nested fastloop question

[mobichan]

I have some code that I can't figure out:

I run a fastloop when an enemy's alt string A is set to "THROWN". In the fastloop, I use an index check to set a counter to the fixed value of the enemy thrown. then I set a detector to the position of the enemy. If the detector overlaps a backdrop, I run another loop an infinite number of times (nested in the first loop) to move the enemy back one pixel at a time. Then, if the enemy is not overlapping a backdrop, I set the alt string A to something other than "THROWN" and stop the nested loop. For some reason, this works fine if I throw an enemy so that it can fly a bit before it hits a backdrop. BUT if I throw the enemy point blank into a backdrop (if I am standing against a backdrop when I throw) then the enemy gets stuck. I assumed the nested loop would move the enemy out of the wall instantaneously. For some reason, the alt string is being changed from "THROWN" even though the "not overlapping" condition isn't true yet.

Does anyone have any idea why this might be happening? My code is kind of complex now, so I don't know if anyone has the patience to look at it. ^_^' Also, it seems like the pause debugger command won't activate mid loop. Is there a way to step through loops?

Any help is appreciated,

mobichan

[Dynasoft]

Can you post a simplified example of the broken code?
i.e. a file with just you, the enemy, detector, and the throwing events.

[mobichan]

Hopefully this is simple enough. There are a lot of little things keeping stuff in check, so I couldn't delete alot of the player and enemy code.

http://www.clickteam.com/epicenter/ubbthreads.php?ubb=showflat&Number=142141&#Post142 141

[DavidN]

The debugger steps through one frame at a time, so all loops within a frame are performed in between its steps - when trying to look at what a set of complex fastloops is doing, I usually set each action to add an identifiable character to a global string, so I can tell which events came up as true in what order. It's not perfect, but it does give you a bit more of an idea as to what's happening within the loops.

[mobichan]

Wow, thanks for the suggestion. I really wish we could truly step through code with the debugger line by line, even in fastloops. Maybe in MMF3? I'll give it a shot, but I could still use help if anyone has some time to spare.

[mobichan]

So after appending a string on each event, I am finding that the loop that should move the enemy out of the backdrop is only run once and then stops. I have a theory: Since I am checking an overlap condition, maybe it isn't retested each loop? By this I mean that the first time the loop is run the overlap condition returns true, but the next time the loop is run, the overlap condition is ignored because it was already tested previously. Are overlap conditions checked only once per frame? I can't really think of another reason, but I would appreciate any advice from some of the more loop savvy devs out there.

[Shawn]

The debugger steps through one frame at a time, so all loops within a frame are performed in between its steps - when trying to look at what a set of complex fastloops is doing, I usually set each action to add an identifiable character to a global string, so I can tell which events came up as true in what order. It's not perfect, but it does give you a bit more of an idea as to what's happening within the loops.

Not related to the topic at hand, but just wanted to mention I was reading about your work on Crystal Towers 2, and your debugging methods are amazing. The outside apps you made to parse what actions the user can take in a level, etc, is quite an achievement.

[mobichan]

On a total fluke, I found out what was causing my problem. But I really want to find out WHY before moving on.

So, I have 2 things I check against when doing this overlap test: Backdrops and a door qualifier group. I put both checks on the same line using an "OR(filtered)" between the 2 checks so I could conserve lines. I just deleted the second thing I was testing against (the door qualifier) and the "OR" and suddenly the code worked.

Why on earth would an OR statement not work in this case? I even tried switching to the filtered OR but that had the same problem as the logical OR. This is making me think I should avoid OR statements all together.

Can anyone explain what is going on?

[EDIT]: In a sudden moment of clarity, I now realize what is going on. I stop the loop when the enemy is NOT overlapping a backdrop (OR) NOT overlapping a door. Since the door condition is returning true, the loop is getting stopped. Sorry for the long post about nothing. You'd think simple things like this would plague me less and less the more I make games in MMF. Sigh... At least I learned a cool debug technique. ^_^'