XY-Pong

[Tim Kleinert]

Inspired by this thread:

http://electro-music.com/forum/topic-18643.html

Imagine an object thrown in a twodimensional square space and bouncing back on the walls. The circuit outputs X and Y position, as well as four individual logic pulses for when the "object" bounces of the respective wall.

My first attempts used feedbacked mixers as variables (positions and velocities) and added circuitry for bouncing. But this turned out to be too expensive. So I figured out a simpler solution using triangle shape LFOs with their "Dir" parameter controlled by a logarithmically decaying envelope -which models the same behaviour, but much more economically. This however results in a different way of parametrisation: Instead of setting initial velocities for X and Y, you have to set initial "bouncing frequencies".

Controls:

X LFO Rate: Sets the initial bouncing frequency for X
Y LFO Rate: Same for Y
X LFO Phase: Sets the initial X position
Y LFO Phase: Same for Y
TIME decay knob: sets the time until all energy is dissipated
"Throw" -logic pulse; throws the object
"Reposit " -logic pulse; repositions the object to the position set by the phase parameters above

Outputs:
X and Y LFO: X and Y positions
X Pong Hi: Logic pulse for when the object bounces off the left wall...
X Pong Lo: ...or the right wall.
Y Pong Hi: ...or the upper wall.
Y Pong Lo: ...or the lower wall.
TIME End: Logic pulse to signal that the object has stopped its movement.

Efficiency notes:
If not needed, the pong logic part of the circuit (the constant and the compare modules) can simply be deleted. Also, if the "End" pulse signal is not required, the AD/R envelope module can be replaced by a simple "Decay" module, saving a module output and some cycles.

I added a rather elaborate demonstration circuit (all the grey modules), which of course can be deleted. (Thanks to Kassen for the 8x8 pixel screen idea.)

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XY Pong TK.pch2
Description:	twodimensional ballistic pingpong circuit	Download (listen)
Filename:	XY Pong TK.pch2
Filesize:	2.6 KB
Downloaded:	1765 Time(s)

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[Tim Kleinert]

Here's a performance-orientated spinoff, which uses the global wheels as controllers. "Throw" the global wheels in positive or negative direction to add momentum to the X and Y movement of the object. (They are mapped as morphs to two constant modules.)

Plus a button to reposition the object, and control to adjust the overall response of the circuit.

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GWheelsXYPong TK.pch2
Description:	XY Pong circuit using the global wheels as performance controllers.	Download (listen)
Filename:	GWheelsXYPong TK.pch2
Filesize:	2.88 KB
Downloaded:	1668 Time(s)

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[electri-fire]

Hi Tim, I can't believe how fast you are!


These patches are brilliant. Thanks a lot.

[electri-fire]

Oh and also Kassen's pixel screen is a cool visual demonstration of what's happening. Lovely.

[electri-fire]

additions in Marine color.

added constant to lenghten bouncing time

Throw module worked with positive values only. Now set to unipolair.

added oscillators demonstrate continuous control properties.

added Textpad user directions.

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xy_pong____tk_712[1].pch2
Description:		Download (listen)
Filename:	xy_pong____tk_712[1].pch2
Filesize:	3.88 KB
Downloaded:	1818 Time(s)

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[Kassen]