I need some help to fully understand the buffers design

[Kevin DuBois]

We will need an implementation of mg::Display that sits on top of the 
SDL/X api. This is how mir's final composition would posted to the screen.

As for the "3rd type" of buffers, the buffers in gbm/android are color 
buffers backed by memory we got from the driver platforms that have 
certain capabilities. (The buffers must be usable as EGLImages, 
transmittable over ipc, mappable for usage in the driver as a GL target) 
I'm unaware of anything in SDL that has this capability, as SDL is (as 
my understanding goes) more of a cross-platform toolkit.

I haven't dived as deep into the problem as you, but I still think that 
the crux of the problem is to create the display type, and then figure 
out the permissions on the GBM buffers so that X and Mir can both 
operate under the same roof

Cheers,
Kevin


On 04/04/2013 01:11 AM, Daniel van Vugt wrote:
> If we can't find a way to work it into the existing GBM implementation 
> then we might need to resolve this first:
>   https://bugs.launchpad.net/mir/+bug/1118909
>
>
> On 04/04/13 16:06, Eleni Maria Stea wrote:
>> Hello everyone :)
>>
>> I am trying to create an SDL backend for mir so that mir can run inside
>> X using SDL functions for the display/input handling. For the buffer
>> exchange part, I tried to use the existing GBM at first, as some people
>> suggested, but after some tests I did outside mir, it seems that you
>> can't have the GBM/DRM working under X (you cannot create the gbm 
>> device).
>>
>> Since, in the current implementation the client and the server can only
>> exchange drm or android buffers, I have to create a 3rd type of buffers
>> that can use the same IPC mechanism with the gbm/android ones. I would
>> really really appreciate if you could give me a high level overview of
>> the buffers design to save me some time!
>>
>> Thanks a lot!!
>> Eleni
>>
>