[mythtv-users] Seasonal theme experiments

[Paul Harrison]

On 11/12/2020 10:30, Mark Kendall wrote:

> On Fri, 11 Dec 2020 at 10:01, Stuart Auchterlonie
> <stuarta at squashedfrog.net> wrote:
>
>> Is it worth handling a file reference in the theme.xml file, so that
>> rather than having to embed GSL into the theme.xml, the GSL can be
>> contained in it's own file (shipped along with the theme) and it's
>> loaded out of that file instead?
>>
>> It does seem a cleaner way to do it. (my 2c's)
> That would be my long term goal - the initial code is very much just a
> proof of concept.
>
> Moving the shaders into their own files also allows the themer to
> reuse them - I would expect that in most cases the vertex shader will
> be the same. We should probably be caching the shaders as well.
>
> The bigger issue is portability; with half an eye on how this would be
> implemented on Vulkan, but also GLSL versions. Strictly speaking an
> OpenGL implementation does not have to offer compatibility with older
> versions and all of our current OpenGL shaders target GLSL 1.2 (GLSL
> ES 1.0)  (although they appear to work with GLSL 1.1 as well). So in
> theory they may not work on newer OpenGL instances but I have seen no
> references to issues in the 'wild'; I suspect all of the major vendors
> just allow backwards compatibility.
>
> Qt works around this by writing all of their shaders with 'vulkan
> style' GLSL and converting to other formats. We would probably need to
> do something similar; we already have glslang support in master -
> though conversion should really be done offline.
>
> Regards
> Mark


Agree putting the GSL into it's own file would be cleaner. Not sure how 
many themers would be able to write there own shaders so having a 
default library of a few more useful ones would be ideal.


How difficult would it be to add something similar to MythUIImage to 
transition between images? I'm thinking of the slide show images or the 
coverart images on the 'Watch Recordings' screen for example it would be 
nice to have a smooth transition when they change rather than the abrupt 
change we have now. In MythQML I have a nice component that can both 
fade between images and also do what I think is called the Ken Burns 
effect which works really well for the Xmas theme slide show images. 
Having something similar in MythUI would be nice.


Paul H.