| // Copyright (c) 2010 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 "app/tween.h" |
| |
| #include <math.h> |
| |
| #if defined(OS_WIN) |
| #include <float.h> |
| #endif |
| |
| #include "base/logging.h" |
| #include "gfx/rect.h" |
| |
| // static |
| double Tween::CalculateValue(Tween::Type type, double state) { |
| DCHECK_GE(state, 0); |
| DCHECK_LE(state, 1); |
| |
| switch (type) { |
| case EASE_IN: |
| return pow(state, 2); |
| |
| case EASE_IN_OUT: |
| if (state < 0.5) |
| return pow(state * 2, 2) / 2.0; |
| return 1.0 - (pow((state - 1.0) * 2, 2) / 2.0); |
| |
| case FAST_IN_OUT: |
| return (pow(state - 0.5, 3) + 0.125) / 0.25; |
| |
| case LINEAR: |
| return state; |
| |
| case EASE_OUT_SNAP: |
| state = 0.95 * (1.0 - pow(1.0 - state, 2)); |
| break; |
| |
| case EASE_OUT: |
| return 1.0 - pow(1.0 - state, 2); |
| |
| case ZERO: |
| return 0; |
| } |
| |
| NOTREACHED(); |
| return state; |
| } |
| |
| // static |
| double Tween::ValueBetween(double value, double start, double target) { |
| return start + (target - start) * value; |
| } |
| |
| // static |
| int Tween::ValueBetween(double value, int start, int target) { |
| if (start == target) |
| return start; |
| double delta = static_cast<double>(target - start); |
| if (delta < 0) |
| delta--; |
| else |
| delta++; |
| #if defined(OS_WIN) |
| return start + static_cast<int>(value * _nextafter(delta, 0)); |
| #else |
| return start + static_cast<int>(value * nextafter(delta, 0)); |
| #endif |
| } |
| |
| // static |
| gfx::Rect Tween::ValueBetween(double value, |
| const gfx::Rect& start_bounds, |
| const gfx::Rect& target_bounds) { |
| return gfx::Rect(ValueBetween(value, start_bounds.x(), target_bounds.x()), |
| ValueBetween(value, start_bounds.y(), target_bounds.y()), |
| ValueBetween(value, start_bounds.width(), |
| target_bounds.width()), |
| ValueBetween(value, start_bounds.height(), |
| target_bounds.height())); |
| } |