lib: add color function collection

outputs/lib/math.nix

@@ -0,0 +1,46 @@
+{lib}: let
+  inherit (lib) min max;
+  inherit (builtins) floor ceil;
+
+  # basic math functions
+  # credits to github:xddxdd/nix-math
+
+  abs = x:
+    if x < 0
+    then 0 - x
+    else x;
+
+  clamp = a: b: v: min (max v (min a b)) (max a b);
+
+  round = x:
+    if (x - floor x) < 0.5
+    then floor x
+    else ceil x;
+
+  hasFraction = x: let
+    splitted = lib.splitString "." (builtins.toString x);
+  in
+    builtins.length splitted >= 2 && builtins.length (builtins.filter (ch: ch != "0") (lib.stringToCharacters (builtins.elemAt splitted 1))) > 0;
+
+  div = a: b: let
+    divideExactly = !(hasFraction (1.0 * a / b));
+    offset =
+      if divideExactly
+      then 0
+      else (0 - 1);
+  in
+    if b < 0
+    then offset - div a (0 - b)
+    else if a < 0
+    then offset - div (0 - a) b
+    else floor (1.0 * a / b);
+
+  mod = a: b:
+    if b < 0
+    then 0 - mod (0 - a) (0 - b)
+    else if a < 0
+    then mod (b - mod (0 - a) b) b
+    else a - b * (div a b);
+in {
+  inherit round mod abs hasFraction clamp;
+}