cell - Lua Separation Steering algorithm groups overlapping rooms into one corner -

i'm trying implement dungeon generation algorithm (presented here , demo-ed here ) involves generating random number of cells overlap each other. cells pushed apart/separated , connected. now, original poster/author described using separation steering algorithm in order uniformly distribute cells on area. haven't had experience flocking algorithm and/or separation steering behavior, turned google explanation (and found this ). implementation (based on article last mentioned) follows:

function pdg:_computeseparation(_agent)   local neighbours = 0   local rtwidth = #self._rooms   local v =   {     x = self._rooms[_agent].startx,     y = self._rooms[_agent].starty,     --velocity = 1,   }    = 1, rtwidth     if _agent ~=       local distance = math.dist(self._rooms[_agent].startx,                                   self._rooms[_agent].starty,                                   self._rooms[i].startx,                                  self._rooms[i].starty)       if distance < 12         --print("separating agent: ".._agent.." agent: "..i.."")         v.x = (v.x + self._rooms[_agent].startx - self._rooms[i].startx) * distance         v.y = (v.y + self._rooms[_agent].starty - self._rooms[i].starty) * distance         neighbours = neighbours + 1       end     end   end     if neighbours == 0     return v   else     v.x = v.x / neighbours     v.y = v.y / neighbours     v.x = v.x * -1     v.y = v.y * -1     pdg:_normalize(v, 1)     return v   end end 

self._rooms table contains original x , y position of room in grid, along it's width , height (endx, endy).

the problem that, instead of tiddly arranging cells on grid, takes overlapping cells , moves them area goes 1,1 distance+2, distance+2 (as seen in video [youtube])

i'm trying understand why happening.

in case it's needed, here parse grid table, separate , fill cells after separation:

function pdg:separate( )   if #self._rooms > 0     --print("nr rooms: "..#self._rooms.."")      -- reset map empty   x = 1, self._pdgmapwidth     y = 1, self._pdgmapheight       self._pdgmap[x][y] = 4     end   end    -- now, separate rooms   local numrooms = #self._rooms   = 1, numrooms     local v = pdg:_computeseparation(i)     --we adjust x , y positions of items in room table     self._rooms[i].startx = v.x     self._rooms[i].starty = v.y     --self._rooms[i].endx = v.x + self._rooms[i].endx      --self._rooms[i].endy = v.y + self._rooms[i].endy   end     -- render them again   = 1, numrooms     local px = math.abs( math.floor(self._rooms[i].startx) )     local py = math.abs( math.floor(self._rooms[i].starty) )      k = self.rectminwidth, self._rooms[i].endx       v = self.rectminheight, self._rooms[i].endy         print("px at: "..px.." , k is: "..k.." , sum is: "..px+k.."")         print("py at: "..py.." , v is: "..v.." , sum is: "..py+v.."")         if k == self.rectminwidth or             v == self.rectminheight or             k == self._rooms[i].endx or             v == self._rooms[i].endy           self._pdgmap[px+k][py+v] = 1         else           self._pdgmap[px+k][py+v] = 2         end       end     end   end end 

i have implemented generation algorithm well, , came across more or less same issue. of rectangles ended in topleft corner.

my problem was normalizing velocity vectors 0 length. if normalize those, divide zero, resulting in nan.

you can fix performing check whether velocity's length 0 before using in further calculations.

i hope helps!