On Fri, Jul 26, 2013 at 7:45 AM, Glenn Maynard <gl...@zewt.org> wrote:
> On Thu, Jul 25, 2013 at 10:29 PM, Rik Cabanier <caban...@gmail.com> wrote: > >> We're getting a bit off track here :-) >> > > We're figuring out an unclear use case. That's as on-track as it gets. :) > > >> No, you need to scale, otherwise the content of your canvas won't scale >> up. >> For instance, if you have a 100x100 device pixel rect, it has to become a >> 110x110 device pixel rect if you zoom by 10% >> > > Okay, that wasn't clear to me. Pixel ratios are peripheral to what you're > describing: you could ask for the same thing any time you're rendering to a > dynamically-sized canvas, which simplifies the discussion. I don't know if > a complex semi-antialiasing mode is a good approach, though. It'll always > have issues (rounded corners won't "connect" cleanly; it's not clear if it > works for fills, or if it works for patterned fills). > > I don't know if this would work well in practice, or if it's > implementable, but here's a two-part approach that might work: > > - First, add the inner and/or outer stroke modes. This seems useful in > and of itself, but the purpose here is to make it so integer coordinates > give hard edges, whether or not you have a 1px stroke. > I'm unsure why this is a requirement... (Not that it wouldn't be nice to have) > - Second, add a mode which causes coordinates to be snapped to integers. > This would happen when you make the API call, and be applied after the > canvas transform. > > If you're in scale(1.25), and you call rect(100, 100, 75, 75), it would > draw a rect from 100x100 to 194x194, instead of to 193.75x193.75. > You probably mean 125x125 to 194x194. Also, if there's a stroke width of 1, it would stay the same thickness. Basically, Canvas would draw artwork like CSS does. A 1 pixel line would stay 1 pixel until the pixel ratio is 2. > > This would give clean output for rounded edges, since you're adjusting the > size of the path as a whole. It would work for fills (which also get > aliased edges when transformed). It also works if the fill is a pattern, > where turning off antialiasing would make the pattern ugly. > I *think* you only want to do it for strokes because otherwise you might get seams.
