Added SDF operations.

diff --git a/Operations.lua b/Operations.lua
new file mode 100644 (file)
index 0000000..d606d39
--- /dev/null
+++ b/Operations.lua
@@ -0,0 +1,20 @@
+-- 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
+
+Operations = {
+   union = union
+}
+
+return Operations