1 files changed, 27 insertions, 0 deletions
diff --git a/gerberex/utility.py b/gerberex/utility.py
new file mode 100644
index 0000000..37de5e8
--- /dev/null
+++ b/gerberex/utility.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
+
+from math import cos, sin, pi, sqrt
+
+def rotate(x, y, angle, center):
+    x0 = x - center[0]
+    y0 = y - center[1]
+    angle = angle * pi / 180.0
+    return (cos(angle) * x0 - sin(angle) * y0 + center[0],
+            sin(angle) * x0 + cos(angle) * y0 + center[1])
+
+def is_equal_value(a, b, error_range=0):
+    return (a - b) * (a - b) <= error_range * error_range
+
+def is_equal_point(a, b, error_range=0):
+    return is_equal_value(a[0], b[0], error_range) and \
+        is_equal_value(a[1], b[1], error_range)
+
+def normalize_vec2d(vec):
+    length = sqrt(vec[0] * vec[0] + vec[1] * vec[1])
+    return (vec[0] / length, vec[1] / length)
+
+def dot_vec2d(vec1, vec2):
+    return vec1[0] * vec2[0] + vec1[1] * vec2[1]
+\ No newline at end of file