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     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

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     7 ** This file is part of the examples of the Qt Toolkit.

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    16 ** GNU Lesser General Public License Usage

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

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    38 ** $QT_END_LICENSE$

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    40 ****************************************************************************/

    41 

    42 #include "glwidget.h"

    43 #include <math.h>

    44 

    45 #ifndef GL_MULTISAMPLE

    46 #define GL_MULTISAMPLE  0x809D

    47 #endif

    48 

    49 GLWidget::GLWidget(QWidget *parent)

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

    51 {

    52     startTimer(40);

    53     setWindowTitle(tr("Sample Buffers"));

    54 }

    55 

    56 void GLWidget::initializeGL()

    57 {

    58     glMatrixMode(GL_PROJECTION);

    59     glLoadIdentity();

    60     glOrtho(-.5, .5, .5, -.5, -1000, 1000);

    61     glMatrixMode(GL_MODELVIEW);

    62     glLoadIdentity();

    63     glClearColor(1.0f, 1.0f, 1.0f, 1.0f);

    64 

    65     makeObject();

    66 }

    67 

    68 void GLWidget::resizeGL(int w, int h)

    69 {

    70     glViewport(0, 0, w, h);

    71 }

    72 

    73 void GLWidget::paintGL()

    74 {

    75     static float rot = 0.0;

    76     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    77 

    78     glMatrixMode(GL_MODELVIEW);

    79     glPushMatrix();

    80     glEnable(GL_MULTISAMPLE);

    81     glTranslatef(-0.25f, -0.10f, 0.0f);

    82     glScalef(0.75f, 1.15f, 0.0f);

    83     glRotatef(rot, 0.0f, 0.f, 1.0f);

    84     glCallList(list);

    85     glPopMatrix();

    86 

    87     glPushMatrix();

    88     glDisable(GL_MULTISAMPLE);

    89     glTranslatef(0.25f, -0.10f, 0.0f);

    90     glScalef(0.75f, 1.15f, 0.0f);

    91     glRotatef(rot, 0.0f, 0.0f, 1.0f);

    92     glCallList(list);

    93     glPopMatrix();

    94 

    95     rot += 0.2f;

    96 

    97     qglColor(Qt::black);

    98     renderText(-0.35, 0.4, 0.0, "Multisampling enabled");

    99     renderText(0.15, 0.4, 0.0, "Multisampling disabled");

   100 }

   101 

   102 void GLWidget::timerEvent(QTimerEvent *)

   103 {

   104     update();

   105 }

   106 

   107 void GLWidget::makeObject()

   108 {

   109     QColor qtGreen(QColor::fromCmykF(0.40, 0.0, 1.0, 0.0));

   110     const double Pi = 3.14159265358979323846;

   111     const int NumSectors = 15;

   112     GLdouble x1 = +0.06;

   113     GLdouble y1 = -0.14;

   114     GLdouble x2 = +0.14;

   115     GLdouble y2 = -0.06;

   116     GLdouble x3 = +0.08;

   117     GLdouble y3 = +0.00;

   118     GLdouble x4 = +0.30;

   119     GLdouble y4 = +0.22;

   120 

   121     list = glGenLists(1);

   122     glNewList(list, GL_COMPILE);

   123     {

   124         for (int i = 0; i < NumSectors; ++i) {

   125             double angle1 = (i * 2 * Pi) / NumSectors;

   126             GLdouble x5 = 0.30 * sin(angle1);

   127             GLdouble y5 = 0.30 * cos(angle1);

   128             GLdouble x6 = 0.20 * sin(angle1);

   129             GLdouble y6 = 0.20 * cos(angle1);

   130 

   131             double angle2 = ((i + 1) * 2 * Pi) / NumSectors;

   132             GLdouble x7 = 0.20 * sin(angle2);

   133             GLdouble y7 = 0.20 * cos(angle2);

   134             GLdouble x8 = 0.30 * sin(angle2);

   135             GLdouble y8 = 0.30 * cos(angle2);

   136 

   137             qglColor(qtGreen);

   138             quad(GL_QUADS, x5, y5, x6, y6, x7, y7, x8, y8);

   139             qglColor(Qt::black);

   140             quad(GL_LINE_LOOP, x5, y5, x6, y6, x7, y7, x8, y8);

   141         }

   142 

   143         qglColor(qtGreen);

   144         quad(GL_QUADS, x1, y1, x2, y2, y2, x2, y1, x1);

   145         quad(GL_QUADS, x3, y3, x4, y4, y4, x4, y3, x3);

   146 

   147         qglColor(Qt::black);

   148         quad(GL_LINE_LOOP, x1, y1, x2, y2, y2, x2, y1, x1);

   149         quad(GL_LINE_LOOP, x3, y3, x4, y4, y4, x4, y3, x3);

   150     }

   151     glEndList();

   152 }

   153 

   154 void GLWidget::quad(GLenum primitive, GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2,

   155                     GLdouble x3, GLdouble y3, GLdouble x4, GLdouble y4)

   156 {

   157     glBegin(primitive);

   158     {

   159         glVertex2d(x1, y1);

   160         glVertex2d(x2, y2);

   161         glVertex2d(x3, y3);

   162         glVertex2d(x4, y4);

   163     }

   164     glEnd();

   165 }