Qt_OpenGL：3D圖形小測

Qt_OpenGL：3D圖形小測

//.h

#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

//.cpp

#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;
}

//這是對虛函數，這裏是重寫該函數
void GLWidget::initializeGL()
{
    setGeometry(300, 150, 640, 480);//設置窗口初始位置和大小
    glShadeModel(GL_SMOOTH);//設置陰影平滑模式
    glClearColor(0.0, 0.0, 0.0, 0);//改變窗口的背景顏色，不過我這裏貌似設置後並沒有什麼效果
    glClearDepth(1.0);//設置深度緩存
    glEnable(GL_DEPTH_TEST);//允許深度測試
    glDepthFunc(GL_LEQUAL);//設置深度測試類型
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);//進行透視校正
}

void GLWidget::paintGL()
{
    //glClear()函數在這裏就是對initializeGL()函數中設置的顏色和緩存深度等起作用
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    /*下面開始畫四棱錐*/
    glLoadIdentity();//重置當前的模型觀察矩陣
    glTranslatef(-0.5, 0.0, -0.5);//將繪製平面移動到屏幕的左半平面和裏面
    glRotatef(rotate_angle1, 0.2, 0.2, 0.0);
    glBegin(GL_TRIANGLES);
    /*前正面的繪製*/
    glColor3f(1.0, 0.0, 0.0);//上頂點紅色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下點藍色
    glVertex3f(-0.3, -0.3, 0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角綠色
    glVertex3f(0.3, -0.3, 0.3);
    /*右側面的繪製*/
    glColor3f(1.0, 0.0, 0.0);//上頂點紅色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下點藍色
    glVertex3f(0.3, -0.3, 0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角綠色
    glVertex3f(0.3, -0.3, -0.3);
    /*後側面的繪製*/
    glColor3f(1.0, 0.0, 0.0);//上頂點紅色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下點藍色
    glVertex3f(0.3, -0.3, -0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角綠色
    glVertex3f(-0.3, -0.3, -0.3);
    /*左側面的繪製*/
    glColor3f(1.0, 0.0, 0.0);//上頂點紅色
    glVertex3f(0.0, 0.3, 0.0);
    glColor3f(0.0, 0.0, 1.0);//左下點藍色
    glVertex3f(-0.3, -0.3, -0.3);
    glColor3f(0.0, 1.0, 0.0);//右下角綠色
    glVertex3f(-0.3, -0.3, 0.3);
    rotate_angle1 += 3.0;
    glEnd();
    /*底面四邊形的繪製,使四棱錐封閉起來*/
    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();

    /*下面開始畫立方體*/
    glLoadIdentity();
    glTranslated(0.5, 0, 0.5);//將繪製平面移動到屏幕的右半平面和外面
    glRotatef(rotate_angle2, -0.2, 0.2, -0.3);
    glBegin(GL_QUADS);
    //上頂面
    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);
    //下頂面
    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);
    //右側面
    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);
    //背後面
    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);
    //左側面
    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();
}

//該程序是設置opengl場景透視圖，程序中至少被執行一次(程序啓動時).
void GLWidget::resizeGL(int width, int height)
{
    if(0 == height)
        height = 1;//防止一條邊爲0
    glViewport(0, 0, (GLint)width, (GLint)height);//重置當前視口，本身不是重置窗口的，只不過是這裏被Qt給封裝好了
    glMatrixMode(GL_PROJECTION);//選擇投影矩陣
    glLoadIdentity();//重置選擇好的投影矩陣
   // gluPerspective(45.0, (GLfloat)width/(GLfloat)height, 0.1, 100.0);//建立透視投影矩陣
    glMatrixMode(GL_MODELVIEW);//以下2句和上面出現的解釋一樣

    glLoadIdentity();


}
void GLWidget::keyPressEvent(QKeyEvent *e)
{
    switch(e->key())
    {
        //F1鍵爲全屏和普通屏顯示切換鍵
        case Qt::Key_F1:
            fullscreen = !fullscreen;
            if(fullscreen)
                showFullScreen();
            else
            {
                setGeometry(300, 150, 640, 480);
                showNormal();
            }
            updateGL();
            break;
        //Ese爲退出程序鍵
        case Qt::Key_Escape:
            close();
    }
}

GLWidget::~GLWidget()
{
}

//.main

#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();
}

//運行結果：