[gameprogrammer] Re: Calculating Line-Of-Sight

On 11/8/05, Jake Briggs <jacob_briggs@xxxxxxxxxxxxxxx> wrote:
>
>
> Olof Bjarnason wrote:
>
> >>Yes, but how do you know which walls are on the line?
> >>
> >>
> >Look here, when you draw a line, you automatically know which points
> >are on that line. Google "line drawing" or "bresenhams line segment
> >algorithm".
> >
> >
> Yes, yes, keep your hair on, I understand bresenhams algorithm.
>
> >
> >
> >>>When you have such an algorithm from drawing lines on Stephen's grid,
> >>>it is easily modified to instead of drawing a "pixel" at location
> >>>(x,y), doing the test I mentioned earlier. That's where my x and y
> >>>comes from.
> >>>
> >>>
> >>>
> >>>
> >>So the x,y position is the point at which the line intersects the wall?
> >>
> >>
> >No, the x,y position is one of the candidate coordinates on the grid.
> >
> >
> Oh, okay, it makes sense now. I didn't realize that the x,y position was
> refering to one of the cells (that can be either a wall or a floor) in
> the 40x40 grid. When you said
>
>  > One simple idea is "drawing" a straight line from point A to point B,
> testing all walls thus "painted".
>
> I thought you were refering to the 4 planes that would line the wall
> cells, not the wall cells themselves. Maybe we should have called the
> cells "roof cells" or "floor cells" instead of "wall" and "floor" cells.

Ok, now let's hope Stephen has some use of our discussion :)

cya,

/Olof

>
>
>
>
>
> --
> Jacob Briggs
> Systems Engineer
>
> Core Technology Limited
> Level 1, NZX Centre
> 11 Cable Street
> Wellington
> Phone +64 4 499-1108
>
> --
>
> Named after its country of origin 'England', English is a little known 
> dialect used by up to 1.5 billion non-Americans worldwide. Some interesting 
> but obviously incorrect features of the language include:
>
> - queues of people
> - wonderful coloUrs
> - the useful metal aluminIum
> - the exotic herbs (h-urbs), basil (ba-zil) and oregano (o-re-gaa-no)
> - specialiSed books called 'dictionaries' that tell you how to spell words 
> correctly
>
> Many people using this bizarre gutter speak also subscribe to the pagan 
> belief that water freezes at 0 degrees and that distances should be measured 
> in the forbidden mathematical system of base-10...
>
>
>
> ---------------------
> To unsubscribe go to http://gameprogrammer.com/mailinglist.html
>
>
>


---------------------
To unsubscribe go to http://gameprogrammer.com/mailinglist.html

Other related posts: