I do not have time to explain this in-depth, but what I always do (it's been a long time since I created a scrolling tilemapper) is like this:

Code: [Select]

(big tilemap here)->GDB1

now display the tilemap from [scrolled X] to [scrolled X]+(96/tile size).
Same for Y.

So if X was the amount scrolled for only horizontal scrolling,i
I'm going to guess what I interpreted
Repeat getkey(15)
For(B,0,8
For(A,X,X+12
{B*13+A+GDB1}->T
If T
T--
Pt-On(A-X*8,B*8,T*8+Pic1
End
End
End
DispgraphClrdraw
End

With scrolling, you need an X offset and a Y offset, in pixels. I use T for the X offset, and S for the Y offset. Assuming you have a pointer to the tilemap in W and the start of the Tile sprites in Pic1, using A, B, C, D, and E as temporary variables...

ClrDraw

0-(T^8)->C
For(A,T/8-1,T/8+11
0-(S^8)->D
For(B,S/8-1,S/8+11

If {B*WIDTH_OF_MAP+A+W}->E
Pt-On(C,D,E-1*8+Pic1
End

D+8->D
End
C+8->C
End

Dispgraph

So when T is 8 and S is 8, you're at the top-left most corner of the tilemap. You can increment/decrement T and S using the arrow keys.

lol yeah, that's correct, assuming your map data is in GDB1.

Changing S and T by 1 increments by 1 pixel at a time, right?

And width of map in tiles?

Does
0-(S^8)->D
Have to be inside the loop?

I'm not sure if it could be out of the loop to optimize, but it seems like it could...

Speed. I only have 6mhz.

Yeah, I know that, but I just wanted to try to move one line in a for loop out of the for loop, and see if it works.

It seems like it has to be in the loop though.