[PD] data structures - color?

[Hans-Christoph Steiner]

On Mar 25, 2006, at 4:39 PM, IOhannes m zmoelnig wrote:

> Mathieu Bouchard wrote:
>> On Thu, 23 Mar 2006, Hans-Christoph Steiner wrote:
>>
>>
>>> The whole color thing is a bit of a mess.  I think that the Gem  
>>> float
>>> RGB scheme should be adopted everywhere.
>>
>>
>> In GF it would be difficult if using the default int types à la GEM.
>> However, unlike GEM and PDP, GF also supports float images, so if you
>> really want to use float colors in GF, you can do it.
>>
>
> where do you see any difficulties?
> the question is how the colours are represented in "pd number space"
> (this is: the numbers you see in numberboxes).
> Gem uses internally "unsigned char" to represent numbers, pdp uses
> "short" and GF uses various types.
> however, when you set a colour in Gem, you say "1.f 0.f 0.f" and not
> "0xff 0xff 0xff"; the user need not know about how the numbers are
> handled internally (sometimes they will have to, e.g. when it comes to
> rounding errors)
>
> i think hc's idea is (and i very much like it), that you could also  
> set
> the iemgui's colours with something like "1.f 0.f 0.f" instead of
> "0.9e7" (or whatever, i haven't checked). it is not really  
> important if
> the the colour-representation in the saved patch is again some magic
> word (though i would be far better (in terms of readability and
> colour-depth) if the colours would be saved with something like
> "#ff00ff" - using symbols to circumvent pd's rounding errors)

I think floats would be simplest, tho there would be three atoms in  
place of one.  If you use one Pd float for each R, G, and B, I don't  
think rounding errors would be an issue, unless you are doing really  
high bitdepth color.  Standard formats are 8-bit per color, Pd can do  
19-bit integers (almost 20-bit).

But of course, that probably makes thing more complicated to change...

.hc


________________________________________________________________________ 
____

"If nature has made any one thing less susceptible than all others of  
exclusive property, it is the action of the thinking power called an  
idea, which an individual may exclusively possess as long as he keeps  
it to himself; but the moment it is divulged, it forces itself into  
the possession of everyone, and the receiver cannot dispossess  
himself of it."
                                                        - Thomas  
Jefferson