FogLayer.cpp

// SPDX-License-Identifier: LGPL-2.1-or-later
//
// SPDX-FileCopyrightText: 2006-2007 Torsten Rahn <[email protected]>
// SPDX-FileCopyrightText: 2007 Inge Wallin <[email protected]>
// SPDX-FileCopyrightText: 2008, 2009, 2010 Jens-Michael Hoffmann <[email protected]>
// SPDX-FileCopyrightText: 2008-2009 Patrick Spendrin <[email protected]>
//
 
#include "FogLayer.h"
 
#include "GeoPainter.h"
#include "ViewportParams.h"
#include "RenderState.h"
 
namespace Marble
{
    
QStringList FogLayer::renderPosition() const
{
    return QStringList(QStringLiteral("ATMOSPHERE"));
}
 
bool FogLayer::render( GeoPainter *painter,
                       ViewportParams *viewParams,
                       const QString &renderPos,
                       GeoSceneLayer *layer )
{
    Q_UNUSED(renderPos)
    Q_UNUSED(layer)
 
    // FIXME: The fog layer is really slow. That's why we defer it to
    //        PrintQuality. Either cache on a pixmap - or maybe
    //        better: Add to GlobeScanlineTextureMapper.
    if ( painter->mapQuality() != PrintQuality )
        return true;
 
    if ( viewParams->projection() != Spherical)
        return true;
 
    // No use to draw the fog if it's not visible in the area.
    if ( viewParams->mapCoversViewport() )
        return true;
 
    int imgWidth2  = viewParams->width() / 2;
    int imgHeight2 = viewParams->height() / 2;
 
    int radius = viewParams->radius();
 
    // Recalculate the atmosphere effect and paint it to canvasImage.
    QRadialGradient grad1( QPointF( imgWidth2, imgHeight2 ), radius );
 
    // FIXME: Add a cosine relationship
    grad1.setColorAt( 0.85, QColor( 255, 255, 255, 0 ) );
    grad1.setColorAt( 1.00, QColor( 255, 255, 255, 64 ) );
 
    QBrush    brush1( grad1 );
    QPen      pen1( Qt::NoPen );
 
    painter->save();
 
    painter->setBrush( brush1 );
    painter->setPen( pen1 );
    painter->setRenderHint( QPainter::Antialiasing, false );
 
    // FIXME: Cut out what's really needed
    painter->drawEllipse( imgWidth2  - radius,
                         imgHeight2 - radius,
                         2 * radius,
                         2 * radius );
 
    painter->restore();
 
    return true;
}
 
RenderState FogLayer::renderState() const
{
    return RenderState(QStringLiteral("Fog"));
}
 
}