[PD] Extracting RGB components of iemgui's

Mathieu Bouchard matju at artengine.ca
Mon Jul 4 19:43:30 CEST 2011


On Mon, 4 Jul 2011, Chris McCormick wrote:

> Thanks for the tip. I did have a look at [#to_iem] as well but all 
> examples and documentation on this topic seems to be around converting 
> to IEM numbers as you point out.

But note that opposite features will have similar code in them. For 
example, >>10 in one formula is <<10 in the other so that it cancels the 
first one.

You can also use [#to_iem] as a testing device to make sure that reverting 
the conversion gets back to the original values of R,G,B.

> Ah, this is great. Thanks for this information! One last thing I am 
> confused about is how I can tell the difference between the 18 bit iem 
> format and the 24 bit format?

The 18-bit iem format is used in constructors (creators) such as the ones 
you find in dynamic patching and pd files.

The 24-bit iem format is used in the method named 'color'.

> Also, what is the iemgui_modulo_color() function all about? I have 
> implemented it for consistency but I don't understand why it is there.

it's a stupid function for doing :

   stuff %= IEM_GUI_MAX_COLOR;

The % operator is not exactly the same as the modulo concept, but when the 
input is never negative, it IS the exactly the same.

IEM_GUI_MAX_COLOR is for size of the built-in palette, that is, 30 
colours.

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| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC


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