src/client/render

-- path.lua
-- Functions for pathpredicting, put in a separate file. 

-- 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] = advtrains.conn_angle_median(conns[mconnid].c, conns[connid].c)
	}
	
	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
	
	advtrains.occ.set_item(train.id, posr, 0)
	return true
end

-- Sets position and connid to properly restore after a crash, e.g. in order
-- to save the train or to invalidate its path
-- Assumes that the train is in clean state
-- if invert ist true, setrestore will use the end index
function advtrains.path_setrestore(train, invert)
	local idx = train.index
	if invert then
		idx = train.end_index
	end
	
	local pos, connid, frac = advtrains.path_getrestore(train, idx, invert, true)
	
	train.last_pos = pos
	train.last_connid = connid
	train.last_frac = frac
end
-- Get restore position, connid and frac (in this order) for a train that will originate at the passed index
-- If invert is set, it will return path_cp and multiply frac by -1, in order to reverse the train there.
function advtrains.path_getrestore(train, index, invert)
	local idx = index
	local cns = train.path_cn
	
	if invert then
		cns = train.path_cp
	end
	
	local fli = atfloor(index)
	advtrains.path_get(train, fli)
	if fli > train.path_trk_f then
		fli = train.path_trk_f
	end
	if fli < train.path_trk_b then
		fli = train.path_trk_b
	end
	return advtrains.path_get(train, fli),
			cns[fli],
			(idx - fli) * (invert and -1 or 1)
end

-- Invalidates a path
-- this is supposed to clear stuff from the occupation tables
function advtrains.path_invalidate(train)
	if train.path then
		for i,p in pairs(train.path) do
			advtrains.occ.clear_item(train.id, advtrains.round_vector_floor_y(p))
		end
	end
	train.path = nil
	train.path_dist = nil
	train.path_cp = nil
	train.path_cn = nil
	train.path_dir = nil
	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

-- Prints a path using the passed print function
-- This function should be 'atprint', 'atlog', 'atwarn' or 'atdebug', because it needs to use print_concat_table
function advtrains.path_print(train, printf)
	printf("i:	CP	Position	Dir	CN		->Dist->")
	for i = train.path_ext_b, train.path_ext_f do
		if i==train.path_trk_b then
			printf("--Back on-track border here--")
		end
		printf(i,":	",train.path_cp[i],"	",train.path[i],"	",train.path_dir[i],"	",train.path_cn[i],"		->",train.path_dist[i],"->")
		if i==train.path_trk_f then
			printf("--Front on-track border here--")		
		end
	end
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 not train.path then
		error("For train "..train.id..": path_get called but there's no path set yet!")
	end
	if index ~= atfloor(index) then
		error("For train "..train.id..": Called path_get() but index="..index.." is not a round number")
	end
Mode	Name	Size
-rw-r--r--	anaglyph.cpp	1638	log plain
-rw-r--r--	anaglyph.h	1149	log plain
-rw-r--r--	core.cpp	2739	log plain
-rw-r--r--	core.h	2051	log plain
-rw-r--r--	factory.cpp	1978	log plain
-rw-r--r--	factory.h	1030	log plain
-rw-r--r--	interlaced.cpp	3661	log plain
-rw-r--r--	interlaced.h	1389	log plain
-rw-r--r--	pageflip.cpp	1795	log plain
-rw-r--r--	pageflip.h	1372	log plain
-rw-r--r--	plain.cpp	2082	log plain
-rw-r--r--	plain.h	1226	log plain
-rw-r--r--	sidebyside.cpp	2326	log plain
-rw-r--r--	sidebyside.h	1423	log plain
-rw-r--r--	stereo.cpp	1729	log plain
-rw-r--r--	stereo.h	1237	log plain