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Old 24 November 2020, 11:23   #41
hooverphonique
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Quote:
Originally Posted by ross View Post
Code:
move.l    #$bada55a0,d0

That seed looks rather suspect - "bad ass a0" ?
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Old 24 November 2020, 13:02   #42
ross
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Originally Posted by hooverphonique View Post
That seed looks rather suspect - "bad ass a0" ?
You do not like it?

Well, there was actually a reason I chose that pattern (apart the usual nerd reasons ).
For good 'oldTV noise' I thought I had to switch between 'spots' on and off quite frequently (but not too regularly, at bit level you can see it).
Since 'the algorithm' does nothing but shecker and scatter these points I had to choose it as representative as possible in the initial 32bit.
And in the end I saw that it worked surprisingly well.
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Old 24 November 2020, 22:08   #43
Antiriad_UK
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Originally Posted by DanScott View Post
Yeah, that's the one, forgot where I stole it from

Of course, the random screen noise we (or at least a lot of us) used back in the day (ie in the credits of Madness 2), was generated by drawing a couple of blitter lines from y = 0 to y = 255, with random x coordinates, then blitter filling the buffer.. and repeat that each frame without clearing the buffer... that generated a really good and convincing noise effect.

It got me thinking recently if that method could be used to generate (for example) a 256 byte random number table each frame
Clever. I'd never seen that demo so just had a look. I'd ass-u-me that doing a blitter fill on that kind of noise twice would end up as the initial noise. Interesting (edit: ah you probably meant draw a couple of lines each frame and refill, I get it)

Last edited by Antiriad_UK; 25 November 2020 at 10:35.
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Old 25 November 2020, 15:35   #44
DanScott
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Originally Posted by Antiriad_UK View Post
Clever. I'd never seen that demo so just had a look. I'd ass-u-me that doing a blitter fill on that kind of noise twice would end up as the initial noise. Interesting (edit: ah you probably meant draw a couple of lines each frame and refill, I get it)
Yes, it stemmed from witnessing what happened when not clearing the screen when rendering filled cubes and stuff
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Old 25 November 2020, 23:16   #45
Antiriad_UK
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Originally Posted by DanScott View Post
Yes, it stemmed from witnessing what happened when not clearing the screen when rendering filled cubes and stuff
I just turned off my clearscreen in my vector routine. It does indeed look like very nice noise. Pro tip!
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