[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Public WebGL] Few questions/comments about context creation attributes



On Thu, May 27, 2010 at 12:51, Vladimir Vukicevic <vladimir@mozilla.com> wrote:
> FWIW, I'd be happy to disable the stencil buffer by default -- RGBA + depth
> seems like a very reasonable default context format.

I think we can discuss on the RGBA versus RGB as well.

Two arguments for this :
- on mobile devices the common default and most efficient color buffer
mode is RGB (565 but the actual bits-per-component is irrelevant here)
- of all WebGL demos available very few do need alpha-compositing with
the HTML page, almost all of them do set clearColor with alpha=1.0,
without passing alpha:false as context attribute, based on this real
usage statistic making WebGL an opaque surface by default makes sense
imho as it helps performance (and memory usage) for the greatest
number of use cases.

In fact when testing RGB context (hardcoded in FF to check all apps) I
realized I forgot to use clearColor in a work-in-progress app when
opaque white was intended (this gone unnoticed since the HTML page
currently has white background but the content was intended to be
white, whatever the HTML background is), so this might also prove
beneficial to avoid unnecessary/unintended/wasteful alpha-blending due
to a simple mistake/typo that would not happen if presence of alpha
channel was set explicitly when actually needed.


Regards,
-----------------------------------------------------------
You are currently subscribed to public_webgl@khronos.org.
To unsubscribe, send an email to majordomo@khronos.org with
the following command in the body of your email: