Performing Union and Intersection to Create New Widgets

[Aras]

Hi,
I have a few task that requires defining shapes based on intersection
of other shapes. For example, I have two circles that overlap and I
want to color the intersection differently and also handle touch
events on that region independently. What do you think would be a good
way of achieving this? Can I do intersection of SVG widgets?

Thanks,
Aras

[Thomas Hansen]

could you just set the blending mode while drawing the circles to get the different color for the intersecting region?  for teh touches you'll have to check if they fall within the circles (distance(touch, center) < radius ).  if its inside both circles, it will be in the intersection.

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Thomas

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[Aras Balali Moghaddam]

Thomas,
Thanks for getting back to me. I'll give that a shot and see how far I can get using this technique. However, I am afraid that things might get complicated as I work with more complex shapes. I cant envision how I could cut out or detach the intersection using this technique. I want to create a new widget from the intersection and then continue working with them even after I move the original shapes (the two circles in this case).

I have seen a feature like this in some other toolkits. For example in SWT you can perform union, subtraction, and intersection on basic shapes and create new shape objects from them. Also the w3c SVG working draft defines methods for performing these functions. This is simple but extremely powerful feature. If it is not already possible to do this with PyMT, I would like to request this feature.

Cheers,
Aras