3 files changed, 5 insertions, 13 deletions
diff --git a/gerbonara/gerber/aperture_macros/expression.py b/gerbonara/gerber/aperture_macros/expression.py
index fb399d3..2375c56 100644
--- a/gerbonara/gerber/aperture_macros/expression.py
+++ b/gerbonara/gerber/aperture_macros/expression.py
@@ -7,8 +7,7 @@ import operator
 import re
 import ast
 
-
-MILLIMETERS_PER_INCH = 25.4
+from ..utils import MM, Inch, MILLIMETERS_PER_INCH
 
 
 def expr(obj):
@@ -81,10 +80,10 @@ class UnitExpression(Expression):
         if self.unit is None or unit is None or self.unit == unit:
             return self._expr
 
-        elif unit == 'mm':
+        elif unit == MM:
             return self._expr * MILLIMETERS_PER_INCH
 
-        elif unit == 'inch':
+        elif unit == Inch:
             return self._expr / MILLIMETERS_PER_INCH
 
         else:
diff --git a/gerbonara/gerber/aperture_macros/parse.py b/gerbonara/gerber/aperture_macros/parse.py
index 375bb5b..43af309 100644
--- a/gerbonara/gerber/aperture_macros/parse.py
+++ b/gerbonara/gerber/aperture_macros/parse.py
@@ -11,6 +11,7 @@ import math
 
 from . import primitive as ap
 from .expression import *
+from ..utils import MM
 
 def rad_to_deg(x):
     return (x / math.pi) * 180
@@ -98,7 +99,7 @@ class ApertureMacro:
     def __hash__(self):
         return hash(self.to_gerber())
 
-    def dilated(self, offset, unit='mm'):
+    def dilated(self, offset, unit=MM):
         dup = copy.deepcopy(self)
         new_primitives = []
         for primitive in dup.primitives:
diff --git a/gerbonara/gerber/aperture_macros/primitive.py b/gerbonara/gerber/aperture_macros/primitive.py
index b569637..4de19c4 100644
--- a/gerbonara/gerber/aperture_macros/primitive.py
+++ b/gerbonara/gerber/aperture_macros/primitive.py
@@ -21,14 +21,6 @@ def point_distance(a, b):
 def deg_to_rad(a):
     return (a / 180) * math.pi
 
-def convert(value, src, dst):
-        if src == dst or src is None or dst is None or value is None:
-            return value
-        elif dst == 'mm':
-            return value * 25.4
-        else:
-            return value / 25.4
-
 class Primitive:
     def __init__(self, unit, args):
         self.unit = unit