Merge pull request #738 from robotools/extract_guidelines_fromMathInfo

Extract guidelines from math info

Author: typesupply

Lib/fontParts/base/info.py

@@ -266,19 +266,17 @@ def _fromMathInfo(self, mathInfo, guidelines=True):
         """
         Subclasses may override this method.
         """
-        self.guidelines = []
         mathInfo.extractInfo(self)
         font = self.font
         if guidelines:
-            for guideline in self.guidelines:
+            for guideline in mathInfo.guidelines:
                 font.appendGuideline(
                     position=(guideline["x"], guideline["y"]),
                     angle=guideline["angle"],
                     name=guideline["name"],
                     color=guideline["color"]
                     # XXX identifier is lost
                 )
-        del self.guidelines
 
     def interpolate(self, factor, minInfo, maxInfo, round=True, suppressError=True):
         """

Lib/fontParts/test/test_font.py

@@ -567,3 +567,23 @@ def test_copy(self):
             copy.selectedGuidelines,
             font.selectedGuidelines
         )
+
+    # -------------
+    # Interpolation
+    # -------------
+
+    def test_interpolate_global_guidelines(self):
+        interpolated_font, _ = self.objectGenerator("font")
+        font_min, _ = self.objectGenerator("font")
+        font_min.appendGuideline(position=(0, 0), angle=0)
+        font_max, _ = self.objectGenerator("font")
+        font_max.appendGuideline(position=(200, 200), angle=0)
+        interpolated_font.info.interpolate(0.5, font_min.info, font_max.info, round=True)
+        self.assertEqual(
+            len(interpolated_font.guidelines),
+            1
+        )
+        self.assertEqual(
+            interpolated_font.guidelines[0].position,
+            (100, 100)
+        )