//keyboard handle function to implement image manipulation
void handleKey(unsigned char key, int x, int y){
switch(key){
//use key 'w' or 'W' to write image
case 'w':
case 'W':
if (writename != NULL)
{
Image.ImageWrite(writename);
}
//if the second parameter is not specified in command line, output the message 'cannot write the image'
else{
std::cout << "You cannot write the image because you didn't specify a filename." << std::endl;
}
break;
//use key 'q' or 'Q' to quit the program
case 'q': // q - quit
case 'Q':
case 27: // esc - quit
exit(0);
default: // not a valid key -- just ignore it
return;
}
}
