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Basic Kliking Concepts: Part 1

Author:

Knudde (Shab)

Submitted:

24th May, 2003

Views:

7293

Rated:

Basic Kliking Concepts.
This article is intended to give you a better understanding of the inner workings of KNP, TGF, and MMF.
===========
Part One - Understanding Program Flow
To put it simply, program flow is the path your game takes until it reaches the end.

Example: A Properly "flowed" process
------------------------------------------------------------
Player presses fire 1 - Set ValueA.Player1 = 1
ValueA.Player1 = 1 - Shoot Bullet at dir32 at speed 100 and Set ValueA.Player1 = 2
ValueA.Player1 = 2 - Shoot Bullet at dir31 at speed 100 and Set ValueA.Player1 = 3
ValueA.Player1 = 3 - Shoot Bullet at dir01 at speed 100 and Set ValueA.Player1 = 0
-----------------------------------------------------------
What's Happening Here:
When Player 1 presses fire, you see him shoot three bullets in slightly different directions.

Example: An Improperly "flowed" process
------------------------------------------------------------
Player presses fire 1 - Set ValueA.Player1 = 1
ValueA.Player1 = 2 - Shoot Bullet at dir32 at speed 100 and Set ValueA.Player1 = 3
ValueA.Player1 = 1 - Shoot Bullet at dir31 at speed 100 and Set ValueA.Player1 = 2
ValueA.Player1 = 3 - Shoot Bullet at dir01 at speed 100 and Set ValueA.Player1 = 0
-----------------------------------------------------------
What's Happening Here:
When Player 1 presses fire, you see him shoot one bullet up.

Why is this happening?
In the second example, after player1 presses fire, Value A is set to one. This trigger the character to shoot a bullet up and set Value A to 2. When this value Reaches 2, it should trigger the Value A = 2 event, but it doesn't.
This "bug" is happening because all programs flow logically from top to bottom. To the program, ValueA will equal 2, but only after it mattered. The program continues towards the bottom line and will then repeat from the top line. So in essence, when the program loops through the events again, it will fire those next to bullets (2+3) but not in the same process (Complete cycle of events). It may not look like anything is wrong, but should player 1 hit the fire button repeatedly in different processes, the gun will only shoot 1 bullet at random points, instead of the three it should.

Summary:
When doing final preparations for release and bug tracking, program flow is a good place to start checking for any abnormalities in the program. Remember, Programs flow from top to bottom, then restart at the top. Programs ca never flow backwards, (unless you tell them to.)
---------------
Shabadage

Posted by Knudde (Shab)

24th May, 2003

Forgive the poor formatting I cut an pasted this.

Posted by Knudde (Shab)

24th May, 2003

Fixed the formatting

Posted by Daniel[Crazy_Productions]

24th May, 2003

...i didnt actually understand this but... i think ure saying that u should have the code in the right order.... right?

Posted by Knudde (Shab)

24th May, 2003

That is correct.

Posted by Knudde (Shab)

24th May, 2003

Daniel, what about it didn't you understand so I can clarify it a bit better.

Posted by

24th May, 2003

He probably didn't understand 'cause he's a newb

The order of events is truly important, but I'm not sure if it'd matter dramatically in this case.
Either way, it's good

Posted by Knudde (Shab)

24th May, 2003

I'm assuming that at the bottom of the firing process it ends. I think I might revamp this article a bit in the future.

Posted by DeadmanDines

24th May, 2003

A huge percentage of bugs that eventually result in people dropping their games are because they don't know about this. When I looked back at my old projects after finding out about it a year or 2 ago, I realised that 90% of the major flaws which led to their demise were simply order mistakes. The importance of ordering events cannot be overstated.

A good example of evental disorder is this:
.start of frame
--Set box2 to edittext$("box1")
--Set box1 to "hello"

That looks identical to...
.start of frame
--Set box1 to "hello"
--Set box2 to edittext$("box1")

...in the event editor, but only the second one will work. The order of events can be editted by right-clicking the line number and choosing 'edit the actions'.

Posted by Assault Andy

24th May, 2003

Another thing to remember that is critical is when your player/enemy dies and you want to create something at his body eg. and explosion:

This doesn't work
enemy dies:
-destroy enemy
-create explosion at enemy

This works
enemy dies:
-create explosion at enemy
-destroy enemy

The first one doesn't work because the enemy is destroyed and then the program doesn't know where to create the explosion because there is no enemy to create it on.

Posted by Crystal Clear (H.E.S)

24th May, 2003

Very nice article shab!!!

Posted by

24th May, 2003

Assault Andy, that's wrong; destroying the enemy and then creating the explosion works. I'd suppose it's because Mmf destroys the object after scrolling through the whole events, including behaviors.

Posted by :JULI@N:

24th May, 2003

assault andy, thats wrong, anyways you can´t destroy the enemy and create the explosion in an specific order. to create the explosion you use the create new object icon (that one with the egg) and to destroy the enemy you use that enemy icon. So it's not in the same action editor box, so there's isn't really an order

Posted by Daniel[Crazy_Productions]

25th May, 2003

...im not a n00b i just thought that you maybe meant sumthing else.... cause this is very basic knowlegde and i thought that it maybe was more advanced than it was

Posted by Knudde (Shab)

25th May, 2003

Basic knowledge that most have no grasp of.

Posted by Knudde (Shab)

25th May, 2003

But maybe the word "Basic" in the title wasn't a clue

Posted by ZeroTau

27th May, 2003

Knowing this has saved me from many frustrating nights.

Posted by ZeroTau

27th May, 2003

...though I didn't learn it from this article, but now more people do. Which is good.

Posted by Weston L

29th May, 2003

Yeah, the title is misleading. I have been kliking for over 5 years, made over 15 full product games, and I have never needed to know this. Although order of events is important to know, and I do fix bugs by re-ordering events all the time.

Posted by Knudde (Shab)

31st May, 2003

Why must I be surrounded by peoplle who do not look closely enough at things and comment them anyway? Ok, there is a part one which is this article, there will be others. Weston you never needed to know this, yet you still fool with the events to bug fix, well maybe you now have an understanding of why this is, and won't spend valuable time mudduling through code that could have been made correctly in the first place. This is basic knowledge and a basic concept that everyone should know.

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Knudde (Shab)
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