Operations.lua

   1 -- Package of geometric operations on SDF objects
   2
   3 local function union(sdfs)
   4    return function (location)
   5       local p = sdfs[1](location)
   6       local pp = nil
   7
   8       for i=2,#sdfs do
   9          pp = sdfs[i](location)
  10          if pp.dist < p.dist then
  11             p = pp
  12          end
  13       end
  14
  15       return p
  16    end
  17 end
  18
  19 local function diff(sdfs)
  20    return function (location)
  21       local p = sdfs[1](location)
  22       local pp = nil
  23
  24       for i=2,#sdfs do
  25          pp = sdfs[i](location)
  26          p.dist = math.max(p.dist, -pp.dist)
  27       end
  28
  29       return p
  30    end
  31 end
  32
  33
  34 Operations = {
  35    union = union,
  36    diff = diff
  37 }
  38
  39 return Operations