-- The grid was clicked
function gridClicked(x, y, b)
  if ((x > 0) and (y > 0) and (x <= w) and (y <= h)) then
    if b == 1 then
      local sweep = {}
      local swept = {}
      local function isSwept(x,y)
        if swept[x] == nil or swept[x][y] == nil then return false end
        return true
      end
      local function addSweep(x,y)
        table.insert(sweep,{x,y})
      end
      local function addSwept(x,y)
        if swept[x] == nil then swept[x] = {} end
        swept[x][y] = true
      end

      addSweep(x,y)

      while #sweep > 0 do
        local x,y = unpack(table.remove(sweep,1))
        addSwept(x,y)
        if devoil[x][y] == 0 then
          displaySquare(x, y)
          if grille[x][y] == 0 then
            for u = -1, 1 do
              for v = -1, 1 do
                if not isSwept(x+u,y+v) then
                  addSweep(x+u,y+v,1)
                end
              end
            end
          end
        end
      end
    end
  end
end