Qt下使用OpenGL（16）-根据NeHe的教程改写的

#ifndef NEHEWIDGET_H
#define NEHEWIDGET_H

#include <QtOpenGL/QGLWidget>
//#include "ui_nehewidget.h"

#include <qgl.h>

class nehewidget : public QGLWidget
{
Q_OBJECT

public:
nehewidget(QWidget *parent = 0,bool fs=false);
~nehewidget();

protected:
void initializeGL();
void paintGL();
void resizeGL(int w,int h);

void keyPressEvent(QKeyEvent *e);
void loadGLTextures();

bool fullscreen;
GLfloat xrot,yrot,zrot;
GLfloat zoom,xspeed,yspeed;
GLuint texture[3],filter;

bool light;
GLuint fogfilter;
};

#endif // NEHEWIDGET_H

#include "nehewidget.h"

#include <gl/GLU.h>
#include <QKeyEvent>

GLfloat lightAmbient[4]={0.5,0.5,0.5,1.0};
GLfloat lightDiffuse[4]={1.0,1.0,1.0,1.0};
GLfloat lightPosition[4]={0.0,0.0,0.0,1.0};

GLuint fogmode[3]={GL_EXP,GL_EXP2,GL_LINEAR};
GLfloat fogcolor[4]={0.5,0.5,0.5,1.0};

nehewidget::nehewidget(QWidget *parent,bool fs)
: QGLWidget(parent)
{
xrot=0.0;
yrot=0.0;
zrot=0.0;
zoom=0.0;
xspeed=yspeed=2.0;
filter=0;
light=false;
fogfilter=0;

fullscreen=fs;
setGeometry(100,100,640,480);
//	setCaption("OpenGL window"); //这个函数，不支持了吧？
setWindowTitle("OpenGL Window");
if(fullscreen) showFullScreen();
}

nehewidget::~nehewidget()
{

}

void nehewidget::initializeGL()
{
loadGLTextures();
glEnable(GL_TEXTURE_2D);

glShadeModel(GL_SMOOTH);
glClearColor(0,0,0,0);
glClearDepth(1.0);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);

glLightfv(GL_LIGHT1,GL_AMBIENT,lightAmbient);
glLightfv(GL_LIGHT1,GL_DIFFUSE,lightDiffuse);
glLightfv(GL_LIGHT1,GL_POSITION,lightPosition);
glEnable(GL_LIGHT1);

glFogi(GL_FOG_MODE,fogmode[fogfilter]);
glFogfv(GL_FOG_COLOR,fogcolor);
glFogf(GL_FOG_DENSITY,0.35);
glHint(GL_FOG_HINT,GL_DONT_CARE);
glFogf(GL_FOG_START,0.0);
glFogf(GL_FOG_END,0.0);
glEnable(GL_FOG);
}

void nehewidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glLoadIdentity();

glTranslatef(0.0,0.0,zoom);
glRotatef(xrot,1.0,0.0,0.0);
glRotatef(yrot,0.0,1.0,0.0);
glBindTexture(GL_TEXTURE_2D,texture[filter]);
glBegin(GL_QUADS);
glNormal3f(0.0,0.0,1.0);
glTexCoord2f(0.0,0.0);glVertex3f(-0.2,-0.2,0.2);
glTexCoord2f(1.0,0.0);glVertex3f(0.2,-0.2,0.2);
glTexCoord2f(1.0,1.0);glVertex3f(0.2,0.2,0.2);
glTexCoord2f(0.0,1.0);glVertex3f(-0.2,0.2,0.2);

glNormal3f(0.0,0.0,-1.0);
glTexCoord2f(1.0,0.0);glVertex3f(-0.2,-0.2,-0.2);
glTexCoord2f(1.0,1.0);glVertex3f(-0.2,0.2,-0.2);
glTexCoord2f(0.0,1.0);glVertex3f(0.2,0.2,-0.2);
glTexCoord2f(0.0,0.0);glVertex3f(0.2,-0.2,-0.2);

glNormal3f(0.0,1.0,0.0);
glTexCoord2f(0.0,1.0);glVertex3f(-0.2,0.2,-0.2);
glTexCoord2f(0.0,0.0);glVertex3f(-0.2,0.2,0.2);
glTexCoord2f(1.0,0.0);glVertex3f(0.2,0.2,0.2);
glTexCoord2f(1.0,1.0);glVertex3f(0.2,0.2,-0.2);

glNormal3f(0.0,-1.0,0.0);
glTexCoord2f(1.0,1.0);glVertex3f(-0.2,-0.2,-0.2);
glTexCoord2f(0.0,1.0);glVertex3f(0.2,-0.2,-0.2);
glTexCoord2f(0.0,0.0);glVertex3f(0.2,-0.2,-0.2);
glTexCoord2f(1.0,0.0);glVertex3f(-0.2,-0.2,0.2);

glNormal3f(1.0,0.0,0.0);
glTexCoord2f(1.0,0.0);glVertex3f(0.2,-0.2,-0.2);
glTexCoord2f(1.0,1.0);glVertex3f(0.2,0.2,-0.2);
glTexCoord2f(0.0,1.0);glVertex3f(0.2,0.2,0.2);
glTexCoord2f(0.0,0.0);glVertex3f(0.2,-0.2,0.2);

glNormal3f(-1.0,0.0,0.0);
glTexCoord2f(0.0,0.0);glVertex3f(-0.2,-0.2,-0.2);
glTexCoord2f(1.0,0.0);glVertex3f(-0.2,-0.2,0.2);
glTexCoord2f(1.0,1.0);glVertex3f(-0.2,0.2,0.2);
glTexCoord2f(0.0,1.0);glVertex3f(-0.2,0.2,-0.2);

glEnd();
xrot+=xspeed;
yrot+=yspeed;
}

void nehewidget::resizeGL(int w,int h)
{
if(h==0) h=1;
glViewport(0,0,(GLint)w,(GLint)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//下面这个函数在Qt和OpenGL新版本中都不支持了！先注释掉吧，以后不得不用时再想办法
//	gluPerspective(45.0,(GLfloat)w/(GLfloat)h,0.1,100.0);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void nehewidget::keyPressEvent(QKeyEvent *e)
{
switch(e->key()) {
case Qt::Key_L:
light=!light;
if(!light) {
glDisable(GL_LIGHTING);
}
else {
glEnable(GL_LIGHTING);
}
updateGL();
break;
case Qt::Key_F:
filter+=1;
if(filter>2) {
filter=0;
}
updateGL();
break;
case Qt::Key_PageUp:
zoom-=0.2;
updateGL();
break;
case Qt::Key_PageDown:
zoom+=0.2;
updateGL();
break;
case Qt::Key_Up:
xspeed-=0.2;
updateGL();
break;
case Qt::Key_Down:
xspeed+=0.2;
updateGL();
break;
case Qt::Key_Right:
yspeed+=0.2;
updateGL();
break;
case Qt::Key_Left:
yspeed-=0.2;
updateGL();
break;
case Qt::Key_F2:
fullscreen=!fullscreen;
if(fullscreen) showFullScreen();
else {
showNormal();
setGeometry(0,0,640,480);
}
updateGL();
break;
case Qt::Key_Escape:
close();
}
}

void nehewidget::loadGLTextures()
{
QImage tex,buf;
if(!buf.load("texture.bmp")) {
qWarning("Please use single-color instead");
QImage dummy(128,128,QImage::Format_RGB32);
dummy.fill(Qt::red);
buf=dummy;
}
tex=QGLWidget::convertToGLFormat(buf);
glGenTextures(3,&texture[0]);
glBindTexture(GL_TEXTURE_2D,texture[0]);
glTexImage2D(GL_TEXTURE_2D,0,3,tex.width(),tex.height(),0,GL_RGB,GL_UNSIGNED_BYTE,tex.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);

glBindTexture(GL_TEXTURE_2D,texture[1]);
glTexImage2D(GL_TEXTURE_2D,0,3,tex.width(),tex.height(),0,GL_RGB,GL_UNSIGNED_BYTE,tex.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);

glBindTexture(GL_TEXTURE_2D,texture[2]);
//	glTexImage2D(GL_TEXTURE_2D,0,3,tex.width(),tex.height(),0,GL_RGB,GL_UNSIGNED_BYTE,tex.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);

gluBuild2DMipmaps(GL_TEXTURE_2D,GL_RGB,tex.width(),tex.height(),GL_RGBA,GL_UNSIGNED_BYTE,tex.bits());
}