Archive: Erm, Atero? (Primer)


2nd April 2003 06:43 UTC

Erm, Atero? | XOR Blending
As i said i was working through your Primer in order to get some more knowledge on 3d stuff. Well i figured out that something was missing.

Originally written by Atero
Minimum Blend
Uses the least amount of color between the two frames. I can't
remember where this is used, but it's not usable in effect lists.
Its used in UnConeD's APE's (Picture RendererII and Corlor Map). I'd advise you to either leave this out, or to explain those APE's too.

Originally written by Atero
XOR
Don't know anything about what this is, but it's trippy.
To understand XOR generally we need to know that eXclusiveOR means nothing else than a boolean or - but excluding the and.

The programming code woud be: x xor y = (x or y) and not (x and y)

And here is a tabe to make this more obvious:

x|y|result
-+-+------
0|0|0
0|1|1
1|0|1
1|1|0]


As we know, the color channels are calculated seperately.

Now we imagine x and y to be the two red-channel values.

First, AVS converts them too boolean values which means dividing by 255 and rounding up or down.

That means a color value of 128-255 is 1, a color value of 0-127 is 0.

Then, AVS does XOR, as explained before.
Finally we need to get a useable color value as a result which means multiplying the result with 255.

To put it in a nutshell, a value above 127 and a value below 128 will result in a full valued color channel with 255, if the values are both above 127 or below 128 this will result in color channel of 0.

Well, i could also have pm'ed this but if Atero did'nt know about XOR there are probably more around who don't either.

2nd April 2003 06:47 UTC

Erhm... You know there is a thread about the primer uptade already at http://forums.winamp.com/showthread....hreadid=121697 Also you could've just PM atero , why make a new thread about it?


2nd April 2003 07:46 UTC

Originally posted by Magic.X
Well, i could also have pm'ed this but if Atero did'nt know about XOR there are probably more around who don't either.
Ok, seems i to sorta missed the primer update thread.

But anyway, this is not just about updating the Primer, but mainly about XOR Blending (renamed the Topic) and this way the 2-3 months old thread wont be revived.

/Edit
And this way there may be more newbies profiting from it because they wont have to work themselves through 50 posts first. Anyway i dont think it would'nt kill anyone to have a new thread

2nd April 2003 07:55 UTC

this way the 2-3 months old thread wont be revived.
I think you as a regular already know what old threads are appropriate to be revived and what not, like take example the Tips&Tricks (which eventually was made into a sticky one)

But anyway... actually i have nothing to say anymore :p

2nd April 2003 12:02 UTC

I don't think that that is how AVS does XOR, because then XOR would only result in a couple of colors being used, not the entire range that it does use.


2nd April 2003 12:18 UTC

I just checked that, seems you're right

I found this out by testing it with large text letters in many color constallations and in most cases this rule works. Maybe it processes some color constellations in a diffrent way.


2nd April 2003 20:52 UTC

I'M WORKING ON IT. I DON'T NEED ANY HELP FROM ANYONE AT THIS POINT. MOST OF ALL, GET OFF MY ASS ABOUT IT. it'll be done when it's done :mad:


2nd April 2003 22:58 UTC

The real way that XOR works has been explained by me in another thread...

http://forums.winamp.com/showthread....&highlight=XOR


3rd April 2003 05:29 UTC

Thanx jheriko, i expected it to be a per byte xor and not a per bit xor - this explains why i got partially those results by playing around.