OpenGL旋转

本文功能类似Nehe教程第三课。对图形进行旋转操作。主要使用函数：

glRotatef(GLfloat angle,GLfloat x,GLfloat y,GLfloat z);

作用是绕从原点到点(x,y,z)的向量顺时针旋转angle弧度。

为了实现旋转动画效果，需要增加计时器处理函数，定时更改旋转角度。其中main.cpp中代码与第一课中一致。其他代码如下：

wglwidget.h

#ifndef WGLWIDGET_H#define WGLWIDGET_H#include <QtGui/QWidget>#include <QtOpenGL/QtOpenGL>#include "ui_wglwidget.h"class WGLWidget : public QGLWidget , public Ui::WGLWidgetClass{Q_OBJECTpublic:WGLWidget(QWidget *parent = 0, const QGLWidget* shareEidget = 0,Qt::WFlags flags = 0);~WGLWidget();protected:virtual void initializeGL();virtual void resizeGL(int w, int h);virtual void paintGL();virtual void mouseDoubleClickEvent(QMouseEvent *event);virtual void closeEvent(QCloseEvent *event);virtual void timerEvent(QTimerEvent *event);private:GLfloat Point[5][3];///< 五角星坐标GLfloat rTri;///< 三角形转动角度GLfloat rQuad;///< 四边形转动角度};#endif // WGLWIDGET_H

wglwidget.cpp

#include "wglwidget.h"#include <math.h>const GLfloat PI = 3.1415926536f;WGLWidget::WGLWidget(QWidget *parent /* = 0 */, const QGLWidget* shareEidget /* = 0 */,Qt::WFlags flags /* = 0 */): QGLWidget(parent, shareEidget, flags), rTri(0.0), rQuad(0.0){setupUi(this);setMinimumSize(320,240);resize(640,480);setWindowTitle(tr("第一个OpenGL程序"));short angle = 18;for(short i=0;i<5;++i){Point[i][0] = cos(angle * PI/180);Point[i][1] = sin(angle * PI/180);Point[i][2] = 0.0;// Z值angle += 72;}// 定时器startTimer(20);}WGLWidget::~WGLWidget(){}void WGLWidget::initializeGL(){glShadeModel(GL_SMOOTH);glClearColor(0.0,0.0,0.0,0.0);glClearDepth(1.0);glEnable(GL_DEPTH_TEST);glDepthFunc(GL_LEQUAL);glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);glEnableClientState(GL_VERTEX_ARRAY);glVertexPointer(3,GL_FLOAT,0,Point);}void WGLWidget::resizeGL(int w, int h){glViewport(0,0,(GLint)width(),(GLint)height());glMatrixMode(GL_PROJECTION);glLoadIdentity();gluPerspective(45.0,(GLfloat)width() / (GLfloat)height(),0.1,100.0);glMatrixMode(GL_MODELVIEW);glLoadIdentity();}void WGLWidget::paintGL(){glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);glPushMatrix();// 绘制三角形，平滑着色glTranslatef(-1.5,0.0,-6.0);glRotatef(rTri,0.0,1.0,0.0);glBegin(GL_TRIANGLES);glColor3f(1.0,0.0,0.0);glVertex3f(0.0,1.0,0.0);glColor3f(0.0,1.0,0.0);glVertex3f(-1.0,-1.0,0.0);glColor3f(0.0,0.0,1.0);glVertex3f(1.0,-1.0,0.0);glEnd();glPopMatrix();// 绘制五角星glPushMatrix();glTranslatef(1.5,-1.5,-6.0);glColor3f(1.0,1.0,1.0);glBegin(GL_LINE_LOOP);glArrayElement(1);glArrayElement(4);glArrayElement(2);glArrayElement(0);glArrayElement(3);glEnd();glPopMatrix();// 绘制四边形填充，单调着色glPushMatrix();glTranslatef(1.5,1.5,-6.0);glRotatef(rTri,1.0,0.0,0.0);glColor3f(0.0,1.0,0.0);glBegin(GL_POLYGON);glVertex3f(-1.0,1.0,0.0);glVertex3f(-1.0,-1.0,0.0);glVertex3f(1.0,-1.0,0.0);glVertex3f(1.0,1.0,0.0);glEnd();glPopMatrix();}void WGLWidget::mouseDoubleClickEvent(QMouseEvent *event){if(windowState() & Qt::WindowFullScreen)showNormal();elseshowFullScreen();}void WGLWidget::timerEvent(QTimerEvent *event){// 角度rTri += 0.5;rQuad -= 0.1;// 更新界面update();}void WGLWidget::closeEvent(QCloseEvent *event){QMessageBox box;box.setWindowTitle(tr("退出"));box.setIcon(QMessageBox::Warning);box.setText(tr("确定要关闭OpenGL窗口吗？"));box.setStandardButtons(QMessageBox::Yes | QMessageBox::No);if(QMessageBox::No == box.exec()){event->ignore();return;}QWidget::closeEvent(event);}