[libcamera-devel] [PATCH v2 1/2] qcam: assets: shader: bayer_8.frag: Add precision

[Laurent Pinchart]

On Thu, Jul 21, 2022 at 11:21:45PM +0300, Laurent Pinchart wrote:
> Hi Kunal,
> 
> Thank you for the patch.
> 
> On Wed, Jun 29, 2022 at 12:42:38AM +0530, Kunal Agarwal via libcamera-devel wrote:
> > Currently there is no defined precision for data types
> > which results in compilation errors for shader.
> 
> That's true for OpenGL ES only, I'd update this to
> 
> The OpenGL ES shading language has no default precision declared
> implicitly for floats in fragment shaders. The lack of an explicit
> default precision results in shader compilation errors
> 
> > Adding precision mediump for sufficient and required
> > range and accuracy. Also suitable for textures.
> 
> What do you mean by "Also suitable for textures" ?
> 
> > Precision highp also works but is not supported by some
> > older hardware devices and consumes more memory.
> 
> Which hardware would that be ? If you don't know, I'd write this as
> 
> Specify a default precision of mediump for floats. This matches the
> other fragment shaders, and is guaranteed by the OpenGL ES shader
> language specification to be supported by all devices, while the higher
> precision highp is optional.
> 
> If you're fine with the above modifications, there's no need to resubmit
> the patch, I can update the commit message when applying.

And I forgot to mention,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> > Signed-off-by: Kunal Agarwal <kunalagarwal1072002 at gmail.com>
> > ---
> >  src/qcam/assets/shader/bayer_8.frag | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/src/qcam/assets/shader/bayer_8.frag b/src/qcam/assets/shader/bayer_8.frag
> > index 4ece44ab..7e35ca88 100644
> > --- a/src/qcam/assets/shader/bayer_8.frag
> > +++ b/src/qcam/assets/shader/bayer_8.frag
> > @@ -15,6 +15,9 @@ Copyright (C) 2021, Linaro
> >  */
> >  
> >  //Pixel Shader
> > +#ifdef GL_ES
> > +precision mediump float;
> > +#endif
> >  
> >  /** Monochrome RGBA or GL_LUMINANCE Bayer encoded texture.*/
> >  uniform sampler2D       tex_y;

-- 
Regards,

Laurent Pinchart