Re: A86: trig in ASM (vectors and raycasting)
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Re: A86: trig in ASM (vectors and raycasting)
BIOSERRORS@aol.com wrote:
>
> I've done some work in BASIC...I've made a raycasting engine that turns a 2-d
> matrix (the map) into a 3d world....very, very slowly of course. I want to
> convert this to ASM. If you want an ASM program to use degrees fast, you need
> to make a table of sine and cosine values (sin 1-360 and cos 1-360).
>
> Here's a simple program in BASIC that simply makes a circle by plotting
> several points along the rim of the circle:
>
> :Degree
> :AxesOff
> :ClDrw
> :FnOff
> :64->X
> :32->Y
> :For(A,1,360,5)
> :X+cos A->X
> :Y+sin A->Y
> (In Radian mode, use X+cos ((A*[pi])/180)->X and sin Y+((A*[pi])/180)->Y)
> :PxOn(iPart Y, iPart X)
> :End
>
> You can also change this program to effectively make it plot a
> vector....simply find the X and Y displacements based on the angle you want
> the ray to go off in, and use a loop to increase the X and Y variables with
> the displacement values. (This is used in raycasting engines to record the
> distance to the nearest wall based on the player's position.)
>
> I don't have enough knowledge of z80 ASM to know how to convert this to ASM,
> but it should be very easy to do...the hardest, most agonizing part is getting
> the sin and cos values into tables...I'm make a header file that contains the
> tables...so that everyone can just use the #include pre-processor command to
> use the tables in their programs....because the table will have 1080 entries
> in it, I'll be making a program in C++ that does this for me. In fact, I
> already have this done, but I don't know how to output values to a file. (In
> C++). If anyone knows how to output text and values to an external file in
> C++, PLEASE let me know ASAP!!
>
> I hope that someone out there will use this knowledge to make a doom-style
> game...You can find more information on raycasting techniques, drawing walls,
> floors, ceilings, texture mapping, variable wall hieght, and anything you ever
> wanted to know about raycasting at:
>
> <A HREF="http://www.ben2.ucla.edu/~permadi/raycast/raycidx.html">
> http://www.ben2.ucla.edu/~permadi/raycast/raycidx.html</A>
>
> It doesn't contain any code, it's all about concepts, and it EXTREMELY
> helpfull.
>
> I REALLY, hope that someone will use this valuable information to make a doom-
> style game in ASM for the ti-86.. I'm sure someone will...eventually.
>
> Hope this helps! I know wish I knew ti-86 ASM better!
>
> -Dave
>
> P.S. -- If someone would like to help me learn ASM, I'd be very grateful!
> Thanks.
I also made a successful BASIC raycaster and I made an ASM raycaster
that worked despite a severe fishbowl effect. When I tried to remove
the fishbowl effect I screwed up something else and now it really
doesn't work. If you want my source I'll give it to you. e-mail me.
--
Tercero -- Email: mailto:tercero@busprod.com
"The stone the builders rejected has become the capstone;"
--Psalms 118:22
"Everyone who falls on that stone will be broken to pieces,
but he on whom it falls will be crushed."
--Luke 20:18
References: