text: /*
   * Copyright (C) 2013 Google Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * 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,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "core/animation/animatable/AnimatableRepeatable.h"
  
  #include "wtf/MathExtras.h"
  
  namespace blink {
  
  bool AnimatableRepeatable::usesDefaultInterpolationWith(
      const AnimatableValue* value) const {
    const Vector<RefPtr<AnimatableValue>>& fromValues = m_values;
    const Vector<RefPtr<AnimatableValue>>& toValues =
        toAnimatableRepeatable(value)->m_values;
    DCHECK(!fromValues.isEmpty() && !toValues.isEmpty());
    size_t size = lowestCommonMultiple(fromValues.size(), toValues.size());
    DCHECK_GT(size, 0U);
    for (size_t i = 0; i < size; ++i) {
      const AnimatableValue* from = fromValues[i % fromValues.size()].get();
      const AnimatableValue* to = toValues[i % toValues.size()].get();
      // Spec: If a pair of values cannot be interpolated, then the lists are not
      // interpolable.
      if (AnimatableValue::usesDefaultInterpolation(from, to))
        return true;
    }
    return false;
  }
  
  bool AnimatableRepeatable::interpolateLists(
      const Vector<RefPtr<AnimatableValue>>& fromValues,
      const Vector<RefPtr<AnimatableValue>>& toValues,
      double fraction,
      Vector<RefPtr<AnimatableValue>>& interpolatedValues) {
    // Interpolation behaviour spec:
    // http://www.w3.org/TR/css3-transitions/#animtype-repeatable-list
    DCHECK(interpolatedValues.isEmpty());
    DCHECK(!fromValues.isEmpty() && !toValues.isEmpty());
    size_t size = lowestCommonMultiple(fromValues.size(), toValues.size());
    DCHECK_GT(size, 0U);
    for (size_t i = 0; i < size; ++i) {
      const AnimatableValue* from = fromValues[i % fromValues.size()].get();
      const AnimatableValue* to = toValues[i % toValues.size()].get();
      // Spec: If a pair of values cannot be interpolated, then the lists are not
      // interpolable.
      if (AnimatableValue::usesDefaultInterpolation(from, to))
        return false;
      interpolatedValues.push_back(interpolate(from, to, fraction));
    }
    return true;
  }
  
  PassRefPtr<AnimatableValue> AnimatableRepeatable::interpolateTo(
      const AnimatableValue* value,
      double fraction) const {
    Vector<RefPtr<AnimatableValue>> interpolatedValues;
    bool success =
        interpolateLists(m_values, toAnimatableRepeatable(value)->m_values,
                         fraction, interpolatedValues);
    if (success)
      return create(interpolatedValues);
    return defaultInterpolateTo(this, value, fraction);
  }
  
  bool AnimatableRepeatable::equalTo(const AnimatableValue* value) const {
    const Vector<RefPtr<AnimatableValue>>& otherValues =
        toAnimatableRepeatable(value)->m_values;
    if (m_values.size() != otherValues.size())
      return false;
    for (size_t i = 0; i < m_values.size(); ++i) {
      if (!m_values[i]->equals(otherValues[i].get()))
        return false;
    }
    return true;
  }
  
  }  // namespace blink
  