Simplify Signal Aspect Table (H#132) [breaks compatibility with signal API]

8 files changed, 146 insertions, 190 deletions

diff --git a/advtrains/signals.lua b/advtrains/signals.lua
index 2bad1d4..1940518 100644
--- a/advtrains/signals.lua
+++ b/advtrains/signals.lua
@@ -12,18 +12,10 @@ end
 
 local function aspect(b)
 return {
-	main = {
-		free = b,
-		speed = -1,
-	},
-	shunt = {
-		free = false,
-		proceed_as_main = true
-	},
-	dst = {
-		free = true,
-		speed = -1,
-	},
+	main = (not b) and 0, -- b ? false : 0
+	shunt = false,
+	proceed_as_main = true,
+	dst = false,
 	info = {}
 }
 end
@@ -81,7 +73,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main != 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_on"..rotation, param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_off"..rotation, param2 = node.param2}, true)
@@ -140,7 +132,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main != 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_on"..rotation, param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_off"..rotation, param2 = node.param2}, true)
@@ -208,7 +200,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main != 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_wall_"..loc.."_on", param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_wall_"..loc.."_off", param2 = node.param2}, true)
diff --git a/advtrains_interlocking/approach.lua b/advtrains_interlocking/approach.lua
index 0894043..151f15a 100644
--- a/advtrains_interlocking/approach.lua
+++ b/advtrains_interlocking/approach.lua
@@ -73,17 +73,17 @@ advtrains.tnc_register_on_approach(function(pos, id, train, index, has_entered,
 		--interpreting aspect and determining speed to proceed
 		if travsht then
 			--shunt move
-			if asp.shunt.free then
+			if asp.shunt then
 				nspd = SHUNT_SPEED_MAX
-			elseif asp.shunt.proceed_as_main and asp.main.free then
-				nspd = asp.main.speed
+			elseif asp.shunt.proceed_as_main and asp.main != 0 then
+				nspd = asp.main
 				travsht = false
 			end
 		else
 			--train move
-			if asp.main.free then
-				nspd = asp.main.speed
-			elseif asp.shunt.free then
+			if asp.main != 0 then
+				nspd = asp.main
+			elseif asp.shunt then
 				nspd = SHUNT_SPEED_MAX
 				travsht = true
 			end
diff --git a/advtrains_interlocking/demosignals.lua b/advtrains_interlocking/demosignals.lua
index ab7a8b6..d5e1065 100644
--- a/advtrains_interlocking/demosignals.lua
+++ b/advtrains_interlocking/demosignals.lua
@@ -6,10 +6,10 @@
 
 
 local setaspect = function(pos, node, asp)
-	if not asp.main.free then
+	if asp.main == 0 then
 		advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_danger"})
 	else
-		if asp.dst.free and asp.main.speed == -1 then
+		if asp.dst != 0 and asp.main == -1 then
 			advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_free"})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_slow"})
@@ -22,18 +22,10 @@ local setaspect = function(pos, node, asp)
 end
 
 local suppasp = {
-		main = {
-			free = nil,
-			speed = {6, -1},
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = false,
-			proceed_as_main = true,
-		},
+		main = {0, 6, -1},
+		dst = {0, false},
+		shunt = false,
+		proceed_as_main = true,
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -74,10 +66,7 @@ minetest.register_node("advtrains_interlocking:ds_free", {
 		supported_aspects = suppasp,
 		get_aspect = function(pos, node)
 			return {
-				main = {
-					free = true,
-					speed = -1,
-				}
+				main = -1,
 			}
 		end,
 	},
@@ -98,10 +87,7 @@ minetest.register_node("advtrains_interlocking:ds_slow", {
 		supported_aspects = suppasp,
 		get_aspect = function(pos, node)
 			return {
-				main = {
-					free = true,
-					speed = 6,
-				}
+				main = 6,
 			}
 		end,
 	},
diff --git a/advtrains_interlocking/routesetting.lua b/advtrains_interlocking/routesetting.lua
index 575b053..f235ce6 100644
--- a/advtrains_interlocking/routesetting.lua
+++ b/advtrains_interlocking/routesetting.lua
@@ -7,17 +7,9 @@ local function sigd_to_string(sigd)
 end
 
 local asp_generic_free = {
-	main = {
-		free = true,
-		speed = -1,
-	},
-	shunt = {
-		free = false,
-	},
-	dst = {
-		free = true,
-		speed = -1,
-	},
+	main = -1,
+	shunt = false,
+	dst = false,
 	info = {}
 }
 
diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua
index 9729195..c419e72 100644
--- a/advtrains_interlocking/signal_api.lua
+++ b/advtrains_interlocking/signal_api.lua
@@ -4,28 +4,38 @@
 --[[
 Signal aspect table:
 asp = {
-	main = {
-		free = <boolean>,
-		speed = <int km/h>,
-	},
-	shunt = {
-		free = <boolean>,
+	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 = 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
-		proceed_as_main = <boolean>,
-		-- If an approaching train is a shunt move and "main.free" is set,
+		-- When main==0, train switches to shunt move and is restricted to speed 8
+	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.free" is set.
+		-- 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 = {
-		free = <boolean>,
-		speed = <int km/h>,
-	}
+	
+	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 = Signal doesn't provide distant signal information.
+	
 	info = {
+		-- 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
@@ -33,12 +43,6 @@ asp = {
 		-- (Example: german Langsamfahrstellen-Signale)
 	}
 }
--- For "speed" and "w_speed" fields, a value of -1 means that the
--- restriction is lifted. If they are omitted, the value imposed at
--- the last aspect received remains valid.
--- The "dst" subtable can be completely omitted when no explicit dst
--- aspect should be signalled to the train. In this case, the last
--- signalled dst aspect remains valid.
 
 == How signals actually work in here ==
 Each signal (in the advtrains universe) is some node that has at least the
@@ -87,22 +91,18 @@ advtrains = {
 				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, this signal should never
-		--  set the corresponding "speed" field in the aspect, which means
-		--  that the previous speed limit stays valid
+		--  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 = {
-			free = <boolean/nil>,
-			speed = {<speed1>, ..., <speedn>} or nil,
-		},
-		dst = {
-			free = <boolean/nil>,
-			speed = {<speed1>, ..., <speedn>} or nil,
-		},
-		shunt = {
-			free = <boolean/nil>,
-		},
+		main = {<speed1>, ..., <speedn>} or nil,
+		dst = {<speed1>, ..., <speedn>} or nil,
+		shunt = <boolean/nil>,
+		
 		info = {
 			call_on = <boolean/nil>,
 			dead_end = <boolean/nil>,
@@ -110,28 +110,36 @@ advtrains = {
 		}
 		
 	},
+	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.
+		
+		info = {
+			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.free=true regardless of
+		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 = {
-			free = true,
-		}
-		dst = {
-			free = true,
-		}
-		shunt = {
-			free = false,
-			proceed_as_main = false,
-		}
+		main = false (unchanged)
+		dst = false (unchanged)
+		shunt = false (shunting not allowed)
+		info = {} (no further information)
 	end,
 }
 on_rightclick = advtrains.interlocking.signal_rc_handler
@@ -155,48 +163,14 @@ This function will query get_aspect to retrieve the new aspect.
 ]]--
 
 local DANGER = {
-	main = {
-		free = false,
-		speed = 0,
-	},
-	shunt = {
-		free = false,
-	},
-	dst = {
-		free = false,
-		speed = 0,
-	},
+	main = 0,
+	dst = false,
+	shunt = false,
 	info = {}
 }
 advtrains.interlocking.DANGER = DANGER
 
 local function fillout_aspect(asp)
-	if not asp.main then
-		asp.main = {
-			free = true,
-		}
-	elseif type(asp.main) ~= "table" then
-		asp.main = {
-			free = asp.main~=0,
-			speed = asp.main,
-		}
-	end
-	if not asp.dst then
-		asp.dst = {
-			free = true,
-		}
-	end 
-	if not asp.shunt then
-		asp.shunt = {
-			free = false,
-			proceed_as_main = false,
-		}
-	elseif type(asp.shunt) ~= "table" then
-		asp.shunt = {
-			free = asp.shunt,
-			proceed_as_main = asp.proceed_as_main,
-		}
-	end
 	if not asp.info then
 		asp.info = {}
 	end
@@ -458,8 +432,10 @@ function advtrains.interlocking.show_signal_aspect_selector(pname, p_suppasp, p_
 	local form = "size[7,5]label[0.5,0.5;Select Signal Aspect:]"
 	form = form.."label[0.5,1;"..purpose.."]"
 	
+	
+	--TODO
 	form = form.."label[0.5,1.5;== Main Signal ==]"
-	if suppasp.main.free == nil then
+	if suppasp.main == 0 then
 		local st = 2
 		if isasp and not isasp.main.free then st=1 end
 		form = form.."dropdown[0.5,2;2;main_free;danger,free;"..st.."]"
diff --git a/advtrains_luaautomation/README.txt b/advtrains_luaautomation/README.txt
index 7c064cc..952efad 100644
--- a/advtrains_luaautomation/README.txt
+++ b/advtrains_luaautomation/README.txt
@@ -95,24 +95,47 @@ Cancels the route that is set from the signal at pos. Has the same effect as cli
 
 get_aspect(pos)
 Returns the signal aspect of the signal at pos. A signal aspect has the following format:
-aspect = {
-	main = { -- the next track section in line. Shows blocked for shunt routes
-		free = <boolean>,
-		speed = <int km/h>,
-	},
-	shunt = { -- whether a "shunting allowed" aspect should be shown
-		free = <boolean>,
-	}
-	dst = { -- the aspect of the next main signal on (at end of) route
-		free = <boolean>,
-		speed = <int km/h>,
-	}
+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 = 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 8
+	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 = Signal doesn't provide distant signal information.
+	
 	info = {
-		call_on = <boolean>, -- Call-on route, expect train in track ahead
-		dead_end = <boolean>, -- Route ends on a dead end (e.g. bumper)
+		-- 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)
 	}
 }
-As of August 2018, only the aspect.main.free field is ever used by the interlocking system.
+As of January 2020, the 'dst', 'call_on' and 'dead_end' fields are not used.
 
 # Lines
 
diff --git a/advtrains_signals_ks/init.lua b/advtrains_signals_ks/init.lua
index c65d5f8..deceb33 100644
--- a/advtrains_signals_ks/init.lua
+++ b/advtrains_signals_ks/init.lua
@@ -6,14 +6,14 @@
 
 local setaspectf = function(rot)
  return function(pos, node, asp)
-	if not asp.main.free then
-		if asp.shunt.free then
+	if asp.main == 0 then
+		if asp.shunt then
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_shunt_"..rot, param2 = node.param2})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_danger_"..rot, param2 = node.param2})
 		end
 	else
-		if asp.dst.free and asp.main.speed == -1 then
+		if asp.dst != 0 and asp.main == -1 then
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_free_"..rot, param2 = node.param2})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_slow_"..rot, param2 = node.param2})
@@ -22,19 +22,12 @@ local setaspectf = function(rot)
  end
 end
 
+
 local suppasp = {
-		main = {
-			free = nil,
-			speed = {6, -1},
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = nil,
-			proceed_as_main = true,
-		},
+		main = {0, 6, -1},
+		dst = {0, false},
+		shunt = nil,
+		proceed_as_main = true,
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -45,7 +38,7 @@ local suppasp = {
 --Rangiersignal
 local setaspectf_ra = function(rot)
  return function(pos, node, asp)
-	if asp.shunt.free then
+	if asp.shunt then
 		advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:ra_shuntd_"..rot, param2 = node.param2})
 	else
 		advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:ra_danger_"..rot, param2 = node.param2})
@@ -58,17 +51,11 @@ local setaspectf_ra = function(rot)
 end
 
 local suppasp_ra = {
-		main = {
-			free = true,
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = nil,
-			proceed_as_main = false,
-		},
+		main = { false },
+		dst = { false },
+		shunt = nil,
+		proceed_as_main = false,
+		
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -90,9 +77,9 @@ for _, rtab in ipairs({
 	local rot = rtab.rot
 	for typ, prts in pairs({
 			danger = {asp = advtrains.interlocking.DANGER, n = "slow", ici=true},
-			slow   = {asp = { main = { free = true, speed = 6 }, shunt = {proceed_as_main = true}} , n = "free"},
-			free   = {asp = { main = { free = true, speed = -1 }, shunt = {proceed_as_main = true}} , n = "shunt"},
-			shunt  = {asp = { main = {free = false}, shunt = {free = true} } , n = "danger"},
+			slow   = {asp = { main =  6, proceed_as_main = true} , n = "free"},
+			free   = {asp = { main = -1, proceed_as_main = true} , n = "shunt"},
+			shunt  = {asp = { main =  0, shunt = true} , n = "danger"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:hs_"..typ.."_"..rot, {
 			description = "Ks Main Signal",
@@ -136,8 +123,8 @@ for _, rtab in ipairs({
 	
 	--Rangiersignale:
 	for typ, prts in pairs({
-			danger = {asp = { main = {free = true}, shunt = {free = false} }, n = "shuntd", ici=true},
-			shuntd = {asp = { main = {free = true}, shunt = {free = true} } , n = "danger"},
+			danger = {asp = { main = false, shunt = false }, n = "shuntd", ici=true},
+			shuntd = {asp = { main = false, shunt = true } , n = "danger"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:ra_"..typ.."_"..rot, {
 			description = "Ks Shunting Signal",
@@ -181,13 +168,13 @@ for _, rtab in ipairs({
 	--Schilder:
 	for typ, prts in pairs({
 			-- Speed restrictions:
-			["8"] = {asp = { main = {free = true, speed = 8}, shunt = {free = true} }, n = "12", ici=true},
-			["12"] = {asp = { main = {free = true, speed = 12}, shunt = {free = true} }, n = "16"},
-			["16"] = {asp = { main = {free = true, speed = 16}, shunt = {free = true} }, n = "e"},
+			["8"] = {asp = { main = 8, shunt = true }, n = "12", ici=true},
+			["12"] = {asp = { main = 12, shunt = true }, n = "16"},
+			["16"] = {asp = { main = 16, shunt = true }, n = "e"},
 			-- Speed restriction lifted
-			["e"] = {asp = { main = {free = true, speed = -1}, shunt = {free = true} }, n = "hfs"},
+			["e"] = {asp = { main = -1, shunt = true }, n = "hfs"},
 			-- Halt for shunt moves:
-			["hfs"] = {asp = { main = {free = true}, shunt = {free = false} }, n = "8"},
+			["hfs"] = {asp = { main = false, shunt = false }, n = "8"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:sign_"..typ.."_"..rot, {
 			description = "Signal Sign",
diff --git a/advtrains_signals_ks/init_degrotate_nodes.lua b/advtrains_signals_ks/init_degrotate_nodes.lua
index a4380d2..da1c980 100644
--- a/advtrains_signals_ks/init_degrotate_nodes.lua
+++ b/advtrains_signals_ks/init_degrotate_nodes.lua
@@ -1,5 +1,5 @@
 -- Ks Signals for advtrains
--- will implement the advtrains signal API (which does not exist yet)
+-- will implement the advtrains signal API
 
 local function place_degrotate(pos, placer, itemstack, pointed_thing)
 	local yaw = placer:get_look_horizontal()