root/Source/core/animation/KeyframeEffectModel.cpp

DEFINITIONS

1. compareOffsets
2. properties
3. sample
4. normalizedKeyframes
5. ensureKeyframeGroups
6. ensureInterpolationEffect
7. isReplaceOnly
8. trace
9. m_composite
10. appendKeyframe
11. removeRedundantKeyframes
12. addSyntheticKeyframeIfRequired
13. trace

/*
 * 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
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 * 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
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#include "config.h"
#include "core/animation/KeyframeEffectModel.h"

#include "core/animation/TimedItem.h"
#include "wtf/text/StringHash.h"

namespace WebCore {

bool Keyframe::compareOffsets(const RefPtrWillBeMember<Keyframe>& a, const RefPtrWillBeMember<Keyframe>& b)
{
    return a->offset() < b->offset();
}

PropertySet KeyframeEffectModelBase::properties() const
{
    PropertySet result;
    if (!m_keyframes.size()) {
        return result;
    }
    result = m_keyframes[0]->properties();
    for (size_t i = 1; i < m_keyframes.size(); i++) {
        PropertySet extras = m_keyframes[i]->properties();
        for (PropertySet::const_iterator it = extras.begin(); it != extras.end(); ++it) {
            result.add(*it);
        }
    }
    return result;
}

PassOwnPtrWillBeRawPtr<WillBeHeapVector<RefPtrWillBeMember<Interpolation> > > KeyframeEffectModelBase::sample(int iteration, double fraction, double iterationDuration) const
{
    ASSERT(iteration >= 0);
    ASSERT(!isNull(fraction));
    ensureKeyframeGroups();
    ensureInterpolationEffect();

    return m_interpolationEffect->getActiveInterpolations(fraction, iterationDuration);
}

KeyframeEffectModelBase::KeyframeVector KeyframeEffectModelBase::normalizedKeyframes(const KeyframeVector& keyframes)
{
    // keyframes [beginIndex, endIndex) will remain after removing all keyframes if they are not
    // loosely sorted by offset, and after removing keyframes with positional offset outide [0, 1].
    size_t beginIndex = 0;
    size_t endIndex = keyframes.size();

    // Becomes the most recent keyframe with an explicit offset.
    size_t lastIndex = endIndex;
    double lastOffset = std::numeric_limits<double>::quiet_NaN();

    for (size_t i = 0; i < keyframes.size(); ++i) {
        double offset = keyframes[i]->offset();
        if (!isNull(offset)) {
            if (lastIndex < i && offset < lastOffset) {
                // The keyframes are not loosely sorted by offset. Exclude all.
                endIndex = beginIndex;
                break;
            }

            if (offset < 0) {
                // Remove all keyframes up to and including this keyframe.
                beginIndex = i + 1;
            } else if (offset > 1) {
                // Remove all keyframes from this keyframe onwards. Note we must complete our checking
                // that the keyframes are loosely sorted by offset, so we can't exit the loop early.
                endIndex = std::min(i, endIndex);
            }

            lastIndex = i;
            lastOffset = offset;
        }
    }

    KeyframeVector result;
    if (beginIndex != endIndex) {
        result.reserveCapacity(endIndex - beginIndex);
        for (size_t i = beginIndex; i < endIndex; ++i) {
            result.append(keyframes[i]->clone());
        }

        if (isNull(result[result.size() - 1]->offset()))
            result[result.size() - 1]->setOffset(1);

        if (result.size() > 1 && isNull(result[0]->offset()))
            result[0]->setOffset(0);

        lastIndex = 0;
        lastOffset = result[0]->offset();
        for (size_t i = 1; i < result.size(); ++i) {
            double offset = result[i]->offset();
            if (!isNull(offset)) {
                if (lastIndex + 1 < i) {
                    for (size_t j = 1; j < i - lastIndex; ++j)
                        result[lastIndex + j]->setOffset(lastOffset + (offset - lastOffset) * j / (i - lastIndex));
                }
                lastIndex = i;
                lastOffset = offset;
            }
        }
    }
    return result;
}


void KeyframeEffectModelBase::ensureKeyframeGroups() const
{
    if (m_keyframeGroups)
        return;

    m_keyframeGroups = adoptPtrWillBeNoop(new KeyframeGroupMap);
    const KeyframeVector keyframes = normalizedKeyframes(getFrames());
    for (KeyframeVector::const_iterator keyframeIter = keyframes.begin(); keyframeIter != keyframes.end(); ++keyframeIter) {
        const Keyframe* keyframe = keyframeIter->get();
        PropertySet keyframeProperties = keyframe->properties();
        for (PropertySet::const_iterator propertyIter = keyframeProperties.begin(); propertyIter != keyframeProperties.end(); ++propertyIter) {
            CSSPropertyID property = *propertyIter;
            KeyframeGroupMap::iterator groupIter = m_keyframeGroups->find(property);
            PropertySpecificKeyframeGroup* group;
            if (groupIter == m_keyframeGroups->end())
                group = m_keyframeGroups->add(property, adoptPtrWillBeNoop(new PropertySpecificKeyframeGroup)).storedValue->value.get();
            else
                group = groupIter->value.get();

            ASSERT(keyframe->composite() == AnimationEffect::CompositeReplace);
            group->appendKeyframe(keyframe->createPropertySpecificKeyframe(property));
        }
    }

    // Add synthetic keyframes.
    for (KeyframeGroupMap::iterator iter = m_keyframeGroups->begin(); iter != m_keyframeGroups->end(); ++iter) {
        iter->value->addSyntheticKeyframeIfRequired(this);
        iter->value->removeRedundantKeyframes();
    }
}

void KeyframeEffectModelBase::ensureInterpolationEffect() const
{
    if (m_interpolationEffect)
        return;
    m_interpolationEffect = InterpolationEffect::create();

    for (KeyframeGroupMap::const_iterator iter = m_keyframeGroups->begin(); iter != m_keyframeGroups->end(); ++iter) {
        const PropertySpecificKeyframeVector& keyframes = iter->value->keyframes();
        ASSERT(keyframes[0]->composite() == AnimationEffect::CompositeReplace);
        for (size_t i = 0; i < keyframes.size() - 1; i++) {
            ASSERT(keyframes[i + 1]->composite() == AnimationEffect::CompositeReplace);
            double applyFrom = i ? keyframes[i]->offset() : (-std::numeric_limits<double>::infinity());
            double applyTo = i == keyframes.size() - 2 ? std::numeric_limits<double>::infinity() : keyframes[i + 1]->offset();
            if (applyTo == 1)
                applyTo = std::numeric_limits<double>::infinity();

            m_interpolationEffect->addInterpolation(keyframes[i]->createInterpolation(iter->key, keyframes[i + 1].get()),
                keyframes[i]->easing(), keyframes[i]->offset(), keyframes[i + 1]->offset(), applyFrom, applyTo);
        }
    }
}

bool KeyframeEffectModelBase::isReplaceOnly()
{
    ensureKeyframeGroups();
    for (KeyframeGroupMap::iterator iter = m_keyframeGroups->begin(); iter != m_keyframeGroups->end(); ++iter) {
        const PropertySpecificKeyframeVector& keyframeVector = iter->value->keyframes();
        for (size_t i = 0; i < keyframeVector.size(); ++i) {
            if (keyframeVector[i]->composite() != AnimationEffect::CompositeReplace)
                return false;
        }
    }
    return true;
}

void KeyframeEffectModelBase::trace(Visitor* visitor)
{
    visitor->trace(m_keyframes);
    visitor->trace(m_interpolationEffect);
#if ENABLE_OILPAN
    visitor->trace(m_keyframeGroups);
#endif
}

Keyframe::PropertySpecificKeyframe::PropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, AnimationEffect::CompositeOperation composite)
    : m_offset(offset)
    , m_easing(easing)
    , m_composite(composite)
{
}

void KeyframeEffectModelBase::PropertySpecificKeyframeGroup::appendKeyframe(PassOwnPtrWillBeRawPtr<Keyframe::PropertySpecificKeyframe> keyframe)
{
    ASSERT(m_keyframes.isEmpty() || m_keyframes.last()->offset() <= keyframe->offset());
    m_keyframes.append(keyframe);
}

void KeyframeEffectModelBase::PropertySpecificKeyframeGroup::removeRedundantKeyframes()
{
    // As an optimization, removes keyframes in the following categories, as
    // they will never be used by sample().
    // - End keyframes with the same offset as their neighbor
    // - Interior keyframes with the same offset as both their neighbors
    // Note that synthetic keyframes must be added before this method is
    // called.
    ASSERT(m_keyframes.size() >= 2);
    for (int i = m_keyframes.size() - 1; i >= 0; --i) {
        double offset = m_keyframes[i]->offset();
        bool hasSameOffsetAsPreviousNeighbor = !i || m_keyframes[i - 1]->offset() == offset;
        bool hasSameOffsetAsNextNeighbor = i == static_cast<int>(m_keyframes.size() - 1) || m_keyframes[i + 1]->offset() == offset;
        if (hasSameOffsetAsPreviousNeighbor && hasSameOffsetAsNextNeighbor)
            m_keyframes.remove(i);
    }
    ASSERT(m_keyframes.size() >= 2);
}

void KeyframeEffectModelBase::PropertySpecificKeyframeGroup::addSyntheticKeyframeIfRequired(const KeyframeEffectModelBase* context)
{
    ASSERT(!m_keyframes.isEmpty());
    if (m_keyframes.first()->offset() != 0.0)
        m_keyframes.insert(0, m_keyframes.first()->neutralKeyframe(0, nullptr));
    if (m_keyframes.last()->offset() != 1.0)
        appendKeyframe(m_keyframes.last()->neutralKeyframe(1, nullptr));
}

void KeyframeEffectModelBase::PropertySpecificKeyframeGroup::trace(Visitor* visitor)
{
#if ENABLE(OILPAN)
    visitor->trace(m_keyframes);
#endif
}

} // namespace