[sdiy] Silly vector synth question

[Tom Wiltshire]

On 6 Feb 2011, at 14:16, Tom Wiltshire wrote:

> 
> On 6 Feb 2011, at 13:54, Colin f wrote:
> 
>> 
>>> I'm going to have to think about what they did to the simple 
>>> X and Y position to get those numbers. It means the two axes 
>>> are not independent, since the amount of E and W is affected 
>>> by the position on the N-S axis.
>> 
>> Took 5 minutes to work it out in Excel...
>> http://www.colinfraser.com/vector-pan.gif
>> For each osc, the % level is the entry in the table found using the x and y
>> distance of the stick from that osc's corner position.
>> If you add up the 4 values reflected around the centre values (in grey),
>> they'll always add up to 100.
>> 
>> Cheers,
>> Colin f
> 
> Nice.
> This is using the method Magnus suggested, isn't it?
> 
> There's one quirk though. If you push the stick fully NE (say), the X and Y positions is *not* 100, 100, since the joystick can only move out the the edge of a circle. From what the Sequential manual says and the examples, it looks like they dealt with that too.

Thinking about it some more, I think you can do that by scaling the true joystick X and Y position based on the hypotenuse. If the joystick is at its maximum extent (eg if the hypotenuse length is equal to the radius of maximum travel) then the X and Y positions need scaling up to 100.

I'll go and try it...

T.