/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
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**
** This file is part of the test suite of the Qt Toolkit.
**
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** GNU General Public License Usage
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** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
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#include "visualtestutil.h"

#include <QtQuick/QQuickItem>
#include <QtCore/QDebug>

bool QQuickVisualTestUtil::delegateVisible(QQuickItem *item)
{
    return item->isVisible() && !QQuickItemPrivate::get(item)->culled;
}

QQuickItem *QQuickVisualTestUtil::findVisibleChild(QQuickItem *parent, const QString &objectName)
{
    QQuickItem *item = 0;
    QList<QQuickItem*> items = parent->findChildren<QQuickItem*>(objectName);
    for (int i = 0; i < items.count(); ++i) {
        if (items.at(i)->isVisible() && !QQuickItemPrivate::get(items.at(i))->culled) {
            item = items.at(i);
            break;
        }
    }
    return item;
}

void QQuickVisualTestUtil::dumpTree(QQuickItem *parent, int depth)
{
    static QString padding("                       ");
    for (int i = 0; i < parent->childItems().count(); ++i) {
        QQuickItem *item = qobject_cast<QQuickItem*>(parent->childItems().at(i));
        if (!item)
            continue;
        qDebug() << padding.left(depth*2) << item;
        dumpTree(item, depth+1);
    }
}

// A custom compare function to avoid issues such as:
// When running on native Nvidia graphics cards on linux, the
// distance field glyph pixels have a measurable, but not visible
// pixel error. This was GT-216 with the ubuntu "nvidia-319" driver package.
// llvmpipe does not show the same issue.
bool QQuickVisualTestUtil::compareImages(const QImage &ia, const QImage &ib)
{
    if (ia.size() != ib.size())
        qDebug() << "images are of different size" << ia.size() << ib.size();
    Q_ASSERT(ia.size() == ib.size());
    Q_ASSERT(ia.format() == ib.format());

    int w = ia.width();
    int h = ia.height();
    const int tolerance = 5;
    for (int y=0; y<h; ++y) {
        const uint *as= (const uint *) ia.constScanLine(y);
        const uint *bs= (const uint *) ib.constScanLine(y);
        for (int x=0; x<w; ++x) {
            uint a = as[x];
            uint b = bs[x];

            // No tolerance for error in the alpha.
            if ((a & 0xff000000) != (b & 0xff000000))
                return false;
            if (qAbs(qRed(a) - qRed(b)) > tolerance)
                return false;
            if (qAbs(qRed(a) - qRed(b)) > tolerance)
                return false;
            if (qAbs(qRed(a) - qRed(b)) > tolerance)
                return false;
        }
    }
    return true;
}
