qt opengl lesson2 绘制一个三角形和一个正方形

#-------------------------------------------------
#
# Project created by QtCreator 2017-01-19T20:33:38
#
#-------------------------------------------------

QT       += core gui opengl

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = lesson2
TEMPLATE = app

SOURCES += main.cpp \
myglwidget.cpp

HEADERS  += \
myglwidget.h

LIBS += -lglut -lGLU

#ifndef MYGLWIDGET_H
#define MYGLWIDGET_H

#include <QGLWidget>
#include <QKeyEvent>

class MyGLWidget : public QGLWidget
{
Q_OBJECT
public:
explicit MyGLWidget(QWidget *parent = 0);
~MyGLWidget();

protected:
virtual void paintGL();
virtual void initializeGL();
virtual void resizeGL(int w, int h);
virtual void keyPressEvent(QKeyEvent *event);

private:
bool mFullScreen;
};

#endif // MYGLWIDGET_H

#include <QApplication>
#include <GL/glu.h>
#include "myglwidget.h"

MyGLWidget::MyGLWidget(QWidget *parent)
{
showNormal();
}

MyGLWidget::~MyGLWidget()
{

}

void MyGLWidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();

glTranslatef(-1.5f, 0.0f, -6.0f);

// draw triangle
glBegin(GL_TRIANGLES);
glVertex3f(0.0f, 1.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glVertex3f(1.0f, -1.0f, 0.0f);
glEnd();

glTranslatef(3.0f, 0.0f, 0.0f);

glBegin(GL_QUADS);
glVertex3f(-1.0f, 1.0f, 0.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glVertex3f(1.0f, -1.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glEnd();
}

void MyGLWidget::initializeGL()
{
glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 1.0f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
}

void MyGLWidget::resizeGL(int width, int height)
{
if (height == 0) height = 1;
glViewport(0, 0, width, height);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f, (GLfloat)width/(GLfloat)height, 0.1f, 100.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void MyGLWidget::keyPressEvent(QKeyEvent *event)
{
switch(event->key()) {
case Qt::Key_F2: {
mFullScreen = !mFullScreen;
if (mFullScreen)
showFullScreen();
else
showNormal();
updateGL();
break;
}
case Qt::Key_Escape: {
qApp->exit();
break;
}
}
}

#include <QApplication>
#include "myglwidget.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyGLWidget w;
w.show();
return a.exec();
}