[magick-users] -draw compositing method

[Cody P. Pace]

Hello,

I am attempting to create an image with a gray background, a white rounded
rectangle, with a transparent interior. I'm using the following command:

$ convert -size 236x160 xc:'rgb(102,102,102)' -stroke white \
 -fill 'rgba(0,0,0,255)' -draw 'roundRectangle 0,0 236,160 8,8' mask.png
 
Unfortunately the transparent interior of the rectangle is composited with
with the opaque background. It seems like there should be a way to change the
composite method used by draw to just replace the background.

-Cody Pace