Player isn't killed; Bullets hit each other [...]

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Francesco
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Player isn't killed; Bullets hit each other [...]

Post by Francesco » Wed Oct 04, 2006 8:19 pm

Some problems I've met while coding things for Rockfighter

Preamble: the CEs in the middle of the map are two multiplicators. They shoot out bullets when hit by bullets. They are pushable - if you manage to switch off the machine-gun effect (it's enough that you stop/destroy the bullet that's travelling between them).


First issue: the bullets seem to hit each other, somehow. In my purpose, they should run and disappear, but they act in this way only on two directions. Seems tied to the engine scan mode: press the R and N elements to reverse the scan mode and see how they change. Also, this is tied to the fact that the two multiplicators are just two tiles away from each other. If you increase this distance, the "machine gun" rate is decreased and the problem can't be noticed.

Second issue: decisely a bug: the player explodes but doesn't die. This happens when you walk down to the tile beside one of the two multiplicators, while they shoot out bullets at the maximum rate (that is, as they appear just starting the level). If they are aligned horizontally, the bug shows up on the right and the left sides, while occupying one of the tiles above or below them will correctly kill the player. This changes if you align them vertically: then the bug shows up on the top and bottom sides.

Tape attached, ready to be ":ist"ed ;)

I've tried it only on 3.2.2.

The multiplicators are being made after one of Zomis' ideas about extending Rockfighter.

Get the example here:
http://www.zomis.net/rnd/download.php?id=570
Anyway, by the way, have fun!
Francesco

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Re: Player isn't killed; Bullets hit each other [...]

Post by Zomis » Wed Oct 04, 2006 8:51 pm

Francesco wrote:The multiplicators are being made after one of Zomis' ideas about extending Rockfighter.
YAY :D:D:D:D That makes me veeery happy!

The player explodes but is not killed may be related to viewtopic.php?t=1168
But an interesting thing is that this seems to be related to the scan mode as well...

The problem with the bullets hitting each other and the scan mode is something I also had a problem with, when developing the rotation project I had problems with the directions right and down, while left and up worked fine. To solve that, I used a workaround using an extra CE, unfortunately I don't think that solution is possible here.

Sometimes I wish there was an "ultimate scan mode"... but I have no idea at all about how that could be implemented... :roll:

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Francesco
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Post by Francesco » Sat Oct 14, 2006 6:49 am

Just an "highlighter" to avoid missing this bug ;)
Anyway, by the way, have fun!
Francesco

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Holger
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Post by Holger » Sat Oct 14, 2006 10:55 am

About the first bug: Hard to say... Maybe somebody with more experience in creating "shooting CEs" has an idea?

The second issue clearly is a bug, but seems not to be related to this (viewtopic.php?t=1168) bug report, which I was so far unable to reproduce. Instead, it seems to be caused by the exploding player being overwritten with another element by the CE change, which changes the player explosion in a way that he survives the explosion.

I think I have to further investigate this bug...

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Post by Francesco » Sat Oct 14, 2006 12:17 pm

The first issue is not about CE coding, I think, because they have all the same settings. The bullets simply collide each other, but they shouldn't, because they travel to the same direction at the same speed. I think it's an engine scan issue, because the behaviour of the bullets changes according to the scan direction. Maybe it's not a bug "per se", but just a situation that brings the engine scan loop to its timing edges. Well, I could use it as a feature, in anycase ;)
Anyway, by the way, have fun!
Francesco

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Post by Holger » Sat Oct 14, 2006 12:57 pm

> The bullets simply collide each other, but they shouldn't, because they
> travel to the same direction at the same speed.

This does not prevent them from colliding at each others! Remember that every moving element uses two tiles while moving. So the distance between two moving elements has to be more than one tile (or more than eight frames, depending if you look at space or time). But indeed, this depends on the game engine scan direction, so there is indeed a difference of exactly one frame when comparing the directions up/left with down/right.

So these timing differences have to be prevented by proper CE editing in most cases.
Last edited by Holger on Sat Oct 14, 2006 8:21 pm, edited 1 time in total.

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Post by Francesco » Sat Oct 14, 2006 6:39 pm

Ok, I'll try to work around this ;)
Anyway, by the way, have fun!
Francesco

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