:: Re: [Frei0r] "rgbnoise" plugin
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Συντάκτης: Steinar H. Gunderson
Ημερομηνία:  
Προς: Minimalistic plugin API for video effects
Αντικείμενο: Re: [Frei0r] "rgbnoise" plugin
On Fri, Sep 28, 2012 at 06:50:30PM +0300, Janne Liljeblad wrote:
>>  1. If you really want to compute three Gaussian noise values per pixel,
>>     you should probably use the Ziggurat method for generating the random
>>     values; the ratio method is very slow. (That, and you should not
>>     do a divide per nextDouble()!)
>>  2. There's absolutely no point in counting downwards in a loop that doesn't
>>     use its index; it doesn't buy any speed, and has not since sometime
>>     during the nineties. The compiler is able to do such transformations if
>>     it is a win.
> "rgbnoise" is a straight port from gimp. We drop it for now if
> consensus is that it is too slow.


Note that two of my three points (division in nextDouble() and pointless loop
reversal) do not come from the original source code; at least they do not
exist in the version of The GIMP that I checked.

/* Steinar */
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