posting your source code will help. basically, you then find  pxl you want to test for. divide the x and y positions by 8, and that's the position of the pixel in the tilemap. assuming 8 is your size, that is.

Hi and welcome, feerik. There are several ways to do collision detection, but the easiest way (without having to do a lot of math stuff) is to use pxl-Test(. Just check if the pixel(s) 8 pixels below your sprite are turned on (assuming you're using 8x8 sprites).

For example, if your sprite is at (X,Y), check with If pxl-Test(X,Y+8) or pxl-Test(X+7,Y+8) (the X+7 is to check for the rightmost column of pixels).

By the way, when you create help topics, you can get a lot more people to notice your post by using a title that tells us what you need help with.

is that the ? mark when you make a new topic?

is that the ? mark when you make a new topic?

Nope, just name your post something like "Help with collision detection".

first, thx for the quick awnser, second, its a tile map of8-10
so youre saying i need to do pxl-test?

(im new and i dont now how to post code)

[code]
*code*
[/code]

will work like so:
i'm code

and no, you do not need to do pxl test. if you want, you can, but that is not tile-based.i'm saying if you have a tilemap like so:
01010101->GDB1
01000001
01000001
01010101
and each tile is 8x8, and your character was at (8,24) and you wanted to check to see if there's at tile beneath him(there is),and your character is 8 pixels tall, you'd do this:
8->X
24->Y
{Y/8*4+(X/8)+GDB1} //returns tile number at pixel position (x,y)


Collisions depend on what you're making, but try using this to Tilemap:

http://ourl.ca/4550

If you're doing  physics based game and you need really accurate physics, try Builderboy's routine (Which I hope he doesn't mind me posting):

Quote

If X1+W1>X2  AND  X2+W2>X1  AND  Y1+H1>Y2  AND  Y2+H2>Y1
there is a collision!
END

Where X and Y are position and W and H are width and Height.  As for collsion velocity tranfer, the equations are this:

V1 = (C*M2*(V2-V1)+M1*V1+M2*V2)/(M1+M2)
V2 = (C*M1*(V1-V2)+M2*V2+M1*V1)/(M2+M1)

Where V is velocity, M is mass, and C is a constant from 1-0.  1 being a perfectly elastic collision (no energy lost) and 0 being a perfectly inelastic collision (objects stick together).

That routine is for collision between objects, not between an object and a tilemap, so thats not what he wants.

So you know how to make a tilemap you say?  How are you storing your data?  What do your sprites look like?

yes i use something like this
(test)
[01020202020202020203]->GBD1
[04050505050505050504]
...