How to draw variable-width UIBezierPath?

I'm wondering how I should go about drawing a uibezierpath where the stroke width peaks at the center of the arc. Here's an example of what I mean:

Either I have to go through each point when drawing, and set the stroke width accordingly, or there's an easier way. Can anyone point me in 开发者_JS百科the right direction?

Thanks

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You can just draw the two outer paths with no stroke, join them, and then fill in the space between them.

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Another way to try this if you're interested:

I ended up getting this to work by creating a loop to draw a couple hundred line segments, and changing the line width accordingly during the draw loop.

To adjust the line width I used the following function: MAX_WIDTH * sinf(M_PI * (i/NUMBER_OF_SEGMENTS)

Looks great and no performance issues as far as I can tell. Worked out particularly well because I already had a list of the points to use on the curve. For other cases I'm guessing it would be better to use sosborn's method.