##// END OF EJS Templates
Optimize polar chart radius calculation a bit....
Optimize polar chart radius calculation a bit. Current algorithm still results in an occasional extra unneeded iteration, as it uses only crude approximation for radius reduction. However, any speedup gained by accurately calculating needed reduction would be very minor compared to approximations used, so it doesn't seem worth the effort to figure out the complex math. Change-Id: If670a1b058a85cd0305b93f62e6388b463bafd0d Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

File last commit:

r2540:18da5db7d538
r2542:189023d9a551
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polarchartaxisradial.cpp
288 lines | 10.9 KiB | text/x-c | CppLexer
/ src / axis / polarchartaxisradial.cpp
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.digia.com
**
** This file is part of the Qt Commercial Charts Add-on.
**
** $QT_BEGIN_LICENSE$
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.digia.com
** $QT_END_LICENSE$
**
****************************************************************************/
#include "polarchartaxisradial_p.h"
#include "chartpresenter_p.h"
#include "abstractchartlayout_p.h"
#include "qabstractaxis_p.h"
#include "linearrowitem_p.h"
QTCOMMERCIALCHART_BEGIN_NAMESPACE
PolarChartAxisRadial::PolarChartAxisRadial(QAbstractAxis *axis, QGraphicsItem *item, bool intervalAxis)
: PolarChartAxis(axis, item, intervalAxis)
{
}
PolarChartAxisRadial::~PolarChartAxisRadial()
{
}
void PolarChartAxisRadial::updateGeometry()
{
const QVector<qreal> &layout = this->layout();
if (layout.isEmpty())
return;
createAxisLabels(layout);
QStringList labelList = labels();
QPointF center = axisGeometry().center();
QList<QGraphicsItem *> arrowItemList = arrowItems();
QList<QGraphicsItem *> gridItemList = gridItems();
QList<QGraphicsItem *> labelItemList = labelItems();
QList<QGraphicsItem *> shadeItemList = shadeItems();
QGraphicsTextItem* title = titleItem();
qreal radius = axisGeometry().height() / 2.0;
QLineF line(center, center + QPointF(0, -radius));
QGraphicsLineItem *axisLine = static_cast<QGraphicsLineItem *>(arrowItemList.at(0));
axisLine->setLine(line);
QRectF previousLabelRect;
bool firstShade = true;
bool nextTickVisible = false;
if (layout.size())
nextTickVisible = !(layout.at(0) < 0.0 || layout.at(0) > radius);
for (int i = 0; i < layout.size(); ++i) {
qreal radialCoordinate = layout.at(i);
QGraphicsEllipseItem *gridItem = static_cast<QGraphicsEllipseItem *>(gridItemList.at(i));
QGraphicsLineItem *tickItem = static_cast<QGraphicsLineItem *>(arrowItemList.at(i + 1));
QGraphicsTextItem *labelItem = static_cast<QGraphicsTextItem *>(labelItemList.at(i));
QGraphicsPathItem *shadeItem = 0;
if (i == 0)
shadeItem = static_cast<QGraphicsPathItem *>(shadeItemList.at(0));
else if (i % 2)
shadeItem = static_cast<QGraphicsPathItem *>(shadeItemList.at((i / 2) + 1));
// Ignore ticks outside valid range
bool currentTickVisible = nextTickVisible;
if ((i == layout.size() - 1)
|| layout.at(i + 1) < 0.0
|| layout.at(i + 1) > radius) {
nextTickVisible = false;
} else {
nextTickVisible = true;
}
qreal labelCoordinate = radialCoordinate;
qreal labelVisible = currentTickVisible;
qreal labelPad = labelPadding() / 2.0;
if (intervalAxis()) {
qreal farEdge;
if (i == (layout.size() - 1))
farEdge = radius;
else
farEdge = qMin(radius, layout.at(i + 1));
// Adjust the labelCoordinate to show it if next tick is visible
if (nextTickVisible)
labelCoordinate = qMax(qreal(0.0), labelCoordinate);
labelCoordinate = (labelCoordinate + farEdge) / 2.0;
if (labelCoordinate > 0.0 && labelCoordinate < radius)
labelVisible = true;
else
labelVisible = false;
}
// Radial axis label
if (axis()->labelsVisible() && labelVisible) {
labelItem->setHtml(labelList.at(i));
QRectF labelRect = labelItem->boundingRect();
QPointF labelCenter = labelRect.center();
labelItem->setTransformOriginPoint(labelCenter.x(), labelCenter.y());
QRectF boundingRect = ChartPresenter::textBoundingRect(axis()->labelsFont(), labelList.at(i), axis()->labelsAngle());
boundingRect.moveCenter(labelCenter);
QPointF positionDiff(labelRect.topLeft() - boundingRect.topLeft());
QPointF labelPoint = center;
if (intervalAxis())
labelPoint += QPointF(labelPad, -labelCoordinate - (boundingRect.height() / 2.0));
else
labelPoint += QPointF(labelPad, labelPad - labelCoordinate);
labelRect.moveTopLeft(labelPoint);
labelItem->setPos(labelRect.topLeft() + positionDiff);
// Label overlap detection
labelRect.setSize(boundingRect.size());
if ((i && previousLabelRect.intersects(labelRect))
|| !axisGeometry().contains(labelRect)) {
labelVisible = false;
} else {
previousLabelRect = labelRect;
labelVisible = true;
}
}
labelItem->setVisible(labelVisible);
if (!currentTickVisible) {
gridItem->setVisible(false);
tickItem->setVisible(false);
if (shadeItem)
shadeItem->setVisible(false);
continue;
}
// Radial grid line
QRectF gridRect;
gridRect.setWidth(radialCoordinate * 2.0);
gridRect.setHeight(radialCoordinate * 2.0);
gridRect.moveCenter(center);
gridItem->setRect(gridRect);
gridItem->setVisible(true);
// Tick
QLineF tickLine(-tickWidth(), 0.0, tickWidth(), 0.0);
tickLine.translate(center.rx(), gridRect.top());
tickItem->setLine(tickLine);
tickItem->setVisible(true);
// Shades
if (i % 2 || (i == 0 && !nextTickVisible)) {
QPainterPath path;
if (i == 0) {
// If first tick is also the last, we need to custom fill the inner circle
// or it won't get filled.
QRectF innerCircle(0.0, 0.0, layout.at(0) * 2.0, layout.at(0) * 2.0);
innerCircle.moveCenter(center);
path.addEllipse(innerCircle);
} else {
QRectF otherGridRect;
if (!nextTickVisible) { // Last visible tick
otherGridRect = axisGeometry();
} else {
qreal otherGridRectDimension = layout.at(i + 1) * 2.0;
otherGridRect.setWidth(otherGridRectDimension);
otherGridRect.setHeight(otherGridRectDimension);
otherGridRect.moveCenter(center);
}
path.addEllipse(gridRect);
path.addEllipse(otherGridRect);
// Add additional shading in first visible shade item if there is a partial tick
// to be filled at the center (log & category axes)
if (firstShade) {
QGraphicsPathItem *specialShadeItem = static_cast<QGraphicsPathItem *>(shadeItemList.at(0));
if (layout.at(i - 1) > 0.0) {
QRectF innerCircle(0.0, 0.0, layout.at(i - 1) * 2.0, layout.at(i - 1) * 2.0);
innerCircle.moveCenter(center);
QPainterPath specialPath;
specialPath.addEllipse(innerCircle);
specialShadeItem->setPath(specialPath);
specialShadeItem->setVisible(true);
} else {
specialShadeItem->setVisible(false);
}
}
}
shadeItem->setPath(path);
shadeItem->setVisible(true);
firstShade = false;
}
}
// Title, along the 0 axis
QString titleText = axis()->titleText();
if (!titleText.isEmpty() && axis()->isTitleVisible()) {
title->setHtml(ChartPresenter::truncatedText(axis()->titleFont(), titleText, qreal(0.0), radius, Qt::Horizontal, QRectF()));
QRectF titleBoundingRect = title->boundingRect();
QPointF titleCenter = titleBoundingRect.center();
QPointF arrowCenter = axisLine->boundingRect().center();
QPointF titleCenterDiff = arrowCenter - titleCenter;
title->setPos(titleCenterDiff.x() - titlePadding() - (titleBoundingRect.height() / 2.0), titleCenterDiff.y());
title->setTransformOriginPoint(titleCenter);
title->setRotation(270.0);
}
QGraphicsLayoutItem::updateGeometry();
}
Qt::Orientation PolarChartAxisRadial::orientation() const
{
return Qt::Vertical;
}
void PolarChartAxisRadial::createItems(int count)
{
if (arrowItems().count() == 0) {
// radial axis center line
QGraphicsLineItem *arrow = new LineArrowItem(this, presenter()->rootItem());
arrow->setPen(axis()->linePen());
arrowGroup()->addToGroup(arrow);
}
for (int i = 0; i < count; ++i) {
QGraphicsLineItem *arrow = new QGraphicsLineItem(presenter()->rootItem());
QGraphicsEllipseItem *grid = new QGraphicsEllipseItem(presenter()->rootItem());
QGraphicsTextItem *label = new QGraphicsTextItem(presenter()->rootItem());
QGraphicsTextItem *title = titleItem();
arrow->setPen(axis()->linePen());
grid->setPen(axis()->gridLinePen());
label->setFont(axis()->labelsFont());
label->setDefaultTextColor(axis()->labelsBrush().color());
label->setRotation(axis()->labelsAngle());
title->setFont(axis()->titleFont());
title->setDefaultTextColor(axis()->titleBrush().color());
title->setHtml(axis()->titleText());
arrowGroup()->addToGroup(arrow);
gridGroup()->addToGroup(grid);
labelGroup()->addToGroup(label);
if (gridItems().size() == 1 || (((gridItems().size() + 1) % 2) && gridItems().size() > 0)) {
QGraphicsPathItem *shade = new QGraphicsPathItem(presenter()->rootItem());
shade->setPen(axis()->shadesPen());
shade->setBrush(axis()->shadesBrush());
shadeGroup()->addToGroup(shade);
}
}
}
void PolarChartAxisRadial::handleArrowPenChanged(const QPen &pen)
{
foreach (QGraphicsItem *item, arrowItems())
static_cast<QGraphicsLineItem *>(item)->setPen(pen);
}
void PolarChartAxisRadial::handleGridPenChanged(const QPen &pen)
{
foreach (QGraphicsItem *item, gridItems())
static_cast<QGraphicsEllipseItem *>(item)->setPen(pen);
}
QSizeF PolarChartAxisRadial::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
Q_UNUSED(which);
Q_UNUSED(constraint);
return QSizeF(-1.0, -1.0);
}
qreal PolarChartAxisRadial::preferredAxisRadius(const QSizeF &maxSize)
{
qreal radius = maxSize.height() / 2.0;
if (maxSize.width() < maxSize.height())
radius = maxSize.width() / 2.0;
return radius;
}
#include "moc_polarchartaxisradial_p.cpp"
QTCOMMERCIALCHART_END_NAMESPACE