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

[Samuel Rødal]

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.

--
Samuel