[whatwg] Processing the zoom level - MS extensions to window.screen
bzbarsky at MIT.EDU
Sat Nov 20 18:57:02 PST 2010
On 11/20/10 3:59 PM, Charles Pritchard wrote:
> This response is from the digest: I'm glad to see activity here.
> Canvas is supposed to be resolution independent,
No, it's not. Vector images are supposed to be resolution independent.
Canvas is very explicitly a _bitmap_. It's not a vector image.
> When a user zooms in, I need to be able to reprint my fillText
> to match their resolution.
This is a valid use case if using canvas is the right requirement,
though it really feels like you're using the wrong tool here; if you
want resolution independence you should be using SVG, which is designed
precisely to accomplish that.
That said, this seems like a general quality-of-implementation issue,
right? Expecting the page to rerender the entire canvas on any zoom
operation doesn't seem reasonable.... A UA could handle this by
supersampling the canvas, for example (and in the past we've considered
doing that for Firefox, actually).
> Boris, Rob: As an accessibility use case, this is quite important.
> Please let me know if there are objections.
I don't think it's reasonable to demand resolution independence from
what is designed to be a bitmap format. We really do have better tools
for them; using them instead seems more appropriate than grafting
poor-man's resolution independence onto canvas.
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