闪烁的星星(Nehe)

 以下代码演示与Nehe教程第九课中一样的效果。第十课中三维的暂不实现。主要使用纹理贴图相关方面知识。

WStar.h

#pragma once#include <QtOpenGL/QtOpenGL>/** @brief星星描述*/class WStar{public:WStar(void);~WStar(void);/** 颜色分量*/int m_iR;int m_iG;int m_iB;// 距离中心距离GLfloat m_dDistance;// 所处角度GLfloat m_dAngle;};  

 

WStar.cpp

#include "WStar.h"WStar::WStar(void): m_iR(0), m_iG(0), m_iB(0), m_dDistance(0.0), m_dAngle(0.0){}WStar::~WStar(void){}

wglwidget.h

#ifndef WGLWIDGET_H#define WGLWIDGET_H#include <QtGui/QWidget>#include <QtOpenGL/QtOpenGL>#include "ui_wglwidget.h"#include "wstar.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 keyPressEvent(QKeyEvent *event);virtual void timerEvent(QTimerEvent *event);virtual void mouseDoubleClickEvent(QMouseEvent *event);virtual void closeEvent(QCloseEvent *event);private:/** @brief创建纹理*/boolmakeGLTexture();/** @brief初始化星星状态*/voidinitStarts();private:GLfloatm_dZoom;///< 星星Z值boolm_bTwinkle;///< 星星是否闪烁GLfloatm_dTilt;///< 星星倾角GLfloat m_dSpin;///< 星星自传角度QVector<WStar>m_vecStars;///< 存储所有星星enum WTexture{texStar = 1};GLuintm_uiTexture[texStar];staticconst int m_iNum = 50;///< 星星个数};#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), m_bTwinkle(false), m_dZoom(-15.0), m_dTilt(90.0), m_dSpin(0.0){setupUi(this);setMinimumSize(320,240);resize(640,480);setWindowTitle(tr("星星动画"));initStarts();startTimer(10);}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);// 加载纹理makeGLTexture();// 启用纹理glEnable(GL_TEXTURE_2D);// 启用混合glBlendFunc(GL_SRC_ALPHA,GL_ONE);// 设置混色函数取得半透明效果glEnable(GL_BLEND);// 启用混色}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();glBindTexture(GL_TEXTURE_2D,m_uiTexture[0]);for (int loop=0;loop<m_iNum;loop++)// 循环设置所有的星星{glPushMatrix();// 绘制每颗星星之前，重置模型观察矩阵glTranslatef(0.0f,0.0f,m_dZoom);// 深入屏幕里面glRotatef(m_dTilt,1.0f,0.0f,0.0f);// 倾斜视角glRotatef(m_vecStars[loop].m_dAngle,0.0f,1.0f,0.0f);// 旋转至当前所画星星的角度glTranslatef(m_vecStars[loop].m_dDistance,0.0f,0.0f);// 沿X轴正向移动glRotatef(-m_vecStars[loop].m_dAngle,0.0f,1.0f,0.0f);// 取消当前星星的角度glRotatef(-m_dTilt,1.0f,0.0f,0.0f);// 取消屏幕倾斜if (m_bTwinkle)// 启用闪烁效果{// 使用byte型数值指定一个颜色glColor4ub(m_vecStars[(m_iNum-loop)-1].m_iR,m_vecStars[(m_iNum-loop)-1].m_iG,m_vecStars[(m_iNum-loop)-1].m_iB,255);glBegin(GL_QUADS);// 开始绘制纹理映射过的四边形glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 0.0f);glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 0.0f);glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 0.0f);glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 0.0f);glEnd();// 四边形绘制结束}glRotatef(m_dSpin,0.0f,0.0f,1.0f);// 绕z轴旋转星星// 使用byte型数值指定一个颜色glColor4ub(m_vecStars[loop].m_iR,m_vecStars[loop].m_iG,m_vecStars[loop].m_iB,255);glBegin(GL_QUADS);// 开始绘制纹理映射过的四边形glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 0.0f);glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 0.0f);glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 0.0f);glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 0.0f);glEnd();// 四边形绘制结束m_dSpin +=0.01f;// 星星的公转m_vecStars[loop].m_dAngle += float(loop)/m_iNum;// 改变星星的自转角度m_vecStars[loop].m_dDistance -= 0.01f;// 改变星星离中心的距离if (m_vecStars[loop].m_dDistance < 0.0f)// 星星到达中心了么{m_vecStars[loop].m_dDistance +=5.0f;// 往外移个单位m_vecStars[loop].m_iR = rand()%256;// 赋一个新红色分量m_vecStars[loop].m_iG = rand()%256;// 赋一个新绿色分量m_vecStars[loop].m_iB = rand()%256;// 赋一个新蓝色分量}glPopMatrix();}glPopMatrix();}void WGLWidget::timerEvent(QTimerEvent *event){update();}void WGLWidget::mouseDoubleClickEvent(QMouseEvent *event){if(windowState() & Qt::WindowFullScreen)showNormal();elseshowFullScreen();}void WGLWidget::keyPressEvent(QKeyEvent *event){switch(event->key()){case Qt::Key_T:{m_bTwinkle = !m_bTwinkle;}break;case Qt::Key_Home:m_dZoom -= 0.2;break;case Qt::Key_End:m_dZoom += 0.2;break;case Qt::Key_Up:m_dTilt += 0.5;break;case Qt::Key_Down:m_dTilt -= 0.5;break;default:break;}}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);}bool WGLWidget::makeGLTexture(){QImage tex,buffer;QString str("Image/Star.bmp");if(!buffer.load(str)){QMessageBox::warning(this,tr("提示"),tr("加载纹理图片失败，程序将异常显示！"));return false;}tex = QGLWidget::convertToGLFormat(buffer);glGenTextures(texStar,&m_uiTexture[0]);glBindTexture(GL_TEXTURE_2D,m_uiTexture[0]);glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,tex.width(),tex.height(),0,GL_RGBA,GL_UNSIGNED_BYTE,tex.bits());glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);return true;}void WGLWidget::initStarts(){m_vecStars.resize(m_iNum);// 创建循环设置全部星星for(int loop=0;loop<m_iNum;++loop){m_vecStars[loop].m_dAngle = 0.0f;// 所有星星都从零角度开始m_vecStars[loop].m_dDistance = (float(loop)/m_iNum)*5.0f;// 计算星星离中心的距离m_vecStars[loop].m_iR = rand()%256;// 设置随机红色分量m_vecStars[loop].m_iG = rand()%256;// 设置随机红色分量m_vecStars[loop].m_iB = rand()%256;// 设置随机红色分量}}

 

程序运行效果如图：