Re: [AL] smoothly scrolling tiles problem

[R. H. G. <luv...@un...>]

On Mon, 3 Aug 1998, Jeff W. wrote:

> At 07:10 AM 8/3/98 -0600, you wrote:
> >mapx and mapy are the variables you want to increment to move around the
> >map, tilesize in this case is 16, map_image is a bitmap with pixels
> >arranged where the tiles should go, and tiles_image is a bitmap full of
> >tiles in 16-tile-wide rows. Obviously, if you're using something else
> >(like a double array) instead of a map_image, you just have to change z.
> >Hope this helps!
> >
> >----------							--------
> >R. Hunter Gough						luv...@un...
> 
> OK, so let me get this straight: map_image is just a bitmap the size of the
> screen with, in this case, a single pixel plotted every 16 pixels? 

Wrong!! :)X map_image is like a shrunk version of the whole map with
pixels instead of tiles. i.e. this in map_image:

XOX
OXO

would draw this to the screen:

XXXXOOOOXXXX
XXXXOOOOXXXX
XXXXOOOOXXXX
OOOOXXXXOOOO
OOOOXXXXOOOO
OOOOXXXXOOOO

(more or less)

the z variable reads the pixel at a point on the map_image by color, and
translates that into a tile to be drawn to the screen. For instance, if
the color at 5,3 were color #19, z=getpixel(map_image,x,y) would return
19, which would tell the function to use tile #19 when it draws that tile
to the screen. Dig it?

> matter what color pixel?  Tiles_image is another bitmap that holds every
> different type of tile used in the game, correct?  Andddddddddd, mapx, mapy
> are just variables to keep track of the position on the map. 

Yep.

-----								--------
R. Hunter Gough						luv...@un...
-----								--------
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