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qwt_point_mapper.cpp
/******************************************************************************
* Qwt Widget Library
* Copyright (C) 1997 Josef Wilgen
* Copyright (C) 2002 Uwe Rathmann
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the Qwt License, Version 1.0
*****************************************************************************/
#include "qwt_point_mapper.h"
#include "qwt_scale_map.h"
#include "qwt_pixel_matrix.h"
#include "qwt_series_data.h"
#include "qwt_math.h"
#include <qpolygon.h>
#include <qimage.h>
#include <qpen.h>
#include <qpainter.h>
#include <qthread.h>
#include <qfuture.h>
#include <qtconcurrentrun.h>
#if !defined( QT_NO_QFUTURE )
#define QWT_USE_THREADS 1
#endif
static QRectF qwtInvalidRect( 0.0, 0.0, -1.0, -1.0 );
static inline int qwtRoundValue( double value )
{
return qRound( value );
}
static inline double qwtRoundValueF( double value )
{
#if 1
// MS Windows and at least IRIX does not have C99's nearbyint() function
return ( value >= 0.0 ) ? std::floor( value + 0.5 ) : std::ceil( value - 0.5 );
#else
return nearbyint( value );
#endif
}
static Qt::Orientation qwtProbeOrientation(
const QwtSeriesData< QPointF >* series, int from, int to )
{
if ( to - from < 20 )
{
// not enough points to "have an orientation"
return Qt::Horizontal;
}
const double x0 = series->sample( from ).x();
const double xn = series->sample( to ).x();
if ( x0 == xn )
return Qt::Vertical;
const int step = ( to - from ) / 10;
const bool isIncreasing = xn > x0;
double x1 = x0;
for ( int i = from + step; i < to; i += step )
{
const double x2 = series->sample( i ).x();
if ( x2 != x1 )
{
if ( ( x2 > x1 ) != isIncreasing )
return Qt::Vertical;
}
x1 = x2;
}
return Qt::Horizontal;
}
namespace
{
template< class Polygon, class Point >
class QwtPolygonQuadrupelX
{
public:
inline void start( int x, int y )
{
m_x0 = x;
m_y1 = m_yMin = m_yMax = m_y2 = y;
}
inline bool append( int x, int y )
{
if ( m_x0 != x )
return false;
if ( y < m_yMin )
m_yMin = y;
else if ( y > m_yMax )
m_yMax = y;
m_y2 = y;
return true;
}
inline void flush( Polygon& polyline )
{
appendTo( m_y1, polyline );
if ( m_y2 > m_y1 )
qSwap( m_yMin, m_yMax );
if ( m_yMax != m_y1 )
appendTo( m_yMax, polyline );
if ( m_yMin != m_yMax )
appendTo( m_yMin, polyline );
if ( m_y2 != m_yMin )
appendTo( m_y2, polyline );
}
private:
inline void appendTo( int y, Polygon& polyline )
{
polyline += Point( m_x0, y );
}
private:
int m_x0, m_y1, m_yMin, m_yMax, m_y2;
};
template< class Polygon, class Point >
class QwtPolygonQuadrupelY
{
public:
inline void start( int x, int y )
{
m_y0 = y;
m_x1 = m_xMin = m_xMax = m_x2 = x;
}
inline bool append( int x, int y )
{
if ( m_y0 != y )
return false;
if ( x < m_xMin )
m_xMin = x;
else if ( x > m_xMax )
m_xMax = x;
m_x2 = x;
return true;
}
inline void flush( Polygon& polyline )
{
appendTo( m_x1, polyline );
if ( m_x2 > m_x1 )
qSwap( m_xMin, m_xMax );
if ( m_xMax != m_x1 )
appendTo( m_xMax, polyline );
if ( m_xMin != m_xMax )
appendTo( m_xMin, polyline );
if ( m_x2 != m_xMin )
appendTo( m_x2, polyline );
}
private:
inline void appendTo( int x, Polygon& polyline )
{
polyline += Point( x, m_y0 );
}
int m_y0, m_x1, m_xMin, m_xMax, m_x2;
};
}
template< class Polygon, class Point, class PolygonQuadrupel >
static Polygon qwtMapPointsQuad( const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to )
{
const QPointF sample0 = series->sample( from );
PolygonQuadrupel q;
q.start( qwtRoundValue( xMap.transform( sample0.x() ) ),
qwtRoundValue( yMap.transform( sample0.y() ) ) );
Polygon polyline;
for ( int i = from; i <= to; i++ )
{
const QPointF sample = series->sample( i );
const int x = qwtRoundValue( xMap.transform( sample.x() ) );
const int y = qwtRoundValue( yMap.transform( sample.y() ) );
if ( !q.append( x, y ) )
{
q.flush( polyline );
q.start( x, y );
}
}
q.flush( polyline );
return polyline;
}
template< class Polygon, class Point, class PolygonQuadrupel >
static Polygon qwtMapPointsQuad( const Polygon& polyline )
{
const int numPoints = polyline.size();
if ( numPoints < 3 )
return polyline;
const Point* points = polyline.constData();
Polygon polylineXY;
PolygonQuadrupel q;
q.start( points[0].x(), points[0].y() );
for ( int i = 0; i < numPoints; i++ )
{
const int x = points[i].x();
const int y = points[i].y();
if ( !q.append( x, y ) )
{
q.flush( polylineXY );
q.start( x, y );
}
}
q.flush( polylineXY );
return polylineXY;
}
template< class Polygon, class Point >
static Polygon qwtMapPointsQuad( const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to )
{
Polygon polyline;
if ( from > to )
return polyline;
/*
probing some values, to decide if it is better
to start with x or y coordinates
*/
const Qt::Orientation orientation = qwtProbeOrientation( series, from, to );
if ( orientation == Qt::Horizontal )
{
polyline = qwtMapPointsQuad< Polygon, Point,
QwtPolygonQuadrupelY< Polygon, Point > >( xMap, yMap, series, from, to );
polyline = qwtMapPointsQuad< Polygon, Point,
QwtPolygonQuadrupelX< Polygon, Point > >( polyline );
}
else
{
polyline = qwtMapPointsQuad< Polygon, Point,
QwtPolygonQuadrupelX< Polygon, Point > >( xMap, yMap, series, from, to );
polyline = qwtMapPointsQuad< Polygon, Point,
QwtPolygonQuadrupelY< Polygon, Point > >( polyline );
}
return polyline;
}
// Helper class to work around the 5 parameters
// limitation of QtConcurrent::run()
class QwtDotsCommand
{
public:
const QwtSeriesData< QPointF >* series;
int from;
int to;
QRgb rgb;
};
static void qwtRenderDots(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtDotsCommand& command, const QPoint& pos, QImage* image )
{
const QRgb rgb = command.rgb;
QRgb* bits = reinterpret_cast< QRgb* >( image->bits() );
const int w = image->width();
const int h = image->height();
const int x0 = pos.x();
const int y0 = pos.y();
for ( int i = command.from; i <= command.to; i++ )
{
const QPointF sample = command.series->sample( i );
const int x = static_cast< int >( xMap.transform( sample.x() ) + 0.5 ) - x0;
const int y = static_cast< int >( yMap.transform( sample.y() ) + 0.5 ) - y0;
if ( x >= 0 && x < w && y >= 0 && y < h )
bits[ y * w + x ] = rgb;
}
}
// some functors, so that the compile can inline
struct QwtRoundI
{
inline int operator()( double value ) const
{
return qwtRoundValue( value );
}
};
struct QwtRoundF
{
inline double operator()( double value ) const
{
return qwtRoundValueF( value );
}
};
struct QwtNoRoundF
{
inline double operator()( double value ) const
{
return value;
}
};
// mapping points without any filtering - beside checking
// the bounding rectangle
template< class Polygon, class Point, class Round >
static inline Polygon qwtToPoints(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to, Round round )
{
Polygon polyline( to - from + 1 );
Point* points = polyline.data();
int numPoints = 0;
if ( boundingRect.isValid() )
{
// iterating over all values
// filtering out all points outside of
// the bounding rectangle
for ( int i = from; i <= to; i++ )
{
const QPointF sample = series->sample( i );
const double x = xMap.transform( sample.x() );
const double y = yMap.transform( sample.y() );
if ( boundingRect.contains( x, y ) )
{
points[ numPoints ].rx() = round( x );
points[ numPoints ].ry() = round( y );
numPoints++;
}
}
polyline.resize( numPoints );
}
else
{
// simply iterating over all values
// without any filtering
for ( int i = from; i <= to; i++ )
{
const QPointF sample = series->sample( i );
const double x = xMap.transform( sample.x() );
const double y = yMap.transform( sample.y() );
points[ numPoints ].rx() = round( x );
points[ numPoints ].ry() = round( y );
numPoints++;
}
}
return polyline;
}
static inline QPolygon qwtToPointsI(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to )
{
return qwtToPoints< QPolygon, QPoint >(
boundingRect, xMap, yMap, series, from, to, QwtRoundI() );
}
template< class Round >
static inline QPolygonF qwtToPointsF(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to, Round round )
{
return qwtToPoints< QPolygonF, QPointF >(
boundingRect, xMap, yMap, series, from, to, round );
}
// Mapping points with filtering out consecutive
// points mapped to the same position
template< class Polygon, class Point, class Round >
static inline Polygon qwtToPolylineFiltered(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to, Round round )
{
// in curves with many points consecutive points
// are often mapped to the same position. As this might
// result in empty lines ( or symbols hidden by others )
// we try to filter them out
Polygon polyline( to - from + 1 );
Point* points = polyline.data();
const QPointF sample0 = series->sample( from );
points[0].rx() = round( xMap.transform( sample0.x() ) );
points[0].ry() = round( yMap.transform( sample0.y() ) );
int pos = 0;
for ( int i = from + 1; i <= to; i++ )
{
const QPointF sample = series->sample( i );
const Point p( round( xMap.transform( sample.x() ) ),
round( yMap.transform( sample.y() ) ) );
if ( points[pos] != p )
points[++pos] = p;
}
polyline.resize( pos + 1 );
return polyline;
}
static inline QPolygon qwtToPolylineFilteredI(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to )
{
return qwtToPolylineFiltered< QPolygon, QPoint >(
xMap, yMap, series, from, to, QwtRoundI() );
}
template< class Round >
static inline QPolygonF qwtToPolylineFilteredF(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series,
int from, int to, Round round )
{
return qwtToPolylineFiltered< QPolygonF, QPointF >(
xMap, yMap, series, from, to, round );
}
template< class Polygon, class Point >
static inline Polygon qwtToPointsFiltered(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to )
{
// F.e. in scatter plots ( no connecting lines ) we
// can sort out all duplicates ( not only consecutive points )
Polygon polygon( to - from + 1 );
Point* points = polygon.data();
QwtPixelMatrix pixelMatrix( boundingRect.toAlignedRect() );
int numPoints = 0;
for ( int i = from; i <= to; i++ )
{
const QPointF sample = series->sample( i );
const int x = qwtRoundValue( xMap.transform( sample.x() ) );
const int y = qwtRoundValue( yMap.transform( sample.y() ) );
if ( pixelMatrix.testAndSetPixel( x, y, true ) == false )
{
points[ numPoints ].rx() = x;
points[ numPoints ].ry() = y;
numPoints++;
}
}
polygon.resize( numPoints );
return polygon;
}
static inline QPolygon qwtToPointsFilteredI(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to )
{
return qwtToPointsFiltered< QPolygon, QPoint >(
boundingRect, xMap, yMap, series, from, to );
}
static inline QPolygonF qwtToPointsFilteredF(
const QRectF& boundingRect,
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to )
{
return qwtToPointsFiltered< QPolygonF, QPointF >(
boundingRect, xMap, yMap, series, from, to );
}
class QwtPointMapper::PrivateData
{
public:
PrivateData()
: boundingRect( qwtInvalidRect )
{
}
QRectF boundingRect;
QwtPointMapper::TransformationFlags flags;
};
QwtPointMapper::QwtPointMapper()
{
m_data = new PrivateData();
}
QwtPointMapper::~QwtPointMapper()
{
delete m_data;
}
void QwtPointMapper::setFlags( TransformationFlags flags )
{
m_data->flags = flags;
}
QwtPointMapper::TransformationFlags QwtPointMapper::flags() const
{
return m_data->flags;
}
void QwtPointMapper::setFlag( TransformationFlag flag, bool on )
{
if ( on )
m_data->flags |= flag;
else
m_data->flags &= ~flag;
}
bool QwtPointMapper::testFlag( TransformationFlag flag ) const
{
return m_data->flags & flag;
}
void QwtPointMapper::setBoundingRect( const QRectF& rect )
{
m_data->boundingRect = rect;
}
QRectF QwtPointMapper::boundingRect() const
{
return m_data->boundingRect;
}
QPolygonF QwtPointMapper::toPolygonF(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to ) const
{
QPolygonF polyline;
if ( m_data->flags & RoundPoints )
{
if ( m_data->flags & WeedOutIntermediatePoints )
{
polyline = qwtMapPointsQuad< QPolygonF, QPointF >(
xMap, yMap, series, from, to );
}
else if ( m_data->flags & WeedOutPoints )
{
polyline = qwtToPolylineFilteredF(
xMap, yMap, series, from, to, QwtRoundF() );
}
else
{
polyline = qwtToPointsF( qwtInvalidRect,
xMap, yMap, series, from, to, QwtRoundF() );
}
}
else
{
if ( m_data->flags & WeedOutPoints )
{
polyline = qwtToPolylineFilteredF(
xMap, yMap, series, from, to, QwtNoRoundF() );
}
else
{
polyline = qwtToPointsF( qwtInvalidRect,
xMap, yMap, series, from, to, QwtNoRoundF() );
}
}
return polyline;
}
QPolygon QwtPointMapper::toPolygon(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to ) const
{
QPolygon polyline;
if ( m_data->flags & WeedOutIntermediatePoints )
{
// TODO WeedOutIntermediatePointsY ...
polyline = qwtMapPointsQuad< QPolygon, QPoint >(
xMap, yMap, series, from, to );
}
else if ( m_data->flags & WeedOutPoints )
{
polyline = qwtToPolylineFilteredI(
xMap, yMap, series, from, to );
}
else
{
polyline = qwtToPointsI(
qwtInvalidRect, xMap, yMap, series, from, to );
}
return polyline;
}
QPolygonF QwtPointMapper::toPointsF(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to ) const
{
QPolygonF points;
if ( m_data->flags & WeedOutPoints )
{
if ( m_data->flags & RoundPoints )
{
if ( m_data->boundingRect.isValid() )
{
points = qwtToPointsFilteredF( m_data->boundingRect,
xMap, yMap, series, from, to );
}
else
{
// without a bounding rectangle all we can
// do is to filter out duplicates of
// consecutive points
points = qwtToPolylineFilteredF(
xMap, yMap, series, from, to, QwtRoundF() );
}
}
else
{
// when rounding is not allowed we can't use
// qwtToPointsFilteredF
points = qwtToPolylineFilteredF(
xMap, yMap, series, from, to, QwtNoRoundF() );
}
}
else
{
if ( m_data->flags & RoundPoints )
{
points = qwtToPointsF( m_data->boundingRect,
xMap, yMap, series, from, to, QwtRoundF() );
}
else
{
points = qwtToPointsF( m_data->boundingRect,
xMap, yMap, series, from, to, QwtNoRoundF() );
}
}
return points;
}
QPolygon QwtPointMapper::toPoints(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to ) const
{
QPolygon points;
if ( m_data->flags & WeedOutPoints )
{
if ( m_data->boundingRect.isValid() )
{
points = qwtToPointsFilteredI( m_data->boundingRect,
xMap, yMap, series, from, to );
}
else
{
// when we don't have the bounding rectangle all
// we can do is to filter out consecutive duplicates
points = qwtToPolylineFilteredI(
xMap, yMap, series, from, to );
}
}
else
{
points = qwtToPointsI(
m_data->boundingRect, xMap, yMap, series, from, to );
}
return points;
}
QImage QwtPointMapper::toImage(
const QwtScaleMap& xMap, const QwtScaleMap& yMap,
const QwtSeriesData< QPointF >* series, int from, int to,
const QPen& pen, bool antialiased, uint numThreads ) const
{
Q_UNUSED( antialiased )
#if QWT_USE_THREADS
if ( numThreads == 0 )
numThreads = QThread::idealThreadCount();
if ( numThreads <= 0 )
numThreads = 1;
#else
Q_UNUSED( numThreads )
#endif
// a very special optimization for scatter plots
// where every sample is mapped to one pixel only.
const QRect rect = m_data->boundingRect.toAlignedRect();
QImage image( rect.size(), QImage::Format_ARGB32 );
image.fill( Qt::transparent );
if ( pen.width() <= 1 && pen.color().alpha() == 255 )
{
QwtDotsCommand command;
command.series = series;
command.rgb = pen.color().rgba();
#if QWT_USE_THREADS
const int numPoints = ( to - from + 1 ) / numThreads;
QList< QFuture< void > > futures;
for ( uint i = 0; i < numThreads; i++ )
{
const QPoint pos = rect.topLeft();
const int index0 = from + i * numPoints;
if ( i == numThreads - 1 )
{
command.from = index0;
command.to = to;
qwtRenderDots( xMap, yMap, command, pos, &image );
}
else
{
command.from = index0;
command.to = index0 + numPoints - 1;
futures += QtConcurrent::run( &qwtRenderDots,
xMap, yMap, command, pos, &image );
}
}
for ( int i = 0; i < futures.size(); i++ )
futures[i].waitForFinished();
#else
command.from = from;
command.to = to;
qwtRenderDots( xMap, yMap, command, rect.topLeft(), &image );
#endif
}
else
{
// fallback implementation: to be replaced later by
// setting the pixels of the image like above, TODO ...
QPainter painter( &image );
painter.setPen( pen );
painter.setRenderHint( QPainter::Antialiasing, antialiased );
const int chunkSize = 1000;
for ( int i = from; i <= to; i += chunkSize )
{
const int indexTo = qMin( i + chunkSize - 1, to );
const QPolygon points = toPoints(
xMap, yMap, series, i, indexTo );
painter.drawPoints( points );
}
}
return image;
}
QList
Definition qwt_abstract_legend.h:17
QwtPixelMatrix
A bit field corresponding to the pixels of a rectangle.
Definition qwt_pixel_matrix.h:25
QwtPointMapper::setBoundingRect
void setBoundingRect(const QRectF &)
Definition qwt_point_mapper.cpp:612
QwtPointMapper::boundingRect
QRectF boundingRect() const
Definition qwt_point_mapper.cpp:621
QwtPointMapper::toPolygonF
QPolygonF toPolygonF(const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
Translate a series of points into a QPolygonF.
Definition qwt_point_mapper.cpp:647
QwtPointMapper::flags
TransformationFlags flags() const
Definition qwt_point_mapper.cpp:573
QwtPointMapper::toImage
QImage toImage(const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to, const QPen &, bool antialiased, uint numThreads) const
Translate a series into a QImage.
Definition qwt_point_mapper.cpp:883
QwtPointMapper::testFlag
bool testFlag(TransformationFlag) const
Definition qwt_point_mapper.cpp:599
QwtPointMapper::toPointsF
QPolygonF toPointsF(const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
Translate a series into a QPolygonF.
Definition qwt_point_mapper.cpp:759
QwtPointMapper::setFlag
void setFlag(TransformationFlag, bool on=true)
Definition qwt_point_mapper.cpp:586
QwtPointMapper::QwtPointMapper
QwtPointMapper()
Constructor.
Definition qwt_point_mapper.cpp:547
QwtPointMapper::~QwtPointMapper
~QwtPointMapper()
Destructor.
Definition qwt_point_mapper.cpp:553
QwtPointMapper::TransformationFlag
TransformationFlag
Flags affecting the transformation process.
Definition qwt_point_mapper.h:40
QwtPointMapper::RoundPoints
@ RoundPoints
Round points to integer values.
Definition qwt_point_mapper.h:42
QwtPointMapper::WeedOutPoints
@ WeedOutPoints
Definition qwt_point_mapper.h:48
QwtPointMapper::WeedOutIntermediatePoints
@ WeedOutIntermediatePoints
Definition qwt_point_mapper.h:68
QwtPointMapper::toPolygon
QPolygon toPolygon(const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
Translate a series of points into a QPolygon.
Definition qwt_point_mapper.cpp:702
QwtPointMapper::setFlags
void setFlags(TransformationFlags)
Definition qwt_point_mapper.cpp:564
QwtPointMapper::TransformationFlags
QFlags< TransformationFlag > TransformationFlags
Definition qwt_point_mapper.h:71
QwtPointMapper::toPoints
QPolygon toPoints(const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtSeriesData< QPointF > *series, int from, int to) const
Translate a series of points into a QPolygon.
Definition qwt_point_mapper.cpp:833
QwtScaleMap
A scale map.
Definition qwt_scale_map.h:27
QwtScaleMap::transform
double transform(double s) const
Definition qwt_scale_map.h:137
QwtSeriesData< QPointF >
QwtSeriesData::sample
virtual T sample(size_t i) const =0