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** this package.

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** General Public License version 2.1 as published by the Free Software

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****************************************************************************/

#include <QtGui>

#include <QtOpenGL>

#include <math.h>

#include "glwidget.h"

#include "qtlogo.h"

#ifndef GL_MULTISAMPLE

#define GL_MULTISAMPLE  0x809D

#endif

//! [0]

GLWidget::GLWidget(QWidget *parent)

    : QGLWidget(QGLFormat(QGL::SampleBuffers), parent)

{

    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);

}

//! [0]

//! [1]

GLWidget::~GLWidget()

{

}

//! [1]

//! [2]

QSize GLWidget::minimumSizeHint() const

{

    return QSize(50, 50);

}

//! [2]

//! [3]

QSize GLWidget::sizeHint() const

//! [3] //! [4]

{

    return QSize(400, 400);

}

//! [4]

static void qNormalizeAngle(int &angle)

{

    while (angle < 0)

        angle += 360 * 16;

    while (angle > 360 * 16)

        angle -= 360 * 16;

}

//! [5]

void GLWidget::setXRotation(int angle)

{

    qNormalizeAngle(angle);

    if (angle != xRot) {

        xRot = angle;

        emit xRotationChanged(angle);

        updateGL();

    }

}

//! [5]

void GLWidget::setYRotation(int angle)

{

    qNormalizeAngle(angle);

    if (angle != yRot) {

        yRot = angle;

        emit yRotationChanged(angle);

        updateGL();

    }

}

void GLWidget::setZRotation(int angle)

{

    qNormalizeAngle(angle);

    if (angle != zRot) {

        zRot = angle;

        emit zRotationChanged(angle);

        updateGL();

    }

}

//! [6]

void GLWidget::initializeGL()

{

    qglClearColor(qtPurple.dark());

    logo = new QtLogo(this, 64);

    logo->setColor(qtGreen.dark());

    glEnable(GL_DEPTH_TEST);

    glEnable(GL_CULL_FACE);

    glShadeModel(GL_SMOOTH);

    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);

}

//! [6]

//! [7]

void GLWidget::paintGL()

{

    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]

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();

#ifdef QT_OPENGL_ES_1

    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);

}

//! [8]

//! [9]

void GLWidget::mousePressEvent(QMouseEvent *event)

{

    lastPos = event->pos();

}

//! [9]

//! [10]

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();

}

//! [10]