Question

用Visual Studio写一个OpenGL程序：实现立方体的转动

我用Visual Studio 2008，建Win32控制台程序，新建一个test.c文件，往里面输入如下代码：发现立方体不会动，这是为什么呢？
#include <windows.h>
#include <gl/glut.h>
GLfloat angle = 0.0f;
void DrawCube( float xPos, float yPos, float zPos )
{
// glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
// glLoadIdentity();
glPushMatrix();
// glTranslatef( xPos, yPos, zPos );
// glRotatef( 50.0f, 1.0f, 1.0f, -1.0f );
glBegin( GL_QUADS ); //top
glColor3f( 1.0f, 0.0f, 0.0f );
glNormal3f( 0.0f, 1.0f, 0.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //forward
glColor3f( 0.0f, 1.0f, 0.0f );
glNormal3f( 0.0f, 0.0f, 1.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //right
glColor3f( 0.0f, 0.0f, 1.0f );
glNormal3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
glBegin( GL_QUADS ); //left
glColor3f( 1.0f, 1.0f, 0.0f );
glNormal3f( -1.0f, 0.0f, 0.0f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //bottom
glColor3f( 1.0f, 0.0f, 1.0f );
glNormal3f( 0.0f, -1.0f, 0.0f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS );
glColor3f( 0.0f, 1.0f, 1.0f ); //back
glNormal3f( 0.0f, 0.0f, -1.0f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
glPopMatrix();
// glFlush(); //flush：刷新
}
void Render(void)
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glLoadIdentity(); //复位模型视图矩阵

glShadeModel( GL_SMOOTH );
angle = angle + 50.0f;
if( angle >= 360.0f )
angle = 0.0f;

glTranslatef( 0.0f, 0.0f, -0.1f );
glRotatef( angle, 1.0f, 1.0f, 1.0f );

DrawCube( 0.0f, 0.0f, 0.0f );

glFlush();

}

int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGB | GLUT_SINGLE );
glutInitWindowPosition( 100, 100 );
glutInitWindowSize( 400, 400 );
glutCreateWindow( "Drawing a Cube" );
glutDisplayFunc( &Render );
glutMainLoop();
return 0;
}
显示出立方体了，但为什么立方体不会动呢？？

Answer 1

#define GLUT_DISABLE_ATEXIT_HACK
#include <gl/glut.h>
#include <math.h>
static float day=360;
void myDisplay(void)
{
glEnable(GL_DEPTH_TEST);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(75,1,1,400);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0,-2,2,0,0,0,0,0,1);

glRotatef(day/30.0*360.0-day/360.0*360.0,0.0f,0.0f,-1.0f);
glTranslatef(1,0.0f,0.0f);
glBegin( GL_QUADS ); //top
glColor3f( 1.0f, 0.0f, 0.0f );
glNormal3f( 0.0f, 1.0f, 0.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //forward
glColor3f( 0.0f, 1.0f, 0.0f );
glNormal3f( 0.0f, 0.0f, 1.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //right
glColor3f( 0.0f, 0.0f, 1.0f );
glNormal3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 0.5f, 0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
glBegin( GL_QUADS ); //left
glColor3f( 1.0f, 1.0f, 0.0f );
glNormal3f( -1.0f, 0.0f, 0.0f );
glVertex3f( -0.5f, 0.5f, 0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS ); //bottom
glColor3f( 1.0f, 0.0f, 1.0f );
glNormal3f( 0.0f, -1.0f, 0.0f );
glVertex3f( -0.5f, -0.5f, 0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( 0.5f, -0.5f, 0.5f );
glEnd();
glBegin( GL_QUADS );
glColor3f( 0.0f, 1.0f, 1.0f ); //back
glNormal3f( 0.0f, 0.0f, -1.0f );
glVertex3f( 0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, -0.5f, -0.5f );
glVertex3f( -0.5f, 0.5f, -0.5f );
glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
glFlush();

glutSwapBuffers();
}

void myIdle()
{

day = day + 0.1;
if (day>=360)
{
day=0;
}
myDisplay();
}

int main(int argc, char* argv[])
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE);
glutInitWindowPosition(100,100);
glutInitWindowSize(600,600);
glutCreateWindow("第一个OpenGL程序");
glutDisplayFunc(&myDisplay);
glutIdleFunc(&myIdle);
glutMainLoop();

return 0;
}