// Copyright (C) 2016 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include <private/qemulationpaintengine_p.h>

#include <private/qpainter_p.h>

#include <private/qtextengine_p.h>

#include <qdebug.h>

QT_BEGIN_NAMESPACE

QEmulationPaintEngine::QEmulationPaintEngine(QPaintEngineEx *engine)

    : real_engine(engine)

{

    QPaintEngine::state = real_engine->state();

}

QPaintEngine::Type QEmulationPaintEngine::type() const

{

    return real_engine->type();

}

bool QEmulationPaintEngine::begin(QPaintDevice *)

{

    return true;

}

bool QEmulationPaintEngine::end()

{

    return true;

}

QPainterState *QEmulationPaintEngine::createState(QPainterState *orig) const

{

    return real_engine->createState(orig);

}

static inline void combineXForm(QBrush *brush, const QRectF &r)

{

    QTransform t(r.width(), 0, 0, r.height(), r.x(), r.y());

    if (brush->gradient() && brush->gradient()->coordinateMode() != QGradient::ObjectMode)

        brush->setTransform(t * brush->transform()); // compat mode

    else

        brush->setTransform(brush->transform() * t);

}

void QEmulationPaintEngine::fill(const QVectorPath &path, const QBrush &brush)

{

    QPainterState *s = state();

    if (s->bgMode == Qt::OpaqueMode) {

        Qt::BrushStyle style = brush.style();

        if ((style >= Qt::Dense1Pattern && style <= Qt::DiagCrossPattern) || (style == Qt::TexturePattern ))

            real_engine->fill(path, s->bgBrush);

    }

    Qt::BrushStyle style = qbrush_style(brush);

    if (style >= Qt::LinearGradientPattern && style <= Qt::ConicalGradientPattern) {

        QGradient::CoordinateMode coMode = brush.gradient()->coordinateMode();

        if (coMode > QGradient::LogicalMode) {

            QBrush copy = brush;

            const QPaintDevice *d = real_engine->painter()->device();

            QRectF r = (coMode == QGradient::StretchToDeviceMode) ? QRectF(0, 0, d->width(), d->height()) : path.controlPointRect();

            combineXForm(&copy, r);

            real_engine->fill(path, copy);

            return;

        }

    } else if (style == Qt::TexturePattern) {

        qreal dpr = qHasPixmapTexture(brush) ? brush.texture().devicePixelRatio() : brush.textureImage().devicePixelRatio();

        if (!qFuzzyCompare(dpr, qreal(1.0))) {

            QBrush copy = brush;

            combineXForm(&copy, QRectF(0, 0, 1.0/dpr, 1.0/dpr));

            real_engine->fill(path, copy);

            return;

        }

    }

    real_engine->fill(path, brush);

}

void QEmulationPaintEngine::stroke(const QVectorPath &path, const QPen &pen)

{

    QPainterState *s = state();

    if (s->bgMode == Qt::OpaqueMode && pen.style() > Qt::SolidLine) {

        QPen bgPen = pen;

        bgPen.setBrush(s->bgBrush);

        bgPen.setStyle(Qt::SolidLine);

        real_engine->stroke(path, bgPen);

    }

    QBrush brush = pen.brush();

    QPen copy = pen;

    Qt::BrushStyle style = qbrush_style(brush);

    if (style >= Qt::LinearGradientPattern && style <= Qt::ConicalGradientPattern ) {

        QGradient::CoordinateMode coMode = brush.gradient()->coordinateMode();

        if (coMode > QGradient::LogicalMode) {

            const QPaintDevice *d = real_engine->painter()->device();

            QRectF r = (coMode == QGradient::StretchToDeviceMode) ? QRectF(0, 0, d->width(), d->height()) : path.controlPointRect();

            combineXForm(&brush, r);

            copy.setBrush(brush);

            real_engine->stroke(path, copy);

            return;

        }

    }

    real_engine->stroke(path, pen);

}

void QEmulationPaintEngine::clip(const QVectorPath &path, Qt::ClipOperation op)

{

    real_engine->clip(path, op);

}

void QEmulationPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pm, const QRectF &sr)

{

    if (state()->bgMode == Qt::OpaqueMode && pm.isQBitmap())

        fillBGRect(r);

    real_engine->drawPixmap(r, pm, sr);

}

void QEmulationPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem)

{

    if (state()->bgMode == Qt::OpaqueMode) {

        const QTextItemInt &ti = static_cast<const QTextItemInt &>(textItem);

        QRectF rect(p.x(), p.y() - ti.ascent.toReal(), ti.width.toReal(), (ti.ascent + ti.descent).toReal());

        fillBGRect(rect);

    }

    QPainterState *s = state();

    Qt::BrushStyle style = qbrush_style(s->pen.brush());

    if (style >= Qt::LinearGradientPattern && style <= Qt::ConicalGradientPattern)

    {

        QPen savedPen = s->pen;

        QGradient g = *s->pen.brush().gradient();

        if (g.coordinateMode() > QGradient::LogicalMode) {

            QBrush copy = s->pen.brush();

            const QPaintDevice *d = real_engine->painter()->device();

            const QTextItemInt &ti = static_cast<const QTextItemInt &>(textItem);

            QRectF r = (g.coordinateMode() == QGradient::StretchToDeviceMode) ?

                        QRectF(0, 0, d->width(), d->height()) :

                        QRectF(p.x(), p.y() - ti.ascent.toReal(), ti.width.toReal(), (ti.ascent + ti.descent + 1).toReal());

            combineXForm(&copy, r);

            g.setCoordinateMode(QGradient::LogicalMode);

            QBrush brush(g);

            brush.setTransform(copy.transform());

            s->pen.setBrush(brush);

            penChanged();

            real_engine->drawTextItem(p, textItem);

            s->pen = savedPen;

            penChanged();

            return;

        }

    }

    real_engine->drawTextItem(p, textItem);

}

void QEmulationPaintEngine::drawStaticTextItem(QStaticTextItem *item)

{

    real_engine->drawStaticTextItem(item);

}

void QEmulationPaintEngine::drawTiledPixmap(const QRectF &r, const QPixmap &pixmap, const QPointF &s)

{

    if (state()->bgMode == Qt::OpaqueMode && pixmap.isQBitmap())

        fillBGRect(r);

    real_engine->drawTiledPixmap(r, pixmap, s);

}

void QEmulationPaintEngine::drawImage(const QRectF &r, const QImage &pm, const QRectF &sr, Qt::ImageConversionFlags flags)

{

    real_engine->drawImage(r, pm, sr, flags);

}

void QEmulationPaintEngine::clipEnabledChanged()

{

    real_engine->clipEnabledChanged();

}

void QEmulationPaintEngine::penChanged()

{

    real_engine->penChanged();

}

void QEmulationPaintEngine::brushChanged()

{

    real_engine->brushChanged();

}

void QEmulationPaintEngine::brushOriginChanged()

{

    real_engine->brushOriginChanged();

}

void QEmulationPaintEngine::opacityChanged()

{

    real_engine->opacityChanged();

}

void QEmulationPaintEngine::compositionModeChanged()

{

    real_engine->compositionModeChanged();

}

void QEmulationPaintEngine::renderHintsChanged()

{

    real_engine->renderHintsChanged();

}

void QEmulationPaintEngine::transformChanged()

{

    real_engine->transformChanged();

}

void QEmulationPaintEngine::setState(QPainterState *s)

{

    QPaintEngine::state = s;

    real_engine->setState(s);

}

void QEmulationPaintEngine::beginNativePainting()

{

    real_engine->beginNativePainting();

}

void QEmulationPaintEngine::endNativePainting()

{

    real_engine->endNativePainting();

}

void QEmulationPaintEngine::fillBGRect(const QRectF &r)

{

    qreal pts[] = { r.x(), r.y(), r.x() + r.width(), r.y(),

                    r.x() + r.width(), r.y() + r.height(), r.x(), r.y() + r.height() };

    QVectorPath vp(pts, 4, nullptr, QVectorPath::RectangleHint);

    real_engine->fill(vp, state()->bgBrush);

}

QT_END_NAMESPACE