| |
Rudi
Account closed
Registered: May 2010
Posts: 125 |
DYPP
Hi,
DYPP - Different Y Pixel Position.
I don't seem to find an explanation on this effect on C64 on codebase or anywhere. Maybe its in another thread here on csdb, then please provide an link.
I know the basics of sines, ive made sinescroll on PC, but its easier there since you can look up the framebuffer directly, via sine-tables and so on.
Im wondering how this effect is easily made on C64. I believe there are more than one way, but i guess one way is slower than the other; for example moving each column-bit (inside a char) in realtime. The other way I think is having the chars animated, similar to a twister. Though, im thinking each angle is used for lookup table. I just dont seem to get it right in my mind to start coding on this effect. I've seen several early cracktros and demos that does this very fast, but haven't had the time to reverse-engineer the binaries. If you have any tips and info i'd appreciate it, or even better; write an explanation for codebase.
Thanks |
|
... 43 posts hidden. Click here to view all posts....
|
| |
Compyx
Registered: Jan 2005
Posts: 631 |
How would we call a DYCP (ie simple sinus-based char scroller) using sprites to make it move over a bitmap or FLI?
I did a few of those, and I wouldn't call them DYSP's. Just some trickery to make them appear as proper DYCP's.
I was thinking about doing a write-up on codebase about DYCP's, should be fun getting the terminology correct :) |
| |
Oswald
Registered: Apr 2002
Posts: 5017 |
Quote: How would we call a DYCP (ie simple sinus-based char scroller) using sprites to make it move over a bitmap or FLI?
I did a few of those, and I wouldn't call them DYSP's. Just some trickery to make them appear as proper DYCP's.
I was thinking about doing a write-up on codebase about DYCP's, should be fun getting the terminology correct :)
DYSPFLI :) normal bitmap just DYSP. |
| |
ChristopherJam
Registered: Aug 2004
Posts: 1378 |
Quoting CompyxHow would we call a DYCP (ie simple sinus-based char scroller) using sprites to make it move over a bitmap or FLI?
I'd still call that a DYCP; the 'character' in the acronym is in my mind a unit of distance, that tells you the granularity of the effect. There are plenty of different ways to achieve it. |
| |
mankeli
Registered: Oct 2010
Posts: 110 |
I would do 8 copies of the charset (one for each pixel column) and then just LDA ORA ORA ORA ORA ORA ORA STA.
If you arrange chars nicely, maybe you can unroll the whole thing and do LDY LDA,y ORA,y ... dunno.
Maybe there's better way as well. |
| |
Oswald
Registered: Apr 2002
Posts: 5017 |
better way: speedcode per char, to skip empty pixels. |
| |
Compyx
Registered: Jan 2005
Posts: 631 |
Even better: use VSP, that way the shape of the dypp doesn't actually change and you can optimize a lot of code (no need to clear stuff, perhaps 'join' a few pixels in a single ORA, etc). |
| |
Oswald
Registered: Apr 2002
Posts: 5017 |
Quote: There exists an old, but pretty good DYPP based on VSP in Anal Intruder. And AFAIK the best completely dynamic DYPP is in Mekanix.
mekanix is cheating as far as I'm concerned, lda sta code, no ORA. |
| |
HCL
Registered: Feb 2003
Posts: 716 |
Quote: mekanix is cheating as far as I'm concerned, lda sta code, no ORA.
Mekanix is using precalculated fonts for a range of angles. It is still calculating individual sinus-values for each pixel-column, and then mapping it to best possible font.. The accuracy is ok i would say :). Also this way it can do more funny sinuses than VSP-stuff. |
| |
Compyx
Registered: Jan 2005
Posts: 631 |
Gotta admit those DYPP's look really smooth, and using a movement you can't get with VSP-trickery.
Never had seen that demo before even, I'm lagging behind badly :) |
| |
ChristopherJam
Registered: Aug 2004
Posts: 1378 |
Ah, so that's how they managed such a large area. It's effectively caching intermediates, so that still counts in my book; just restricted to reasonably smooth functions :) |
| Previous - 1 | 2 | 3 | 4 | 5 | 6 - Next |
