root/Source/core/svg/SVGPathBlender.cpp

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DEFINITIONS

This source file includes following definitions.
  1. m_isInFirstHalfOfAnimation
  2. blendFloatPoint
  3. blendAnimatedDimensonalFloat
  4. blendAnimatedFloatPoint
  5. blendMoveToSegment
  6. blendLineToSegment
  7. blendLineToHorizontalSegment
  8. blendLineToVerticalSegment
  9. blendCurveToCubicSegment
  10. blendCurveToCubicSmoothSegment
  11. blendCurveToQuadraticSegment
  12. blendCurveToQuadraticSmoothSegment
  13. blendArcToSegment
  14. coordinateModeOfCommand
  15. isSegmentEqual
  16. addAnimatedPath
  17. blendAnimatedPath
  18. cleanup

/*
 * Copyright (C) Research In Motion Limited 2010, 2011. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "core/svg/SVGPathBlender.h"

#include "core/svg/SVGPathSeg.h"
#include "core/svg/SVGPathSource.h"
#include "platform/animation/AnimationUtilities.h"
#include "wtf/TemporaryChange.h"

namespace WebCore {

SVGPathBlender::SVGPathBlender()
    : m_fromSource(0)
    , m_toSource(0)
    , m_consumer(0)
    , m_progress(0)
    , m_addTypesCount(0)
    , m_isInFirstHalfOfAnimation(false)
{
}

// Helper functions
static inline FloatPoint blendFloatPoint(const FloatPoint& a, const FloatPoint& b, float progress)
{
    return FloatPoint(blend(a.x(), b.x(), progress), blend(a.y(), b.y(), progress));
}

float SVGPathBlender::blendAnimatedDimensonalFloat(float from, float to, FloatBlendMode blendMode)
{
    if (m_addTypesCount) {
        ASSERT(m_fromMode == m_toMode);
        return from + to * m_addTypesCount;
    }

    if (m_fromMode == m_toMode)
        return blend(from, to, m_progress);

    float fromValue = blendMode == BlendHorizontal ? m_fromCurrentPoint.x() : m_fromCurrentPoint.y();
    float toValue = blendMode == BlendHorizontal ? m_toCurrentPoint.x() : m_toCurrentPoint.y();

    // Transform toY to the coordinate mode of fromY
    float animValue = blend(from, m_fromMode == AbsoluteCoordinates ? to + toValue : to - toValue, m_progress);

    if (m_isInFirstHalfOfAnimation)
        return animValue;

    // Transform the animated point to the coordinate mode, needed for the current progress.
    float currentValue = blend(fromValue, toValue, m_progress);
    return m_toMode == AbsoluteCoordinates ? animValue + currentValue : animValue - currentValue;
}

FloatPoint SVGPathBlender::blendAnimatedFloatPoint(const FloatPoint& fromPoint, const FloatPoint& toPoint)
{
    if (m_addTypesCount) {
        ASSERT(m_fromMode == m_toMode);
        FloatPoint repeatedToPoint = toPoint;
        repeatedToPoint.scale(m_addTypesCount, m_addTypesCount);
        return fromPoint + repeatedToPoint;
    }

    if (m_fromMode == m_toMode)
        return blendFloatPoint(fromPoint, toPoint, m_progress);

    // Transform toPoint to the coordinate mode of fromPoint
    FloatPoint animatedPoint = toPoint;
    if (m_fromMode == AbsoluteCoordinates)
        animatedPoint += m_toCurrentPoint;
    else
        animatedPoint.move(-m_toCurrentPoint.x(), -m_toCurrentPoint.y());

    animatedPoint = blendFloatPoint(fromPoint, animatedPoint, m_progress);

    if (m_isInFirstHalfOfAnimation)
        return animatedPoint;

    // Transform the animated point to the coordinate mode, needed for the current progress.
    FloatPoint currentPoint = blendFloatPoint(m_fromCurrentPoint, m_toCurrentPoint, m_progress);
    if (m_toMode == AbsoluteCoordinates)
        return animatedPoint + currentPoint;

    animatedPoint.move(-currentPoint.x(), -currentPoint.y());
    return animatedPoint;
}

bool SVGPathBlender::blendMoveToSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint toTargetPoint;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseMoveToSegment(fromTargetPoint))
        || !m_toSource->parseMoveToSegment(toTargetPoint))
        return false;

    m_consumer->moveTo(blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint), false, m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendLineToSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint toTargetPoint;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseLineToSegment(fromTargetPoint))
        || !m_toSource->parseLineToSegment(toTargetPoint))
        return false;

    m_consumer->lineTo(blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint), m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendLineToHorizontalSegment()
{
    float fromX = 0;
    float toX = 0;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseLineToHorizontalSegment(fromX))
        || !m_toSource->parseLineToHorizontalSegment(toX))
        return false;

    m_consumer->lineToHorizontal(blendAnimatedDimensonalFloat(fromX, toX, BlendHorizontal), m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint.setX(m_fromMode == AbsoluteCoordinates ? fromX : m_fromCurrentPoint.x() + fromX);
    m_toCurrentPoint.setX(m_toMode == AbsoluteCoordinates ? toX : m_toCurrentPoint.x() + toX);
    return true;
}

bool SVGPathBlender::blendLineToVerticalSegment()
{
    float fromY = 0;
    float toY = 0;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseLineToVerticalSegment(fromY))
        || !m_toSource->parseLineToVerticalSegment(toY))
        return false;

    m_consumer->lineToVertical(blendAnimatedDimensonalFloat(fromY, toY, BlendVertical), m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint.setY(m_fromMode == AbsoluteCoordinates ? fromY : m_fromCurrentPoint.y() + fromY);
    m_toCurrentPoint.setY(m_toMode == AbsoluteCoordinates ? toY : m_toCurrentPoint.y() + toY);
    return true;
}

bool SVGPathBlender::blendCurveToCubicSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint fromPoint1;
    FloatPoint fromPoint2;
    FloatPoint toTargetPoint;
    FloatPoint toPoint1;
    FloatPoint toPoint2;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseCurveToCubicSegment(fromPoint1, fromPoint2, fromTargetPoint))
        || !m_toSource->parseCurveToCubicSegment(toPoint1, toPoint2, toTargetPoint))
        return false;

    m_consumer->curveToCubic(blendAnimatedFloatPoint(fromPoint1, toPoint1),
                             blendAnimatedFloatPoint(fromPoint2, toPoint2),
                             blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint),
                             m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendCurveToCubicSmoothSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint fromPoint2;
    FloatPoint toTargetPoint;
    FloatPoint toPoint2;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseCurveToCubicSmoothSegment(fromPoint2, fromTargetPoint))
        || !m_toSource->parseCurveToCubicSmoothSegment(toPoint2, toTargetPoint))
        return false;

    m_consumer->curveToCubicSmooth(blendAnimatedFloatPoint(fromPoint2, toPoint2),
                                   blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint),
                                   m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendCurveToQuadraticSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint fromPoint1;
    FloatPoint toTargetPoint;
    FloatPoint toPoint1;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseCurveToQuadraticSegment(fromPoint1, fromTargetPoint))
        || !m_toSource->parseCurveToQuadraticSegment(toPoint1, toTargetPoint))
        return false;

    m_consumer->curveToQuadratic(blendAnimatedFloatPoint(fromPoint1, toPoint1),
                                 blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint),
                                 m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendCurveToQuadraticSmoothSegment()
{
    FloatPoint fromTargetPoint;
    FloatPoint toTargetPoint;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseCurveToQuadraticSmoothSegment(fromTargetPoint))
        || !m_toSource->parseCurveToQuadraticSmoothSegment(toTargetPoint))
        return false;

    m_consumer->curveToQuadraticSmooth(blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint), m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

bool SVGPathBlender::blendArcToSegment()
{
    float fromRx = 0;
    float fromRy = 0;
    float fromAngle = 0;
    bool fromLargeArc = false;
    bool fromSweep = false;
    FloatPoint fromTargetPoint;
    float toRx = 0;
    float toRy = 0;
    float toAngle = 0;
    bool toLargeArc = false;
    bool toSweep = false;
    FloatPoint toTargetPoint;
    if ((m_fromSource->hasMoreData() && !m_fromSource->parseArcToSegment(fromRx, fromRy, fromAngle, fromLargeArc, fromSweep, fromTargetPoint))
        || !m_toSource->parseArcToSegment(toRx, toRy, toAngle, toLargeArc, toSweep, toTargetPoint))
        return false;

    if (m_addTypesCount) {
        ASSERT(m_fromMode == m_toMode);
        FloatPoint scaledToTargetPoint = toTargetPoint;
        scaledToTargetPoint.scale(m_addTypesCount, m_addTypesCount);
        m_consumer->arcTo(fromRx + toRx * m_addTypesCount,
                          fromRy + toRy * m_addTypesCount,
                          fromAngle + toAngle * m_addTypesCount,
                          fromLargeArc || toLargeArc,
                          fromSweep || toSweep,
                          fromTargetPoint + scaledToTargetPoint,
                          m_fromMode);
    } else {
        m_consumer->arcTo(blend(fromRx, toRx, m_progress),
                          blend(fromRy, toRy, m_progress),
                          blend(fromAngle, toAngle, m_progress),
                          m_isInFirstHalfOfAnimation ? fromLargeArc : toLargeArc,
                          m_isInFirstHalfOfAnimation ? fromSweep : toSweep,
                          blendAnimatedFloatPoint(fromTargetPoint, toTargetPoint),
                          m_isInFirstHalfOfAnimation ? m_fromMode : m_toMode);
    }
    m_fromCurrentPoint = m_fromMode == AbsoluteCoordinates ? fromTargetPoint : m_fromCurrentPoint + fromTargetPoint;
    m_toCurrentPoint = m_toMode == AbsoluteCoordinates ? toTargetPoint : m_toCurrentPoint + toTargetPoint;
    return true;
}

static inline PathCoordinateMode coordinateModeOfCommand(const SVGPathSegType& type)
{
    if (type < PathSegMoveToAbs)
        return AbsoluteCoordinates;

    // Odd number = relative command
    if (type % 2)
        return RelativeCoordinates;

    return AbsoluteCoordinates;
}

static inline bool isSegmentEqual(const SVGPathSegType& fromType, const SVGPathSegType& toType, const PathCoordinateMode& fromMode, const PathCoordinateMode& toMode)
{
    if (fromType == toType && (fromType == PathSegUnknown || fromType == PathSegClosePath))
        return true;

    unsigned short from = fromType;
    unsigned short to = toType;
    if (fromMode == toMode)
        return from == to;
    if (fromMode == AbsoluteCoordinates)
        return from == to - 1;
    return to == from - 1;
}

bool SVGPathBlender::addAnimatedPath(SVGPathSource* fromSource, SVGPathSource* toSource, SVGPathConsumer* consumer, unsigned repeatCount)
{
    TemporaryChange<unsigned> change(m_addTypesCount, repeatCount);
    return blendAnimatedPath(0, fromSource, toSource, consumer);
}

bool SVGPathBlender::blendAnimatedPath(float progress, SVGPathSource* fromSource, SVGPathSource* toSource, SVGPathConsumer* consumer)
{
    ASSERT(fromSource);
    ASSERT(toSource);
    ASSERT(consumer);
    m_fromSource = fromSource;
    m_toSource = toSource;
    m_consumer = consumer;
    m_isInFirstHalfOfAnimation = progress < 0.5f;
    m_progress = progress;

    bool fromSourceHadData = m_fromSource->hasMoreData();
    while (m_toSource->hasMoreData()) {
        SVGPathSegType fromCommand;
        SVGPathSegType toCommand;
        if ((fromSourceHadData && !m_fromSource->parseSVGSegmentType(fromCommand)) || !m_toSource->parseSVGSegmentType(toCommand))
            return false;

        m_toMode = coordinateModeOfCommand(toCommand);
        m_fromMode = fromSourceHadData ? coordinateModeOfCommand(fromCommand) : m_toMode;
        if (m_fromMode != m_toMode && m_addTypesCount)
            return false;

        if (fromSourceHadData && !isSegmentEqual(fromCommand, toCommand, m_fromMode, m_toMode))
            return false;

        switch (toCommand) {
        case PathSegMoveToRel:
        case PathSegMoveToAbs:
            if (!blendMoveToSegment())
                return false;
            break;
        case PathSegLineToRel:
        case PathSegLineToAbs:
            if (!blendLineToSegment())
                return false;
            break;
        case PathSegLineToHorizontalRel:
        case PathSegLineToHorizontalAbs:
            if (!blendLineToHorizontalSegment())
                return false;
            break;
        case PathSegLineToVerticalRel:
        case PathSegLineToVerticalAbs:
            if (!blendLineToVerticalSegment())
                return false;
            break;
        case PathSegClosePath:
            m_consumer->closePath();
            break;
        case PathSegCurveToCubicRel:
        case PathSegCurveToCubicAbs:
            if (!blendCurveToCubicSegment())
                return false;
            break;
        case PathSegCurveToCubicSmoothRel:
        case PathSegCurveToCubicSmoothAbs:
            if (!blendCurveToCubicSmoothSegment())
                return false;
            break;
        case PathSegCurveToQuadraticRel:
        case PathSegCurveToQuadraticAbs:
            if (!blendCurveToQuadraticSegment())
                return false;
            break;
        case PathSegCurveToQuadraticSmoothRel:
        case PathSegCurveToQuadraticSmoothAbs:
            if (!blendCurveToQuadraticSmoothSegment())
                return false;
            break;
        case PathSegArcRel:
        case PathSegArcAbs:
            if (!blendArcToSegment())
                return false;
            break;
        case PathSegUnknown:
            return false;
        }

        if (!fromSourceHadData)
            continue;
        if (m_fromSource->hasMoreData() != m_toSource->hasMoreData())
            return false;
        if (!m_fromSource->hasMoreData() || !m_toSource->hasMoreData())
            return true;
    }

    return true;
}

void SVGPathBlender::cleanup()
{
    ASSERT(m_toSource);
    ASSERT(m_fromSource);
    ASSERT(m_consumer);

    m_consumer->cleanup();
    m_toSource = 0;
    m_fromSource = 0;
    m_consumer = 0;
    m_fromCurrentPoint = FloatPoint();
    m_toCurrentPoint = FloatPoint();
}

}

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