[PATCH V10 23/30] lib/igt_color: Add 1D LUT color transformation support

[Aurabindo Pillai]

On 8/15/25 12:06 AM, Alex Hung wrote:
> Add definitions and functions for setting 1D LUT on a
> drm_colorop.
> 
> Add support for the SIZE prop of a colorop, as that's
> required for understanding the size of the LUT to
> construct.
> 
> Signed-off-by: Alex Hung <alex.hung at amd.com>
> Co-developed-by: Harry Wentland <harry.wentland at amd.com>
> Signed-off-by: Harry Wentland <harry.wentland at amd.com>
> ---
>   include/drm-uapi/drm_mode.h | 12 ++++++++++++
>   lib/igt_color.c             |  8 ++++++++
>   lib/igt_color.h             | 20 ++++++++++++++++++++
>   lib/igt_kms.c               |  1 +
>   lib/igt_kms.h               |  1 +
>   5 files changed, 42 insertions(+)
> 
> diff --git a/include/drm-uapi/drm_mode.h b/include/drm-uapi/drm_mode.h
> index fce45b5cf..106fbb889 100644
> --- a/include/drm-uapi/drm_mode.h
> +++ b/include/drm-uapi/drm_mode.h
> @@ -874,6 +874,18 @@ struct drm_color_lut {
>   	__u16 reserved;
>   };
>   
> +/*
> + * struct drm_color_lut32
> + *
> + * 32-bit per channel color LUT entry, similar to drm_color_lut.
> + */
> +struct drm_color_lut32 {
> +	__u32 red;
> +	__u32 green;
> +	__u32 blue;
> +	__u32 reserved;
> +};
> +
>   enum drm_colorop_type {
>   	DRM_COLOROP_1D_CURVE,
>   	DRM_COLOROP_1D_LUT,
> diff --git a/lib/igt_color.c b/lib/igt_color.c
> index 6a639813f..a58ba0e57 100644
> --- a/lib/igt_color.c
> +++ b/lib/igt_color.c
> @@ -428,3 +428,11 @@ void igt_colorop_set_ctm_3x4(igt_display_t *display,
>   	/* set blob property */
>   	igt_colorop_replace_prop_blob(colorop, IGT_COLOROP_DATA, &ctm, sizeof(ctm));
>   }
> +
> +void igt_colorop_set_custom_1dlut(igt_display_t *display,
> +				  igt_colorop_t *colorop,
> +				  const igt_1dlut_t *lut1d,
> +				  const size_t lut_size)
> +{
> +	igt_colorop_replace_prop_blob(colorop, IGT_COLOROP_DATA, lut1d, lut_size);
> +}
> diff --git a/lib/igt_color.h b/lib/igt_color.h
> index 9f56536a3..88de8166f 100644
> --- a/lib/igt_color.h
> +++ b/lib/igt_color.h
> @@ -17,6 +17,8 @@
>   #include "igt_fb.h"
>   #include "igt_kms.h"
>   
> +#define MAX_COLOR_LUT_ENTRIES 4096
> +
>   struct igt_color_tf {
>   	float g, a, b, c, d, e, f;
>   };
> @@ -37,6 +39,17 @@ typedef struct igt_pixel {
>   	float b;
>   } igt_pixel_t;
>   
> +typedef struct igt_1dlut {
> +	struct drm_color_lut32 lut[MAX_COLOR_LUT_ENTRIES];
> +} igt_1dlut_t;
> +
> +igt_1dlut_t igt_1dlut_srgb_inv_eotf = { {
> +} };
> +
> +
> +igt_1dlut_t igt_1dlut_srgb_eotf = { {
> +} };
> +
>   typedef struct igt_matrix_3x4 {
>   	/*
>   	 * out   matrix          in
> @@ -94,11 +107,18 @@ void igt_colorop_set_ctm_3x4(igt_display_t *display,
>   			     igt_colorop_t *colorop,
>   			     const igt_matrix_3x4_t *matrix);
>   
> +void igt_colorop_set_custom_1dlut(igt_display_t *display,
> +				  igt_colorop_t *colorop,
> +				  const igt_1dlut_t *lut1d,
> +				  const size_t lut_size);
> +
>   /* transformations */
>   
>   void igt_color_srgb_inv_eotf(igt_pixel_t *pixel);
>   void igt_color_srgb_eotf(igt_pixel_t *pixel);
>   
> +void igt_color_srgb_inv_eotf_custom_lut(igt_pixel_t *pixel);
> +

This is missing implementation. Maybe remove for now ?

>   void igt_color_pq_inv_eotf(igt_pixel_t *pixel);
>   void igt_color_pq_eotf(igt_pixel_t *pixel);
>   
> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
> index d1c23b4a4..bdde2fc72 100644
> --- a/lib/igt_kms.c
> +++ b/lib/igt_kms.c
> @@ -710,6 +710,7 @@ const char * const igt_colorop_prop_names[IGT_NUM_COLOROP_PROPS] = {
>   	[IGT_COLOROP_TYPE] = "TYPE",
>   	[IGT_COLOROP_BYPASS] = "BYPASS",
>   	[IGT_COLOROP_CURVE_1D_TYPE] = "CURVE_1D_TYPE",
> +	[IGT_COLOROP_SIZE] = "SIZE",
>   	[IGT_COLOROP_DATA] = "DATA",
>   	[IGT_COLOROP_NEXT] = "NEXT",
>   };
> diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> index 2a401cd3b..d0a7ed037 100644
> --- a/lib/igt_kms.h
> +++ b/lib/igt_kms.h
> @@ -374,6 +374,7 @@ enum igt_atomic_colorop_properties {
>   	IGT_COLOROP_TYPE,
>   	IGT_COLOROP_BYPASS,
>   	IGT_COLOROP_CURVE_1D_TYPE,
> +	IGT_COLOROP_SIZE,
>   	IGT_COLOROP_DATA,
>   	IGT_COLOROP_NEXT,
>   	IGT_NUM_COLOROP_PROPS