glwidget.cpp Example File
opengl/hellogl/glwidget.cpp
/****************************************************************************
**
** Copyright (C) 2005-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file. Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
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** review the following information:
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** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/
#include <QtGui>
#include <QtOpenGL>
#include <math.h>
#include "glwidget.h"
GLWidget::GLWidget(QWidget *parent)
: QGLWidget(parent)
{
object = 0;
xRot = 0;
yRot = 0;
zRot = 0;
trolltechGreen = QColor::fromCmykF(0.40, 0.0, 1.0, 0.0);
trolltechPurple = QColor::fromCmykF(0.39, 0.39, 0.0, 0.0);
}
GLWidget::~GLWidget()
{
makeCurrent();
glDeleteLists(object, 1);
}
QSize GLWidget::minimumSizeHint() const
{
return QSize(50, 50);
}
QSize GLWidget::sizeHint() const
{
return QSize(400, 400);
}
void GLWidget::setXRotation(int angle)
{
normalizeAngle(&angle);
if (angle != xRot) {
xRot = angle;
emit xRotationChanged(angle);
updateGL();
}
}
void GLWidget::setYRotation(int angle)
{
normalizeAngle(&angle);
if (angle != yRot) {
yRot = angle;
emit yRotationChanged(angle);
updateGL();
}
}
void GLWidget::setZRotation(int angle)
{
normalizeAngle(&angle);
if (angle != zRot) {
zRot = angle;
emit zRotationChanged(angle);
updateGL();
}
}
void GLWidget::initializeGL()
{
qglClearColor(trolltechPurple.dark());
object = makeObject();
glShadeModel(GL_FLAT);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
}
void GLWidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslated(0.0, 0.0, -10.0);
glRotated(xRot / 16.0, 1.0, 0.0, 0.0);
glRotated(yRot / 16.0, 0.0, 1.0, 0.0);
glRotated(zRot / 16.0, 0.0, 0.0, 1.0);
glCallList(object);
}
void GLWidget::resizeGL(int width, int height)
{
int side = qMin(width, height);
glViewport((width - side) / 2, (height - side) / 2, side, side);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-0.5, +0.5, +0.5, -0.5, 4.0, 15.0);
glMatrixMode(GL_MODELVIEW);
}
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();
}
GLuint GLWidget::makeObject()
{
GLuint list = glGenLists(1);
glNewList(list, GL_COMPILE);
glBegin(GL_QUADS);
GLdouble x1 = +0.06;
GLdouble y1 = -0.14;
GLdouble x2 = +0.14;
GLdouble y2 = -0.06;
GLdouble x3 = +0.08;
GLdouble y3 = +0.00;
GLdouble x4 = +0.30;
GLdouble y4 = +0.22;
quad(x1, y1, x2, y2, y2, x2, y1, x1);
quad(x3, y3, x4, y4, y4, x4, y3, x3);
extrude(x1, y1, x2, y2);
extrude(x2, y2, y2, x2);
extrude(y2, x2, y1, x1);
extrude(y1, x1, x1, y1);
extrude(x3, y3, x4, y4);
extrude(x4, y4, y4, x4);
extrude(y4, x4, y3, x3);
const double Pi = 3.14159265358979323846;
const int NumSectors = 200;
for (int i = 0; i < NumSectors; ++i) {
double angle1 = (i * 2 * Pi) / NumSectors;
GLdouble x5 = 0.30 * sin(angle1);
GLdouble y5 = 0.30 * cos(angle1);
GLdouble x6 = 0.20 * sin(angle1);
GLdouble y6 = 0.20 * cos(angle1);
double angle2 = ((i + 1) * 2 * Pi) / NumSectors;
GLdouble x7 = 0.20 * sin(angle2);
GLdouble y7 = 0.20 * cos(angle2);
GLdouble x8 = 0.30 * sin(angle2);
GLdouble y8 = 0.30 * cos(angle2);
quad(x5, y5, x6, y6, x7, y7, x8, y8);
extrude(x6, y6, x7, y7);
extrude(x8, y8, x5, y5);
}
glEnd();
glEndList();
return list;
}
void GLWidget::quad(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2,
GLdouble x3, GLdouble y3, GLdouble x4, GLdouble y4)
{
qglColor(trolltechGreen);
glVertex3d(x1, y1, -0.05);
glVertex3d(x2, y2, -0.05);
glVertex3d(x3, y3, -0.05);
glVertex3d(x4, y4, -0.05);
glVertex3d(x4, y4, +0.05);
glVertex3d(x3, y3, +0.05);
glVertex3d(x2, y2, +0.05);
glVertex3d(x1, y1, +0.05);
}
void GLWidget::extrude(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2)
{
qglColor(trolltechGreen.dark(250 + int(100 * x1)));
glVertex3d(x1, y1, +0.05);
glVertex3d(x2, y2, +0.05);
glVertex3d(x2, y2, -0.05);
glVertex3d(x1, y1, -0.05);
}
void GLWidget::normalizeAngle(int *angle)
{
while (*angle < 0)
*angle += 360 * 16;
while (*angle > 360 * 16)
*angle -= 360 * 16;
}
