Define accelerated steps time function.

ui/gfx/geometry/steps_unittest.cc

+// Copyright 2014 Samsung. 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/steps.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gfx {
+namespace {
+
+TEST(StepsTest, Basic) {
+  Steps function(36, false);
+
+  EXPECT_DOUBLE_EQ(function.Solve(0), 1.0);

[ajuma, 2014/02/24 21:11:16]

Shouldn't this be 0.0?

+  EXPECT_DOUBLE_EQ(function.Solve(0.05), 0.01136);
+  EXPECT_DOUBLE_EQ(function.Solve(0.1), 0.03978);
+  EXPECT_DOUBLE_EQ(function.Solve(0.15), 0.079780);
+  EXPECT_DOUBLE_EQ(function.Solve(0.2), 0.12803);
+  EXPECT_DOUBLE_EQ(function.Solve(0.25), 0.18235);
+  EXPECT_DOUBLE_EQ(function.Solve(0.3), 0.24115);
+  EXPECT_DOUBLE_EQ(function.Solve(0.35), 0.30323);
+  EXPECT_DOUBLE_EQ(function.Solve(0.4), 0.36761);
+  EXPECT_DOUBLE_EQ(function.Solve(0.45), 0.43345);
+  EXPECT_DOUBLE_EQ(function.Solve(0.5), 0.5);
+  EXPECT_DOUBLE_EQ(function.Solve(0.6), 0.63238);
+  EXPECT_DOUBLE_EQ(function.Solve(0.65), 0.69676);
+  EXPECT_DOUBLE_EQ(function.Solve(0.7), 0.75884);
+  EXPECT_DOUBLE_EQ(function.Solve(0.75), 0.81764);

[ajuma, 2014/02/24 21:11:16]

Shouldn't this be 0.75, not 0.81764?

+  EXPECT_DOUBLE_EQ(function.Solve(0.8), 0.87196);
+  EXPECT_DOUBLE_EQ(function.Solve(0.85), 0.92021);
+  EXPECT_DOUBLE_EQ(function.Solve(0.9), 0.96021);
+  EXPECT_DOUBLE_EQ(function.Solve(0.95), 0.98863);
+  EXPECT_DOUBLE_EQ(function.Solve(1), 1);
+}
+
+TEST(TimingFunctionTest, StepsTimingFunctionStepsAtStart) {
+  Steps function(36, true);
+
+  EXPECT_DOUBLE_EQ(function.Solve(0), 1.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.05), 2.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.1), 4.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.15), 6.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.2), 8.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.25), 10.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.3), 11.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.35), 13.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.4), 15.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.45), 17.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.5), 19.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.6), 22.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.65), 24.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.7), 26.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.75), 28.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.8), 29.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.85), 31.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.9), 33.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(0.95), 35.0/36.0);
+  EXPECT_DOUBLE_EQ(function.Solve(1), 1);
+}
+
+TEST(TimingFunctionTest, StepsTimingFunctionRange) {
+  double min, max;
+
+  Steps function1(36, false);
+
+  function1.Range(&min, &max);
+  EXPECT_DOUBLE_EQ(0.0, min);
+  EXPECT_DOUBLE_EQ(1.0, max);
+
+  Steps function2(36, true);
+  function2.Range(&min, &max);
+  EXPECT_DOUBLE_EQ(min, 1.0/36.0);
+  EXPECT_DOUBLE_EQ(1.0, max);
+}
+
+}  // namespace
+}  // namespace gfx