sphere-orbit/myglwidget.cpp

   1 #include <iostream>
   2 #include <QKeyEvent>
   3 #include <QtOpenGL>
   4
   5 #include <cmath>
   6 #include "myglwidget.h"
   7
   8 MyGLWidget::MyGLWidget(QWidget *parent)
   9     : QGLWidget(parent)
  10 {
  11     std::cout << "GLWidget() constructor\n";
  12
  13     nStacks = 10;
  14     nSlices = 10;
  15
  16     xRot = 0.0f;
  17     yRot = 0.0f;
  18     zRot = 0.0f;
  19
  20     //
  21     thread.setData(&this->data);
  22     thread.start();
  23
  24     // Setup timer
  25     connect(&timer, SIGNAL(timeout()), this, SLOT(pullData()));
  26     timer.start(10);
  27
  28     this->setMinimumWidth(300);
  29     this->setMinimumHeight(300);
  30 }
  31
  32 MyGLWidget::~MyGLWidget()
  33 {
  34     std::cout << "~GLWidget() deconstructor\n";
  35 }
  36
  37 void MyGLWidget::setNumOfStacks(int dir)
  38 {
  39     std::cout << "myglWidget::setNumOfStacks()" << std::endl;
  40
  41     nStacks += dir;
  42     if (nStacks < 4)
  43         nStacks = 3;
  44
  45     makeCurrent();
  46     glClear(GL_COLOR_BUFFER_BIT);
  47     drawSphere(nStacks, nSlices, 0.5f);
  48     updateGL();
  49 }
  50
  51 void MyGLWidget::setNumOfSlices(int dir)
  52 {
  53     std::cout << "myglWidget::setNumOfSlices()" << std::endl;
  54
  55     nSlices += dir;
  56     if (nSlices < 4)
  57         nSlices = 3;
  58
  59     makeCurrent();
  60     glClear(GL_COLOR_BUFFER_BIT);
  61     drawSphere(nStacks, nSlices, 0.5f);
  62     updateGL();
  63 }
  64
  65 void MyGLWidget::rotateX(GLfloat angle)
  66 {
  67     std::cout << "MyGLWidget::rotateX()\n";
  68
  69     xRot += angle;
  70     updateGL();
  71 }
  72
  73 void MyGLWidget::rotateY(GLfloat angle)
  74 {
  75     std::cout << "MyGLWidget::rotateY()\n";
  76
  77     yRot += angle;
  78     updateGL();
  79 }
  80
  81 void MyGLWidget::rotateZ(GLfloat angle)
  82 {
  83     std::cout << "MyGLWidget::rotateZ()\n";
  84
  85     zRot += angle;
  86     updateGL();
  87 }
  88
  89 void MyGLWidget::initializeGL()
  90 {
  91     std::cout << "MyGLWidget::initializeGL()\n";
  92
  93     // Enable backface culling
  94     glEnable(GL_CULL_FACE);
  95
  96     // Clear color is set to black
  97     glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  98     glShadeModel(GL_SMOOTH);
  99
 100     // Reset modelview matrix
 101     glMatrixMode(GL_MODELVIEW);
 102     glLoadIdentity();
 103
 104     // We don't need to call drawSphere() here,
 105     // since the resizeGL() will be called upon
 106     // the initial creation of the window.
 107 }
 108
 109 void MyGLWidget::paintGL()
 110 {
 111     std::cout << "MyGLWidget::paintGL()\n";
 112
 113     // Clear scene
 114     glClear(GL_COLOR_BUFFER_BIT);
 115
 116     // Reset modelview matrix
 117     glMatrixMode(GL_MODELVIEW);
 118     glLoadIdentity();
 119
 120     // Rotate appropriately
 121     glRotatef(xRot, 1.0f, 0.0f, 0.0f);
 122     glRotatef(yRot, 0.0f, 1.0f, 0.0f);
 123     glRotatef(zRot, 0.0f, 0.0f, 1.0f);
 124
 125     // Draw x, y, z axis
 126     drawAxis();
 127
 128     // Draw sphere
 129     drawSphere(nStacks, nSlices, 0.5f);
 130
 131     glFlush();
 132 }
 133
 134 void MyGLWidget::resizeGL(int width, int height)
 135 {
 136     std::cout << "MyGLWidget::resizeGL()\n";
 137     std::cout << "New width = " << width
 138               << "\nNew height = " << height << "\n";
 139
 140     // Update viewport to cover the whole screen
 141     glViewport(0, 0, width, height);
 142
 143     // Reset projection matrix
 144     glMatrixMode(GL_PROJECTION);
 145     glLoadIdentity();
 146     //gluPerspective(45.0, (GLfloat)width/(GLfloat)height, 0.1f, 100.0f);
 147
 148     // Reset modelview matrix
 149     glMatrixMode(GL_MODELVIEW);
 150     glLoadIdentity();
 151 }
 152
 153 void MyGLWidget::drawAxis(void)
 154 {
 155     // Draw axis
 156     glLineWidth(3);
 157     glEnable(GL_LINE_SMOOTH);
 158     glColor3f(0.0f, 1.0f, 0.0f);
 159
 160     glBegin(GL_LINES);
 161         glVertex3f(0.0f, 0.0f, 0.0f);    // x axis
 162         glVertex3f(1.0f, 0.0f, 0.0f);
 163
 164         glVertex3f(0.0f, 0.0f, 0.0f);    // y axis
 165         glVertex3f(0.0f, 1.0f, 0.0f);
 166
 167         glVertex3f(0.0f, 0.0f, 0.0f);    // z axis
 168         glVertex3f(0.0f, 0.0f, 1.0f);
 169     glEnd();
 170
 171     // Restore color and line width
 172     glColor3f(1.0f, 1.0f, 1.0f);
 173     glDisable(GL_LINE_SMOOTH);
 174     glLineWidth(1);
 175 }
 176
 177 void MyGLWidget::drawSphere(GLuint nStacks, GLuint nSlices, GLfloat r)
 178 {
 179     GLfloat theta, phi, x, y, z, stepTheta, stepPhi;
 180
 181     stepTheta = M_PI / nStacks;
 182     stepPhi = 2 * M_PI / nSlices;
 183
 184     for (theta = 0; theta <= M_PI; theta += stepTheta) {
 185         glBegin(GL_QUAD_STRIP);
 186         for (phi = 0; phi <= 2.0 * M_PI + 0.1; phi += stepPhi) {
 187             x = r * sin(theta) * cos(phi);
 188             y = r * sin(theta) * sin(phi);
 189             z = r * cos(theta);
 190             glVertex3f(x, y, z);
 191
 192             x = r * sin(theta + stepTheta) * cos(phi);
 193             y = r * sin(theta + stepTheta) * sin(phi);
 194             z = r * cos(theta + stepTheta);
 195             glVertex3f(x, y, z);
 196         }
 197         glEnd();
 198     }
 199
 200     // The boundary edges of the polygon are drawn as line segments.
 201     glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 202 }
 203
 204 void MyGLWidget::pullData(void)
 205 {
 206     float r;
 207
 208     mutex.lock();
 209     if (!data.isEmpty()) {
 210         r = data.dequeue();
 211         //std::cout << "r = " << r << std::endl;
 212         xRot = yRot = zRot = r;
 213     }
 214     else {
 215         mutex.unlock();
 216         std::cout << "MyGLWidget::pullData()\t[WAKING THREAD]\n";
 217         thread.condition.wakeOne();
 218         return;
 219     }
 220     mutex.unlock();
 221     updateGL();
 222 }