glwidget.cpp Example File
opengl/grabber/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)
{
gear1 = 0;
gear2 = 0;
gear3 = 0;
xRot = 0;
yRot = 0;
zRot = 0;
gear1Rot = 0;
QTimer *timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(advanceGears()));
timer->start(20);
}
GLWidget::~GLWidget()
{
makeCurrent();
glDeleteLists(gear1, 1);
glDeleteLists(gear2, 1);
glDeleteLists(gear3, 1);
}
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()
{
static const GLfloat lightPos[4] = { 5.0f, 5.0f, 10.0f, 1.0f };
static const GLfloat reflectance1[4] = { 0.8f, 0.1f, 0.0f, 1.0f };
static const GLfloat reflectance2[4] = { 0.0f, 0.8f, 0.2f, 1.0f };
static const GLfloat reflectance3[4] = { 0.2f, 0.2f, 1.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
gear1 = makeGear(reflectance1, 1.0, 4.0, 1.0, 0.7, 20);
gear2 = makeGear(reflectance2, 0.5, 2.0, 2.0, 0.7, 10);
gear3 = makeGear(reflectance3, 1.3, 2.0, 0.5, 0.7, 10);
glEnable(GL_NORMALIZE);
}
void GLWidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
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);
drawGear(gear1, -3.0, -2.0, 0.0, gear1Rot / 16.0);
drawGear(gear2, +3.1, -2.0, 0.0, -2.0 * (gear1Rot / 16.0) - 9.0);
glRotated(+90.0, 1.0, 0.0, 0.0);
drawGear(gear3, -3.1, -1.8, -2.2, +2.0 * (gear1Rot / 16.0) - 2.0);
glPopMatrix();
}
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();
glFrustum(-1.0, +1.0, -1.0, 1.0, 5.0, 60.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslated(0.0, 0.0, -40.0);
}
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::advanceGears()
{
gear1Rot += 2 * 16;
updateGL();
}
GLuint GLWidget::makeGear(const GLfloat *reflectance, GLdouble innerRadius,
GLdouble outerRadius, GLdouble thickness,
GLdouble toothSize, GLint toothCount)
{
const double Pi = 3.14159265358979323846;
GLuint list = glGenLists(1);
glNewList(list, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, reflectance);
GLdouble r0 = innerRadius;
GLdouble r1 = outerRadius - toothSize / 2.0;
GLdouble r2 = outerRadius + toothSize / 2.0;
GLdouble delta = (2.0 * Pi / toothCount) / 4.0;
GLdouble z = thickness / 2.0;
int i, j;
glShadeModel(GL_FLAT);
for (i = 0; i < 2; ++i) {
GLdouble sign = (i == 0) ? +1.0 : -1.0;
glNormal3d(0.0, 0.0, sign);
glBegin(GL_QUAD_STRIP);
for (j = 0; j <= toothCount; ++j) {
GLdouble angle = 2.0 * Pi * j / toothCount;
glVertex3d(r0 * cos(angle), r0 * sin(angle), sign * z);
glVertex3d(r1 * cos(angle), r1 * sin(angle), sign * z);
glVertex3d(r0 * cos(angle), r0 * sin(angle), sign * z);
glVertex3d(r1 * cos(angle + 3 * delta), r1 * sin(angle + 3 * delta),
sign * z);
}
glEnd();
glBegin(GL_QUADS);
for (j = 0; j < toothCount; ++j) {
GLdouble angle = 2.0 * Pi * j / toothCount;
glVertex3d(r1 * cos(angle), r1 * sin(angle), sign * z);
glVertex3d(r2 * cos(angle + delta), r2 * sin(angle + delta),
sign * z);
glVertex3d(r2 * cos(angle + 2 * delta), r2 * sin(angle + 2 * delta),
sign * z);
glVertex3d(r1 * cos(angle + 3 * delta), r1 * sin(angle + 3 * delta),
sign * z);
}
glEnd();
}
glBegin(GL_QUAD_STRIP);
for (i = 0; i < toothCount; ++i) {
for (j = 0; j < 2; ++j) {
GLdouble angle = 2.0 * Pi * (i + (j / 2.0)) / toothCount;
GLdouble s1 = r1;
GLdouble s2 = r2;
if (j == 1)
qSwap(s1, s2);
glNormal3d(cos(angle), sin(angle), 0.0);
glVertex3d(s1 * cos(angle), s1 * sin(angle), +z);
glVertex3d(s1 * cos(angle), s1 * sin(angle), -z);
glNormal3d(s2 * sin(angle + delta) - s1 * sin(angle),
s1 * cos(angle) - s2 * cos(angle + delta), 0.0);
glVertex3d(s2 * cos(angle + delta), s2 * sin(angle + delta), +z);
glVertex3d(s2 * cos(angle + delta), s2 * sin(angle + delta), -z);
}
}
glVertex3d(r1, 0.0, +z);
glVertex3d(r1, 0.0, -z);
glEnd();
glShadeModel(GL_SMOOTH);
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= toothCount; ++i) {
GLdouble angle = i * 2.0 * Pi / toothCount;
glNormal3d(-cos(angle), -sin(angle), 0.0);
glVertex3d(r0 * cos(angle), r0 * sin(angle), +z);
glVertex3d(r0 * cos(angle), r0 * sin(angle), -z);
}
glEnd();
glEndList();
return list;
}
void GLWidget::drawGear(GLuint gear, GLdouble dx, GLdouble dy, GLdouble dz,
GLdouble angle)
{
glPushMatrix();
glTranslated(dx, dy, dz);
glRotated(angle, 0.0, 0.0, 1.0);
glCallList(gear);
glPopMatrix();
}
void GLWidget::normalizeAngle(int *angle)
{
while (*angle < 0)
*angle += 360 * 16;
while (*angle > 360 * 16)
*angle -= 360 * 16;
}
