qt5base-lts/examples/opengl/overpainting/glwidget.cpp

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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** 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:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtWidgets>
#include <QtOpenGL>
#include <stdlib.h>
#include <math.h>
#include "bubble.h"
#include "qtlogo.h"
#include "glwidget.h"
#ifndef GL_MULTISAMPLE
#define GL_MULTISAMPLE 0x809D
#endif
//! [0]
GLWidget::GLWidget(QWidget *parent)
: QGLWidget(QGLFormat(QGL::SampleBuffers), parent)
{
QTime midnight(0, 0, 0);
qsrand(midnight.secsTo(QTime::currentTime()));
logo = 0;
xRot = 0;
yRot = 0;
zRot = 0;
qtGreen = QColor::fromCmykF(0.40, 0.0, 1.0, 0.0);
qtPurple = QColor::fromCmykF(0.39, 0.39, 0.0, 0.0);
animationTimer.setSingleShot(false);
connect(&animationTimer, SIGNAL(timeout()), this, SLOT(animate()));
animationTimer.start(25);
setAutoFillBackground(false);
setMinimumSize(200, 200);
setWindowTitle(tr("Overpainting a Scene"));
}
//! [0]
//! [1]
GLWidget::~GLWidget()
{
}
//! [1]
static void qNormalizeAngle(int &angle)
{
while (angle < 0)
angle += 360 * 16;
while (angle > 360 * 16)
angle -= 360 * 16;
}
void GLWidget::setXRotation(int angle)
{
qNormalizeAngle(angle);
if (angle != xRot)
xRot = angle;
}
void GLWidget::setYRotation(int angle)
{
qNormalizeAngle(angle);
if (angle != yRot)
yRot = angle;
}
void GLWidget::setZRotation(int angle)
{
qNormalizeAngle(angle);
if (angle != zRot)
zRot = angle;
}
//! [2]
void GLWidget::initializeGL()
{
glEnable(GL_MULTISAMPLE);
logo = new QtLogo(this);
logo->setColor(qtGreen.dark());
}
//! [2]
void GLWidget::mousePressEvent(QMouseEvent *event)
{
lastPos = event->pos();
}
void GLWidget::mouseMoveEvent(QMouseEvent *event)
{
int dx = event->x() - lastPos.x();
int dy = event->y() - lastPos.y();
if (event->buttons() & Qt::LeftButton) {
setXRotation(xRot + 8 * dy);
setYRotation(yRot + 8 * dx);
} else if (event->buttons() & Qt::RightButton) {
setXRotation(xRot + 8 * dy);
setZRotation(zRot + 8 * dx);
}
lastPos = event->pos();
}
void GLWidget::paintEvent(QPaintEvent *event)
{
makeCurrent();
//! [4]
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
//! [4]
//! [6]
qglClearColor(qtPurple.dark());
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_MULTISAMPLE);
static GLfloat lightPosition[4] = { 0.5, 5.0, 7.0, 1.0 };
glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);
setupViewport(width(), height());
//! [6]
//! [7]
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0, 0.0, -10.0);
glRotatef(xRot / 16.0, 1.0, 0.0, 0.0);
glRotatef(yRot / 16.0, 0.0, 1.0, 0.0);
glRotatef(zRot / 16.0, 0.0, 0.0, 1.0);
logo->draw();
//! [7]
//! [8]
glShadeModel(GL_FLAT);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glDisable(GL_LIGHTING);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
//! [8]
//! [10]
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
foreach (Bubble *bubble, bubbles) {
if (bubble->rect().intersects(event->rect()))
bubble->drawBubble(&painter);
}
drawInstructions(&painter);
painter.end();
}
//! [10]
//! [11]
void GLWidget::resizeGL(int width, int height)
{
setupViewport(width, height);
}
//! [11]
//! [12]
void GLWidget::showEvent(QShowEvent *event)
{
Q_UNUSED(event);
createBubbles(20 - bubbles.count());
}
//! [12]
QSize GLWidget::sizeHint() const
{
return QSize(400, 400);
}
void GLWidget::createBubbles(int number)
{
for (int i = 0; i < number; ++i) {
QPointF position(width()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))),
height()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))));
qreal radius = qMin(width(), height())*(0.0125 + 0.0875*qrand()/(RAND_MAX+1.0));
QPointF velocity(width()*0.0125*(-0.5 + qrand()/(RAND_MAX+1.0)),
height()*0.0125*(-0.5 + qrand()/(RAND_MAX+1.0)));
bubbles.append(new Bubble(position, radius, velocity));
}
}
//! [13]
void GLWidget::animate()
{
QMutableListIterator<Bubble*> iter(bubbles);
while (iter.hasNext()) {
Bubble *bubble = iter.next();
bubble->move(rect());
}
update();
}
//! [13]
//! [14]
void GLWidget::setupViewport(int width, int height)
{
int side = qMin(width, height);
glViewport((width - side) / 2, (height - side) / 2, side, side);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
#ifdef QT_OPENGL_ES
glOrthof(-0.5, +0.5, -0.5, 0.5, 4.0, 15.0);
#else
glOrtho(-0.5, +0.5, -0.5, 0.5, 4.0, 15.0);
#endif
glMatrixMode(GL_MODELVIEW);
}
//! [14]
//! [15]
void GLWidget::drawInstructions(QPainter *painter)
{
QString text = tr("Click and drag with the left mouse button "
"to rotate the Qt logo.");
QFontMetrics metrics = QFontMetrics(font());
int border = qMax(4, metrics.leading());
QRect rect = metrics.boundingRect(0, 0, width() - 2*border, int(height()*0.125),
Qt::AlignCenter | Qt::TextWordWrap, text);
painter->setRenderHint(QPainter::TextAntialiasing);
painter->fillRect(QRect(0, 0, width(), rect.height() + 2*border),
QColor(0, 0, 0, 127));
painter->setPen(Qt::white);
painter->fillRect(QRect(0, 0, width(), rect.height() + 2*border),
QColor(0, 0, 0, 127));
painter->drawText((width() - rect.width())/2, border,
rect.width(), rect.height(),
Qt::AlignCenter | Qt::TextWordWrap, text);
}
//! [15]