Qt_OpenGL：3D图形小测

#ifndef GLWIDGET_H
#define GLWIDGET_H

#include <QtOpenGL>
#include <QWidget>

class GLWidget : public QGLWidget
{
    Q_OBJECT

public:
    explicit GLWidget(QGLWidget *parent = 0);
    ~GLWidget();

protected:
    void initializeGL();
    void paintGL();
    void resizeGL(int width, int height);
    void keyPressEvent(QKeyEvent *e);
    bool fullscreen;

private:
    float triangle_rotate;
    float circle_rotate;
    float quads_rotate;
    float rotate_angle1;
    float rotate_angle2;

};

#endif // GLWIDGET_H

#include "glwidget.h"

#include <QtGui>
#include <QtCore>
#include <QtOpenGL>

GLWidget::GLWidget(QGLWidget *parent) :
    QGLWidget(parent)
{
  //  setCaption("The Opengl for Qt Framework");
    fullscreen = false;
    rotate_angle1 = 0.0;
    rotate_angle2 = 0.0;
}

//这是对虚函数，这里是重写该函数
void GLWidget::initializeGL()
{
    setGeometry(300, 150, 640, 480);//设置窗口初始位置和大小
    glShadeModel(GL_SMOOTH);//设置阴影平滑模式
    glClearColor(0.0, 0.0, 0.0, 0);//改变窗口的背景颜色，不过我这里貌似设置后并没有什么效果
    glClearDepth(1.0);//设置深度缓存
    glEnable(GL_DEPTH_TEST);//允许深度测试
    glDepthFunc(GL_LEQUAL);//设置深度测试类型
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);//进行透视校正
}

void GLWidget::paintGL()
{
    //glClear()函数在这里就是对initializeGL()函数中设置的颜色和缓存深度等起作用
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    /*下面开始画四棱锥*/
    glLoadIdentity();//重置当前的模型观察矩阵
    glTranslatef(-0.5, 0.0, -0.5);//将绘制平面移动到屏幕的左半平面和里面
    glRotatef(rotate_angle1, 0.2, 0.2, 0.0);
    glBegin(GL_TRIANGLES);
    /*前正面的绘制*/
    glColor3f(1.0, 0.0, 0.0);//上顶点红色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下点蓝色
    glVertex3f(-0.3, -0.3, 0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角绿色
    glVertex3f(0.3, -0.3, 0.3);
    /*右侧面的绘制*/
    glColor3f(1.0, 0.0, 0.0);//上顶点红色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下点蓝色
    glVertex3f(0.3, -0.3, 0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角绿色
    glVertex3f(0.3, -0.3, -0.3);
    /*后侧面的绘制*/
    glColor3f(1.0, 0.0, 0.0);//上顶点红色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下点蓝色
    glVertex3f(0.3, -0.3, -0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角绿色
    glVertex3f(-0.3, -0.3, -0.3);
    /*左侧面的绘制*/
    glColor3f(1.0, 0.0, 0.0);//上顶点红色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下点蓝色
    glVertex3f(-0.3, -0.3, -0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角绿色
    glVertex3f(-0.3, -0.3, 0.3);
    rotate_angle1 += 3.0;
    glEnd();
    /*底面四边形的绘制,使四棱锥封闭起来*/
    glBegin(GL_QUADS);
    glColor3f(0.0, 0.0, 1.0);
    glVertex3f(-0.3, -0.3, 0.3);
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(0.3, -0.3, 0.3);
    glColor3f(0.0, 0.0, 1.0);
    glVertex3f(0.3, -0.3, -0.3);
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(-0.3, -0.3, -0.3);
    glEnd();

    /*下面开始画立方体*/
    glLoadIdentity();
    glTranslated(0.5, 0, 0.5);//将绘制平面移动到屏幕的右半平面和外面
    glRotatef(rotate_angle2, -0.2, 0.2, -0.3);
    glBegin(GL_QUADS);
    //上顶面
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(-0.3, 0.3, -0.3);
    glVertex3f(-0.3, 0.3, 0.3);
    glVertex3f(0.3, 0.3, 0.3);
    glVertex3f(0.3, 0.3, -0.3);
    //下顶面
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(-0.3, -0.3, -0.3);
    glVertex3f(-0.3, -0.3, 0.3);
    glVertex3f(0.3, -0.3, 0.3);
    glVertex3f(0.3, -0.3, -0.3);
    //正前面
    glColor3f(1.0, 0.0, 0.0);
    glVertex3f(-0.3, 0.3, 0.3);
    glVertex3f(-0.3, -0.3, 0.3);
    glVertex3f(0.3, -0.3, 0.3);
    glVertex3f(0.3, 0.3, 0.3);
    //右侧面
    glColor3f(1.0, 1.0, 0.0);
    glVertex3f(0.3, 0.3, 0.3);
    glVertex3f(0.3, -0.3, 0.3);
    glVertex3f(0.3, -0.3, -0.3);
    glVertex3f(0.3, 0.3, -0.3);
    //背后面
    glColor3f(0.0, 1.0, 1.0);
    glVertex3f(-0.3, 0.3, -0.3);
    glVertex3f(0.3, 0.3, -0.3);
    glVertex3f(0.3, -0.3, -0.3);
    glVertex3f(-0.3, -0.3, -0.3);
    //左侧面
    glColor3f(1.0, 0.0, 1.0);
    glVertex3f(-0.3, 0.3, -0.3);
    glVertex3f(-0.3, -0.3, -0.3);
    glVertex3f(-0.3, -0.3, 0.3);
    glVertex3f(-0.3, 0.3, 0.3);
    rotate_angle2 -= 3;
    glEnd();
}

//该程序是设置opengl场景透视图，程序中至少被执行一次(程序启动时).
void GLWidget::resizeGL(int width, int height)
{
    if(0 == height)
        height = 1;//防止一条边为0
    glViewport(0, 0, (GLint)width, (GLint)height);//重置当前视口，本身不是重置窗口的，只不过是这里被Qt给封装好了
    glMatrixMode(GL_PROJECTION);//选择投影矩阵
    glLoadIdentity();//重置选择好的投影矩阵
   // gluPerspective(45.0, (GLfloat)width/(GLfloat)height, 0.1, 100.0);//建立透视投影矩阵
    glMatrixMode(GL_MODELVIEW);//以下2句和上面出现的解释一样

    glLoadIdentity();

}
void GLWidget::keyPressEvent(QKeyEvent *e)
{
    switch(e->key())
    {
        //F1键为全屏和普通屏显示切换键
        case Qt::Key_F1:
            fullscreen = !fullscreen;
            if(fullscreen)
                showFullScreen();
            else
            {
                setGeometry(300, 150, 640, 480);
                showNormal();
            }
            updateGL();
            break;
        //Ese为退出程序键
        case Qt::Key_Escape:
            close();
    }
}

GLWidget::~GLWidget()
{
}

#include "glwidget.h"
#include <QApplication>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsItem>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    GLWidget w;
    w.show();

    return a.exec();
}