Qt_OpenGL：3D空间中移动图像
//.h
#ifndef GLWIDGET_H
#define GLWIDGET_H
#include <QGLWidget>
#include <QtOpenGL>
class QGLWidget;
class QTimer;
typedef struct Stars{
public:
int r, g, b;
GLfloat dist, angle;
}Stars;
class GLWidget : public QGLWidget
{
Q_OBJECT
public:
GLWidget(QWidget *parent = 0);
~GLWidget();
protected:
void initializeGL();
void paintGL();
void resizeGL(int w, int h);
void keyPressEvent(QKeyEvent*);
void timerEvent(QTimerEvent*);
private:
bool fullscreen;
GLfloat rotate_angle;
GLfloat zoom;
GLfloat title;
GLfloat spin;
GLuint loop;
bool twinkle;
GLfloat blend;
private:
void loadTextures();
GLuint texture[1];
};
#endif // GLWIDGET_H
//.cpp
#include "glwidget.h"
#include <glut.h>
#include <QtGui>
#include <QtCore>
//好吧我承认全部变量不好
GLfloat light_ambient[4] = {0.5,0.5,0.5,1.0};
GLfloat light_diffiuse[4] = {1.0,1.0,1.0,1.0};
GLfloat light_position[4] = {0.0,0.0,2.0,0.0};
static const int num = 50;
static Stars stars[num];
GLWidget::GLWidget(QWidget *parent)
: QGLWidget(parent)
{
fullscreen = false;
rotate_angle = 0.0;
zoom = -15.0;
title = 90.0;
spin = 0.1;
loop = 0;
twinkle = false;
blend = false;
startTimer(5);
}
void GLWidget::initializeGL(){
setGeometry(300,150,500,500);
loadTextures();
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glClearColor(0.0, 0.0, 0.0, 0.5);
glClearDepth(1.0);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glEnable(GL_BLEND);
//为num个星星对象赋初值
for(loop = 0; loop < num; ++loop){
stars[loop].angle = 0.0;
stars[loop].dist = (float(loop)/num) * 5.0;
stars[loop].r = rand() % 256;
stars[loop].g = rand() % 256;
stars[loop].b = rand() % 256;
}
}
void GLWidget::paintGL(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D, texture[0]);
for(loop = 0; loop < num; ++loop){
glLoadIdentity();
glTranslatef(0.0, 0.0, zoom); //移向屏幕里面
glRotatef(title, 1.0, 0.0, 0.0); //沿x轴旋转title
glRotatef(stars[loop].angle, 0.0, 1.0, 0.0); //每个星星沿y轴旋转自己的角度
glTranslatef(stars[loop].dist, 0.0, 0.0); //平移
glRotatef(-stars[loop].angle, 0.0, 1.0, 0.0); //沿y轴反转
glRotatef(-title, 1.0, 0.0, 0.0); //沿x轴反转
if(twinkle){ //如果星星闪烁
glColor4ub(stars[num-loop-1].r, stars[num-loop-1].g,
stars[num-loop-1].b, 255);
glBegin(GL_QUADS);
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();
}
//如果星星不闪烁
glRotatef(spin, 0.0f, 0.0f, 1.0f); //沿z轴自转spin
glColor4ub(stars[loop].r, stars[loop].g, stars[loop].b, 255);
glBegin(GL_QUADS);
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();
spin += 0.01f;
stars[loop].angle += float(loop)/num;
stars[loop].dist -= 0.01f; //距离逐渐减小，即越来越靠近屏幕
if(stars[loop].dist < 0){
stars[loop].dist += 5.0f;
stars[loop].r = rand() % 256;
stars[loop].g = rand() % 256;
stars[loop].b = rand() % 256;
}
}
}
void GLWidget::resizeGL(int w, int h){
if( 0 == h){
h = 1;
}
glViewport(0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (GLdouble)w/(GLdouble)h, 0.1, 100.0);
glColor4f(1.0f, 1.0f, 1.0f, 0.5f);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void GLWidget::keyPressEvent(QKeyEvent *event){
switch(event->key()){
case Qt::Key_T:{
twinkle = !twinkle;
updateGL();
break;
}
case Qt::Key_B:{
blend = !blend;
if(blend){
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
}else{
glDisable(GL_BLEND);
glEnable(GL_DEPTH_TEST); //色彩混合和深度缓存不能同时开启
}
updateGL();
break;
}
case Qt::Key_PageUp:{ //移向屏幕
zoom -= 0.2;
updateGL();
break;
}
case Qt::Key_PageDown:{ //移向屏幕外
zoom += 0.2;
updateGL();
break;
}
case Qt::Key_Up:{ //加快旋转速度
title += 0.5;
updateGL();
break;
}
case Qt::Key_Down:{
title -= 0.5;
updateGL();
break;
}
case Qt::Key_F1:{
fullscreen = !fullscreen;
if(fullscreen){
showFullScreen();
}else{
setGeometry(300,150,500,500);
showNormal();
}
updateGL();
break;
}
case Qt::Key_Escape:{
close();
}
}
}
void GLWidget::loadTextures(){
QImage tex, buf;
if(!buf.load(":Star.bmp")){
qWarning("Cannot open the image...");
QImage dummy(128, 128, QImage::Format_RGB32);
dummy.fill(Qt::green);
buf = dummy;
}
tex = convertToGLFormat(buf);
glGenTextures(1, &texture[0]);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glTexImage2D(GL_TEXTURE_2D, 0, 3, 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_NEAREST);
}
void GLWidget::timerEvent(QTimerEvent *){
updateGL();
}
GLWidget::~GLWidget()
{
}
//main.cpp
#include "glwidget.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
GLWidget w;
w.show();
return a.exec();
}
//运行结果截图：
