static QRectF qwtStripRect(const QRectF &rect, const QRectF &area,
const QwtScaleMap &xMap, const QwtScaleMap &yMap,
const QwtInterval &xInterval, const QwtInterval &yInterval)
{
QRectF r = rect;
if ( xInterval.borderFlags() & QwtInterval::ExcludeMinimum )
{
if ( area.left() <= xInterval.minValue() )
{
if ( xMap.isInverting() )
r.adjust(0, 0, -1, 0);
else
r.adjust(1, 0, 0, 0);
}
}
if ( xInterval.borderFlags() & QwtInterval::ExcludeMaximum )
{
if ( area.right() >= xInterval.maxValue() )
{
if ( xMap.isInverting() )
r.adjust(1, 0, 0, 0);
else
r.adjust(0, 0, -1, 0);
}
}
if ( yInterval.borderFlags() & QwtInterval::ExcludeMinimum )
{
if ( area.top() <= yInterval.minValue() )
{
if ( yMap.isInverting() )
r.adjust(0, 0, 0, -1);
else
r.adjust(0, 1, 0, 0);
}
}
if ( yInterval.borderFlags() & QwtInterval::ExcludeMaximum )
{
if ( area.bottom() >= yInterval.maxValue() )
{
if ( yMap.isInverting() )
r.adjust(0, 1, 0, 0);
else
r.adjust(0, 0, 0, -1);
}
}
return r;
}
static inline bool isCombinable( const QwtInterval &d1,
const QwtInterval &d2 )
{
if ( d1.isValid() && d2.isValid() )
{
if ( d1.maxValue() == d2.minValue() )
{
if ( !( d1.borderFlags() & QwtInterval::ExcludeMaximum
&& d2.borderFlags() & QwtInterval::ExcludeMinimum ) )
{
return true;
}
}
}
return false;
}
/*!
\brief Draw the raster data
\param painter Painter
\param xMap X-Scale Map
\param yMap Y-Scale Map
\param canvasRect Contents rectangle of the plot canvas
*/
void QwtPlotRasterItem::draw( QPainter *painter,
const QwtScaleMap &xMap, const QwtScaleMap &yMap,
const QRectF &canvasRect ) const
{
if ( canvasRect.isEmpty() || d_data->alpha == 0 )
return;
const bool doCache = qwtUseCache( d_data->cache.policy, painter );
const QwtInterval xInterval = interval( Qt::XAxis );
const QwtInterval yInterval = interval( Qt::YAxis );
/*
Scaling an image always results in a loss of
precision/quality. So we always render the image in
paint device resolution.
*/
QwtScaleMap xxMap, yyMap;
qwtTransformMaps( painter->transform(), xMap, yMap, xxMap, yyMap );
QRectF paintRect = painter->transform().mapRect( canvasRect );
QRectF area = QwtScaleMap::invTransform( xxMap, yyMap, paintRect );
const QRectF br = boundingRect();
if ( br.isValid() && !br.contains( area ) )
{
area &= br;
if ( !area.isValid() )
return;
paintRect = QwtScaleMap::transform( xxMap, yyMap, area );
}
QRectF imageRect;
QImage image;
QRectF pixelRect = pixelHint(area);
if ( !pixelRect.isEmpty() )
{
// pixel in target device resolution
const double dx = qAbs( xxMap.invTransform( 1 ) - xxMap.invTransform( 0 ) );
const double dy = qAbs( yyMap.invTransform( 1 ) - yyMap.invTransform( 0 ) );
if ( dx > pixelRect.width() && dy > pixelRect.height() )
{
/*
When the resolution of the data pixels is higher than
the resolution of the target device we render in
target device resolution.
*/
pixelRect = QRectF();
}
}
if ( pixelRect.isEmpty() )
{
if ( QwtPainter::roundingAlignment( painter ) )
{
// we want to have maps, where the boundaries of
// the aligned paint rectangle exactly match the area
paintRect = qwtAlignRect(paintRect);
qwtAdjustMaps(xxMap, yyMap, area, paintRect);
}
// When we have no information about position and size of
// data pixels we render in resolution of the paint device.
image = compose(xxMap, yyMap,
area, paintRect, paintRect.size().toSize(), doCache);
if ( image.isNull() )
return;
// Remove pixels at the boundaries, when explicitly
// excluded in the intervals
imageRect = qwtStripRect(paintRect, area,
xxMap, yyMap, xInterval, yInterval);
if ( imageRect != paintRect )
{
const QRect r(
qRound( imageRect.x() - paintRect.x()),
qRound( imageRect.y() - paintRect.y() ),
qRound( imageRect.width() ),
qRound( imageRect.height() ) );
image = image.copy(r);
}
}
else
{
if ( QwtPainter::roundingAlignment( painter ) )
paintRect = qwtAlignRect(paintRect);
// align the area to the data pixels
QRectF imageArea = qwtExpandToPixels(area, pixelRect);
if ( imageArea.right() == xInterval.maxValue() &&
!( xInterval.borderFlags() & QwtInterval::ExcludeMaximum ) )
{
imageArea.adjust(0, 0, pixelRect.width(), 0);
}
if ( imageArea.bottom() == yInterval.maxValue() &&
!( yInterval.borderFlags() & QwtInterval::ExcludeMaximum ) )
{
imageArea.adjust(0, 0, 0, pixelRect.height() );
}
QSize imageSize;
imageSize.setWidth( qRound( imageArea.width() / pixelRect.width() ) );
imageSize.setHeight( qRound( imageArea.height() / pixelRect.height() ) );
image = compose(xxMap, yyMap,
imageArea, paintRect, imageSize, doCache );
if ( image.isNull() )
return;
imageRect = qwtStripRect(paintRect, area,
xxMap, yyMap, xInterval, yInterval);
if ( ( image.width() > 1 || image.height() > 1 ) &&
testPaintAttribute( PaintInDeviceResolution ) )
{
// Because of rounding errors the pixels
// need to be expanded manually to rectangles of
// different sizes
image = qwtExpandImage(image, xxMap, yyMap,
imageArea, area, paintRect, xInterval, yInterval );
}
}
painter->save();
painter->setWorldTransform( QTransform() );
QwtPainter::drawImage( painter, imageRect, image );
painter->restore();
}