- From: Vladimir Vukicevic <vladimir@pobox.com>
- Date: Sat, 10 May 2008 19:13:21 -0700
On May 10, 2008, at 5:44 PM, Oliver Hunt wrote:
>
> On May 10, 2008, at 4:53 PM, Vladimir Vukicevic wrote:
>
>> Another approach would be to not try to solve this in canvas at
>> all, and instead specify that by default, all canvas elements are
>> 96dpi, and provide authors a way to explicitly override this --
>> then using a combination of CSS Media Queries and other CSS, the
>> exact dpi desired could be specified. (You can sort of do this
>> today, given that the canvas width/height attributes are in CSS
>> pixels, and that if CSS dimensions are present a canvas is scaled
>> like an image... so canvas { width: 100px; height: 100px; } ...
>> <canvas width="200" height="200"/> would give a 192dpi canvas
>> today, no?)
>
> Canvas was designed with the intent of allowing resolution
> independent, removing that intent in the name of a feature that is
> not used in the general case seems to be a fairly substantial step
> back from that goal. Unfortunately the "solution" of using a larger
> canvas scaled to fit a smaller region isn't a real solution. For
> lower resolution displays it results in higher memory usage and
> greater computational cost than is otherwise necessary, and for high
> dpi displays it results either the same issues as the low dpi case
> (if the canvas resolution is still too high) or it results in a
> lower resolution display than the display is capable of.
Eh? The resolution used should be whatever the appropriate resolution
should be; I'm certainly not suggesting that everyone unilaterally
create canvases with 2x pixel resolution, I'm saying that the features
exist to allow authors to (dynamically) create a canvas at whatever
the appropriate resolution is relative to CSS resolution. Canvas was
designed to allow for programmatic 2D rendering for web content;
resolution independence would certainly be nice, but it was never a
goal of the canvas spec. In fact, the spec explicitly states that the
"canvas element represents a resolution-dependent bitmap canvas".
- Vlad
Received on Saturday, 10 May 2008 19:13:21 UTC