##// 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:

r2539:74f3dbde7a75
r2542:189023d9a551
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chartlogvalueaxisy.cpp
137 lines | 4.6 KiB | text/x-c | CppLexer
/****************************************************************************
**
** 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 "chartlogvalueaxisy_p.h"
#include "chartpresenter_p.h"
#include "qlogvalueaxis.h"
#include "abstractchartlayout_p.h"
#include <QGraphicsLayout>
#include <qmath.h>
#include <QDebug>
QTCOMMERCIALCHART_BEGIN_NAMESPACE
ChartLogValueAxisY::ChartLogValueAxisY(QLogValueAxis *axis, QGraphicsItem *item)
: VerticalAxis(axis, item),
m_axis(axis)
{
QObject::connect(m_axis, SIGNAL(baseChanged(qreal)), this, SLOT(handleBaseChanged(qreal)));
QObject::connect(m_axis, SIGNAL(labelFormatChanged(QString)), this, SLOT(handleLabelFormatChanged(QString)));
}
ChartLogValueAxisY::~ChartLogValueAxisY()
{
}
QVector<qreal> ChartLogValueAxisY::calculateLayout() const
{
QVector<qreal> points;
qreal logMax = log10(m_axis->max()) / log10(m_axis->base());
qreal logMin = log10(m_axis->min()) / log10(m_axis->base());
qreal leftEdge = logMin < logMax ? logMin : logMax;
qreal ceilEdge = ceil(leftEdge);
int tickCount = qAbs(ceil(logMax) - ceil(logMin));
points.resize(tickCount);
const QRectF &gridRect = gridGeometry();
const qreal deltaY = gridRect.height() / qAbs(logMax - logMin);
for (int i = 0; i < tickCount; ++i)
points[i] = (ceilEdge + qreal(i)) * -deltaY - leftEdge * -deltaY + gridRect.bottom();
return points;
}
void ChartLogValueAxisY::updateGeometry()
{
const QVector<qreal> &layout = ChartAxisElement::layout();
if (layout.isEmpty())
return;
setLabels(createLogValueLabels(m_axis->min(), m_axis->max(), m_axis->base(), layout.size(), m_axis->labelFormat()));
VerticalAxis::updateGeometry();
}
void ChartLogValueAxisY::handleBaseChanged(qreal base)
{
Q_UNUSED(base);
QGraphicsLayoutItem::updateGeometry();
if(presenter()) presenter()->layout()->invalidate();
}
void ChartLogValueAxisY::handleLabelFormatChanged(const QString &format)
{
Q_UNUSED(format);
QGraphicsLayoutItem::updateGeometry();
if(presenter()) presenter()->layout()->invalidate();
}
QSizeF ChartLogValueAxisY::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
Q_UNUSED(constraint)
QSizeF sh;
QSizeF base = VerticalAxis::sizeHint(which, constraint);
QStringList ticksList;
qreal logMax = log10(m_axis->max()) / log10(m_axis->base());
qreal logMin = log10(m_axis->min()) / log10(m_axis->base());
int tickCount = qAbs(ceil(logMax) - ceil(logMin));
if (m_axis->max() > m_axis->min() && tickCount > 0)
ticksList = createLogValueLabels(m_axis->min(), m_axis->max(), m_axis->base(), tickCount, m_axis->labelFormat());
else
ticksList.append(QString(" "));
qreal width = 0;
// Height of vertical axis sizeHint indicates the maximum distance labels can extend past
// first and last ticks. Base height is irrelevant.
qreal height = 0;
switch (which) {
case Qt::MinimumSize: {
QRectF boundingRect = ChartPresenter::textBoundingRect(axis()->labelsFont(), "...", axis()->labelsAngle());
width = boundingRect.width() + labelPadding() + base.width() + 1.0;
height = boundingRect.height() / 2.0;
sh = QSizeF(width, height);
break;
}
case Qt::PreferredSize: {
qreal labelWidth = 0.0;
qreal firstHeight = -1.0;
foreach (const QString& s, ticksList) {
QRectF rect = ChartPresenter::textBoundingRect(axis()->labelsFont(), s, axis()->labelsAngle());
labelWidth = qMax(rect.width(), labelWidth);
height = rect.height();
if (firstHeight < 0.0)
firstHeight = height;
}
width = labelWidth + labelPadding() + base.width() + 2.0; //two pixels of tolerance
height = qMax(height, firstHeight) / 2.0;
sh = QSizeF(width, height);
break;
}
default:
break;
}
return sh;
}
#include "moc_chartlogvalueaxisy_p.cpp"
QTCOMMERCIALCHART_END_NAMESPACE