0.714285714 (c[a,o]s[a,o][s] de justin)

ah, 1997. or: nostalgia

Sat, 25 Oct 2008 10:14:00 -0700

So in 1996 and 1997 I wrote a 3D library called Plush. Here is a screenshot from then:

It was written in C, it tried to be very portable (reading through it now, I'd say almost to a fault -- kinda annoying ;). There were some nifty things about it:

256 color output with adaptive palette creation and management
multiple light sources
piecewise linear perspective corrected texture mapping
Gouraud shading with color ramps that let you do fakePhong
optional Z-buffering
environment mapping
object hierarchies
frustum clipping
cameras
splines
matrix functions
primitive generation
very basic translucency

Totally useless today. But it would run SO fast with 20x the power available...

The code itself wasn't too bad, some stuff that I had spent ages tweaking and getting to run smoothly would surely be reusable.

So in about 8 hours of work I transformed it into Plush2, which is similar to the above, except simplified in C++, renders to 32 bit per pixel output, integrates with our LICE compositing engine, and supports the following new features:

24 bit color output
multiple COLORED light sources
Texture mapping (piecewise linear perspective corrected) with optional BILINEAR filtering and support for any sized texture, support for texture transparency.
Colored Gouraud shading
Z-buffering
True surface transparency support
Multitexture support (one or both textures can be used as environment maps)
Full control over how pixels are combined at render -- add, mulitply are supported replace, all with alpha control.
No limits on number of light sources, triangles, etc.

A screenshot:

Yes yes I know 3D stuff has all been done a ton, just thought it was interesting bringing things back from the dead to see what would be reusable. Now I'm going to go hug my 2.4ghz multicore processor.

This will be a part of the next WDL release, in case anybody cares, ha ha. It does compile down to pretty small (though not small enough to go making a 4k demo with it)

stumbling in code

Wed, 01 Oct 2008 10:14:00 -0700

So while playing with some code to model a resonating spring (F=-k*pos), I discovered that the model I was using produced a very good sine wave approximation. This isn't normally something terribly interesting, as you can approximate sine/cosines very easily, but it was actually quite low complexity -- an iterative approximation with only 2 multiplies and 3 adds per sample. It can also generate the cos() (well, a 90 degree shifted signal) for each point for just one additional multiply.

The error is pretty low for the first few cycles, though after a bit it does drift in relation to the correct wave. I'm not going to spend too much more time on this, but if anybody wants to see if there's some way to correct it, go for it (it may just be rounding error, though, of course).

Here is the code:

// iterate to next sample
double newpos = pos*mul1 + vel*mul2;
vel -= (pos+newpos);
pos = newpos;

Ta-da! If anybody wants to go and do some fancy pants math to show why this works, too, I'd love to hear it... :)

mobile update

Sun, 07 Sep 2008 04:44:00 -0700

Another tag, yay

Come on, sf dpw

Wed, 03 Sep 2008 23:46:00 -0700

Time to request a hearing, as I do not have any "graffiti" but they seem to think I do....

After 18 hours

Thu, 21 Aug 2008 20:22:00 -0700

The smiley face was me...

Front door

Thu, 21 Aug 2008 00:46:00 -0700

We'll see if this works-- both with the kids and with the city...

Interesting sense of humor

Sun, 10 Aug 2008 19:09:00 -0700

(note the car #)

cures for jet lag:

Sat, 02 Aug 2008 20:15:00 -0700

The 3 Cs: caffeine, calories, and cocktails... Of course you need the right amount of all, and the right sequencing, but if you get that all is forgiven.

And days like this don't hurt either...

Spring Cleaning

Tue, 29 Jul 2008 02:55:00 -0700

Found my laptop with ergonomic keyboard!

I love PHP

Fri, 25 Jul 2008 10:14:00 -0700

Can I just say it? It's such a great tool. I know, I know, it's for web pages, you say.. But I've been using it for tasks people would use perl for, and it's great. Converting Windows .rc files into SWELL-able C++, converting at&t assembly syntax to intel syntax for Jesusonic, such great things. Hooray for PHP. Easy to install on Win32 (just unzip), comes on OS X, it's a good time. A+.

Thank you that is all.

Cubs vs Giants

Fri, 04 Jul 2008 01:43:00 -0700

Still hot out, for now.. Time to shotgun a contraband Bud Lite in the bathroom...

Rad toy

Tue, 24 Jun 2008 06:54:00 -0700

Woohoo the tiny maudio ekeys 37, $49, arrived... It's small, and light.