Variable Checking Question

[wild8900]

Hey how do you see if a variabe equals any number in a list or a matrix? (preferably on a list).

[tr1p1ea]

Is this from BASIC (as in a BASIC variable) or an ASM program checking a TIOS list/matrix?

Either way you would just need to traverse the list/matrix in a loop and compare it against your variable. But then there are of course cases where the number appears more than once in the list etc ...

[King Harold]

If it's a list, don't use a loop!
for matrices, unfortunately, you'll have to use a loop..

Code: Select all

if sum(L1=X)

this will check the value of X against all values in L1, create a list with only 1's and 0's in it and sum it up, it there is any 1 in it then the condition will be regarded as "true", if NO VALUE in the list matches X then it will be FALSE, ofcourse you can put something like ">5" behind the sum() to make the number of required matches higher, or only cause 'true' if the number of matches equals a value, etc.
this is like 100 times as fast as a loop since the parser will only have to parse your line once and then execute the loop in asm.
For matrices, you can first split them up in lists and then use a loop as long as the number of lists, that would still be a lot faster then a nested loop over each element.

[Super Speler]

max(L1=X is faster if it doesn't matter how many times it appears in the list.

[King Harold]

it's not faster, and like you said, you won't know how many times the value is in the list.
the TIOS will still have to loop through the whole list for max(

[Super Speler]

PROGRAM:TEST
:{0,1,0,1,0,1->L1
:startTmr->T
:for(A,1,E4
:max(L1
:End
:startTmr-T
Output: 48

PROGRAM:TEST
:{0,1,0,1,0,1->L1
:startTmr->T
:for(A,1,E4
:sum(L1
:End
:startTmr-T
Output: 56

I win.

[threefingeredguy]

Super Speler, that test isn't accurate. He isn't saying sum(L1, he's saying sum(L1=X.

While adding the =X will undoubtedly make it slower, you should do it to make sure your tests are correct.

[Super Speler]

No the =X is the same amount of time in each example leaving my test intact (I can test this if you want).

[wild8900]

Well you see, Its for my BASIC game and the list contains the tile numbers of the tiles that you CAN walk through. Constantly checking every step in a loop for each var in the list would be unplayable.

[Floodkiller]

Ohhh, you mean collision detection .

There is a good example in the xLIB demo provided, but a simpler, less optimized version would be:

Code: Select all

:If (X+#>0)(Y+#>0)(X+#<$+1)(Y+#<$+1)=1:Then - Replace X and Y with your character positions, the # signs added to your X and Y with numbers to tell the matrix where your character is moving, and the $ signs with the matrix limits
:If [A](X+#,Y+#)<@:Then - the @ is the first tile that you cannot walk through.
:[i]movement code[/i]
:End
:End

I am sure you could do it a different way, but thats just the basics.

[wild8900]

No, I know how to do collision detection, I need to know how to see if a variable equals ANY number in a list without having to start a seperate loop.

[Super Speler]

Yes, max(List=Number, It's been said before in the thread.

[wild8900]

Oh sorry I didnt see your post, I was replying in response to Floodkiller.
Thanks! Ill try out your method.

[CDI]

Why not just have section of your pic for solid tiles, and a section for non-solid tiles. For instance, Metroid Infinity will have any tile in the top 2 rows be able to walk through, any tile in the 3rd row be for morph ball only, and anything below the 3rd row is solid

[wild8900]

Yeah I thought of doing that but then that would mean having to redo every single map in the game.... I might just end up doing that though.... >.>
I really dont look forward to redoing the maps....