-- Package of geometric operations on SDF objects

local function union(sdfs)
   return function (location)
      local p = sdfs[1](location)
      local pp = nil

      for i=2,#sdfs do
         pp = sdfs[i](location)
         if pp.dist < p.dist then
            p = pp
         end
      end

      return p
   end
end

local function diff(sdfs)
   return function (location)
      local p = sdfs[1](location)
      local pp = nil

      for i=2,#sdfs do
         pp = sdfs[i](location)
         p.dist = math.max(p.dist, -pp.dist)
      end
      
      return p
   end
end


Operations = {
   union = union,
   diff = diff
}

return Operations