hi guys,

i'm pretty new with pd...need some advice before started anything...

I need to create a colour object which it should works proportionally as the parameters of audio are changing.

e.g- red = 100-250Hz
green= 250-400Hz
blue= 450-600Hz

so, as i'm increasing the frequency, the colour object should change from red to blue respectively (meaning to say there should be yellow, orange in between and so on)..it will something like fade in and fade on stuff...

i know both canvas and gem would create colour object..but which one would be easier and handy if doing this kind of function??

pls advice.

if it's just one or two channels, a canvas should be ok. more than that and you'd probably be better to go for gem, as it will use less resources than constantly updating a canvas.

for info, right click on the top left hand corner of a canvas and open [pd edit], that wil show you how to send the colour change.

the help file is rather confusing...could anyone explain why
red = *65536; green= *-256 and so on??

Try to visualise it. In an RGB coordinate system you have a space made of 3 dimensions, all the colours are stored in a matrix with 0,0,0 = black at one corner and 1,1,1 = white at the other corner.

Now, have you seen those Pantone colour charts you get in paint or print shops? The collapse the 3D matrix onto a set of 2D charts. Each row steps over 8 or 16 increments of red (or whatever), until all the red values have been done, then the next sheet starts changing the blues....

Okay - now imagine this Pantone chart cut into strips, stuck together as one long ticket tape and laid out in a line. This is a 1D representation (probably because Pd uses linked lists for a lot of structures). It starts on black at 0 then adds 256 increments of just blue. After that it adds one increment of green and cycles round another 256 increments of blue. Only when it gets to 65536 does it add one increment of red, then it repeats.... To index a particular RGB value you have to multiply a 256 matrix by (1, 256, 65536) to collapse it to a 1D index.

Does this make sense?

@obiwannabe said:

Try to visualise it. In an RGB coordinate system you have a space made of 3 dimensions, all the colours are stored in a matrix with 0,0,0 = black at one corner and 1,1,1 = white at the other corner.

Now, have you seen those Pantone colour charts you get in paint or print shops? The collapse the 3D matrix onto a set of 2D charts. Each row steps over 8 or 16 increments of red (or whatever), until all the red values have been done, then the next sheet starts changing the blues....

Okay - now imagine this Pantone chart cut into strips, stuck together as one long ticket tape and laid out in a line. This is a 1D representation (probably because Pd uses linked lists for a lot of structures). It starts on black at 0 then adds 256 increments of just blue. After that it adds one increment of green and cycles round another 256 increments of blue. Only when it gets to 65536 does it add one increment of red, then it repeats.... To index a particular RGB value you have to multiply a 256 matrix by (1, 256, 65536) to collapse it to a 1D index.

Does this make sense?

thank u!! it makes sense to me now!!

is this color value thing just to see how pd deals with colors?
or can you use these numbers (1-65536-...) to feed some color object?

have a look at 'data structures' (there's lots about them in pd help)

i think you can use these colour values to fill them.

I am looking for a way to determine color with just one number. so I like this line representation.
I can't just feed color objects with a number box. (doesn't work)Is there an object that transforms the line-repr-numbers to RGB-values?

ok I fixed this quite simply with an abstraction. I obviously have a lot more to learn if I want to work with pd fluently.

thanks for all the help hardoff!