Fix a bunch of rendering bugs.

  - 'clear' polarity primitives no longer erase background
  - Added aperture macro support for polygons
  - Added aperture macro rendring support
  - Renderer now creates a new surface for each layer and merges them instead of working
    directly on a single surface
  - Updated examples accordingly

1 files changed, 5 insertions, 1 deletions

diff --git a/gerber/excellon_statements.py b/gerber/excellon_statements.py
index 2be7a05..971a81d 100644
--- a/gerber/excellon_statements.py
+++ b/gerber/excellon_statements.py
@@ -55,6 +55,7 @@ class ExcellonStatement(object):
     def to_excellon(self, settings=None):
         raise NotImplementedError('to_excellon must be implemented in a '
                                   'subclass')
+
     def to_inch(self):
         self.units = 'inch'
 
@@ -67,6 +68,7 @@ class ExcellonStatement(object):
     def __eq__(self, other):
         return self.__dict__ == other.__dict__
 
+
 class ExcellonTool(ExcellonStatement):
     """ Excellon Tool class
 
@@ -210,7 +212,6 @@ class ExcellonTool(ExcellonStatement):
             if self.diameter is not None:
                 self.diameter = inch(self.diameter)
 
-
     def to_metric(self):
         if self.settings.units != 'metric':
             self.settings.units = 'metric'
@@ -573,6 +574,7 @@ class EndOfProgramStmt(ExcellonStatement):
         if self.y is not None:
             self.y += y_offset
 
+
 class UnitStmt(ExcellonStatement):
 
     @classmethod
@@ -598,6 +600,7 @@ class UnitStmt(ExcellonStatement):
     def to_metric(self):
         self.units = 'metric'
 
+
 class IncrementalModeStmt(ExcellonStatement):
 
     @classmethod
@@ -689,6 +692,7 @@ class MeasuringModeStmt(ExcellonStatement):
     def to_metric(self):
         self.units = 'metric'
 
+
 class RouteModeStmt(ExcellonStatement):
 
     def __init__(self, **kwargs):