Hello to all on the forum! If any you happen to know Mr. (Henry) Rich, I'm
one of his students.
The most direct way to create a constantly updating screen in J is to run
the relevant gl2 commands in a sys_timer verb, set to repeat at a certain
interval by the window driver. However, for a video game with any more than
rudimentary complexity, one would wish to separate "frames" (drawing the
image to the screen) from "ticks" (computing the game logic). Preferably,
ticks would happen at a constant rate per second, and then the remaining
computation time would be spent rendering frames. In Java, that would be
implemented somehow similar to this:
long lastTime = System.nanoTime();
double nsPerTick = 1000000000D / 60D;
double delta = 0;
while (running) {
long now = System.nanoTime();
// Determine how long it has been since the last tick
delta += (now - lastTime) / nsPerTick;
lastTime = now;
// If more than 1/60th of a second has passed, tick for each
60th.
while (delta >= 1) {
ticks++;
tick();
delta -= 1;
}
render();
}
Of course, J is *much* different than Java in many respects. "While" loops
are frowned upon in this situation, because functional languages get hung
up in the while loop until it is "finished;" however, for video games this
"hanging up" seems to be exactly what is needed (without the side effects
of freezing the terminal, of course).
I have been directed towards sockets for this sort of situation in the
past, but I've never progressed far enough down that route to understand
the gritty details of how to implement such a system.
Would someone on the forum be able to guide me towards a solution? To
restate the problem, I'm looking for the functional (J) equivalent of a
"while" loop that repeats one function at a fixed rate and runs the other
as frequently as the host machine safely allows.
Thank you for your assistance, and apologies for the protracted & ugly Java
example!
--
-Neill
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
