Really really nice. Good job!

gorgeous

I was researching the construction of ellipses in wikipedia and followed some links which took me to the Spirograph. I used to have a Spirograph toy but had forgotten all about it. I thought an animation might be fun although creating it turned out to be more challenging than I first thought but that always seems to be the way with programming.

Anyway I am glad you all enjoyed playing with it.

Truly impressive, for the quality of the display and of the simulation, and for the supposed [1] complexity of the implementation.
It really has the look and feel of the real thing.
Suggestion: maybe allow to adjust the starting point of the drawing, if we want to have a pointy end placed relative to an existing previous pointy end. I don't know if I am clear, or if this makes sense...

[1] Because I haven't looked at the code yet. But I know I would have trouble to implement such sketch.

Suggestion: maybe allow to adjust the starting point of the drawing, if we want to have a pointy end placed relative to an existing previous pointy end. I don't know if I am clear, or if this makes sense...

It makes perfect sense, it would involve

1. enabling the starting point of the cogwheel inside the ring to be set and
2. enable also the start rotation angle of the cogwheel

The first will be more challenging if the teeth are to mesh.

@phi.lho thanks for your comments and suggestions and I am glad I managed to impress you.
 

Really great!

I have implemented phi.lho's suggestion, so now there is a knob you can use to position one of the peaks iprior to drawing drawing.


 Updated version of the SPIROGRAPH


@mbraendle  I did consider the ring having teeth inside and outside as per your suggestion but the drawing area would need to be much bigger thatn the 400x400 if any detail in the drawing was not to be lost. If you look at the pictures from your link you will see that there is so much more to implement and although it is possible to simulate a full Spirograph toy I would probably get into trouble over copyright.