在lesson1的基礎上加入一個三角形和一個正方形。

#-------------------------------------------------
#
# 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();
}