From: Gary King <gking@leland.stanford.edu>
Newsgroups: su.class.cs248
Subject: smooth keyboard input
Date: Sat, 06 Nov 1999 16:11:39 -0800

After toying around in GLUT 3.7 some more, I have discovered a way to
handle keyboard functions that doens't rely on keyboard repeat rates
or repeated keypresses to handle interaction.

In addition to glutKeyboardFunc, there is an identically prototyped
glutKeyboardUpFunc in GLUT 3.7 (I don't believe it exists in 3.6).
Instead of handling repeated events in your Keyboard callback, use an
array of 256 values (1 for each key value), and set myKeyList[key]=1
in your callback, then handle the event in your onIdle function.

Example:  Imagine the key 'w' moving the camera along the positive Z
axis.

in your global variables, you would have:

static float camera_x, camera_y, camera_z;
static unsigned char myKeyList[256] = {0,0,...0};

in your Display function, you would have

{
...
glTranslatef(camera_x, camera_y, camera_z);
... // draw objects
}

in your Idle function, you would have

{
unsigned int i;
...
for (i=0; i<256;i++)
	if (myKeyList[i])
	{
		switch(i)
		{
		case 'w': camera_z += 0.01; break;
		.. // insert other repeated events here.
		}
	}
...
}

in your keyboard function, you would have

{
switch (key)
{
case 27: exit(0); break;  //  27 = escape.
...
default: myKeyList[key] = 1;
}
}

and in your keyboardup function, you would have
{
myKeyList[key]=0;
}

Hope this helps someone