Hey all. Hope someone can help.

I'm in the process of creating a custom interface in TouchOsc running through PD to control a specific VST synth. Most of the work is done except the x/y pad controller, as I need to reverse the Y axis.

Now I know some hosts can invert the controller data coming in. But I need to do this in PD before it reaches the host.

This is what I have for the Y axis:

[ OSCroute /xy1 ]
|
[ unpack 0.1 0.1 ]
|
[ *127 ]
|
[ ctlout 1 2 ]

I'm sure it must be really simple to reverse the value, but I'm still new to this! Can anyone help??

Take the maximum value and subtract from that, so if it is 127:

[unpack]
|
[127 $1(
|
[- ]
|
[ctlout]

Thanks for your reply Maelstorm.

But I'm still clueless!

If I use the [-] after the

• it makes no difference at all.

ie;

[unpack]
|
[*200]
|
[-]
|
[ctlout]

In my example where the input value is multiplied by 200, don't I need to use a division somewhere to get the opposite effect that I want?

I'm pulling my hair out over this!

Okay, let me break it down for you.

[unpack .1 .1] <-- I assume the y axis is coming out of here, in a 0.0 - 1.0 range
|

• <-- scale it to 0.0 - 127.0 range
  |
  [127 $1( <-- this is a message box. $1 is a variable and is replaced by the output of
  |
• , which creates a two element list of 127 and the input number
  |
  [- ] <-- Many objects in Pd accept a list, which is divied up among its inputs. So,
  | the number replacing $1 becomes the right input value, and 127 becomes
  | the left input value, resulting in "127 - $1". This is the inverse value.
  |
  [ctlout 1 2]

Hope that's clearer.

neat trick with the message box, I never knew that!

Maelstorm, thank you for the explanation, it now works perfectly!

Thanks again for your help/patience!