3D engine

Stonemonkey · Posted: Jun 28, 2005 22:58 Post subject: 3D engine

A small demo/test of a software engine i've started re writing in freebasic, got a fair bit of work to do. Sorry no source atm.

http://freespace.virgin.net/r.fryer/soft3d_7.exe

SotSvart · Posted: Jun 29, 2005 0:57 Post subject:

Looks nize! Got abit dizzy there for a second

v1ctor · Site Admin

Great, the textures seem perspective-correct, it runs fast enough here, a 1.8 Athlon.. i guess you used 90% of inline asm anyway. Btw, why not hardware accel, because the challenge? ;)

D.J.Peters · Guru

(sorry bad english!)

Hi Stonemonkey,
i write an software shader too i was intersting how you make the h-line loop i have tryed read your code with an disambler (from nasm) and it seams that you are use th single data type in the loop. You can speed it up if you are use an fixed point data type. the result can be an power of 2.

80 fps > 160 fps

currently i'm writing the color spotlight part. will your shader support color lightning too?

Good work Joshy

Hexadecimal Dude! · Sr. Member

well, it completely froze my (rubbish) computer, had to cold boot it!
ah well, it was worth it for the first frame ;-).....

Stonemonkey · Posted: Jun 30, 2005 16:47 Post subject:

HI,

Sorry about the freeze hexadecimal dude, i've not really got any explanation for that.

D.J.Peters, I use singles for interpolating U/Z,V/Z and 1/Z. I've tried using fixed point for those but 32 bits doesn't quite give enough accuracy with the way I do the perspective correction although i have played around with using an extra integer for the z buffer instead of the single which has improved things a bit.

v1ctor, been asked that a few times and tbh don't really know, probably the challenge and the satisfaction when it's all finally working. The vertex/shading calculations and some of the tri drawing routine are done in asm but i think i need to learn more about optimising asm.

btw, what's the best way to clear an area of memory in freebasic?

Sorry about the dizzyness Sotvart.

EDIT:
Hexadecimal dude, i think i can explain the freeze. I use a method of keeping the control of programs at a constant rate independant of the framerate but it can sometimes get stuck in a never ending loop if there's too much for it to do or if it's run on a slow pc, sorry about that.

DrV · Site Admin

To clear an area of memory, you can use the built-in CLEAR, or libc's memset(), or write your own (faster :) routine. For example, if you know that your memory area is always a multiple of 4 bytes in length, you can do a very fast rep stosd:

Stonemonkey · Posted: Jun 30, 2005 18:32 Post subject:

Thanks DrV.

SotSvart · Posted: Jun 30, 2005 19:45 Post subject:

jupiter3888 · Posted: Jul 01, 2005 1:43 Post subject:

hey nice work there. i felt the need to duck on several occasions when a block was heading straight for me! and thats a hard feeling to replicate in software.
it runs very well on my intel celeron 2.8 GHz, just to let you know. nice smooth animation and movement.

Stonemonkey · Posted: Jul 01, 2005 9:11 Post subject:

Thanks jupiter.

v1ctor and D.J.Peters, thought you might be interested so here's the source with only the buffer clearing written in asm, it still runs pretty well. I've also removed the delta timing so it wont have problems on slower comps other than just running slow

http://freespace.virgin.net/r.fryer/soft3d.bas

relsoft · Master

Nice!!!!!

v1ctor · Site Admin

Cool, not bad for an almost "pure" FB implementation, i thought you were using fixed-point and interpolation inside the inner-loop every n-texels, what could make it way more complex and look not too great, but at least twice as fast.

I changed it to 320x240 and got dizzy after 3 secs ;). Btw, to compile with the latest FB changes, the pointer operations must be changed.. "p += expr" is now like in C to make type-casting supported.

D.J.Peters · Guru

(Sorry bad english!)

Yes and without fixedpoint math you can speed up the 3 add parts too.

Stonemonkey · Posted: Jul 04, 2005 9:30 Post subject:

Ah, thanks D.J.Peters. As i said before i need to look into how to optimise asm and that's a start.