X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=Operations.lua;h=617916d90c9d1682ecf9eeb2d95de50d78d2ea36;hb=b2d510f61cb4ffa581aa62c1c97ee2ce73e5b1fb;hp=d606d391006d73963666bf64df483672922c2d15;hpb=bbd8d6d0b901e62730562d6cddfa80ca1c00bbbe;p=raymarcher.git

diff --git a/Operations.lua b/Operations.lua
index d606d39..617916d 100644
--- a/Operations.lua
+++ b/Operations.lua
@@ -13,8 +13,20 @@ local function union(s1, s2)
    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
+   union = union,
+   diff = diff
 }
 
 return Operations