[webkit-dev] Clarifying 3D feature defines

[Martin Robinson]

Thanks for bringing up the point about perspective versus 3D
transforms. For the sake of clarity, one reason 3D_GRAPHICS may be
different from WebGL is that GraphicsContext3D is used to render
accelerated compositing contents when using the TextureMapper and not
simply WebGL.

--Martin

On Thu, Apr 23, 2015 at 4:48 PM, Simon Fraser <simon.fraser at apple.com> wrote:
> On Apr 23, 2015, at 4:39 PM, Martin Robinson <mrobinson at webkit.org> wrote:
>>
>> In the process of cleaning up and dusting off the GTK+ cmake build
>> system, we have rediscovered the pair of somewhat confusing feature
>> defines WTF_USE_3D_GRAPHICS and ENABLE_3D_RENDERING. From a brief
>> audit, it appears that WTF_USE_3D_GRAPHICS is a generic flag for any
>> kind of 3D rendering at all (including WebGL), while
>> ENABLE_3D_RENDERING refers specifically to perspective
>> transformations.
>>
>> Would it be worthwhile to clarify these flags slightly? My proposal is
>> to rename ENABLE_3D_RENDERING to either ENABLE_3D_TRANSFORMS or
>> ENABLE_PERSPECTIVE_TRANSFORMS, though I support any names that reduce
>> the possible confusion between these flags.
>
> USE(3D_GRAPHICS) appears to surround WebGL code in general. I don’t see any non-WebGL bits in a quick search.
>
> ENABLE(3D_RENDERING) means “turn on the ability to support and render 3D CSS transforms)”. I would be OK with  ENABLE_3D_TRANSFORMS, which is more accurate than ENABLE_PERSPECTIVE_TRANSFORMS.
>
> Simon
>