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

[Laurent Pinchart]

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.

> 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