[PATCH weston 2/4] gles2: update texture only if needed

[Pekka Paalanen]

On Thu, 8 Nov 2012 19:20:56 +0100
Samuel Rødal <samuel.rodal at digia.com> wrote:

> On 11/07/2012 03:19 PM, Pekka Paalanen wrote:
> > On Wed, 7 Nov 2012 13:27:50 +0000
> > Sundararaj Prabhu-B36876 <B36876 at freescale.com> wrote:
> >
> >> Wondering whether the extension EGL_KHR_image_pixmap can be used instead of glTex(Sub)Image2D.
> >> This would reduce much of the CPU copying. Do you see any problems?
> >
> > Hi,
> >
> > do you mean creating an EGLImage from a Dispmanx resource, and so
> > eventually a GL texture? That would be ideal for switching between
> > Dispmanx elements and GLESv2, if it works. It would allow removing one
> > or two buffers per surface, saving lots of memory. However considering
> > the current limitations in writing to Dispmanx resources, the data
> > upload itself might be only slightly faster. But I can't imagine any
> > serious negative effects. Maybe you might lose linear texture
> > filtering; mipmaps are not even wanted.
> >
> > The problem is, I don't know what a native pixmap is on RPi, or is it
> > implemented.
> >
> > It looks like the native pixmap type would be a uint32_t[2], but I
> > don't know what to do with that.
> 
> Sounds like their EGL global image extension, with 
> eglCreateGlobalImageBRCM(), eglQueryGlobalImageBRCM(), etc.

Indeed, but I don't know how that relates to Dispmanx Resouces, that I
could shove into elements (overlays/planes).


Thanks,
pq