Merge pull request #94 from jaseg/master

Make primitives with unset level polarity inherit from region

gerber/gerber_statements.py

@@ -236,11 +236,6 @@ class LPParamStmt(ParamStmt):
         lp = 'clear' if stmt_dict.get('lp') == 'C' else 'dark'
         return cls(param, lp)
 
-    @classmethod
-    def from_region(cls, region):
-        #todo what is the first param?
-        return cls(None, region.level_polarity)
-
     def __init__(self, param, lp):
         """ Initialize LPParamStmt class
 

gerber/primitives.py

@@ -206,8 +206,9 @@ class Line(Primitive):
     """
     """
 
-    def __init__(self, start, end, aperture, **kwargs):
+    def __init__(self, start, end, aperture, level_polarity=None, **kwargs):
         super(Line, self).__init__(**kwargs)
+        self.level_polarity = level_polarity
         self._start = start
         self._end = end
         self.aperture = aperture
@@ -324,8 +325,9 @@ class Arc(Primitive):
     """
 
     def __init__(self, start, end, center, direction, aperture, quadrant_mode,
-                 **kwargs):
+            level_polarity=None, **kwargs):
         super(Arc, self).__init__(**kwargs)
+        self.level_polarity = level_polarity
         self._start = start
         self._end = end
         self._center = center

gerber/render/rs274x_backend.py

@@ -178,11 +178,11 @@ class Rs274xContext(GerberContext):
         if hasattr(primitive, 'comment'):
             self.body.append(CommentStmt(primitive.comment))
 
-    def _render_line(self, line, color):
+    def _render_line(self, line, color, default_polarity='dark'):
 
         self._select_aperture(line.aperture)
 
-        self._render_level_polarity(line)
+        self._render_level_polarity(line, default_polarity)
 
         # Get the right function
         if self._func != CoordStmt.FUNC_LINEAR:
@@ -206,7 +206,7 @@ class Rs274xContext(GerberContext):
         elif func:
             self.body.append(CoordStmt.mode(func))
 
-    def _render_arc(self, arc, color):
+    def _render_arc(self, arc, color, default_polarity='dark'):
 
         # Optionally set the quadrant mode if it has changed:
         if arc.quadrant_mode != self._quadrant_mode:
@@ -221,7 +221,7 @@ class Rs274xContext(GerberContext):
         # Select the right aperture if not already selected
         self._select_aperture(arc.aperture)
 
-        self._render_level_polarity(arc)
+        self._render_level_polarity(arc, default_polarity)
 
         # Find the right movement mode. Always set to be sure it is really right
         dir = arc.direction
@@ -252,20 +252,23 @@ class Rs274xContext(GerberContext):
 
         for p in region.primitives:
 
+            # Make programmatically generated primitives within a region with
+            # unset level polarity inherit the region's level polarity
             if isinstance(p, Line):
-                self._render_line(p, color)
+                self._render_line(p, color, default_polarity=region.level_polarity)
             else:
-                self._render_arc(p, color)
+                self._render_arc(p, color, default_polarity=region.level_polarity)
 
         if self.explicit_region_move_end:
             self.body.append(CoordStmt.move(None, None))
 
         self.body.append(RegionModeStmt.off())
 
-    def _render_level_polarity(self, region):
-        if region.level_polarity != self._level_polarity:
-            self._level_polarity = region.level_polarity
-            self.body.append(LPParamStmt.from_region(region))
+    def _render_level_polarity(self, obj, default='dark'):
+        obj_polarity = obj.level_polarity if obj.level_polarity is not None else default
+        if obj_polarity != self._level_polarity:
+            self._level_polarity = obj_polarity
+            self.body.append(LPParamStmt('LP', obj_polarity))
 
     def _render_flash(self, primitive, aperture):