qt5base-lts/examples/opengl/2dpainting/helper.cpp
hjk 0136252cb2 Polish code of some opengl examples
Change-Id: If24ae1845176fc525cf6a239a5079f4802f8df3f
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
2012-12-28 20:44:55 +01:00

95 lines
3.3 KiB
C++

/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
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** the documentation and/or other materials provided with the
** distribution.
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****************************************************************************/
#include "helper.h"
#include <QPainter>
#include <QPaintEvent>
#include <QWidget>
//! [0]
Helper::Helper()
{
QLinearGradient gradient(QPointF(50, -20), QPointF(80, 20));
gradient.setColorAt(0.0, Qt::white);
gradient.setColorAt(1.0, QColor(0xa6, 0xce, 0x39));
background = QBrush(QColor(64, 32, 64));
circleBrush = QBrush(gradient);
circlePen = QPen(Qt::black);
circlePen.setWidth(1);
textPen = QPen(Qt::white);
textFont.setPixelSize(50);
}
//! [0]
//! [1]
void Helper::paint(QPainter *painter, QPaintEvent *event, int elapsed)
{
painter->fillRect(event->rect(), background);
painter->translate(100, 100);
//! [1]
//! [2]
painter->save();
painter->setBrush(circleBrush);
painter->setPen(circlePen);
painter->rotate(elapsed * 0.030);
qreal r = elapsed / 1000.0;
int n = 30;
for (int i = 0; i < n; ++i) {
painter->rotate(30);
qreal factor = (i + r) / n;
qreal radius = 0 + 120.0 * factor;
qreal circleRadius = 1 + factor * 20;
painter->drawEllipse(QRectF(radius, -circleRadius,
circleRadius * 2, circleRadius * 2));
}
painter->restore();
//! [2]
//! [3]
painter->setPen(textPen);
painter->setFont(textFont);
painter->drawText(QRect(-50, -50, 100, 100), Qt::AlignCenter, QStringLiteral("Qt"));
}
//! [3]