From b465dcff751dbeadcec51df6e4d8742353de1306 Mon Sep 17 00:00:00 2001
From: Cosimo Lupo <clupo@google.com>
Date: Fri, 15 Jan 2021 17:37:11 +0000
Subject: [PATCH] rename function to round_start_circle_stable_containment

as suggested in https://github.com/fonttools/fonttools/pull/2148#discussion_r557656073
---
 Lib/fontTools/colorLib/builder.py  |  4 ++--
 Lib/fontTools/colorLib/geometry.py |  4 ++--
 Tests/colorLib/builder_test.py     | 11 +++++------
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/Lib/fontTools/colorLib/builder.py b/Lib/fontTools/colorLib/builder.py
index c0329abcc..56a048de9 100644
--- a/Lib/fontTools/colorLib/builder.py
+++ b/Lib/fontTools/colorLib/builder.py
@@ -34,7 +34,7 @@ from fontTools.ttLib.tables.otTables import (
     VariableInt,
 )
 from .errors import ColorLibError
-from .geometry import nudge_start_circle_almost_inside
+from .geometry import round_start_circle_stable_containment
 
 
 # TODO move type aliases to colorLib.types?
@@ -534,7 +534,7 @@ class LayerV1ListBuilder:
         r1 = _to_variable_value(r1)
 
         # avoid abrupt change after rounding when c0 is near c1's perimeter
-        c = nudge_start_circle_almost_inside(
+        c = round_start_circle_stable_containment(
             (x0.value, y0.value), r0.value, (x1.value, y1.value), r1.value
         )
         x0, y0 = x0._replace(value=c.centre[0]), y0._replace(value=c.centre[1])
diff --git a/Lib/fontTools/colorLib/geometry.py b/Lib/fontTools/colorLib/geometry.py
index c23a84126..bf7268823 100644
--- a/Lib/fontTools/colorLib/geometry.py
+++ b/Lib/fontTools/colorLib/geometry.py
@@ -78,8 +78,8 @@ class Circle:
         self.centre = _nudge_point(self.centre, direction)
 
 
-def nudge_start_circle_almost_inside(c0, r0, c1, r1):
-    """Nudge c0 so it continues to be inside/outside c1 after rounding.
+def round_start_circle_stable_containment(c0, r0, c1, r1):
+    """Round start circle so that it stays inside/outside end circle after rounding.
 
     The rounding of circle coordinates to integers may cause an abrupt change
     if the start circle c0 is so close to the end circle c1's perimiter that
diff --git a/Tests/colorLib/builder_test.py b/Tests/colorLib/builder_test.py
index d4376f455..003e53d97 100644
--- a/Tests/colorLib/builder_test.py
+++ b/Tests/colorLib/builder_test.py
@@ -1,7 +1,7 @@
 from fontTools.ttLib import newTable
 from fontTools.ttLib.tables import otTables as ot
 from fontTools.colorLib import builder
-from fontTools.colorLib.geometry import nudge_start_circle_almost_inside, Circle
+from fontTools.colorLib.geometry import round_start_circle_stable_containment, Circle
 from fontTools.colorLib.builder import LayerV1ListBuilder
 from fontTools.colorLib.errors import ColorLibError
 import pytest
@@ -1066,10 +1066,10 @@ class TrickyRadialGradientTest:
         else:
             return Circle(c0, r0).inside(Circle(c1, r1))
 
-    def nudge_start_circle_position(self, c0, r0, c1, r1, inside=True):
+    def round_start_circle(self, c0, r0, c1, r1, inside=True):
         assert self.circle_inside_circle(c0, r0, c1, r1) is inside
         assert self.circle_inside_circle(c0, r0, c1, r1, rounded=True) is not inside
-        r = nudge_start_circle_almost_inside(c0, r0, c1, r1)
+        r = round_start_circle_stable_containment(c0, r0, c1, r1)
         assert (
             self.circle_inside_circle(r.centre, r.radius, c1, r1, rounded=True)
             is inside
@@ -1082,8 +1082,7 @@ class TrickyRadialGradientTest:
         r0 = 0
         c1 = (642.99108, 104.70327999999995)
         r1 = 260.0072
-        result = self.nudge_start_circle_position(c0, r0, c1, r1, inside=True)
-        assert result == ((386, 71), 0)
+        assert self.round_start_circle(c0, r0, c1, r1, inside=True) == ((386, 71), 0)
 
     @pytest.mark.parametrize(
         "c0, r0, c1, r1, inside, expected",
@@ -1105,4 +1104,4 @@ class TrickyRadialGradientTest:
         ],
     )
     def test_nudge_start_circle_position(self, c0, r0, c1, r1, inside, expected):
-        assert self.nudge_start_circle_position(c0, r0, c1, r1, inside) == expected
+        assert self.round_start_circle(c0, r0, c1, r1, inside) == expected