[whatwg] Enabling LCD Text and antialiasing in canvas

[Stephen White]

Thanks for your comments.

On Fri, Apr 19, 2013 at 12:53 PM, Rik Cabanier <cabanier at gmail.com> wrote:

> Nice!
>
> The behaviour of putImageData() and putImageDataHD() is to premultiply the
> RGB components by the alpha component as usual, but write 1.0 into
> destination alpha. In other words, if (r, g, b, a) are the component values
> in a given pixel passed to putImageData[HD](), then r' = ar, g' = ag, b' =
> ab are the colour components of the resulting canvas pixel, and (r', g',
> b', 1.0) is written to the canvas backing store.
>
> I think that's confusing. Maybe cut that sentence since it isn't needed.
> (Having the black backing store implies this behavior)
>

Do you mean, remove both sentences, or just the last one?  I wanted to make
it clear that the RGB is still premultiplied with the original alpha, even
though the alpha is subsequently ignored.

attribute boolean alpha;
>
> Should it be read-only?


Hmm, I have no idea.  WebGL's doesn't have it, but I'm not enough of an IDL
expert to know whether it's necessary.


>
> Canvas2DContextAttributes getContextAttributes();
>
> Maybe make it an attribute:
>
> attribute Canvas2DContextAttributes attributes:
>
>
I'm following WebGL syntax here as well.  Apparently WebGL's is nullable,
though, so I've added ? here.

Stephen

>
> On Fri, Apr 19, 2013 at 9:13 AM, Stephen White <senorblanco at chromium.org>wrote:
>
>> Here's a short proposal I've written up for the getContext('2d', { alpha:
>> false } ) version of this idea (much of it culled from the mega-thread
>> above).
>>
>> http://wiki.whatwg.org/wiki/CanvasOpaque
>>
>> Comments are welcome.
>>
>> Stephen
>>
>
>