PATCH (beta): Teleporting within a level

[adurdin]

This patch changes the secret-level teleporter in Keen 1 so that it works only for teleporting within a level.

Code: Select all

%ext ck1
%version 1.31

# Change the teleporter so it works within the level (updated 24/09/03)
%patch $8919                           $89 $F0 $F7 $2E $08 $6C $01
   $F8 $D1 $E0 $C4 $1E $4C $6C $01 $C3 $26 $8B $07 $50 $88 $E0 $98
   $99 $01 $F0 $83 $D2 $00 $B1 $0C $E8 $16 $58 $89 $16 $E4 $6E $A3
   $E2 $6E $05 $00 $B0 $83 $D2 $FF $A3 $D4 $6E $89 $16 $D6 $6E $58
   $98 $99 $01 $F8 $83 $D2 $00 $B1 $0C $E8 $F5 $57 $89 $16 $E0 $6E
   $A3 $DE $6E $05 $00 $70 $83 $D2 $FF $A3 $D0 $6E $89 $16 $D2 $6E
   $C3

%patch $4572  $E8 $A4 $43 $EB $13 $90

%end

In order to use this, you must work out the x and y coordinates of the destination relative to the location of the teleporter, then set the sprite number on the teleporter to yyxx, where yy and xx are the hex values of the relative y and x coordinates (note that this sprite number is calculated the same way as that for a bridge switch).

For example, if I want a teleporter at (132, 6) to take Keen to (54, 41), then the relative coordinates are x:(54-132)=-78, y:(41-6)=35, and in hex these become xx:$B2, yy:$23, giving a sprite number $23B2, or 9138.

The only thing to be aware of when using this is that the teleporter destination must be at least 10 tiles away from the sides of the level, and at least 6 tiles away from the top and bottom of the level.

If you are using TileInfo, and your teleporter is made up of more than one tile, then you'd be best off setting only one of the tiles of it to the "teleporter" behaviour, so that you only need to calculate and put sprite numbers on one of its tiles in the levels.

Update: The bug I mentioned earlier has been fixed. And consequently (though unexpectedly), the resulting code is 10 bytes shorter!

[adurdin]

Something worth noting with this patch is that it will free up about 350 bytes of code, which can then potentially be used for lots of other patches. (For comparison, this patch has the longest single block of code out of any of the patches I've written so far, and it's only 98 bytes long)

[xtraverse]

:droooooooool

You are my god adurdin.

[Matze82]

:D Wow!
That's fabolous. You're the best!

Thanks, Matze82

[Scizor CT]

Andrew, at the rate you're going, we'll never even need the source code to make changes. Great job.

[KeenRush]

WOW!!!!!!!!!111!!
This is so GREAT!!! I can't hardly sit on my chair without falling down!
AWESOME!!!!!!!!!!!!!! This makes possible so many cool things, ah, can't wait to get using it! Perfect in CKCM too..

[Yowza]

*Drooool*

[CommanderSpleen]

Woah... Sorry to use your name in vain, but MY GOD THIS ROCKS!

Woo. 30 whacked out insane patched-up levels, here I come!

:D:D:D:D:D

>Commander Spleen

[adurdin]

OK, there was a bug in the initial patch file, but I've fixed it now. The patch in the first message is now the latest, correct version.

But there still could be other issues -- those mod makers who are using this, please let me know how you're going with it.

[AutomaticGarg]

i tried it out and it works very well... could you maybe make a patch so that by setting to a certain value u can teleport to somewhere on the map? not that i'd use it, but others might.

[adurdin]

Teleporting onto the map is *much* more complicated. That's what the original teleport code used to do; in fact this code is taking the place of the original code.
I could make a patch so that you can specify in the level where on the map you'd like to go, but I'm not sure how useful it would be...

[KeenRush]

Hmmm, I think it could be pretty useful; if making different looking places for map. I bet community mod will have use for it.

[grelphy]

*klunk*

You may be sure that i'll be making a new mod by the time i pick my jaw up off the floor just to use this patch...

[ckguy]

Would it be possible to go through the teleport when the player pressed a certain key ... like Alt, say?

[KeenRush]

I have thought the exactly same question, with the alt-button too! :)
That would be pretty neat, it could add more "choice" for the player, for example there could be something corridor full of teleports and player would need to choose. "The problem is choice."