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_OBJECT public: 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*/ bool makeGLTexture(); /** @brief 初始化星星状态*/ void initStarts(); private: GLfloat m_dZoom; ///< 星星Z值 bool m_bTwinkle; ///< 星星是否闪烁 GLfloat m_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 }; GLuint m_uiTexture[texStar]; static const 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(); else showFullScreen(); } 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：