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- > >Doing the actual texture mapping should be easy, but figuring out were to
- > >start in the texture, horizontally and vertically will be worse.
- > Well, as far as I can remember, there are some data which tell you if the
- > texture should be aligned on the top or the bottom of the wall pane. As for
-
- Yes there is something like that.
-
- > the horizontal position, I think it should depend on the actual position on
- > the map, line or column, depending on which one has the largest slope for
- > this wall, to give seamless walls. I'm almost sure doom does it this way.
-
- The problem is that the top or left part of a wall may be covered by another
- wall closer to the screen. When that happens, the distance 'into' the wall
- segment has to be calculated. I believe that will mostly be taken care of
- automatically by the table based clipping routines, however, if a simple
- fixed point accumulator is added.
-
- > >The last changes I made to DVIEW (did I send that version to anyone?) was to
- > I think I have this one. Do you put version numbers?
-
- Below it doesn't seem like you have the version with the map drawing. Do you?
- Unfortunately there are no version numbers so far. That'll be one of the next
- things to add as well.
-
- > >large. Disallowing crossing of walls has to be done in another way, but I've
- > >not yet figured out exactly how I'll do it.
- > Doom's way to do it must be very approximate, because sometimes, when you
- > move along a wall, it seems like you bump on lines or columns, see what I
-
- Yes, I know.
-
- > mean? You move away, then closer, then away. It's not very smooth. You must
- > have a table telling you all the objects that are contained in each square
- > of a map (independant from ssectors). This table's initial state is in the
-
- What square? There are no squares in a DOOM map AFAIK. You can easily get
- hold of all the lines enclosing a sector, though. Then you only have to
- check if you cross any of them. If you don't there's no problem, if you do
- a further check will have to be done to see if the line you crossed was
- actually a wall.
- Not very difficult in principle, but the checks against the lines could take
- quite a bit of time. Do you remember reading anything about the sector
- breakdown in DOOM? Are they always convex perhaps?
-
- > The easiest way must be to check all the walls that are in the same
- > square as you. The same algo will rule the behaviour of monsters,
- > projectiles, etc.
-
- Yes, apart from the 'squares' that's how I envision it.
-
- > >different colours depending on when they're clipped. The map rotates when
- > >you turn around so that 'up' is always in front of you. Looks really nifty!
- > How do you bring that to the screen?
-
- Well, the screen is always drawn in a chunky buffer at first and then
- converted for the screen, so I simply wrote a fixed point line routine
- that writes into the buffer. I didn't bother optimizing the routine since
- it's fast enough not to matter at the moment.
-
- > >I'll try to get a screen dump of a really bad case for you.
- > Yes, please do so. My mailer supports MIME.
-
- I'll post it uuencoded to the list.
-
-
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