第四課:旋轉
只增加了幾個變量,幾行代碼。我的機器運行特別慢,故增大了旋轉增量,有興趣的可以減小一些試試……
nehewidget.h 文件:
#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);
bool fullscreen;
GLfloat rtri,rquad;
};
#endif // NEHEWIDGET_H
nehewidget.cpp 文件:
#include "nehewidget.h"
#include <gl/GLU.h>
#include <QKeyEvent>
nehewidget::nehewidget(QWidget *parent,bool fs)
: QGLWidget(parent)
{
rtri=0.0;
rquad=0.0;
fullscreen=fs;
setGeometry(50,50,640,480);
// setCaption("OpenGL window"); //這個函數,不支持了吧?
setWindowTitle("OpenGL Window");
if(fullscreen) showFullScreen();
}
nehewidget::~nehewidget()
{
}
void nehewidget::initializeGL()
{
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);
}
void nehewidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
//難道是gluPerspective的緣故?參數必須小一些才能看到圖形
//而且圓形和屏幕大小有關係,屏幕不對勁,正方形變長方形了……
glTranslatef(-0.3,0.3,-0.6);
glRotatef(rtri,0.0,1.0,0.0);
glBegin(GL_TRIANGLES);
glColor3f(1.0,0.0,0.0);
glVertex3f(0.0,0.2,0.0);
glColor3f(0.0,1.0,0.0);
glVertex3f(-0.2,-0.2,0.0);
glColor3f(0.0,0.0,1.0);
glVertex3f(0.2,-0.2,0.0);
glEnd();
rtri+=30;
glLoadIdentity();
glTranslatef(0.3,0.3,0.0);
glRotatef(rquad,1.0,0.0,0.0);
glColor3f(0.5,0.5,1.0);
glBegin(GL_QUADS);
glVertex3f(-0.2,0.2,0);
glVertex3f(0.2,0.2,0);
glVertex3f(0.2,-0.2,0);
glVertex3f(-0.2,-0.2,0);
glEnd();
rquad-=20;
//下面被註釋的一段是另添加的,有興趣的可以去掉註釋運行一下
//用連續的點或三角形來逼近圓,一個空心,一個實心
/*
glTranslatef(-0.5,-0.5,0.0);
GLfloat x,y,angle;
glBegin(GL_POINTS);
for(angle=0;angle<2*3.1415926;angle+=0.001) {
x=0.2*sin(angle);
y=0.2*cos(angle);
glVertex3f(x,y,0.0);
}
glEnd();
glTranslatef(0.5,0.0,0.0);
glBegin(GL_TRIANGLE_FAN);
for(int i=0;i<100;i++) {
float angle=2*3.1415926*i/100;
glVertex3f(0.2*cos(angle),0.2*sin(angle),0);
}
glEnd();
*/
}
void nehewidget::resizeGL(int w,int h)
{
if(h==0) h=1;
glViewport(0,0,(GLint)w,(GLint)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//下面這個函數在Qt和OpenGL新版本中都不支持了!先註釋掉吧,以後不得不用時再想辦法
// 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_F2:
fullscreen=!fullscreen;
if(fullscreen) showFullScreen();
else {
showNormal();
setGeometry(0,0,640,480);
}
updateGL();
break;
case Qt::Key_Escape:
close();
}
}