void rotate()
{
int i;
const int w = 64;
const int h = 64;
QImage image( w, h, 8, 128 ); // create image
for ( i=0; i<128; i++ ) // build color table
image.setColor( i, qRgb(i,0,0) );
for ( int y=0; y<h; y++ ) { // set image pixels
uchar *p = image.scanLine(y);
for ( int x=0; x<w; x++ )
*p++ = (x+y)%128;
}
QPixmap pm;
pm = image; // convert image to pixmap
pm.optimize( TRUE ); // rotation will be faster
QWidget *d = QApplication::desktop(); // w = desktop widget
for ( i=0; i<=360; i += 2 ) {
QWMatrix m;
m.rotate( i ); // rotate coordinate system
QPixmap rpm = pm.xForm( m ); // rpm = rotated pixmap
d->setBackgroundPixmap( rpm ); // set desktop pixmap
d->update(); // repaint desktop
}
}
