UI GFX Geometry: Make UnitBezier a wrapper for gfx::CubicBezier

ui/gfx/geometry/cubic_bezier_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/geometry/cubic_bezier.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace gfx {
@@ skipping 17 matching lines @@
   EXPECT_NEAR(function.Solve(0.5), 0.5, epsilon);
   EXPECT_NEAR(function.Solve(0.6), 0.63238, epsilon);
   EXPECT_NEAR(function.Solve(0.65), 0.69676, epsilon);
   EXPECT_NEAR(function.Solve(0.7), 0.75884, epsilon);
   EXPECT_NEAR(function.Solve(0.75), 0.81764, epsilon);
   EXPECT_NEAR(function.Solve(0.8), 0.87196, epsilon);
   EXPECT_NEAR(function.Solve(0.85), 0.92021, epsilon);
   EXPECT_NEAR(function.Solve(0.9), 0.96021, epsilon);
   EXPECT_NEAR(function.Solve(0.95), 0.98863, epsilon);
   EXPECT_NEAR(function.Solve(1), 1, epsilon);
+
+  CubicBezier basic_use(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(0.875, basic_use.Solve(0.5));
+
+  CubicBezier overshoot(0.5, 2.0, 0.5, 2.0);
+  EXPECT_EQ(1.625, overshoot.Solve(0.5));
+
+  CubicBezier undershoot(0.5, -1.0, 0.5, -1.0);
+  EXPECT_EQ(-0.625, undershoot.Solve(0.5));
 }
 
 // Tests that solving the bezier works with knots with y not in (0, 1).
 TEST(CubicBezierTest, UnclampedYValues) {
   CubicBezier function(0.5, -1.0, 0.5, 2.0);
 
   double epsilon = 0.00015;
 
   EXPECT_NEAR(function.Solve(0.0), 0.0, epsilon);
   EXPECT_NEAR(function.Solve(0.05), -0.08954, epsilon);
@@ skipping 86 matching lines @@
   function->Range(&min, &max);
   EXPECT_EQ(0.f, min);
   EXPECT_EQ(1.f, max);
 }
 
 TEST(CubicBezierTest, Slope) {
   CubicBezier function(0.25, 0.0, 0.75, 1.0);
 
   double epsilon = 0.00015;
 
+  EXPECT_NEAR(function.Slope(-0.1), 0, epsilon);
   EXPECT_NEAR(function.Slope(0), 0, epsilon);
   EXPECT_NEAR(function.Slope(0.05), 0.42170, epsilon);
   EXPECT_NEAR(function.Slope(0.1), 0.69778, epsilon);
   EXPECT_NEAR(function.Slope(0.15), 0.89121, epsilon);
   EXPECT_NEAR(function.Slope(0.2), 1.03184, epsilon);
   EXPECT_NEAR(function.Slope(0.25), 1.13576, epsilon);
   EXPECT_NEAR(function.Slope(0.3), 1.21239, epsilon);
   EXPECT_NEAR(function.Slope(0.35), 1.26751, epsilon);
   EXPECT_NEAR(function.Slope(0.4), 1.30474, epsilon);
   EXPECT_NEAR(function.Slope(0.45), 1.32628, epsilon);
   EXPECT_NEAR(function.Slope(0.5), 1.33333, epsilon);
   EXPECT_NEAR(function.Slope(0.55), 1.32628, epsilon);
   EXPECT_NEAR(function.Slope(0.6), 1.30474, epsilon);
   EXPECT_NEAR(function.Slope(0.65), 1.26751, epsilon);
   EXPECT_NEAR(function.Slope(0.7), 1.21239, epsilon);
   EXPECT_NEAR(function.Slope(0.75), 1.13576, epsilon);
   EXPECT_NEAR(function.Slope(0.8), 1.03184, epsilon);
   EXPECT_NEAR(function.Slope(0.85), 0.89121, epsilon);
   EXPECT_NEAR(function.Slope(0.9), 0.69778, epsilon);
   EXPECT_NEAR(function.Slope(0.95), 0.42170, epsilon);
   EXPECT_NEAR(function.Slope(1), 0, epsilon);
+  EXPECT_NEAR(function.Slope(1.1), 0, epsilon);
 }
 
 TEST(CubicBezierTest, InputOutOfRange) {
   CubicBezier simple(0.5, 1.0, 0.5, 1.0);
   EXPECT_EQ(-2.0, simple.Solve(-1.0));
   EXPECT_EQ(1.0, simple.Solve(2.0));
 
-  CubicBezier coincidentEndpoints(0.0, 0.0, 1.0, 1.0);
-  EXPECT_EQ(-1.0, coincidentEndpoints.Solve(-1.0));
-  EXPECT_EQ(2.0, coincidentEndpoints.Solve(2.0));
+  CubicBezier at_edge_of_range(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(0.0, at_edge_of_range.Solve(0.0));
+  EXPECT_EQ(1.0, at_edge_of_range.Solve(1.0));
 
-  CubicBezier verticalGradient(0.0, 1.0, 1.0, 0.0);
-  EXPECT_EQ(0.0, verticalGradient.Solve(-1.0));
-  EXPECT_EQ(1.0, verticalGradient.Solve(2.0));
+  CubicBezier large_epsilon(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(-2.0, large_epsilon.SolveWithEpsilon(-1.0, 1.0));
+  EXPECT_EQ(1.0, large_epsilon.SolveWithEpsilon(2.0, 1.0));
 
-  CubicBezier distinctEndpoints(0.1, 0.2, 0.8, 0.8);
-  EXPECT_EQ(-2.0, distinctEndpoints.Solve(-1.0));
-  EXPECT_EQ(2.0, distinctEndpoints.Solve(2.0));
+  CubicBezier coincident_endpoints(0.0, 0.0, 1.0, 1.0);
+  EXPECT_EQ(-1.0, coincident_endpoints.Solve(-1.0));
+  EXPECT_EQ(2.0, coincident_endpoints.Solve(2.0));
 
-  CubicBezier coincidentEndpoint(0.0, 0.0, 0.8, 0.8);
-  EXPECT_EQ(-1.0, coincidentEndpoint.Solve(-1.0));
-  EXPECT_EQ(2.0, coincidentEndpoint.Solve(2.0));
+  CubicBezier vertical_gradient(0.0, 1.0, 1.0, 0.0);
+  EXPECT_EQ(0.0, vertical_gradient.Solve(-1.0));
+  EXPECT_EQ(1.0, vertical_gradient.Solve(2.0));
 
-  CubicBezier threeCoincidentPoints(0.0, 0.0, 0.0, 0.0);
-  EXPECT_EQ(0, threeCoincidentPoints.Solve(-1.0));
-  EXPECT_EQ(2.0, threeCoincidentPoints.Solve(2.0));
+  CubicBezier distinct_endpoints(0.1, 0.2, 0.8, 0.8);
+  EXPECT_EQ(-2.0, distinct_endpoints.Solve(-1.0));
+  EXPECT_EQ(2.0, distinct_endpoints.Solve(2.0));
+
+  CubicBezier coincident_endpoint(0.0, 0.0, 0.8, 0.8);
+  EXPECT_EQ(-1.0, coincident_endpoint.Solve(-1.0));
+  EXPECT_EQ(2.0, coincident_endpoint.Solve(2.0));
+
+  CubicBezier three_coincident_points(0.0, 0.0, 0.0, 0.0);
+  EXPECT_EQ(0, three_coincident_points.Solve(-1.0));
+  EXPECT_EQ(2.0, three_coincident_points.Solve(2.0));
 
 }
 
 }  // namespace
 }  // namespace gfx