(December 1994)
Hi there,

                

First of all I want to thank all of you who wrote to me because
of the DEMOSTUF.ZIP source codes. I really appreciate all of your
support and finally I decided that perhaps I would do some more
sources.

                

This time it's also bits and scraps of demo code. Gouraud shading,
texture mapping and other kinds of shading are the main issues.
Tried to comment the sources a bit better, but I still lack much
I think (really hate writing documentation).

                

As usual I use Borland Pascal v7.0 with loads of in-line assembly.
Many had problems with my sources last time. Some because of a bug
in the code that crashed some machines. But most were trying to run
the sources from TP6.0 (or lower):
If you have TP6.0 you need to take care of the "SEGA000". I think
I have fixed it with the "SEGA000 : word = $A000".

                

Anyway. To compile these sources, turn on '286 code generation, put
all stack/range checking off. And hope it all works well.
Units are not totally compatible with DEMOSTUF.ZIP. In some cases you
need to include the PICTURE unit.
If you run low on memory, compile it, quit the IDE and run it from
dos!

                

Hints:
The red area on the screen is how much raster-time the routine takes
up!
You can turn it off by setting an "{" i front of the "{$DEFINE DEBUG}"
line!
The "r:=LongMul(x,y)" is "r:=x*y" and "r:=LongDiv(x,y)" is
 "r:=x DIV y"!

                

The one routine that is used by allmost ALL sources is:
  xpos:=x1 SHL 16;
  xadd:=((x2-x1) SHL 16) DIV (y2-y1);
  for i:=y1 to y2 do begin
    writeln(xpos SHR 16);
    inc(xpos,xadd);
  end;

                

or some variation written in asm. It produces a slope-array of
 (y2-y1) positions ranging from [x1..x2] ( = interpolation?)!

                

And one thing, I don't know how you intend to use these source codes
out there. But I'm NOT in favour of the "hey, rip my source code"
feeling.

                

I actually don't care if you simply replace the colours and release
it in your name; but try to be a bit more clever than that:
Look at the sources, try to figure out what happens, and make your
own version (much better and ten times faster, of course! :)
Anyway, there are about 40 downloads of my DEMOSTUF.ZIP sources right
now every week. Imagine how boring it would be to see 40 demos with
the same crappy routines every week!
If you do use them, please remeber to mention my name :)

                

Special thanx, hellos and acknowledgements:

Commodore Amiga
Mark Feldman and PCGPE
Peter V and friends from Lyngby Udd.Center.
John B, Ervin and Aaron from Australia for nice talks lately.
All x-Parasite/Amiga members and members of Polka Brothers/Amiga!

                

If you have any questions or wanna chat, write to me at:
  Bjarke Viksoe
  Norrebred 139
  2625 Vallensbaek
  Denmark

                

Please don't use the e-mail address from the DEMOSTUF.ZIP! I will
have left school when you read this and don't have an account on
the net anymore. Sorry, I'll miss you all.

                

; Legal stuff:
; These source codes may be used freely as you please.
; They can be copied freely as long as nothing is charged for a copy
; and as long as all files are included and nothing is modified.
; I offer no warranty with this code whatsoever, including its
; fitness for any particular purpose. Neither shall I
; be liable for damages of any kind that may arise from its use.

                

And remember: Pascal rulez, but asm rulez even more!

                

                                         happy programming
                                               Bjarke Viksoe