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

Re: [Public WebGL] Re: s3tc compression and UNPACK_FLIP_Y_WEBGL

On Mon, Sep 10, 2012 at 2:37 PM, Florian Bösch <pyalot@gmail.com> wrote:
> On Mon, Sep 10, 2012 at 11:32 PM, Brandon Jones <bajones@google.com> wrote:
>> On Mon, Sep 10, 2012 at 2:23 PM, Jeff Russell <jeffdr@gmail.com> wrote:
>>> Flipping, at the very least, is doable without
>>> decompressing/recompressing the image...
>> Not necessarily. In order to properly flip the image you need to know the
>> details of the compression format, which the browser tries not to do. Since
>> I'm pretty sure that UNPACK_FLIP_Y_WEBGL affects the texture upload, rather
>> than flipping a bit in the driver, it's sensible to exclude compressed
>> textures from it's affected targets.
>> Not that I wouldn't like to have it work everywhere, but I understand the
>> reasoning behind it.
> At least we should probably mention these little incoveniences somewhere
> because WebGL users are quite used to the fact that flip Y and
> generateMipmap just works (tm) and lest people just start throwing
> compressed textures into their code trusting their framework to glance over
> the details, they'll end up with garbage and errors.

Looking at the WebGL spec,
is pretty clear about those pixel storage parameters only affecting
calls to texImage2D and texSubImage2D. compressedTexImage2D and
compressedTexSubImage2D are notably absent. For this reason I don't
think any additional normative text is needed. However, if you have a
suggestion about non-normative text to add, please submit a pull
request on Github -- will be happy to review it.



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:
unsubscribe public_webgl