void QgsPointDisplacementRenderer::drawGrid( int gridSizeUnits, QgsSymbolRenderContext &context,
QList<QPointF> pointSymbolPositions, int nSymbols )
{
QPainter *p = context.renderContext().painter();
if ( nSymbols < 2 || !p ) //draw grid only if multiple features
{
return;
}
QPen gridPen( mCircleColor );
gridPen.setWidthF( context.outputLineWidth( mCircleWidth ) );
p->setPen( gridPen );
for ( int i = 0; i < pointSymbolPositions.size(); ++i )
{
if ( i + 1 < pointSymbolPositions.size() && 0 != ( i + 1 ) % gridSizeUnits )
{
QLineF gridLineRow( pointSymbolPositions[i], pointSymbolPositions[i + 1] );
p->drawLine( gridLineRow );
}
if ( i + gridSizeUnits < pointSymbolPositions.size() )
{
QLineF gridLineColumn( pointSymbolPositions[i], pointSymbolPositions[i + gridSizeUnits] );
p->drawLine( gridLineColumn );
}
}
}
void QgsPointDisplacementRenderer::drawCircle( double radiusPainterUnits, QgsSymbolRenderContext &context, QPointF centerPoint, int nSymbols )
{
QPainter *p = context.renderContext().painter();
if ( nSymbols < 2 || !p ) //draw circle only if multiple features
{
return;
}
//draw Circle
QPen circlePen( mCircleColor );
circlePen.setWidthF( context.outputLineWidth( mCircleWidth ) );
p->setPen( circlePen );
p->drawArc( QRectF( centerPoint.x() - radiusPainterUnits, centerPoint.y() - radiusPainterUnits, 2 * radiusPainterUnits, 2 * radiusPainterUnits ), 0, 5760 );
}
void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRenderContext &symbolContext, QPointF centerPoint, int nPosition,
double symbolDiagonal, QList<QPointF> &symbolPositions, QList<QPointF> &labelShifts, double &circleRadius, double &gridRadius,
int &gridSize ) const
{
symbolPositions.clear();
labelShifts.clear();
if ( nPosition < 1 )
{
return;
}
else if ( nPosition == 1 ) //If there is only one feature, draw it exactly at the center position
{
symbolPositions.append( centerPoint );
labelShifts.append( QPointF( symbolDiagonal / 2.0, -symbolDiagonal / 2.0 ) );
return;
}
double circleAdditionPainterUnits = symbolContext.outputLineWidth( mCircleRadiusAddition );
switch ( mPlacement )
{
case Ring:
{
double minDiameterToFitSymbols = nPosition * symbolDiagonal / ( 2.0 * M_PI );
double radius = std::max( symbolDiagonal / 2, minDiameterToFitSymbols ) + circleAdditionPainterUnits;
double fullPerimeter = 2 * M_PI;
double angleStep = fullPerimeter / nPosition;
for ( double currentAngle = 0.0; currentAngle < fullPerimeter; currentAngle += angleStep )
{
double sinusCurrentAngle = std::sin( currentAngle );
double cosinusCurrentAngle = std::cos( currentAngle );
QPointF positionShift( radius * sinusCurrentAngle, radius * cosinusCurrentAngle );
QPointF labelShift( ( radius + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radius + symbolDiagonal / 2 ) * cosinusCurrentAngle );
symbolPositions.append( centerPoint + positionShift );
labelShifts.append( labelShift );
}
circleRadius = radius;
break;
}
case ConcentricRings:
{
double centerDiagonal = mCenterSymbol->size( symbolContext.renderContext() ) * M_SQRT2;
int pointsRemaining = nPosition;
int ringNumber = 1;
double firstRingRadius = centerDiagonal / 2.0 + symbolDiagonal / 2.0;
while ( pointsRemaining > 0 )
{
double radiusCurrentRing = std::max( firstRingRadius + ( ringNumber - 1 ) * symbolDiagonal + ringNumber * circleAdditionPainterUnits, 0.0 );
int maxPointsCurrentRing = std::max( std::floor( 2 * M_PI * radiusCurrentRing / symbolDiagonal ), 1.0 );
int actualPointsCurrentRing = std::min( maxPointsCurrentRing, pointsRemaining );
double angleStep = 2 * M_PI / actualPointsCurrentRing;
double currentAngle = 0.0;
for ( int i = 0; i < actualPointsCurrentRing; ++i )
{
double sinusCurrentAngle = std::sin( currentAngle );
double cosinusCurrentAngle = std::cos( currentAngle );
QPointF positionShift( radiusCurrentRing * sinusCurrentAngle, radiusCurrentRing * cosinusCurrentAngle );
QPointF labelShift( ( radiusCurrentRing + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radiusCurrentRing + symbolDiagonal / 2 ) * cosinusCurrentAngle );
symbolPositions.append( centerPoint + positionShift );
labelShifts.append( labelShift );
currentAngle += angleStep;
}
pointsRemaining -= actualPointsCurrentRing;
ringNumber++;
circleRadius = radiusCurrentRing;
}
break;
}
case Grid:
{
double centerDiagonal = mCenterSymbol->size( symbolContext.renderContext() ) * M_SQRT2;
int pointsRemaining = nPosition;
gridSize = std::ceil( std::sqrt( pointsRemaining ) );
if ( pointsRemaining - std::pow( gridSize - 1, 2 ) < gridSize )
gridSize -= 1;
double originalPointRadius = ( ( centerDiagonal / 2.0 + symbolDiagonal / 2.0 ) + symbolDiagonal ) / 2;
double userPointRadius = originalPointRadius + circleAdditionPainterUnits;
int yIndex = 0;
while ( pointsRemaining > 0 )
{
for ( int xIndex = 0; xIndex < gridSize && pointsRemaining > 0; ++xIndex )
{
QPointF positionShift( userPointRadius * xIndex, userPointRadius * yIndex );
QPointF labelShift( ( userPointRadius + symbolDiagonal / 2 ) * xIndex, ( userPointRadius + symbolDiagonal / 2 ) * yIndex );
symbolPositions.append( centerPoint + positionShift );
labelShifts.append( labelShift );
pointsRemaining--;
}
yIndex++;
}
centralizeGrid( symbolPositions, userPointRadius, gridSize );
centralizeGrid( labelShifts, userPointRadius, gridSize );
gridRadius = userPointRadius;
break;
}
}
}
void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRenderContext& symbolContext, QPointF centerPoint, int nPosition,
double symbolDiagonal, QList<QPointF>& symbolPositions, QList<QPointF>& labelShifts, double& circleRadius ) const
{
symbolPositions.clear();
labelShifts.clear();
if ( nPosition < 1 )
{
return;
}
else if ( nPosition == 1 ) //If there is only one feature, draw it exactly at the center position
{
symbolPositions.append( centerPoint );
labelShifts.append( QPointF( symbolDiagonal / 2.0, -symbolDiagonal / 2.0 ) );
return;
}
double circleAdditionPainterUnits = symbolContext.outputLineWidth( mCircleRadiusAddition );
switch ( mPlacement )
{
case Ring:
{
double minDiameterToFitSymbols = nPosition * symbolDiagonal / ( 2.0 * M_PI );
double radius = qMax( symbolDiagonal / 2, minDiameterToFitSymbols ) + circleAdditionPainterUnits;
double fullPerimeter = 2 * M_PI;
double angleStep = fullPerimeter / nPosition;
for ( double currentAngle = 0.0; currentAngle < fullPerimeter; currentAngle += angleStep )
{
double sinusCurrentAngle = sin( currentAngle );
double cosinusCurrentAngle = cos( currentAngle );
QPointF positionShift( radius * sinusCurrentAngle, radius * cosinusCurrentAngle );
QPointF labelShift(( radius + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radius + symbolDiagonal / 2 ) * cosinusCurrentAngle );
symbolPositions.append( centerPoint + positionShift );
labelShifts.append( labelShift );
}
circleRadius = radius;
break;
}
case ConcentricRings:
{
double centerDiagonal = symbolContext.renderContext().convertToPainterUnits( M_SQRT2 * mCenterSymbol->size(),
mCenterSymbol->sizeUnit(), mCenterSymbol->sizeMapUnitScale() );
int pointsRemaining = nPosition;
int ringNumber = 1;
double firstRingRadius = centerDiagonal / 2.0 + symbolDiagonal / 2.0;
while ( pointsRemaining > 0 )
{
double radiusCurrentRing = qMax( firstRingRadius + ( ringNumber - 1 ) * symbolDiagonal + ringNumber * circleAdditionPainterUnits, 0.0 );
int maxPointsCurrentRing = qMax( floor( 2 * M_PI * radiusCurrentRing / symbolDiagonal ), 1.0 );
int actualPointsCurrentRing = qMin( maxPointsCurrentRing, pointsRemaining );
double angleStep = 2 * M_PI / actualPointsCurrentRing;
double currentAngle = 0.0;
for ( int i = 0; i < actualPointsCurrentRing; ++i )
{
double sinusCurrentAngle = sin( currentAngle );
double cosinusCurrentAngle = cos( currentAngle );
QPointF positionShift( radiusCurrentRing * sinusCurrentAngle, radiusCurrentRing * cosinusCurrentAngle );
QPointF labelShift(( radiusCurrentRing + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radiusCurrentRing + symbolDiagonal / 2 ) * cosinusCurrentAngle );
symbolPositions.append( centerPoint + positionShift );
labelShifts.append( labelShift );
currentAngle += angleStep;
}
pointsRemaining -= actualPointsCurrentRing;
ringNumber++;
circleRadius = radiusCurrentRing;
}
break;
}
}
}