-- Package of geometric operations on SDF objects

local function union(s1, s2)
   return function (location)
      local p1 = s1(location)
      local p2 = s2(location)

      if p1.dist < p2.dist then
         return {dist = p1.dist, texture = p1.texture}
      else
         return {dist = p2.dist, texture = p2.texture}
      end
   end
end

local function diff(s1, s2)
   return function (location)
      local p1 = s1(location)
      local p2 = s2(location)

      return {dist = math.max(p1.dist, -p2.dist),
              texture = p1.texture}
   end
end


Operations = {
   union = union,
   diff = diff
}

return Operations