taxicab style color comparison

main.js

@@ -19,3 +19,13 @@ function deRasterize(i, width){
         x: i % width
     });
 }
+function compareColors(c1,c2){ //compare two rgba color structs
+        //general basic distance nothing too special
+
+        let sum1 = c1.r + c1.g + c1.b + c1.a;
+        let sum2 = c2.r + c2.g + c2.b + c2.a;
+
+        if (Math.abs(sum1-sum2) < (tolerance*4)) {
+            return true;
+        } else return false;
+}