--advtrains by orwell96, see readme.txt local dir_trans_tbl={ [0]={x=0, z=1, y=0}, [1]={x=1, z=2, y=0}, [2]={x=1, z=1, y=0}, [3]={x=2, z=1, y=0}, [4]={x=1, z=0, y=0}, [5]={x=2, z=-1, y=0}, [6]={x=1, z=-1, y=0}, [7]={x=1, z=-2, y=0}, [8]={x=0, z=-1, y=0}, [9]={x=-1, z=-2, y=0}, [10]={x=-1, z=-1, y=0}, [11]={x=-2, z=-1, y=0}, [12]={x=-1, z=0, y=0}, [13]={x=-2, z=1, y=0}, [14]={x=-1, z=1, y=0}, [15]={x=-1, z=2, y=0}, } local dir_angle_tbl={} for d,v in pairs(dir_trans_tbl) do local uvec = vector.normalize(v) dir_angle_tbl[d] = math.atan2(-uvec.x, uvec.z) end function advtrains.dir_to_angle(dir) return dir_angle_tbl[dir] or error("advtrains: in helpers.lua/dir_to_angle() given dir="..(dir or "nil")) end function advtrains.dirCoordSet(coord, dir) return vector.add(coord, advtrains.dirToCoord(dir)) end advtrains.pos_add_dir = advtrains.dirCoordSet function advtrains.pos_add_angle(pos, ang) -- 0 is +Z -> meaning of sin/cos swapped return vector.add(pos, {x = -math.sin(ang), y = 0, z = math.cos(ang)}) end function advtrains.dirToCoord(dir) return dir_trans_tbl[dir] or error("advtrains: in helpers.lua/dir_to_vector() given dir="..(dir or "nil")) end advtrains.dir_to_vector = advtrains.dirToCoord function advtrains.maxN(list, expectstart) local n=expectstart or 0 while list[n] do n=n+1 end return n-1 end function advtrains.minN(list, expectstart) local n=expectstart or 0 while list[n] do n=n-1 end return n+1 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)} end 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 = advtrains.dir_to_angle(conn1) local yaw2 = advtrains.dir_to_angle(conn2) local adiff1 = advtrains.minAngleDiffRad(yaw, yaw1) local adiff2 = advtrains.minAngleDiffRad(yaw, yaw2) if math.abs(adiff2)pi2 do r1=r1-pi2 end while r1<0 do r1=r1+pi2 end while r2>pi2 do r2=r2-pi2 end while r1<0 do r2=r2+pi2 end local try1=r2-r1 local try2=r2+pi2-r1 local try3=r2-pi2-r1 local minabs = math.min(math.abs(try1), math.abs(try2), math.abs(try3)) if minabs==math.abs(try1) then return try1 end if minabs==math.abs(try2) then return try2 end if minabs==math.abs(try3) then return try3 end end -- Takes 2 connections (0...AT_CMAX) as argument -- Returns the angle median of those 2 positions from the pov -- of standing on the cdir1 side and looking towards cdir2 -- cdir1 - >NODE> - cdir2 function advtrains.conn_angle_median(cdir1, cdir2) local ang1 = advtrains.dir_to_angle(advtrains.oppd(cdir1)) local ang2 = advtrains.dir_to_angle(cdir2) return ang1 + advtrains.minAngleDiffRad(ang1, ang2)/2 end function advtrains.merge_tables(a, ...) local new={} for _,t in ipairs({a,...}) do for k,v in pairs(t) do new[k]=v end end return new end function advtrains.save_keys(tbl, keys) local new={} for _,key in ipairs(keys) do new[key] = tbl[key] end return new end function advtrains.get_real_index_position(path, index) if not path or not index then return end local first_pos=path[math.floor(index)] local second_pos=path[math.floor(index)+1] if not first_pos or not second_pos then return nil end local factor=index-math.floor(index) local actual_pos={x=first_pos.x-(first_pos.x-second_pos.x)*factor, y=first_pos.y-(first_pos.y-second_pos.y)*factor, z=first_pos.z-(first_pos.z-second_pos.z)*factor,} return actual_pos end function advtrains.pos_median(pos1, pos2) return {x=pos1.x-(pos1.x-pos2.x)*0.5, y=pos1.y-(pos1.y-pos2.y)*0.5, z=pos1.z-(pos1.z-pos2.z)*0.5} end function advtrains.abs_ceil(i) return math.ceil(math.abs(i))*math.sign(i) end function advtrains.serialize_inventory(inv) local ser={} local liszts=inv:get_lists() for lisztname, liszt in pairs(liszts) do ser[lisztname]={} for idx, item in ipairs(liszt) do local istring=item:to_string() if istring~="" then ser[lisztname][idx]=istring end end end return minetest.serialize(ser) end function advtrains.deserialize_inventory(sers, inv) local ser=minetest.deserialize(sers) if ser then inv:set_lists(ser) return true end return false end --is_protected wrapper that checks for protection_bypass privilege function advtrains.is_protected(pos, name) if not name then error("advtrains.is_protected() called without name parameter!") end if minetest.check_player_privs(name, {protection_bypass=true}) then --player can bypass protection return false end return minetest.is_protected(pos, name) end function advtrains.is_creative(name) if not name then error("advtrains.is_creative() called without name parameter!") end if minetest.check_player_privs(name, {creative=true}) then return true end return minetest.settings:get_bool("creative_mode") end function advtrains.is_damage_enabled(name) if not name then error("advtrains.is_damage_enabled() called without name parameter!") end if minetest.check_player_privs(name, "train_admin") then return false end return minetest.settings:get_bool("enable_damage") end function advtrains.ms_to_kmh(speed) return speed * 3.6 end -- 4 possible inputs: -- integer: just do that modulo calculation -- table with c set: rotate c -- table with tables: rotate each -- table with integers: rotate each (probably no use case) function advtrains.rotate_conn_by(conn, rotate) if tonumber(conn) then return (conn+rotate)%AT_CMAX elseif conn.c then return { c = (conn.c+rotate)%AT_CMAX, y = conn.y} end local tmp={} for connid, data in ipairs(conn) do tmp[connid]=advtrains.rotate_conn_by(data, rotate) end return tmp end function advtrains.oppd(dir) return advtrains.rotate_conn_by(dir, AT_CMAX/2) end --conn_to_match like rotate_conn_by --other_conns have to be a table of conn tables! function advtrains.conn_matches_to(conn, other_conns) if tonumber(conn) then for connid, data in ipairs(other_conns) do if advtrains.oppd(conn) == data.c then return connid end end return false elseif conn.c then for connid, data in ipairs(other_conns) do local cmp = advtrains.oppd(conn) if cmp.c == data.c and (cmp.y or 0) == (data.y or 0) then return connid end end return false end local tmp={} for connid, data in ipairs(conn) do local backmatch = advtrains.conn_matches_to(data, other_conns) if backmatch then return backmatch, connid end --returns end return false end -- returns: , , , function advtrains.get_adjacent_rail(this_posnr, this_conns_p, conn_idx, drives_on) local this_pos = advtrains.round_vector_floor_y(this_posnr) local this_conns = this_conns_p if not this_conns then _, this_conns = advtrains.get_rail_info_at(this_pos) end if not conn_idx then for coni, _ in ipairs(this_conns) do local adj_pos, adj_conn_idx, _, nry, nco = advtrains.get_adjacent_rail(this_pos, this_conns, coni) if adj_pos then return adj_pos,adj_conn_idx,coni,nry, nco end end return nil end local conn = this_conns[conn_idx] local conn_y = conn.y or 0 local adj_pos = advtrains.dirCoordSet(this_pos, conn.c); while conn_y>=1 do conn_y = conn_y - 1 adj_pos.y = adj_pos.y + 1 end local nextnode_ok, nextconns, nextrail_y=advtrains.get_rail_info_at(adj_pos, drives_on) if not nextnode_ok then adj_pos.y = adj_pos.y - 1 conn_y = conn_y + 1 nextnode_ok, nextconns, nextrail_y=advtrains.get_rail_info_at(adj_pos, drives_on) if not nextnode_ok then return nil end end local adj_connid = advtrains.conn_matches_to({c=conn.c, y=conn_y}, nextconns) if adj_connid then return adj_pos, adj_connid, conn_idx, nextrail_y, nextconns end return nil end local connlku={[2]={2,1}, [3]={2,1,1}, [4]={2,1,4,3}} function advtrains.get_matching_conn(conn, nconns) return connlku[nconns][conn] end function advtrains.random_id() local idst="" for i=0,5 do idst=idst..(math.random(0,9)) end return idst end -- Shorthand for pos_to_string and round_vector_floor_y function advtrains.roundfloorpts(pos) return minetest.pos_to_string(advtrains.round_vector_floor_y(pos)) end -- insert an element into a table if it does not yet exist there -- equalfunc is a function to compare equality, defaults to == -- returns true if the element was inserted function advtrains.insert_once(tab, elem, equalfunc) for _,e in pairs(tab) do if equalfunc and equalfunc(elem, e) or e==elem then return false end end tab[#tab+1] = elem return true end local hext = { [0]="0",[1]="1",[2]="2",[3]="3",[4]="4",[5]="5",[6]="6",[7]="7",[8]="8",[9]="9",[10]="A",[11]="B",[12]="C",[13]="D",[14]="E",[15]="F"} local dect = { ["0"]=0,["1"]=1,["2"]=2,["3"]=3,["4"]=4,["5"]=5,["6"]=6,["7"]=7,["8"]=8,["9"]=9,["A"]=10,["B"]=11,["C"]=12,["D"]=13,["E"]=14,["F"]=15} local f = atfloor local function hex(i) local x=i+32768 local c4 = x % 16 x = f(x / 16) local c3 = x % 16 x = f(x / 16) local c2 = x % 16 x = f(x / 16) local c1 = x % 16 return (hext[c1]) .. (hext[c2]) .. (hext[c3]) .. (hext[c4]) end local function c(s,i) return dect[string.sub(s,i,i)] end local function dec(s) return (c(s,1)*4096 + c(s,2)*256 + c(s,3)*16 + c(s,4))-32768 end -- Takes a position vector and outputs a encoded value suitable as table index -- This is essentially a hexadecimal representation of the position (+32768) -- Order (YYY)YXXXXZZZZ function advtrains.encode_pos(pos) return hex(pos.y) .. hex(pos.x) .. hex(pos.z) end -- decodes a position encoded with encode_pos function advtrains.decode_pos(pts) if not pts or not #pts==6 then return nil end local stry = string.sub(pts, 1,4) local strx = string.sub(pts, 5,8) local strz = string.sub(pts, 9,12) return vector.new(dec(strx), dec(stry), dec(strz)) end -- Solve quadratic equations (i.e. a*x^2 + b*x + c = 0) function advtrains.solve_quadratic_equation(a, b, c) if not (a and b and c) then return nil end if a == 0 then return {-c/b, -c/b} end -- avoid division by zero local delta = (b*b - 4*a*c) if delta < 0 then return {-b/2/a,-b/2/a} end -- ignore imaginary part return {((-b+math.sqrt(delta))/2/a),((-b-math.sqrt(delta))/2/a)} end -- safe square root -- Negative return values indicate imaginary numbers. function advtrains.safesqrt(a) if a >= 0 then return math.sqrt(a) end return 0 - math.sqrt(-a) end --[[ Benchmarking code local tdt = {} local tlt = {} local tet = {} for i=1,1000000 do tdt[i] = vector.new(math.random(-65536, 65535), math.random(-65536, 65535), math.random(-65536, 65535)) if i%1000 == 0 then tlt[#tlt+1] = tdt[i] end end local t1=os.clock() for i=1,1000000 do local pe = advtrains.encode_pos(tdt[i]) local pb = advtrains.decode_pos(pe) tet[pe] = i end for i,v in ipairs(tlt) do local lk = tet[advtrains.encode_pos(v)] end atdebug("endec",os.clock()-t1,"s") tet = {} t1=os.clock() for i=1,1000000 do local pe = minetest.pos_to_string(tdt[i]) local pb = minetest.string_to_pos(pe) tet[pe] = i end for i,v in ipairs(tlt) do local lk = tet[minetest.pos_to_string(v)] end atdebug("pts",os.clock()-t1,"s") --Results: --2018-11-29 16:57:08: ACTION[Main]: [advtrains]endec 1.786451 s --2018-11-29 16:57:10: ACTION[Main]: [advtrains]pts 2.566377 s ]]