[cairo] Circular Ring Gradient

[cecashon at aol.com]

Hi Cairo folks,

What is the best way to make a circular gradient in a ring? I have tried using both a Bezier approximation to a circle and just using trapezoids. The trapezoids work fine if I have 16 of them and then clip the ring. A little problem with not having continuous values in a ring so if I cut the ring at a particular location it has to be at the end of a trapezoid section if I want the gradient to fill to the end. Otherwise it looks to work well. Think there might be an easier way to do this though so I am asking about it. Has anyone had good success drawing circular gradients in a ring? I am looking to be able to add some Cairo gradients to a gauge widget so efficiency would be a good thing if the gauge needed to work with a frame clock.

Thanks,
Eric

https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/cairo_drawings/circular_gradient2.c
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