Restructure path system

The changes to the path system have not yet been integrated...

4 files changed, 204 insertions, 24 deletions

diff --git a/advtrains/helpers.lua b/advtrains/helpers.lua
index 5f5521f..5dbfd8d 100644
--- a/advtrains/helpers.lua
+++ b/advtrains/helpers.lua
@@ -28,9 +28,12 @@ function advtrains.dirCoordSet(coord, dir)
 	end

 	return {x=coord.x+x, y=coord.y, z=coord.z+z}

 end

+advtrains.pos_add_dir = advtrains.dirCoordSet

+

 function advtrains.dirToCoord(dir)

 	return advtrains.dirCoordSet({x=0, y=0, z=0}, dir)

 end

+advtrains.dir_to_vector = advtrains.dirToCoord

 

 function advtrains.maxN(list, expectstart)

 	local n=expectstart or 0

@@ -51,6 +54,8 @@ end
 function atround(number)

 	return math.floor(number+0.5)

 end

+atfloor = math.floor

+

 

 function advtrains.round_vector_floor_y(vec)

 	return {x=math.floor(vec.x+0.5), y=math.floor(vec.y), z=math.floor(vec.z+0.5)}

@@ -60,8 +65,8 @@ function advtrains.yawToDirection(yaw, conn1, conn2)
 	if not conn1 or not conn2 then

 		error("given nil to yawToDirection: conn1="..(conn1 or "nil").." conn2="..(conn1 or "nil"))

 	end

-	local yaw1=math.pi*(conn1/8)

-	local yaw2=math.pi*(conn2/8)

+	local yaw1 = advtrains.dir_to_angle(conn1)

+	local yaw2 = advtrains.dir_to_angle(conn2)

 	local adiff1 = advtrains.minAngleDiffRad(yaw, yaw1)

 	local adiff2 = advtrains.minAngleDiffRad(yaw, yaw2)

 	

@@ -75,8 +80,7 @@ end
 function advtrains.yawToAnyDir(yaw)

 	local min_conn, min_diff=0, 10

 	for conn, vec in pairs(advtrains.dir_trans_tbl) do

-		local uvec = vector.normalize(advtrains.dirToCoord(conn))

-		local yaw1 = math.atan2(uvec.z, uvec.x)

+		local yaw1 = advtrains.dir_to_angle(conn)

 		local diff = advtrains.minAngleDiffRad(yaw, yaw1)

 		if diff < min_diff then

 			min_conn = conn

@@ -88,8 +92,7 @@ end
 function advtrains.yawToClosestConn(yaw, conns)

 	local min_connid, min_diff=1, 10

 	for connid, conn in ipairs(conns) do

-		local uvec = vector.normalize(advtrains.dirToCoord(conn.c))

-		local yaw1 = math.atan2(uvec.z, uvec.x)

+		local yaw1 = advtrains.dir_to_angle(conn.c)

 		local diff = advtrains.minAngleDiffRad(yaw, yaw1)

 		if diff < min_diff then

 			min_connid = connid

@@ -99,6 +102,11 @@ function advtrains.yawToClosestConn(yaw, conns)
 	return min_connid

 end

 

+function advtrains.dir_to_angle(dir)

+	local uvec = vector.normalize(advtrains.dirToCoord())

+	local yaw1 = math.atan2(uvec.z, -uvec.x)

+end

+

 

 function advtrains.minAngleDiffRad(r1, r2)

 	local pi, pi2 = math.pi, 2*math.pi

diff --git a/advtrains/init.lua b/advtrains/init.lua
index 65e5048..0043c22 100644
--- a/advtrains/init.lua
+++ b/advtrains/init.lua
@@ -184,6 +184,10 @@ function advtrains.avt_load()
 			if tbl.version then
 				--congrats, we have the new save format.
 				advtrains.trains = tbl.trains
+				--Save the train id into the train table to avoid having to pass id around
+				for id, train in pairs(advtrains.trains) do
+					train.id = id
+				end
 				advtrains.wagon_save = tbl.wagon_save
 				advtrains.player_to_train_mapping = tbl.ptmap or {}
 				advtrains.ndb.load_data(tbl.ndb)
diff --git a/advtrains/path.lua b/advtrains/path.lua
index 506f27f..07b60b2 100644
--- a/advtrains/path.lua
+++ b/advtrains/path.lua
@@ -24,17 +24,7 @@ function advtrains.conway(midreal, prev, drives_on)--in order prev,mid,return
 	return vector.add(advtrains.round_vector_floor_y(next), {x=0, y=nextrailheight, z=0}), midconns[nconnid].c
 end
 
---about regular: Used by 1. to ensure path gets generated far enough, since end index is not known at this time.
-function advtrains.pathpredict(id, train, regular)
-	--TODO duplicate code under 5b.
-	local path_pregen=10
-	
-	local gen_front= path_pregen
-	local gen_back= - train.trainlen - path_pregen
-	if regular then
-		gen_front=math.max(train.index, train.detector_old_index) + path_pregen
-		gen_back=math.min(train.end_index, train.detector_old_end_index) - path_pregen
-	end
+function advtrains.pathpredict(id, train, gen_front, gen_back)
 	
 	local maxn=train.path_extent_max or 0
 	while maxn < gen_front do--pregenerate
@@ -80,3 +70,155 @@ function advtrains.pathpredict(id, train, regular)
 	if not train.min_index_on_track then train.min_index_on_track=-1 end
 	if not train.max_index_on_track then train.max_index_on_track=0 end
 end
+
+-- Naming conventions:
+-- 'index' - An index of the train.path table.
+-- 'offset' - A value in meters that determines how far on the path to walk relative to a certain index
+-- 'n' - Referring or pointing towards the 'next' path item, the one with index+1
+-- 'p' - Referring or pointing towards the 'prev' path item, the one with index-1
+-- 'f' - Referring to the positive end of the path (the end with the higher index)
+-- 'b' - Referring to the negative end of the path (the end with the lower index)
+
+-- New path structure of trains:
+--Tables:
+-- path      - path positions. 'indices' are relative to this. At the moment, at.round_vector_floor_y(path[i])
+--              is the node this item corresponds to, however, this will change in the future.
+-- path_node - (reserved)
+-- path_cn   - Connid of the current node that points towards path[i+1]
+-- path_cp   - Connid of the current node that points towards path[i-1]
+--     When the day comes on that path!=node, these will only be set if this index represents a transition between rail nodes
+-- path_dist - The distance (in meters) between this (path[i]) and the next (path[i+1]) item of the path
+-- path_dir  - The direction of this path item's transition to the next path item, which is the angle of conns[path_cn[i]].c
+--Variables:
+-- path_ext_f/b - how far path[i] is set
+-- path_trk_f/b - how far the path extends along a track. beyond those values, paths are generated in a straight line.
+-- path_req_f/b - how far path items were requested in the last step
+
+-- creates the path data structure, reconstructing the train from a position and a connid
+-- Important! train.drives_on must exist while calling this method
+-- returns: true - successful
+--           nil - node not yet available/unloaded, please wait
+--         false - node definitely gone, remove train
+function advtrains.path_create(train, pos, connid, rel_index)
+	local posr = advtrains.round_vector_floor_y(pos)
+	local node_ok, conns, rhe = advtrains.get_rail_info_at(pos, train.drives_on)
+	if not node_ok then
+		return node_ok
+	end
+	local mconnid = advtrains.get_matching_conn(connid, #conns)
+	train.index = rel_index
+	train.path = { [0] = { x=posr.x, y=posr.y+rhe, z=posr.z } }
+	train.path_cn = { [0] = connid }
+	train.path_cp = { [0] = mconnid }
+	train.path_dist = {}
+	
+	train.path_dir = {
+		[ 0] = conns[connid],
+		[-1] = conns[mconnid]
+	}
+	
+	train.path_ext_f=0
+	train.path_ext_b=0
+	train.path_trk_f=0
+	train.path_trk_b=0
+	train.path_req_f=0
+	train.path_req_b=0
+	
+end
+
+-- Function to get path entry at a position. This function will automatically calculate more of the path when required.
+-- returns: pos, on_track
+function advtrains.path_get(train, index)
+	if index ~= atfloor(index) then
+		error("For train "..train.id..": Called path_get() but index="..index.." is not a round number")
+	end
+	while index > train.path_ext_f do
+		local pos = train.path[train.path_ext_f]
+		local connid = train.path_cn[train.path_ext_f]
+		local node_ok, this_conns, adj_pos, adj_connid, conn_idx, nextrail_y
+		if train.path_ext_f == train.path_trk_f then
+			node_ok, this_conns = advtrains.get_rail_info_at(this_pos)
+			if not node_ok then error("For train "..train.id..": Path item "..train.path_ext_f.." on-track but not a valid node!") end
+			adj_pos, adj_connid, conn_idx, nextrail_y = advtrains.get_adjacent_rail(pos, this_conns, connid, train.drives_on)
+		end
+		train.path_ext_f = train.path_ext_f + 1
+		if adj_pos then
+			adj_pos.y = adj_pos.y + nextrail_y
+			train.path_cp[train.path_ext_f] = adj_connid
+			local mconnid = advtrains.get_matching_conn(adj_connid)
+			train.path_cn[train.path_ext_f] = mconnid
+			train.path_dir[train.path_ext_f] = this_conns[mconnid]
+			train.path_trk_f = train.path_ext_f
+		else
+			-- off-track fallback behavior
+			adj_pos = advtrains.pos_add_dir(pos, train.path_dir[train.path_ext_f-1])
+			train.path_dir[train.path_ext_f] = train.path_dir[train.path_ext_f-1]
+		end
+		train.path[train.path_ext_f] = adj_pos
+		train.path_dist[train.path_ext_f - 1] = vector.distance(pos, adj_pos)
+	end
+	while index < train.path_ext_b do
+		local pos = train.path[train.path_ext_b]
+		local connid = train.path_cp[train.path_ext_b]
+		local node_ok, this_conns, adj_pos, adj_connid, conn_idx, nextrail_y
+		if train.path_ext_b == train.path_trk_b then
+			node_ok, this_conns = advtrains.get_rail_info_at(this_pos)
+			if not node_ok then error("For train "..train.id..": Path item "..train.path_ext_f.." on-track but not a valid node!") end
+			adj_pos, adj_connid, conn_idx, nextrail_y = advtrains.get_adjacent_rail(pos, this_conns, connid, train.drives_on)
+		end
+		train.path_ext_b = train.path_ext_b - 1
+		if adj_pos then
+			adj_pos.y = adj_pos.y + nextrail_y
+			train.path_cp[train.path_ext_b] = adj_connid
+			local mconnid = advtrains.get_matching_conn(adj_connid)
+			train.path_cn[train.path_ext_b] = mconnid
+			train.path_dir[train.path_ext_b] = advtrains.oppd(this_conns[mconnid]) --we need to rotate this here so that it points in positive path direction
+			train.path_trk_b = train.path_ext_b
+		else
+			-- off-track fallback behavior
+			adj_pos = advtrains.pos_add_dir(pos, train.path_dir[train.path_ext_b-1])
+			train.path_dir[train.path_ext_b] = train.path_dir[train.path_ext_b-1]
+		end
+		train.path[train.path_ext_b] = adj_pos
+		train.path_dist[train.path_ext_b] = vector.distance(pos, adj_pos)
+	end
+	
+	return train.path[index], (index<=train.path_trk_f and index>=train.path_trk_b)
+	
+end
+
+-- interpolated position to fractional index given, and angle based on path_dir
+-- returns: pos, angle(yaw)
+function advtrains.path_get_interpolated(train, index)
+	local i_floor = atfloor(index)
+	local i_ceil = i_floor + 1
+	local frac = index - i_floor
+	local p_floor,  = advtrains.path_get(train, i_floor)
+	local p_ceil = advtrains.path_get(train, i_ceil)
+	
+	local d_floor = train.path_dir[i_floor]
+	local d_ceil = train.path_dir[i_ceil]
+	local a_floor = advtrains.dir_to_angle(d_floor)
+	local a_ceil = advtrains.dir_to_angle(d_ceil)
+	
+	local ang = advtrains.minAngleDiffRad(a_floor, a_ceil)
+	
+	return vector.add(p_floor, vector.multiply(vector.subtract(p_ceil, p_floor), frac), (a_floor + frac * ang)%(2*math.pi) -- TODO does this behave correctly?
+end
+
+function advtrains.path_get_by_offset(train, index, offset)
+	local pos_in_train_left=pit
+	local index=train.index
+	if pos_in_train_left>(index-math.floor(index))*(train.path_dist[math.floor(index)] or 1) then
+		pos_in_train_left=pos_in_train_left - (index-math.floor(index))*(train.path_dist[math.floor(index)] or 1)
+		index=math.floor(index)
+		while pos_in_train_left>(train.path_dist[index-1] or 1) do
+			pos_in_train_left=pos_in_train_left - (train.path_dist[index-1] or 1)
+			index=index-1
+		end
+		index=index-(pos_in_train_left/(train.path_dist[index-1] or 1))
+	else
+		index=index-(pos_in_train_left/(train.path_dist[math.floor(index-1)] or 1))
+	end
+	return index
+end
diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua
index 449d624..181446c 100644
--- a/advtrains/trainlogic.lua
+++ b/advtrains/trainlogic.lua
@@ -219,7 +219,7 @@ function advtrains.train_step_a(id, train, dtime)
 		- The next step, mistake is recognized, train leaves some positions. From there, everything works again.
 		To overcome this, we will generate the full required path here so that path_dist is available for get_train_end_index(). 
 		]]
-		advtrains.pathpredict(id, train)
+		advtrains.pathpredict(id, train, 3, -train.trainlen-3)
 	end
 	
 	--- 2a. set train.end_index which is required in different places, IF IT IS NOT SET YET by STMT afterwards. ---
@@ -359,9 +359,36 @@ function advtrains.train_step_a(id, train, dtime)
 	--- 4a. update train.end_index to the new position ---
 	train.end_index=advtrains.get_train_end_index(train)
 	
+	--- 4b calculate how far a path is required ---
+	local path_req_dd = 10 -- path required in driving direction
+	local path_req_ndd = 4 -- path required against driving direction
+	
+	-- when using easyBSS (block signalling), we need to make sure that the whole brake distance is known
+	if advtrains_easybss then
+		local acc_all = t_accel_all[1]
+		local acc_eng = t_accel_eng[1]
+		local nwagons = #train.trainparts
+		local acc = acc_all + (acc_eng*train.locomotives_in_train)/nwagons
+		local vel = train.velocity
+		local brakedst = (vel*vel) / (2*acc)
+		path_req_dd = math.ceil(brakedst+10)
+	end
+	
+	
+	local idx_front=math.max(train.index, train.detector_old_index)
+	local idx_back=math.min(train.end_index, train.detector_old_end_index)
+	local path_req_front, path_req_back
+	if train.movedir == 1 then
+		path_req_front = atround(idx_front + path_req_dd)
+		path_req_back = atround(idx_back - path_req_ndd)
+	else
+		path_req_front = atround(idx_front + path_req_ndd)
+		path_req_back = atround(idx_back - path_req_dd)		
+	end
+	
 	--- 5. extend path as necessary ---
 	--why this is an extra function, see under 3.
-	advtrains.pathpredict(id, train, true)
+	advtrains.pathpredict(id, train, path_req_front, path_req_back)
 	
 	--- 5a. make pos/yaw available for possible recover calls ---
 	if train.max_index_on_track<train.index then --whoops, train went too far. the saved position will be the last one that lies on a track, and savedpos_off_track_index_offset will hold how far to go from here
@@ -382,13 +409,11 @@ function advtrains.train_step_a(id, train, dtime)
 	
 	--- 5b. Remove path items that are no longer used ---
 	-- Necessary since path items are no longer invalidated in save steps
-	local path_pregen_keep=20
+	local del_keep=8
 	local offtrack_keep=4
-	local gen_front_keep= path_pregen_keep
-	local gen_back_keep= atround(- train.trainlen - path_pregen_keep)
 	
-	local delete_min=math.min(train.max_index_on_track - offtrack_keep, atround(train.index)+gen_back_keep)
-	local delete_max=math.max(train.min_index_on_track + offtrack_keep, atround(train.index)+gen_front_keep)
+	local delete_min=math.min(train.max_index_on_track - offtrack_keep, path_req_back - del_keep)
+	local delete_max=math.max(train.min_index_on_track + offtrack_keep, path_req_front + del_keep)
 	
 	if train.path_extent_min<delete_min then
 		--atprint(sid(id),"clearing path min ",train.path_extent_min," to ",delete_min)
@@ -582,6 +607,7 @@ function advtrains.create_new_train_at(pos, pos_prev)
 	while advtrains.trains[newtrain_id] do newtrain_id=advtrains.random_id() end--ensure uniqueness
 	
 	advtrains.trains[newtrain_id]={}
+	advtrains.trains[newtrain_id].id = newtrain_id
 	advtrains.trains[newtrain_id].last_pos=pos
 	advtrains.trains[newtrain_id].last_pos_prev=pos_prev
 	advtrains.trains[newtrain_id].tarvelocity=0