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#include "context2d.h"

#include <QVariant>

#include <math.h>

static const double Q_PI   = 3.14159265358979323846;   // pi

#define DEGREES(t) ((t) * 180.0 / Q_PI)

#define qClamp(val, min, max) qMin(qMax(val, min), max)

static QList<qreal> parseNumbersList(QString::const_iterator &itr)

{

    QList<qreal> points;

    QString temp;

    while ((*itr).isSpace())

        ++itr;

    while ((*itr).isNumber() ||

           (*itr) == '-' || (*itr) == '+' || (*itr) == '.') {

        temp = QString();

        if ((*itr) == '-')

            temp += *itr++;

        else if ((*itr) == '+')

            temp += *itr++;

        while ((*itr).isDigit())

            temp += *itr++;

        if ((*itr) == '.')

            temp += *itr++;

        while ((*itr).isDigit())

            temp += *itr++;

        while ((*itr).isSpace())

            ++itr;

        if ((*itr) == ',')

            ++itr;

        points.append(temp.toDouble());

        //eat spaces

        while ((*itr).isSpace())

            ++itr;

    }

    return points;

}

QColor colorFromString(const QString &name)

{

    QString::const_iterator itr = name.constBegin();

    QList<qreal> compo;

    if (name.startsWith("rgba(")) {

        ++itr; ++itr; ++itr; ++itr; ++itr;

        compo = parseNumbersList(itr);

        if (compo.size() != 4) {

            return QColor();

        }

        //alpha seems to be always between 0-1

        compo[3] *= 255;

        return QColor((int)compo[0], (int)compo[1],

                      (int)compo[2], (int)compo[3]);

    } else if (name.startsWith("rgb(")) {

        ++itr; ++itr; ++itr; ++itr;

        compo = parseNumbersList(itr);

        if (compo.size() != 3) {

            return QColor();

        }

        return QColor((int)qClamp(compo[0], qreal(0), qreal(255)),

                      (int)qClamp(compo[1], qreal(0), qreal(255)),

                      (int)qClamp(compo[2], qreal(0), qreal(255)));

    } else {

        //QRgb color;

        //CSSParser::parseColor(name, color);

        return QColor(name);

    }

}

static QPainter::CompositionMode compositeOperatorFromString(const QString &compositeOperator)

{

    if ( compositeOperator == "source-over" ) {

        return QPainter::CompositionMode_SourceOver;

    } else if ( compositeOperator == "source-out" ) {

        return QPainter::CompositionMode_SourceOut;

    } else if ( compositeOperator == "source-in" ) {

        return QPainter::CompositionMode_SourceIn;

    } else if ( compositeOperator == "source-atop" ) {

        return QPainter::CompositionMode_SourceAtop;

    } else if ( compositeOperator == "destination-atop" ) {

        return QPainter::CompositionMode_DestinationAtop;

    } else if ( compositeOperator == "destination-in" ) {

        return QPainter::CompositionMode_DestinationIn;

    } else if ( compositeOperator == "destination-out" ) {

        return QPainter::CompositionMode_DestinationOut;

    } else if ( compositeOperator == "destination-over" ) {

        return QPainter::CompositionMode_DestinationOver;

    } else if ( compositeOperator == "darker" ) {

        return QPainter::CompositionMode_SourceOver;

    } else if ( compositeOperator == "lighter" ) {

        return QPainter::CompositionMode_SourceOver;

    } else if ( compositeOperator == "copy" ) {

        return QPainter::CompositionMode_Source;

    } else if ( compositeOperator == "xor" ) {

        return QPainter::CompositionMode_Xor;

    }

    return QPainter::CompositionMode_SourceOver;

}

static QString compositeOperatorToString(QPainter::CompositionMode op)

{

    switch (op) {

    case QPainter::CompositionMode_SourceOver:

        return "source-over";

    case QPainter::CompositionMode_DestinationOver:

        return "destination-over";

    case QPainter::CompositionMode_Clear:

        return "clear";

    case QPainter::CompositionMode_Source:

        return "source";

    case QPainter::CompositionMode_Destination:

        return "destination";

    case QPainter::CompositionMode_SourceIn:

        return "source-in";

    case QPainter::CompositionMode_DestinationIn:

        return "destination-in";

    case QPainter::CompositionMode_SourceOut:

        return "source-out";

    case QPainter::CompositionMode_DestinationOut:

        return "destination-out";

    case QPainter::CompositionMode_SourceAtop:

        return "source-atop";

    case QPainter::CompositionMode_DestinationAtop:

        return "destination-atop";

    case QPainter::CompositionMode_Xor:

        return "xor";

    case QPainter::CompositionMode_Plus:

        return "plus";

    case QPainter::CompositionMode_Multiply:

        return "multiply";

    case QPainter::CompositionMode_Screen:

        return "screen";

    case QPainter::CompositionMode_Overlay:

        return "overlay";

    case QPainter::CompositionMode_Darken:

        return "darken";

    case QPainter::CompositionMode_Lighten:

        return "lighten";

    case QPainter::CompositionMode_ColorDodge:

        return "color-dodge";

    case QPainter::CompositionMode_ColorBurn:

        return "color-burn";

    case QPainter::CompositionMode_HardLight:

        return "hard-light";

    case QPainter::CompositionMode_SoftLight:

        return "soft-light";

    case QPainter::CompositionMode_Difference:

        return "difference";

    case QPainter::CompositionMode_Exclusion:

        return "exclusion";

    default:

        break;

    }

    return QString();

}

void Context2D::save()

{

    m_stateStack.push(m_state);

}

void Context2D::restore()

{

    if (!m_stateStack.isEmpty()) {

        m_state = m_stateStack.pop();

        m_state.flags = AllIsFullOfDirt;

    }

}

void Context2D::scale(qreal x, qreal y)

{

    m_state.matrix.scale(x, y);

    m_state.flags |= DirtyTransformationMatrix;

}

void Context2D::rotate(qreal angle)

{

    m_state.matrix.rotate(DEGREES(angle));

    m_state.flags |= DirtyTransformationMatrix;

}

void Context2D::translate(qreal x, qreal y)

{

    m_state.matrix.translate(x, y);

    m_state.flags |= DirtyTransformationMatrix;

}

void Context2D::transform(qreal m11, qreal m12, qreal m21, qreal m22,

                          qreal dx, qreal dy)

{

    QMatrix mat(m11, m12,

                m21, m22,

                dx, dy);

    m_state.matrix *= mat;

    m_state.flags |= DirtyTransformationMatrix;

}

void Context2D::setTransform(qreal m11, qreal m12, qreal m21, qreal m22,

                             qreal dx, qreal dy)

{

    QMatrix mat(m11, m12,

                m21, m22,

                dx, dy);

    m_state.matrix = mat;

    m_state.flags |= DirtyTransformationMatrix;

}

QString Context2D::globalCompositeOperation() const

{

    return compositeOperatorToString(m_state.globalCompositeOperation);

}

void Context2D::setGlobalCompositeOperation(const QString &op)

{

    QPainter::CompositionMode mode =

        compositeOperatorFromString(op);

    m_state.globalCompositeOperation = mode;

    m_state.flags |= DirtyGlobalCompositeOperation;

}

QVariant Context2D::strokeStyle() const

{

    return m_state.strokeStyle;

}

void Context2D::setStrokeStyle(const QVariant &style)

{

    if (qVariantCanConvert<CanvasGradient>(style)) {

        CanvasGradient cg = qvariant_cast<CanvasGradient>(style);

        m_state.strokeStyle = cg.value;

    } else {

        QColor color = colorFromString(style.toString());

        m_state.strokeStyle = color;

    }

    m_state.flags |= DirtyStrokeStyle;

}

QVariant Context2D::fillStyle() const

{

    return m_state.fillStyle;

}

//! [3]

void Context2D::setFillStyle(const QVariant &style)

{

    if (qVariantCanConvert<CanvasGradient>(style)) {

        CanvasGradient cg = qvariant_cast<CanvasGradient>(style);

        m_state.fillStyle = cg.value;

    } else {

        QColor color = colorFromString(style.toString());

        m_state.fillStyle = color;

    }

    m_state.flags |= DirtyFillStyle;

}

//! [3]

qreal Context2D::globalAlpha() const

{

    return m_state.globalAlpha;

}

void Context2D::setGlobalAlpha(qreal alpha)

{

    m_state.globalAlpha = alpha;

    m_state.flags |= DirtyGlobalAlpha;

}

CanvasGradient Context2D::createLinearGradient(qreal x0, qreal y0,

                                               qreal x1, qreal y1)

{

    QLinearGradient g(x0, y0, x1, y1);

    return CanvasGradient(g);

}

CanvasGradient Context2D::createRadialGradient(qreal x0, qreal y0,

                                               qreal r0, qreal x1,

                                               qreal y1, qreal r1)

{

    QRadialGradient g(QPointF(x1, y1), r0+r1, QPointF(x0, y0));

    return CanvasGradient(g);

}

qreal Context2D::lineWidth() const

{

    return m_state.lineWidth;

}

void Context2D::setLineWidth(qreal w)

{

    m_state.lineWidth = w;

    m_state.flags |= DirtyLineWidth;

}

//! [0]

QString Context2D::lineCap() const

{

    switch (m_state.lineCap) {

    case Qt::FlatCap:

        return "butt";

    case Qt::SquareCap:

        return "square";

    case Qt::RoundCap:

        return "round";

    default: ;

    }

    return QString();

}

void Context2D::setLineCap(const QString &capString)

{

    Qt::PenCapStyle style;

    if (capString == "round")

        style = Qt::RoundCap;

    else if (capString == "square")

        style = Qt::SquareCap;

    else //if (capString == "butt")

        style = Qt::FlatCap;

    m_state.lineCap = style;

    m_state.flags |= DirtyLineCap;

}

//! [0]

QString Context2D::lineJoin() const

{

    switch (m_state.lineJoin) {

    case Qt::RoundJoin:

        return "round";

    case Qt::BevelJoin:

        return "bevel";

    case Qt::MiterJoin:

        return "miter";

    default: ;

    }

    return QString();

}

void Context2D::setLineJoin(const QString &joinString)

{

    Qt::PenJoinStyle style;

    if (joinString == "round")

        style = Qt::RoundJoin;

    else if (joinString == "bevel")

        style = Qt::BevelJoin;

    else //if (joinString == "miter")

        style = Qt::MiterJoin;

    m_state.lineJoin = style;

    m_state.flags |= DirtyLineJoin;

}

qreal Context2D::miterLimit() const

{

    return m_state.miterLimit;

}

void Context2D::setMiterLimit(qreal m)

{

    m_state.miterLimit = m;

    m_state.flags |= DirtyMiterLimit;

}

void Context2D::setShadowOffsetX(qreal x)

{

    m_state.shadowOffsetX = x;

    m_state.flags |= DirtyShadowOffsetX;

}

void Context2D::setShadowOffsetY(qreal y)

{

    m_state.shadowOffsetY = y;

    m_state.flags |= DirtyShadowOffsetY;

}

void Context2D::setShadowBlur(qreal b)

{

    m_state.shadowBlur = b;

    m_state.flags |= DirtyShadowBlur;

}

void Context2D::setShadowColor(const QString &str)

{

    m_state.shadowColor = colorFromString(str);

    m_state.flags |= DirtyShadowColor;

}

qreal Context2D::shadowOffsetX() const

{

    return m_state.shadowOffsetX;

}

qreal Context2D::shadowOffsetY() const

{

    return m_state.shadowOffsetY;

}

qreal Context2D::shadowBlur() const

{

    return m_state.shadowBlur;

}

QString Context2D::shadowColor() const

{

    return m_state.shadowColor.name();

}

void Context2D::clearRect(qreal x, qreal y, qreal w, qreal h)

{

    beginPainting();

    m_painter.save();

    m_painter.setMatrix(m_state.matrix, false);

    m_painter.setCompositionMode(QPainter::CompositionMode_Source);

    m_painter.fillRect(QRectF(x, y, w, h), QColor(0, 0, 0, 0));

    m_painter.restore();

    scheduleChange();

}

//! [1]

void Context2D::fillRect(qreal x, qreal y, qreal w, qreal h)

{

    beginPainting();

    m_painter.save();

    m_painter.setMatrix(m_state.matrix, false);

    m_painter.fillRect(QRectF(x, y, w, h), m_painter.brush());

    m_painter.restore();

    scheduleChange();

}

//! [1]

void Context2D::strokeRect(qreal x, qreal y, qreal w, qreal h)

{

    QPainterPath path;

    path.addRect(x, y, w, h);

    beginPainting();

    m_painter.save();

    m_painter.setMatrix(m_state.matrix, false);

    m_painter.strokePath(path, m_painter.pen());

    m_painter.restore();

    scheduleChange();

}

void Context2D::beginPath()

{

    m_path = QPainterPath();

}

void Context2D::closePath()

{

    m_path.closeSubpath();

}

void Context2D::moveTo(qreal x, qreal y)

{

    QPointF pt = m_state.matrix.map(QPointF(x, y));

    m_path.moveTo(pt);

}

void Context2D::lineTo(qreal x, qreal y)

{

    QPointF pt = m_state.matrix.map(QPointF(x, y));

    m_path.lineTo(pt);

}