,
 }
 advtrains.interlocking.DANGER = DANGER
@@ -178,8 +177,6 @@ advtrains.interlocking.GENERIC_FREE = {
 	dst = false,
 }
 
-local supposed_aspects = {}
-
 local function convert_aspect_if_necessary(asp)
 	if type(asp.main) == "table" then
 		local newasp = {} 
@@ -200,24 +197,7 @@ local function convert_aspect_if_necessary(asp)
 	end
 	return asp
 end
-
-function advtrains.interlocking.load_supposed_aspects(tbl)
-	if tbl then
-		supposed_aspects = tbl
-	end
-end
-
-function advtrains.interlocking.save_supposed_aspects()
-	return supposed_aspects
-end
-
-local function set_supposed_aspect(pos, asp)
-	supposed_aspects[advtrains.roundfloorpts(pos)] = asp
-end
-
-local function get_supposed_aspect(pos)
-	return supposed_aspects[advtrains.roundfloorpts(pos)]
-end
+advtrains.interlocking.signal_convert_aspect_if_necessary = convert_aspect_if_necessary
 
 function advtrains.interlocking.update_signal_aspect(tcbs)
 	if tcbs.signal then
@@ -233,27 +213,8 @@ end
 function advtrains.interlocking.signal_after_dig(pos)
 	-- clear influence point
 	advtrains.interlocking.db.clear_ip_by_signalpos(pos)
-	set_supposed_aspect(pos, nil)
-end
-
-function advtrains.interlocking.signal_set_aspect(pos, asp)
-	asp = convert_aspect_if_necessary(asp)
-	local node=advtrains.ndb.get_node(pos)
-	local ndef=minetest.registered_nodes[node.name]
-	if ndef and ndef.advtrains and ndef.advtrains.set_aspect then
-		local oldasp = advtrains.interlocking.signal_get_aspect(pos) or DANGER
-		local suppasp = advtrains.interlocking.signal_get_supported_aspects(pos) or {}
-		local newasp = asp
-		if suppasp.type == 2 then
-			asp = advtrains.interlocking.aspects.type1_to_type2main(asp, suppasp.group)
-		end
-		set_supposed_aspect(pos, newasp)
-		ndef.advtrains.set_aspect(pos, node, asp)
-		local aspect_changed = advtrains.interlocking.aspects.not_equalp(oldasp, newasp)
-		if aspect_changed then
-			advtrains.interlocking.signal_on_aspect_changed(pos)
-		end
-	end
+	advtrains.interlocking.signal_clear_aspect(pos)
+	advtrains.distant.unassign_all(pos, true)
 end
 
 -- should be called when aspect has changed on this signal.
@@ -312,46 +273,6 @@ function advtrains.interlocking.signal_get_supposed_aspect(pos)
 	return DANGER;
 end
 
--- Returns the actual aspect of the signal at position, as returned by the nodedef.
--- returns nil when there's no signal at the position
-function advtrains.interlocking.signal_get_real_aspect(pos)
-	local node=advtrains.ndb.get_node(pos)
-	local ndef=minetest.registered_nodes[node.name]
-	if ndef and ndef.advtrains and ndef.advtrains.get_aspect then
-		local asp = ndef.advtrains.get_aspect(pos, node)
-		local suppasp = advtrains.interlocking.signal_get_supported_aspects(pos) or {}
-		if suppasp.type == 2 then
-			asp = advtrains.interlocking.aspects.type2main_to_type1(suppasp.group, asp)
-		end
-		if not asp then asp = DANGER end
-		asp = convert_aspect_if_necessary(asp)
-		return asp
-	end
-	return nil
-end
-
--- Returns the signal aspect as reported in the suppasp table.
-function advtrains.interlocking.signal_get_aspect(pos)
-	local asp = get_supposed_aspect(pos)
-	if not asp then
-		asp = advtrains.interlocking.signal_get_real_aspect(pos)
-		set_supposed_aspect(pos, asp)
-	end
-	return asp
-end
-
--- Returns the "supported_aspects" of the signal at position, as returned by the nodedef.
--- returns nil when there's no signal at the position
-function advtrains.interlocking.signal_get_supported_aspects(pos)
-	local node=advtrains.ndb.get_node(pos)
-	local ndef=minetest.registered_nodes[node.name]
-	if ndef and ndef.advtrains and ndef.advtrains.supported_aspects then
-		local asp = ndef.advtrains.supported_aspects
-		return asp
-	end
-	return nil
-end
-
 local players_assign_ip = {}
 
 local function ipmarker(ipos, connid)
-- 
cgit v1.2.3


From 875968f078ef89b13afae6d02a2dabe5ea7897cb Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sun, 3 Jul 2022 12:45:27 +0200
Subject: Unassign distant signals when canceling route

---
 advtrains_interlocking/signal_api.lua | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 1fd4e34..eec70f9 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -176,6 +176,11 @@ advtrains.interlocking.GENERIC_FREE = {
 	shunt = false,
 	dst = false,
 }
+advtrains.interlocking.FULL_FREE = {
+	main = -1,
+	shunt = false,
+	proceed_as_main = true,
+}
 
 local function convert_aspect_if_necessary(asp)
 	if type(asp.main) == "table" then
@@ -212,7 +217,7 @@ end
 
 function advtrains.interlocking.signal_after_dig(pos)
 	-- clear influence point
-	advtrains.interlocking.db.clear_ip_by_signalpos(pos)
+
 	advtrains.interlocking.signal_clear_aspect(pos)
 	advtrains.distant.unassign_all(pos, true)
 end
-- 
cgit v1.2.3


From 4a3d442601a800e28a274026392461bd1a7cb127 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sun, 3 Jul 2022 15:34:42 +0200
Subject: Reduce number of set_aspect calls

---
 advtrains_interlocking/signal_api.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index eec70f9..1c6ed27 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -204,10 +204,10 @@ local function convert_aspect_if_necessary(asp)
 end
 advtrains.interlocking.signal_convert_aspect_if_necessary = convert_aspect_if_necessary
 
-function advtrains.interlocking.update_signal_aspect(tcbs)
+function advtrains.interlocking.update_signal_aspect(tcbs, skipdst)
 	if tcbs.signal then
 		local asp = tcbs.aspect or DANGER
-		advtrains.interlocking.signal_set_aspect(tcbs.signal, asp)
+		advtrains.interlocking.signal_set_aspect(tcbs.signal, asp, skipdst)
 	end
 end
 
-- 
cgit v1.2.3


From a4abbf8824f893558861bff2893181ae02ed284d Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sat, 13 Aug 2022 16:16:17 +0200
Subject: Add hotfix for path invalidation

---
 advtrains_interlocking/signal_api.lua | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 1c6ed27..e615692 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -227,8 +227,10 @@ function advtrains.interlocking.signal_on_aspect_changed(pos)
 	local ipts, iconn = advtrains.interlocking.db.get_ip_by_signalpos(pos)
 	if not ipts then return end
 	local ipos = minetest.string_to_pos(ipts)
-	
-	advtrains.invalidate_all_paths_ahead(ipos)
+
+	-- FIXME: invalidate_all_paths_ahead does not appear to always work as expected
+	--advtrains.invalidate_all_paths_ahead(ipos)
+	minetest.after(0, advtrains.invalidate_all_paths, ipos)
 end
 
 function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack, pointed_thing)
-- 
cgit v1.2.3


From 7c9fd9179dfcec06107ad1a66346418827bdc4eb Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Mon, 31 Oct 2022 10:57:37 +0100
Subject: Add API documentation

---
 advtrains_interlocking/signal_api.lua | 165 ----------------------------------
 1 file changed, 165 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index e615692..54202f0 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -1,170 +1,5 @@
 -- Signal API implementation
 
-
---[[
-Signal aspect table:
-Note: All speeds are measured in m/s, aka the number of + signs in the HUD.
-asp = {
-	main = <int speed>,
-		-- Main signal aspect, tells state and permitted speed of next section
-		-- 0 = section is blocked
-		-- >0 = section is free, speed limit is this value
-		-- -1 = section is free, maximum speed permitted
-		-- false/nil = Signal doesn't provide main signal information, retain current speed limit.
-	shunt = <boolean>,
-		-- Whether train may proceed as shunt move, on sight
-		-- main aspect takes precedence over this
-		-- When main==0, train switches to shunt move and is restricted to speed 6
-	proceed_as_main = <boolean>,
-		-- If an approaching train is a shunt move and 'shunt' is false,
-		-- the train may proceed as a train move under the "main" aspect
-		-- if the main aspect permits it (i.e. main!=0)
-		-- If this is not set, shunt moves are NOT allowed to switch to
-		-- a train move, and must stop even if "main" would permit passing.
-		-- This is intended to be used for "Halt for shunt moves" signs.
-	
-	dst = <int speed>,
-		-- Distant signal aspect, tells state and permitted speed of the section after next section
-		-- The character of these information is purely informational
-		-- At this time, this field is not actively used
-		-- 0 = section is blocked
-		-- >0 = section is free, speed limit is this value
-		-- -1 = section is free, maximum speed permitted
-		-- false/nil = Signal doesn't provide distant signal information.
-	
-	-- the character of call_on and dead_end is purely informative
-	call_on = <boolean>, -- Call-on route, expect train in track ahead (not implemented yet)
-	dead_end = <boolean>, -- Route ends on a dead end (e.g. bumper) (not implemented yet)
-
-	w_speed = <integer>,
-	-- "Warning speed restriction". Supposed for short-term speed
-	-- restrictions which always override any other restrictions
-	-- imposed by "speed" fields, until lifted by a value of -1
-	-- (Example: german Langsamfahrstellen-Signale)
-	}
-}
-
-== How signals actually work in here ==
-Each signal (in the advtrains universe) is some node that has at least the
-following things:
-- An "influence point" that is set somewhere on a rail
-- An aspect which trains that pass the "influence point" have to obey
-
-There can be static and dynamic signals. Static signals are, roughly
-spoken, signs, while dynamic signals are "real" signals which can display
-different things.
-
-The node definition of a signal node should contain those fields:
-groups = {
-  	advtrains_signal = 2,
-	save_in_at_nodedb = 1,
-}
-advtrains = {
-	set_aspect = function(pos, node, asp)
-		-- This function gets called whenever the signal should display
-		-- a new or changed signal aspect. It is not required that
-		-- the signal actually displays the exact same aspect, since
-		-- some signals can not do this by design. However, it must
-		-- display an aspect that is at least as restrictive as the passed
-		-- aspect as far as it is capable of doing so.
-		-- Examples:
-		-- - pure shunt signals can not display a "main" aspect
-		--   and have no effect on train moves, so they will only ever
-		--   honor the shunt.free field for their aspect.
-		-- - the german Hl system can only signal speeds of 40, 60
-		--   and 100 km/h, a speed of 80km/h should then be signalled
-		--   as 60 km/h instead.
-		-- In turn, it is not guaranteed that the aspect will fulfill the
-		-- criteria put down in supported_aspects.
-		-- If set_aspect is present, supported_aspects should also be declared.
-		
-		-- The aspect passed in here can always be queried using the
-		-- advtrains.interlocking.signal_get_supposed_aspect(pos) function.
-		-- It is always DANGER when the signal is not used as route signal.
-		
-		-- For static signals, this function should be completely omitted
-		-- If this function is omitted, it won't be possible to use
-		-- route setting on this signal.
-	end,
-	supported_aspects = {
-		-- A table which tells which different types of aspects this signal
-		--  is able to display. It is used to construct the "aspect editing"
-		--  formspec for route programming (and others) It should always be
-		--  present alongside with set_aspect. If this is not specified but
-		--  set_aspect is, the user will be allowed to select any aspect.
-		-- Any of the fields marked with <boolean/nil> support 3 types of values:
-				nil: if this signal can switch between free/blocked
-				false: always shows "blocked", unchangable
-				true: always shows "free", unchangable
-		-- Any of the "speed" fields should contain a list of possible values
-		--  to be set as restriction. If omitted, the value of the described
-		--  field is always assumed to be false (no information)
-		-- A speed of 0 means that the signal can show a "blocked" aspect
-		--  (which is probably the case for most signals)
-		-- If the signal can signal "no information" on one of the fields
-		--  (thus false is an acceptable value), include false in the list
-		-- If your signal can only display a single speed (may it be -1),
-		--  always enclose that single value into a list. (such as {-1})
-		main = {<speed1>, ..., <speedn>} or nil,
-		dst = {<speed1>, ..., <speedn>} or nil,
-		shunt = <boolean/nil>,
-		
-		call_on = <boolean/nil>,
-		dead_end = <boolean/nil>,
-		w_speed = {<speed1>, ..., <speedn>} or nil,
-		
-	},
-	Example for supported_aspects:
-	supported_aspects = {
-		main = {0, 6, -1}, -- can show either "Section blocked", "Proceed at speed 6" or "Proceed at maximum speed"
-		dst = {0, false}, -- can show only if next signal shows "blocked", no other information.
-		shunt = false, -- shunting by this signal is never allowed.
-		
-		call_on = false,
-		dead_end = false,
-		w_speed = nil,
-		-- none of the information can be shown by the signal
-		
-	},
-	
-	get_aspect = function(pos, node)
-		-- This function gets called by the train safety system. It
-		should return the aspect that this signal actually displays,
-		not preferably the input of set_aspect.
-		-- For regular, full-featured light signals, they will probably
-		honor all entries in the original aspect, however, e.g.
-		simple shunt signals always return main=false regardless of
-		the set_aspect input because they can not signal "Halt" to
-		train moves.
-		-- advtrains.interlocking.DANGER contains a default "all-danger" aspect.
-		-- If your signal does not cover certain sub-tables of the aspect,
-		the following reasonable defaults are automatically assumed:
-		main = false (unchanged)
-		dst = false (unchanged)
-		shunt = false (shunting not allowed)
-		info = {} (no further information)
-	end,
-}
-on_rightclick = advtrains.interlocking.signal_rc_handler
-can_dig =  advtrains.interlocking.signal_can_dig
-after_dig_node = advtrains.interlocking.signal_after_dig
-
-(If you need to specify custom can_dig or after_dig_node callbacks,
-please call those functions anyway!)
-
-Important note: If your signal should support external ways to set its
-aspect (e.g. via mesecons), there are some things that need to be considered:
-- advtrains.interlocking.signal_get_supposed_aspect(pos) won't respect this
-- Whenever you change the signal aspect, and that aspect change
-did not happen through a call to
-advtrains.interlocking.signal_set_aspect(pos, asp), you are
-*required* to call this function:
-advtrains.interlocking.signal_on_aspect_changed(pos)
-in order to notify trains about the aspect change.
-This function will query get_aspect to retrieve the new aspect.
-
-]]--
-
 local DANGER = {
 	main = 0,
 	shunt = false,
-- 
cgit v1.2.3


From 67efae9c9ad6f93aaa418d512c4ae1817eed6d24 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sun, 18 Dec 2022 11:01:26 +0100
Subject: Adjust signal aspect formspecs to be of similar size

---
 advtrains_interlocking/signal_api.lua | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 54202f0..8bb92bf 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -137,14 +137,18 @@ function advtrains.interlocking.show_ip_form(pos, pname, only_notset)
 	if not minetest.check_player_privs(pname, "interlocking") then
 		return
 	end
-	local form = "size[7,5]label[0.5,0.5;Signal at "..minetest.pos_to_string(pos).."]"
-	form = form .. advtrains.interlocking.make_signal_formspec_tabheader(pname, pos, 7, 2)
+	local form = "size[7,6.5]label[0.5,0.5;Signal at "..minetest.pos_to_string(pos).."]"
+	local node = advtrains.ndb.get_node(pos)
+	local ndef = minetest.registered_nodes[node.name] or {}
+	if ndef.advtrains and ndef.advtrains.set_aspect then
+		form = form .. advtrains.interlocking.make_signal_formspec_tabheader(pname, pos, 7, 2)
+	end
 	advtrains.interlocking.db.check_for_duplicate_ip(pos)
 	local pts, connid = advtrains.interlocking.db.get_ip_by_signalpos(pos)
 	if pts then
 		form = form.."label[0.5,1.5;Influence point is set at "..pts.."/"..connid.."]"
-		form = form.."button_exit[0.5,2.5;  5,1;set;Move]"
-		form = form.."button_exit[0.5,3.5;  5,1;clear;Clear]"
+		form = form.."button_exit[0.5,4.25;  6,1;set;Move]"
+		form = form.."button_exit[0.5,5.25;  6,1;clear;Clear]"
 		local ipos = minetest.string_to_pos(pts)
 		ipmarker(ipos, connid)
 	else
@@ -152,7 +156,7 @@ function advtrains.interlocking.show_ip_form(pos, pname, only_notset)
 		form = form.."label[0.5,2.0;It is recommended to set an influence point.]"
 		form = form.."label[0.5,2.5;This is the point where trains will obey the signal.]"
 		
-		form = form.."button_exit[0.5,3.5;  5,1;set;Set]"
+		form = form.."button_exit[0.5,5.25;  6,1;set;Set]"
 	end
 	if not only_notset or not pts then
 		minetest.show_formspec(pname, "at_il_ipassign_"..minetest.pos_to_string(pos), form)
-- 
cgit v1.2.3


From 2d072cdc67ec3018eaba36b7c79c2b19e574a94d Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Fri, 6 Jan 2023 14:45:03 +0100
Subject: Rework formspecs; add description to JP signal group

---
 advtrains_interlocking/signal_api.lua | 75 ++++++++++++++++++++---------------
 1 file changed, 44 insertions(+), 31 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 8bb92bf..cd408d7 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -1,5 +1,7 @@
 -- Signal API implementation
 
+local F = advtrains.formspec
+
 local DANGER = {
 	main = 0,
 	shunt = false,
@@ -131,57 +133,68 @@ local function ipmarker(ipos, connid)
 	})
 end
 
--- shows small info form for signal IP state/assignment
+function advtrains.interlocking.make_ip_formspec_component(pos, x, y, w)
+	advtrains.interlocking.db.check_for_duplicate_ip(pos)
+	local pts, connid = advtrains.interlocking.db.get_ip_by_signalpos(pos)
+	if pts then
+		return table.concat {
+			F.S_label(x, y, "Influence point is set at @1.", string.format("%s/%s", pts, connid)),
+			F.S_button_exit(x, y+0.5, w/2-0.125, "ip_set", "Modify"),
+			F.S_button_exit(x+w/2+0.125, y+0.5, w/2-0.125, "ip_clear", "Clear"),
+		}, pts, connid
+	else
+		return table.concat {
+			F.S_label(x, y, "Influence point is not set."),
+			F.S_button_exit(x, y+0.5, w, "ip_set", "Set influence point"),
+		}
+	end
+end
+
+-- shows small info form for signal properties
+-- This function is named show_ip_form because it was originally only intended
+-- for assigning/changing the influence point.
 -- only_notset: show only if it is not set yet (used by signal tcb assignment)
 function advtrains.interlocking.show_ip_form(pos, pname, only_notset)
 	if not minetest.check_player_privs(pname, "interlocking") then
 		return
 	end
-	local form = "size[7,6.5]label[0.5,0.5;Signal at "..minetest.pos_to_string(pos).."]"
-	local node = advtrains.ndb.get_node(pos)
-	local ndef = minetest.registered_nodes[node.name] or {}
-	if ndef.advtrains and ndef.advtrains.set_aspect then
-		form = form .. advtrains.interlocking.make_signal_formspec_tabheader(pname, pos, 7, 2)
-	end
-	advtrains.interlocking.db.check_for_duplicate_ip(pos)
-	local pts, connid = advtrains.interlocking.db.get_ip_by_signalpos(pos)
+	local ipform, pts, connid = advtrains.interlocking.make_ip_formspec_component(pos, 0.5, 0.5, 7)
+	local form = table.concat {
+		"formspec_version[4]",
+		"size[8,6.75]",
+		ipform,
+		advtrains.interlocking.make_dst_formspec_component(pos, 0.5, 2, 7, 4.25),
+	}
 	if pts then
-		form = form.."label[0.5,1.5;Influence point is set at "..pts.."/"..connid.."]"
-		form = form.."button_exit[0.5,4.25;  6,1;set;Move]"
-		form = form.."button_exit[0.5,5.25;  6,1;clear;Clear]"
 		local ipos = minetest.string_to_pos(pts)
 		ipmarker(ipos, connid)
-	else
-		form = form.."label[0.5,1.5;Influence point is not set.]"
-		form = form.."label[0.5,2.0;It is recommended to set an influence point.]"
-		form = form.."label[0.5,2.5;This is the point where trains will obey the signal.]"
-		
-		form = form.."button_exit[0.5,5.25;  6,1;set;Set]"
 	end
 	if not only_notset or not pts then
-		minetest.show_formspec(pname, "at_il_ipassign_"..minetest.pos_to_string(pos), form)
+		minetest.show_formspec(pname, "at_il_propassign_"..minetest.pos_to_string(pos), form)
 	end
 end
 
-minetest.register_on_player_receive_fields(function(player, formname, fields)
-	local pname = player:get_player_name()
-	if advtrains.interlocking.handle_signal_formspec_tabheader_fields(pname, fields) then
-		return true
-	end
-	if not minetest.check_player_privs(pname, {train_operator=true, interlocking=true}) then
+function advtrains.interlocking.handle_ip_formspec_fields(pname, pos, fields)
+	if not (pos and minetest.check_player_privs(pname, {train_operator=true, interlocking=true})) then
 		return
 	end
-	local pts = string.match(formname, "^at_il_ipassign_([^_]+)$")
+	if fields.ip_set then
+		advtrains.interlocking.signal_init_ip_assign(pos, pname)
+	elseif fields.ip_clear then
+		advtrains.interlocking.db.clear_ip_by_signalpos(pos)
+	end
+end
+
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	local pname = player:get_player_name()
+	local pts = string.match(formname, "^at_il_propassign_([^_]+)$")
 	local pos
 	if pts then
 		pos = minetest.string_to_pos(pts)
 	end
 	if pos then
-		if fields.set then
-			advtrains.interlocking.signal_init_ip_assign(pos, pname)
-		elseif fields.clear then
-			advtrains.interlocking.db.clear_ip_by_signalpos(pos)
-		end
+		advtrains.interlocking.handle_ip_formspec_fields(pname, pos, fields)
+		advtrains.interlocking.handle_dst_formspec_fields(pname, pos, fields)
 	end
 end)
 
-- 
cgit v1.2.3


From d443d8e07af89665a6bb3d87af91f43f08a6c47e Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Fri, 6 Jan 2023 18:23:15 +0100
Subject: Distant signaling: avoid signal signs

---
 advtrains_interlocking/signal_api.lua | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index cd408d7..1b4a21c 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -159,16 +159,20 @@ function advtrains.interlocking.show_ip_form(pos, pname, only_notset)
 		return
 	end
 	local ipform, pts, connid = advtrains.interlocking.make_ip_formspec_component(pos, 0.5, 0.5, 7)
-	local form = table.concat {
+	local form = {
 		"formspec_version[4]",
-		"size[8,6.75]",
+		"size[8,2.25]",
 		ipform,
-		advtrains.interlocking.make_dst_formspec_component(pos, 0.5, 2, 7, 4.25),
 	}
 	if pts then
 		local ipos = minetest.string_to_pos(pts)
 		ipmarker(ipos, connid)
 	end
+	if advtrains.distant.appropriate_signal(pos) then
+		form[#form+1] = advtrains.interlocking.make_dst_formspec_component(pos, 0.5, 2, 7, 4.25)
+		form[2] = "size[8,6.75]"
+	end
+	form = table.concat(form)
 	if not only_notset or not pts then
 		minetest.show_formspec(pname, "at_il_propassign_"..minetest.pos_to_string(pos), form)
 	end
-- 
cgit v1.2.3


From e25b1c744dad7daa561ee0b23b006bc616f88f23 Mon Sep 17 00:00:00 2001
From: "Y. Wang" <yw05@forksworld.de>
Date: Sun, 26 Mar 2023 11:53:00 +0200
Subject: Cancel type 2 signals; introduce signal groups for all signals

---
 advtrains_interlocking/signal_api.lua | 28 ++++------------------------
 1 file changed, 4 insertions(+), 24 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 1b4a21c..ce8854a 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -19,27 +19,7 @@ advtrains.interlocking.FULL_FREE = {
 	proceed_as_main = true,
 }
 
-local function convert_aspect_if_necessary(asp)
-	if type(asp.main) == "table" then
-		local newasp = {} 
-		if asp.main.free then
-			newasp.main = asp.main.speed
-		else
-			newasp.main = 0
-		end
-		if asp.dst and asp.dst.free then
-			newasp.dst = asp.dst.speed
-		else
-			newasp.dst = 0
-		end
-		newasp.proceed_as_main = asp.shunt.proceed_as_main
-		newasp.shunt = asp.shunt.free
-		-- Note: info table not transferred, it's not used right now
-		return newasp
-	end
-	return asp
-end
-advtrains.interlocking.signal_convert_aspect_if_necessary = convert_aspect_if_necessary
+advtrains.interlocking.signal_convert_aspect_if_necessary = advtrains.interlocking.aspect
 
 function advtrains.interlocking.update_signal_aspect(tcbs, skipdst)
 	if tcbs.signal then
@@ -79,7 +59,7 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 	end
 	advtrains.interlocking.show_signal_form(pos, node, pname)
 end
-	
+
 function advtrains.interlocking.show_signal_form(pos, node, pname)
 	local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
 	if sigd then
@@ -92,7 +72,7 @@ function advtrains.interlocking.show_signal_form(pos, node, pname)
 				advtrains.interlocking.signal_set_aspect(pos, aspect)
 			end
 			local isasp = advtrains.interlocking.signal_get_aspect(pos, node)
-			
+
 			advtrains.interlocking.show_signal_aspect_selector(
 				pname,
 				ndef.advtrains.supported_aspects,
@@ -123,7 +103,7 @@ local function ipmarker(ipos, connid)
 	local node_ok, conns, rhe = advtrains.get_rail_info_at(ipos, advtrains.all_tracktypes)
 	if not node_ok then return end
 	local yaw = advtrains.dir_to_angle(conns[connid].c)
-	
+
 	-- using tcbmarker here
 	local obj = minetest.add_entity(vector.add(ipos, {x=0, y=0.2, z=0}), "advtrains_interlocking:tcbmarker")
 	if not obj then return end
-- 
cgit v1.2.3


From aa9033f9010b01e7ad28f2b8bb0c002f065ddc08 Mon Sep 17 00:00:00 2001
From: orwell <orwell@bleipb.de>
Date: Sun, 28 Jan 2024 23:42:56 +0100
Subject: Implementation Plan

---
 advtrains_interlocking/signal_api.lua | 53 +++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index ce8854a..743e8e1 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -19,6 +19,59 @@ advtrains.interlocking.FULL_FREE = {
 	proceed_as_main = true,
 }
 
+--[[
+Implementation plan orwell 2024-01-28:
+Most parts of ywang's implementation are fine, especially I like the formspecs. But I would like to change a few aspects (no pun intended) of this.
+- Signal gets distant assigned via field in signal aspect table (instead of explicitly)
+- Signal speed/shunt are no longer free-text but rather they need to be predefined in the node definition
+To do this: Differentiation between:
+== Aspect Group ==
+This is what a signal is assigned by either the route system or the user.
+It is a string key which has an appropriate entry in the node definition (where it has a description assigned)
+The signal mod defines a function to set a signal to the most appropriate aspect. This function gets
+a) the aspect group name
+b) the distant signal's aspect group name & aspect table
+EVERY signal must define the special aspect group "halt". This must always be the most restrictive aspect possible.
+The "halt" aspect group should ignore any distant info, in most cases it is called without them anyway.
+
+== Aspect ==
+One concrete combination of lights/shapes that a signal signal shows. Handling these is at the discretion of
+the signal mod defining the signal, and they are typically combinations of main aspect and distant aspect
+Example:
+- A Ks signal has the aspect_group="proceed_12" set for a route
+- The signal at the end of the route shows aspect_group="proceed_8", advtrains also passes on that this means {main=8, shunt=false}
+- The ndef.advtrains.apply_aspect(pos, asp_group, dst_aspgrp, dst_aspinfo) determines that the signal should now show
+		blinking green with main indicator 12 and dst indicator 8, and sets the nodes accordingly.
+		This function can now return the Aspect Info table, which will be cached by advtrains until the aspect changes again
+		and will be used when a train approaches the signal. If nil is returned, then the aspect will be queried next time
+		by calling ndef.advtrains.get_aspect_info(pos)
+
+Note that once apply_aspect returns, there is no need for advtrains anymore to query the aspect info.
+When the signal, for any reason, wants to change its aspect by itself *without* going through the signal API then
+it should update the aspect info cache by calling advtrains.interlocking.signal.update_aspect_info(pos)
+
+== Aspect Info ==
+The actual signal aspect in the already-known format. This is what the trains use to determine halt/proceed and speed. In this, the dst field has to be resolved.
+asp = {
+	main = 0 (halt) / -1 (max speed) / false (no info) / <number> (speed limit)
+	shunt = true (shunt free) / false (shunt not free)
+	proceed_as_main = true (shunt move can proceed and become train move when main!=0) / false (no)
+	dst = (like main, informative character, not actually used)
+}
+
+Node definition of signals:
+- The signal needs some logic to figure out, for each combination of its own aspect group and the distant signal's aspect, what aspect info it can/will show.
+ndef.advtrains = {
+	aspect_groups = { [name] = { description = "Proceed at full speed", <more data at discretion of signal>} }
+	apply_aspect = function(pos, asp_group, dst_aspgrp, dst_aspinfo)
+		-- set the node to show the desired aspect
+		-- called by advtrains when this signal's aspect group or the distant signal's aspect changes
+		-- MAY return the aspect_info. If it returns nil then get_aspect_info will be queried at a later point.
+	get_aspect_info(pos)
+		-- Returns the aspect info table (main, shunt, dst etc.)W
+}
+]]
+
 advtrains.interlocking.signal_convert_aspect_if_necessary = advtrains.interlocking.aspect
 
 function advtrains.interlocking.update_signal_aspect(tcbs, skipdst)
-- 
cgit v1.2.3


From 2dab59f05572fe6cf73cde353446a5a501550b41 Mon Sep 17 00:00:00 2001
From: orwell <orwell@bleipb.de>
Date: Tue, 6 Feb 2024 21:10:40 +0100
Subject: Start changing APIs and applying proof-of-concept to ks signals

---
 advtrains_interlocking/signal_api.lua | 105 ++++++++++++++++++++++------------
 1 file changed, 68 insertions(+), 37 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 743e8e1..c2cc08b 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -2,18 +2,19 @@
 
 local F = advtrains.formspec
 
-local DANGER = {
-	main = 0,
-	shunt = false,
+local signal = {}
+
+signal.MASP_HALT = {
+	name = "halt"
+	halt = true,
 }
-advtrains.interlocking.DANGER = DANGER
 
-advtrains.interlocking.GENERIC_FREE = {
-	main = -1,
+signal.ASPI_HALT = {
+	main = 0,
 	shunt = false,
-	dst = false,
 }
-advtrains.interlocking.FULL_FREE = {
+
+signal.ASPI_FREE = {
 	main = -1,
 	shunt = false,
 	proceed_as_main = true,
@@ -25,14 +26,12 @@ Most parts of ywang's implementation are fine, especially I like the formspecs.
 - Signal gets distant assigned via field in signal aspect table (instead of explicitly)
 - Signal speed/shunt are no longer free-text but rather they need to be predefined in the node definition
 To do this: Differentiation between:
-== Aspect Group ==
+== Main Aspect ==
 This is what a signal is assigned by either the route system or the user.
 It is a string key which has an appropriate entry in the node definition (where it has a description assigned)
 The signal mod defines a function to set a signal to the most appropriate aspect. This function gets
-a) the aspect group name
+a) the main aspect table (straight from node def)
 b) the distant signal's aspect group name & aspect table
-EVERY signal must define the special aspect group "halt". This must always be the most restrictive aspect possible.
-The "halt" aspect group should ignore any distant info, in most cases it is called without them anyway.
 
 == Aspect ==
 One concrete combination of lights/shapes that a signal signal shows. Handling these is at the discretion of
@@ -50,6 +49,11 @@ Note that once apply_aspect returns, there is no need for advtrains anymore to q
 When the signal, for any reason, wants to change its aspect by itself *without* going through the signal API then
 it should update the aspect info cache by calling advtrains.interlocking.signal.update_aspect_info(pos)
 
+Note that the apply_aspect function MUST accept the following main aspect, even if it is not defined in the main_aspects table:
+{ name = "halt", halt = true }
+It should cause the signal to show its most restrictive aspect. Typically it is a halt aspect, but e.g. for distant-only
+signals this would be "expect stop".
+
 == Aspect Info ==
 The actual signal aspect in the already-known format. This is what the trains use to determine halt/proceed and speed. In this, the dst field has to be resolved.
 asp = {
@@ -62,7 +66,10 @@ asp = {
 Node definition of signals:
 - The signal needs some logic to figure out, for each combination of its own aspect group and the distant signal's aspect, what aspect info it can/will show.
 ndef.advtrains = {
-	aspect_groups = { [name] = { description = "Proceed at full speed", <more data at discretion of signal>} }
+	main_aspects = {
+		{ name = "proceed" description = "Proceed at full speed", <more data at discretion of signal>}
+		{ name = "proceed2" description = "Proceed at full speed", <more data at discretion of signal>}
+	} -- The numerical order determines the layout of the list in the selection dialog.
 	apply_aspect = function(pos, asp_group, dst_aspgrp, dst_aspinfo)
 		-- set the node to show the desired aspect
 		-- called by advtrains when this signal's aspect group or the distant signal's aspect changes
@@ -72,28 +79,61 @@ ndef.advtrains = {
 }
 ]]
 
-advtrains.interlocking.signal_convert_aspect_if_necessary = advtrains.interlocking.aspect
+-- Set a signal's aspect.
+-- Signal aspects should only be set through this function. It takes care of:
+-- - Storing the main aspect and dst pos for this signal permanently (until next change)
+-- - Assigning the distant signal for this signal
+-- - Calling apply_aspect() in the signal's node definition to make the signal show the aspect
+-- - Calling apply_aspect() again whenever the distant signal changes its aspect
+-- - Notifying this signal's distant signals about changes to this signal (unless skip_dst_notify is specified)
+function signal.set_aspect(pos, main_aspect, dst_pos, skip_dst_notify)
+	-- TODO
+end
+
+-- Gets the stored main aspect and distant signal position for this signal
+-- This information equals the information last passed to set_aspect
+-- It does not take into consideration the actual speed signalling, please use
+-- get_aspect_info() for this
+-- returns: main_aspect, dst_pos
+function signal.get_aspect(pos)
+	--TODO
+end
+
+function signal.get_distant_signals_of(pos)
+	--TODO
+end
 
-function advtrains.interlocking.update_signal_aspect(tcbs, skipdst)
+-- Called when either this signal has changed its main aspect
+-- or when this distant signal's currently assigned main signal has changed its aspect
+-- It retrieves the signal's main aspect and aspect info and calls apply_aspect of the node definition
+-- to update the signal's appearance and aspect info
+-- pts: The signal position to update as encoded_pos
+function signal.reapply_aspect(pts, p_mainaspect)
+	--TODO
+end
+
+-- Update this signal's aspect based on the set route
+-- 
+function signal.update_route_aspect(tcbs, skip_dst_notify)
 	if tcbs.signal then
-		local asp = tcbs.aspect or DANGER
-		advtrains.interlocking.signal_set_aspect(tcbs.signal, asp, skipdst)
+		local asp = tcbs.aspect or signal.MASP_HALT
+		signal.set_aspect(tcbs.signal, asp, skip_dst_notify)
 	end
 end
 
-function advtrains.interlocking.signal_can_dig(pos)
+function signal.can_dig(pos)
 	return not advtrains.interlocking.db.get_sigd_for_signal(pos)
 end
 
 function advtrains.interlocking.signal_after_dig(pos)
 	-- clear influence point
-
 	advtrains.interlocking.signal_clear_aspect(pos)
-	advtrains.distant.unassign_all(pos, true)
+	advtrains.distant.unassign_all(pos, true) -- TODO
 end
 
--- should be called when aspect has changed on this signal.
-function advtrains.interlocking.signal_on_aspect_changed(pos)
+-- Update waiting trains and distant signals about a changed signal aspect
+function signal.notify_on_aspect_changed(pos, skip_dst_notify)
+	--TODO update distant?
 	local ipts, iconn = advtrains.interlocking.db.get_ip_by_signalpos(pos)
 	if not ipts then return end
 	local ipos = minetest.string_to_pos(ipts)
@@ -103,7 +143,7 @@ function advtrains.interlocking.signal_on_aspect_changed(pos)
 	minetest.after(0, advtrains.invalidate_all_paths, ipos)
 end
 
-function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack, pointed_thing)
+function signal.on_rightclick(pos, node, player, itemstack, pointed_thing)
 	local pname = player:get_player_name()
 	local control = player:get_player_control()
 	if control.aux1 then
@@ -122,7 +162,7 @@ function advtrains.interlocking.show_signal_form(pos, node, pname)
 		if ndef.advtrains and ndef.advtrains.set_aspect then
 			-- permit to set aspect manually
 			local function callback(pname, aspect)
-				advtrains.interlocking.signal_set_aspect(pos, aspect)
+				signal.set_aspect(pos, aspect)
 			end
 			local isasp = advtrains.interlocking.signal_get_aspect(pos, node)
 
@@ -138,18 +178,6 @@ function advtrains.interlocking.show_signal_form(pos, node, pname)
 	end
 end
 
--- Returns the aspect the signal at pos is supposed to show
-function advtrains.interlocking.signal_get_supposed_aspect(pos)
-	local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
-	if sigd then
-		local tcbs = advtrains.interlocking.db.get_tcbs(sigd)
-		if tcbs.aspect then
-			return convert_aspect_if_necessary(tcbs.aspect)
-		end
-	end
-	return DANGER;
-end
-
 local players_assign_ip = {}
 
 local function ipmarker(ipos, connid)
@@ -236,7 +264,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 end)
 
 -- inits the signal IP assignment process
-function advtrains.interlocking.signal_init_ip_assign(pos, pname)
+function signal.init_ip_assign(pos, pname)
 	if not minetest.check_player_privs(pname, "interlocking") then
 		minetest.chat_send_player(pname, "Insufficient privileges to use this!")
 		return
@@ -281,3 +309,6 @@ minetest.register_on_punchnode(function(pos, node, player, pointed_thing)
 		players_assign_ip[pname] = nil
 	end
 end)
+
+
+advtrains.interlocking.signal = signal
-- 
cgit v1.2.3


From eb03b5f301c4244bbc79a101dd9f990b01503ab5 Mon Sep 17 00:00:00 2001
From: orwell <orwell@bleipb.de>
Date: Fri, 5 Apr 2024 00:35:40 +0200
Subject: Continue with new-ks rework

---
 advtrains_interlocking/signal_api.lua | 274 ++++++++++++++++++++++++++++++----
 1 file changed, 243 insertions(+), 31 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index c2cc08b..ce3b03f 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -5,7 +5,8 @@ local F = advtrains.formspec
 local signal = {}
 
 signal.MASP_HALT = {
-	name = "halt"
+	name = "halt",
+	description = "HALT",
 	halt = true,
 }
 
@@ -55,12 +56,12 @@ It should cause the signal to show its most restrictive aspect. Typically it is
 signals this would be "expect stop".
 
 == Aspect Info ==
-The actual signal aspect in the already-known format. This is what the trains use to determine halt/proceed and speed. In this, the dst field has to be resolved.
+The actual signal aspect in the already-known format. This is what the trains use to determine halt/proceed and speed.
 asp = {
 	main = 0 (halt) / -1 (max speed) / false (no info) / <number> (speed limit)
 	shunt = true (shunt free) / false (shunt not free)
 	proceed_as_main = true (shunt move can proceed and become train move when main!=0) / false (no)
-	dst = (like main, informative character, not actually used)
+	dst = speed of the remote signal (like main, informative character, not actually used)
 }
 
 Node definition of signals:
@@ -68,17 +69,84 @@ Node definition of signals:
 ndef.advtrains = {
 	main_aspects = {
 		{ name = "proceed" description = "Proceed at full speed", <more data at discretion of signal>}
-		{ name = "proceed2" description = "Proceed at full speed", <more data at discretion of signal>}
-	} -- The numerical order determines the layout of the list in the selection dialog.
-	apply_aspect = function(pos, asp_group, dst_aspgrp, dst_aspinfo)
+		{ name = "reduced" description = "Proceed at reduced speed", <more data at discretion of signal>}
+	}
+		-- This list is mainly for the selection dialog. Order of entries determines list order in the dropdown.
+		-- Some fields have special meaning:
+		-- name: A unique key to identify the main aspect. Only this key is saved, but APIs always receive the whole table
+		-- description: Text shown in UI dropdown
+		-- speed: a number. When present, a speed field is shown in the UI next to the dropdown (prefilled with the value).
+		--		When user selects a different speed there, this different speed replaces the value in the table whenever the main_aspect is applied.
+		-- Node can set any other fields at its discretion. They are not touched.
+		-- Note: On first call advtrains automatically inserts into the ndef.advtrains table a main_aspects_lookup hashtable
+		-- Note: Pure distant signals (that cannot show halt) should NOT have a main_aspects table
+	apply_aspect = function(pos, main_aspect, rem_aspect, rem_aspinfo)
 		-- set the node to show the desired aspect
-		-- called by advtrains when this signal's aspect group or the distant signal's aspect changes
+		-- called by advtrains when this signal's aspect group or the remote signal's aspect changes
 		-- MAY return the aspect_info. If it returns nil then get_aspect_info will be queried at a later point.
-	get_aspect_info(pos)
-		-- Returns the aspect info table (main, shunt, dst etc.)W
+	get_aspect_info(pos, main_aspect)
+		-- Returns the aspect info table (main, shunt, dst etc.)
+	distant_support = true or false
+		-- If true, signal is considered in distant signalling. If false or nil, rem_aspect and rem_aspinfo are never set.
+	route_role = one of "main", "shunt", "distant", "distant_repeater", "end"
+		-- Determines how the signal behaves when routes are set. Only in effect when signal is assigned to a TCB.
+		-- main: The signal is a possible endpoint for a train move route. Distant signals before it refer to it.
+		-- shunt: The signal is a possible endpoint for a shunt move route. Ignored for distant signals.
+		-- distant, distant_repeater: When route is set, signal is always assigned its first main aspect. The next signal with role="main" is set as the remote signal. (currently no further distinction)
+		-- end: like main, but signifies that it marks an end of track and trains cannot continue further. (currently no practical implications above main)
 }
+
+== Nomenclature ==
+The distant/main relation is named as follows:
+     V    M
+=====>====>
+Main signal (main) always refers to the signal that is in focus right now (even if that is a distant-only signal)
+From the standpoint of M, V is the distant (dst) signal. M does not need to concern itself with V's aspect but needs to notify V when it changes
+From the standpoint of V, M is the remote (rem) signal. V needs to show an aspect that matches its remote signal M
+
+== Criteria for which signals are eligible for routes ==
+
+All signals must define:
+- get_aspect_info()
+
+Signals that can be assigned to a TCB must satisfy:
+- apply_aspect() defined
+
+Signals that are possible start and end points for a route must satisfy:
+- main_aspects defined (note, pure distant signals should therefore not define main_aspects)
+
 ]]
 
+-- Database
+-- Signal Aspect store
+-- Stores for each signal the main aspect and other info, like the assigned remote signal
+-- [signal encodePos] = { main_aspect = "proceed", [speed = 12], [remote = encodedPos] }
+signal.aspects = {}
+
+-- Distant signal notification. Records for each signal the distant signals that refer to it
+-- Note: this mapping is weak. Needs always backreference check.
+-- [signal encodePos] = { [distant signal encodePos] = true }
+signal.distant_refs = {}
+
+function signal.load(data)
+	signal.aspects = data.aspects or {}
+	-- rebuild distant_refs after load
+	signal.distant_refs = {}
+	for main, aspt in pairs(signal.aspects) do
+		if aspt.remote then
+			if not signal.distant_refs[aspt.remote] then
+				signal.distant_refs[aspt.remote] = {}
+			end
+			signal.distant_refs[aspt.remote][main] = true
+		end
+	end
+end
+
+function signal.save(data)
+	data.aspects = signal.aspects
+end
+
+
 -- Set a signal's aspect.
 -- Signal aspects should only be set through this function. It takes care of:
 -- - Storing the main aspect and dst pos for this signal permanently (until next change)
@@ -86,30 +154,184 @@ ndef.advtrains = {
 -- - Calling apply_aspect() in the signal's node definition to make the signal show the aspect
 -- - Calling apply_aspect() again whenever the distant signal changes its aspect
 -- - Notifying this signal's distant signals about changes to this signal (unless skip_dst_notify is specified)
-function signal.set_aspect(pos, main_aspect, dst_pos, skip_dst_notify)
-	-- TODO
+function signal.set_aspect(pos, main_asp_name, main_asp_speed, rem_pos, skip_dst_notify)
+	local main_pts = advtrains.encode_pos(pos)
+	local old_tbl = signal.aspects[main_pts]
+	local old_remote = old_tbl and old_tbl.remote
+	local new_remote = rem_pos and advtrains.encode_pos(rem_pos)
+	
+	-- if remote has changed, unregister from old remote
+	if old_remote and old_remote~=new_remote and signal.distant_refs[old_remote] then
+		signal.distant_refs[old_remote][main_pts] = nil
+	end
+		
+	signal.aspects[main_pts] = { main_aspect = main_asp_name, speed = main_asp_speed, remote = new_remote }
+	-- apply aspect on main signal, this also checks new_remote
+	signal.reapply_aspect(main_pts)	
+	
+	-- notify my distants about this change (with limit 2)
+	if not skip_dst_notify then
+		signal.notify_distants_of(main_pts, 2)
+	end
+end
+
+function signal.clear_aspect(pos, skip_dst_notify)
+	local main_pts = advtrains.encode_pos(pos)
+	local old_tbl = signal.aspects[main_pts]
+	local old_remote = old_tbl and old_tbl.remote
+	
+	-- unregister from old remote
+	if old_remote then
+		signal.distant_refs[old_remote][main_pts] = nil
+	end
+		
+	signal.aspects[main_pts] = nil
+	-- apply aspect on main signal, this also checks new_remote
+	signal.reapply_aspect(main_pts)	
+	
+	-- notify my distants about this change (with limit 2)
+	if not skip_dst_notify then
+		signal.notify_distants_of(main_pts, 2)
+	end
+end
+
+-- Notify distant signals of main_pts of a change in the aspect of this signal
+-- 
+function signal.notify_distants_of(main_pts, limit)
+	if limit <= 0 then
+		return
+	end
+	local dstrefs = signal.distant_refs[main_pts]
+	if dstrefs then
+		for dst,_ in pairs(dstrefs) do
+			-- ensure that the backref is still valid
+			local dst_asp = signal.aspects[dst]
+			if dst_asp and dst_asp.remote == main_pts then
+				signal.reapply_aspect(dst)
+				signal.notify_distants_of(dst, limit - 1)
+			else
+				atwarn("Distant signal backref is not purged: main =",main_pts,", distant =",dst,", remote =",dst_asp.remote,"")
+			end
+		end
+	end
+end
+
+function signal.notify_trains(pos)
+	local ipts, iconn = advtrains.interlocking.db.get_ip_by_signalpos(pos)
+	if not ipts then return end
+	local ipos = minetest.string_to_pos(ipts)
+
+	-- FIXME: invalidate_all_paths_ahead does not appear to always work as expected
+	--advtrains.invalidate_all_paths_ahead(ipos)
+	minetest.after(0, advtrains.invalidate_all_paths, ipos)
+end
+
+-- Update waiting trains and distant signals about a changed signal aspect
+-- Must be called when a signal's aspect changes through some other means
+-- and not via the signal mechanism
+function signal.notify_on_aspect_changed(pos, skip_dst_notify)
+	signal.notify_trains(pos)
+	if not skip_dst_notify then
+		signal.notify_distants_of(advtrains.encode_pos(pos), 2)
+	end
 end
 
 -- Gets the stored main aspect and distant signal position for this signal
 -- This information equals the information last passed to set_aspect
 -- It does not take into consideration the actual speed signalling, please use
 -- get_aspect_info() for this
+-- pos: the position of the signal
 -- returns: main_aspect, dst_pos
 function signal.get_aspect(pos)
-	--TODO
+	local aspt = signal.aspects[advtrains.encode_pos(pos)]
+	local ma,dp = signal.get_aspect_internal(pos, aspt)
+	return ma, advtrains.decode_pos(dp)
+end
+
+local function cache_mainaspects(ndefat)
+	ndefat.main_aspects_lookup = {
+		-- always define halt aspect
+		halt = signal.MASP_HALT
+	}
+	for _,ma in ipairs(ndefat.main_aspects) then
+		ndefat.main_aspects_lookup[ma.name] = ma
+	end
+end
+
+function signal.get_aspect_internal(pos, aspt)
+	if not aspt then
+		-- oh, no main aspect, nevermind
+		return nil, aspt.remote, nil
+	end
+	-- look aspect in nodedef
+	local node = advtrains.ndb.get_node_or_nil(pos)
+	local ndef = node and minetest.registered_nodes[node.name]
+	local ndefat = ndef and ndef.advtrains
+	-- only if signal defines main aspect and its set in aspt
+	if ndefat and ndefat.main_aspects and aspt.main_aspect then
+		if not ndefat.main_aspects_lookup then
+			cache_mainaspects(ndefat)
+		end
+		local masp = ndefat.main_aspects_lookup[aspt.name]
+		-- if speed, then apply speed
+		if masp.speed and aspt.speed then
+			masp = table.copy(masp)
+			masp.speed = aspt.speed
+		end
+		return masp, aspt.remote, ndef
+	end
+	-- invalid node or no main aspect, return nil for masp
+	return nil, aspt.remote, ndef
 end
 
-function signal.get_distant_signals_of(pos)
-	--TODO
+-- For the signal at pos, get the "aspect info" table. This contains the speed signalling information at this location
+function signal.get_aspect_info(pos)
+	-- get aspect internal
+	local aspt = signal.aspects[advtrains.encode_pos(pos)]
+	local masp, remote, ndef = signal.get_aspect_internal(pos, aspt)
+	-- call into ndef
+	if ndef.advtrains and ndef.advtrains.get_aspect_info then
+		return ndef.advtrains.get_aspect_info(pos, masp)
+	end
 end
 
+
 -- Called when either this signal has changed its main aspect
 -- or when this distant signal's currently assigned main signal has changed its aspect
 -- It retrieves the signal's main aspect and aspect info and calls apply_aspect of the node definition
 -- to update the signal's appearance and aspect info
 -- pts: The signal position to update as encoded_pos
-function signal.reapply_aspect(pts, p_mainaspect)
-	--TODO
+-- returns: the return value of the nodedef call which may be aspect_info
+function signal.reapply_aspect(pts)
+	-- get aspt
+	local aspt = signal.aspects[pts]
+	if not aspt then
+		return -- oop, nothing to do
+	end
+	-- resolve mainaspect table by name
+	local pos = advtrains.decode_pos(pts)
+	-- note: masp may be nil, when aspt.main_aspect was nil. Valid case for distant-only signals
+	local masp, remote, ndef = signal.get_aspect_internal(pos, aspt)
+	-- if we have remote, resolve remote
+	local rem_masp, rem_aspi
+	if remote then
+		local rem_aspt = signal.aspects[remote]
+		if rem_aspt and rem_aspt.name then
+			local rem_pos = advtrains.decode_pos(remote)
+			rem_masp, _, rem_ndef = signal.get_aspect_internal(rem_pos, rem_aspt)
+			if rem_masp then
+				if rem_ndef.advtrains and rem_ndef.advtrains.get_aspect_info then
+					rem_aspi = rem_ndef.advtrains.get_aspect_info(pos, rem_masp)
+				end
+			end
+		end
+	end
+	-- call into ndef
+	if ndef.advtrains and ndef.advtrains.apply_aspect then
+		return ndef.advtrains.apply_aspect(pos, masp, rem_masp, rem_aspi)
+	end
+	-- notify trains
+	signal.notify_trains(pos)
 end
 
 -- Update this signal's aspect based on the set route
@@ -121,26 +343,16 @@ function signal.update_route_aspect(tcbs, skip_dst_notify)
 	end
 end
 
+
+----------------
+
 function signal.can_dig(pos)
 	return not advtrains.interlocking.db.get_sigd_for_signal(pos)
 end
 
 function advtrains.interlocking.signal_after_dig(pos)
-	-- clear influence point
-	advtrains.interlocking.signal_clear_aspect(pos)
-	advtrains.distant.unassign_all(pos, true) -- TODO
-end
-
--- Update waiting trains and distant signals about a changed signal aspect
-function signal.notify_on_aspect_changed(pos, skip_dst_notify)
-	--TODO update distant?
-	local ipts, iconn = advtrains.interlocking.db.get_ip_by_signalpos(pos)
-	if not ipts then return end
-	local ipos = minetest.string_to_pos(ipts)
-
-	-- FIXME: invalidate_all_paths_ahead does not appear to always work as expected
-	--advtrains.invalidate_all_paths_ahead(ipos)
-	minetest.after(0, advtrains.invalidate_all_paths, ipos)
+	-- TODO clear influence point
+	advtrains.interlocking.signal.clear_aspect(pos)
 end
 
 function signal.on_rightclick(pos, node, player, itemstack, pointed_thing)
-- 
cgit v1.2.3


From 1f74697e85d456e97e201cdd9edef91a2df4fc14 Mon Sep 17 00:00:00 2001
From: orwell <orwell@bleipb.de>
Date: Mon, 8 Apr 2024 21:46:43 +0200
Subject: Fully implement and test new aspect support/distant signalling on ks
 and japan signals

---
 advtrains_interlocking/signal_api.lua | 42 ++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 13 deletions(-)

(limited to 'advtrains_interlocking/signal_api.lua')

diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index ce3b03f..d27a045 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -80,7 +80,7 @@ ndef.advtrains = {
 		-- Node can set any other fields at its discretion. They are not touched.
 		-- Note: On first call advtrains automatically inserts into the ndef.advtrains table a main_aspects_lookup hashtable
 		-- Note: Pure distant signals (that cannot show halt) should NOT have a main_aspects table
-	apply_aspect = function(pos, main_aspect, rem_aspect, rem_aspinfo)
+	apply_aspect = function(pos, node, main_aspect, rem_aspect, rem_aspinfo)
 		-- set the node to show the desired aspect
 		-- called by advtrains when this signal's aspect group or the remote signal's aspect changes
 		-- MAY return the aspect_info. If it returns nil then get_aspect_info will be queried at a later point.
@@ -120,7 +120,7 @@ Signals that are possible start and end points for a route must satisfy:
 -- Database
 -- Signal Aspect store
 -- Stores for each signal the main aspect and other info, like the assigned remote signal
--- [signal encodePos] = { main_aspect = "proceed", [speed = 12], [remote = encodedPos] }
+-- [signal encodePos] = { name = "proceed", [speed = 12], [remote = encodedPos] }
 signal.aspects = {}
 
 -- Distant signal notification. Records for each signal the distant signals that refer to it
@@ -162,10 +162,11 @@ function signal.set_aspect(pos, main_asp_name, main_asp_speed, rem_pos, skip_dst
 	
 	-- if remote has changed, unregister from old remote
 	if old_remote and old_remote~=new_remote and signal.distant_refs[old_remote] then
+		atdebug("unregister old remote: ",old_remote,"from",main_pts)
 		signal.distant_refs[old_remote][main_pts] = nil
 	end
 		
-	signal.aspects[main_pts] = { main_aspect = main_asp_name, speed = main_asp_speed, remote = new_remote }
+	signal.aspects[main_pts] = { name = main_asp_name, speed = main_asp_speed, remote = new_remote }
 	-- apply aspect on main signal, this also checks new_remote
 	signal.reapply_aspect(main_pts)	
 	
@@ -198,10 +199,12 @@ end
 -- Notify distant signals of main_pts of a change in the aspect of this signal
 -- 
 function signal.notify_distants_of(main_pts, limit)
+	atdebug("notify_distants_of",advtrains.decode_pos(main_pts),"limit",limit)
 	if limit <= 0 then
 		return
 	end
 	local dstrefs = signal.distant_refs[main_pts]
+	atdebug("dstrefs",dstrefs,"")
 	if dstrefs then
 		for dst,_ in pairs(dstrefs) do
 			-- ensure that the backref is still valid
@@ -253,7 +256,7 @@ local function cache_mainaspects(ndefat)
 		-- always define halt aspect
 		halt = signal.MASP_HALT
 	}
-	for _,ma in ipairs(ndefat.main_aspects) then
+	for _,ma in ipairs(ndefat.main_aspects) do
 		ndefat.main_aspects_lookup[ma.name] = ma
 	end
 end
@@ -263,32 +266,37 @@ function signal.get_aspect_internal(pos, aspt)
 		-- oh, no main aspect, nevermind
 		return nil, aspt.remote, nil
 	end
+	atdebug("get_aspect_internal",pos,aspt)
 	-- look aspect in nodedef
 	local node = advtrains.ndb.get_node_or_nil(pos)
 	local ndef = node and minetest.registered_nodes[node.name]
 	local ndefat = ndef and ndef.advtrains
 	-- only if signal defines main aspect and its set in aspt
-	if ndefat and ndefat.main_aspects and aspt.main_aspect then
+	if ndefat and ndefat.main_aspects and aspt.name then
 		if not ndefat.main_aspects_lookup then
 			cache_mainaspects(ndefat)
 		end
 		local masp = ndefat.main_aspects_lookup[aspt.name]
+		if not masp then
+			atwarn(pos,"invalid main aspect",aspt.name,"valid are",ndefat.main_aspects_lookup)
+			return nil, aspt.remote, node, ndef
+		end
 		-- if speed, then apply speed
 		if masp.speed and aspt.speed then
 			masp = table.copy(masp)
 			masp.speed = aspt.speed
 		end
-		return masp, aspt.remote, ndef
+		return masp, aspt.remote, node, ndef
 	end
 	-- invalid node or no main aspect, return nil for masp
-	return nil, aspt.remote, ndef
+	return nil, aspt.remote, node, ndef
 end
 
 -- For the signal at pos, get the "aspect info" table. This contains the speed signalling information at this location
 function signal.get_aspect_info(pos)
 	-- get aspect internal
 	local aspt = signal.aspects[advtrains.encode_pos(pos)]
-	local masp, remote, ndef = signal.get_aspect_internal(pos, aspt)
+	local masp, remote, node, ndef = signal.get_aspect_internal(pos, aspt)
 	-- call into ndef
 	if ndef.advtrains and ndef.advtrains.get_aspect_info then
 		return ndef.advtrains.get_aspect_info(pos, masp)
@@ -305,30 +313,38 @@ end
 function signal.reapply_aspect(pts)
 	-- get aspt
 	local aspt = signal.aspects[pts]
+	atdebug("reapply_aspect",advtrains.decode_pos(pts),"aspt",aspt)
 	if not aspt then
 		return -- oop, nothing to do
 	end
 	-- resolve mainaspect table by name
 	local pos = advtrains.decode_pos(pts)
-	-- note: masp may be nil, when aspt.main_aspect was nil. Valid case for distant-only signals
-	local masp, remote, ndef = signal.get_aspect_internal(pos, aspt)
+	-- note: masp may be nil, when aspt.name was nil. Valid case for distant-only signals
+	local masp, remote, node, ndef = signal.get_aspect_internal(pos, aspt)
 	-- if we have remote, resolve remote
 	local rem_masp, rem_aspi
 	if remote then
+		-- register in remote signal as distant
+		if not signal.distant_refs[remote] then
+			signal.distant_refs[remote] = {}
+		end
+		signal.distant_refs[remote][pts] = true
 		local rem_aspt = signal.aspects[remote]
+		atdebug("resolving remote",advtrains.decode_pos(remote),"aspt",rem_aspt)
 		if rem_aspt and rem_aspt.name then
 			local rem_pos = advtrains.decode_pos(remote)
-			rem_masp, _, rem_ndef = signal.get_aspect_internal(rem_pos, rem_aspt)
+			rem_masp, _, _, rem_ndef = signal.get_aspect_internal(rem_pos, rem_aspt)
 			if rem_masp then
 				if rem_ndef.advtrains and rem_ndef.advtrains.get_aspect_info then
-					rem_aspi = rem_ndef.advtrains.get_aspect_info(pos, rem_masp)
+					rem_aspi = rem_ndef.advtrains.get_aspect_info(rem_pos, rem_masp)
 				end
 			end
 		end
 	end
 	-- call into ndef
+	atdebug("applying to",pos,": main_asp",masp,"rem_masp",rem_masp,"rem_aspi",rem_aspi)
 	if ndef.advtrains and ndef.advtrains.apply_aspect then
-		return ndef.advtrains.apply_aspect(pos, masp, rem_masp, rem_aspi)
+		ndef.advtrains.apply_aspect(pos, node, masp, rem_masp, rem_aspi)
 	end
 	-- notify trains
 	signal.notify_trains(pos)
-- 
cgit v1.2.3