This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
I'd like to request that the canvas 2d context fill style is extended with support for the even/odd winding algorithm, in addition to the non-zero winding algorithm, so that drawing shapes on the canvas that are based on paths obtained from graphics sources that encode shapes using the even/odd winding algorithm can be drawn without having to manually analyse the path for subpaths that need their direction flipped. Use cases are using image from .svg resource with the intention of using them as rasterised image data (not vector graphics) and shapes such as font outlines (for use as polygon graphics, not "letters") to the canvas. (As a bonus, this algorithm is already available for reuse in every current browser, since SVG requires algorithms both to be available, making implementing it for canvas 2d mostly a matter of hooking it up correctly)
This bug was cloned to create bug 17893 as part of operation convergence.
This is indeed very useful and widely used. Moving to HTML.Next as it is a new feature request
Mass move to "HTML WG"
Making this a higher priority to actively seek more feedback on from implementers and webdevs.
This was implemented by every browser 1-2 years ago.
indeed, this bug has since been resolved, but never got closed. http://jsbin.com/kemogesubu/edit?html,js,output demonstrates "evenodd" as fill rule working (I only tested it in firefox, chrome, and IE, but kind of assume that means evreyone supports it). You can change "evenodd" to "nonzero" to see it do a flood fill, or keep it "evenodd" to see it only fill the parts that uniquely cordon off a polygonal section.