Add support for HQx

[GoogleCodeExporter]

I've completed a shader implementation of HQx available here: 
https://github.com/Armada651/hqx-shader

I've not yet implemented a GLSL version, because the shader requires the 
following functionality:

* Passing additional textures to the shader.
* Applying multiply shaders to the output for better performance. (optional)

Could you add this functionality? I can provide a GLSL version if necessary, 
the shader code itself is pretty simple.

Attached you'll find a screenshot of the HQ4x shader running in RetroArch, 
they've included it in their common shaders repository.

Original issue reported on code.google.com by Jules.B...@gmail.com on 4 Jun 2014 at 9:27

[GoogleCodeExporter]

Thanks. Will consider supporting multi-pass shaders.

Original comment by fastemul...@gmail.com on 5 Jun 2014 at 3:58

[GoogleCodeExporter]

There is also a single-pass version in the "legacy" folder, you can implement 
it with just the additional texture support.

Original comment by Jules.B...@gmail.com on 5 Jun 2014 at 4:28

[GoogleCodeExporter]

I really think we should integrate a proper version of HQx in this shader pack. 
Even without multi-pass shaders HQx2 can already preform very well.

The only problem is the alpha pre-multiplication, but even that can be worked 
around by using two lookup textures.

I've attached my latest version of HQx for myboy. But it still requires lookup 
texture support.

Original comment by Jules.B...@gmail.com on 1 Aug 2015 at 11:44

Attachments:

• hqx-myboy.zip