/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include "sky/engine/core/animation/animatable/AnimatableValue.h"

#include <algorithm>
#include "sky/engine/core/animation/animatable/AnimatableNeutral.h"
#include "sky/engine/wtf/StdLibExtras.h"

namespace {

const double defaultDistance = 1;

} // namespace

namespace blink {

const AnimatableValue* AnimatableValue::neutralValue()
{
    DEFINE_STATIC_REF_WILL_BE_PERSISTENT(AnimatableNeutral, neutralSentinelValue, (AnimatableNeutral::create()));
    return neutralSentinelValue;
}

PassRefPtr<AnimatableValue> AnimatableValue::interpolate(const AnimatableValue* left, const AnimatableValue* right, double fraction)
{
    ASSERT(left);
    ASSERT(right);
    ASSERT(!left->isNeutral());
    ASSERT(!right->isNeutral());

    if (fraction && fraction != 1 && left->isSameType(right))
        return left->interpolateTo(right, fraction);

    return defaultInterpolateTo(left, right, fraction);
}

double AnimatableValue::distance(const AnimatableValue* left, const AnimatableValue* right)
{
    ASSERT(left);
    ASSERT(right);

    if (left->isSameType(right))
        return left->distanceTo(right);

    return defaultDistance;
}

double AnimatableValue::distanceTo(const AnimatableValue*) const
{
    return defaultDistance;
}

} // namespace blink