[PATCH v7 02/10] libcamera: software_isp: Use RGB type to represent gains

[Kieran Bingham]

Quoting Milan Zamazal (2025-02-07 10:16:54)
> Rather than using a custom struct to represent RGB values, let's use the
> corresponding type and its facilities.
> 
> Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/ipa/simple/algorithms/awb.cpp | 16 +++++++++-------
>  src/ipa/simple/algorithms/lut.cpp | 14 ++++----------
>  src/ipa/simple/ipa_context.h      |  7 ++-----
>  3 files changed, 15 insertions(+), 22 deletions(-)
> 
> diff --git a/src/ipa/simple/algorithms/awb.cpp b/src/ipa/simple/algorithms/awb.cpp
> index 1efc7090..310be6a7 100644
> --- a/src/ipa/simple/algorithms/awb.cpp
> +++ b/src/ipa/simple/algorithms/awb.cpp
> @@ -25,7 +25,7 @@ int Awb::configure(IPAContext &context,
>                    [[maybe_unused]] const IPAConfigInfo &configInfo)
>  {
>         auto &gains = context.activeState.awb.gains;
> -       gains.red = gains.green = gains.blue = 1.0;
> +       gains = { { 1.0, 1.0, 1.0 } };
>  
>         return 0;
>  }
> @@ -56,16 +56,18 @@ void Awb::process(IPAContext &context,
>          * Clamp max gain at 4.0, this also avoids 0 division.
>          */
>         auto &gains = context.activeState.awb.gains;
> -       gains.red = sumR <= sumG / 4 ? 4.0 : static_cast<double>(sumG) / sumR;
> -       gains.blue = sumB <= sumG / 4 ? 4.0 : static_cast<double>(sumG) / sumB;
> -       /* Green gain is fixed to 1.0 */
> +       gains = { {
> +               sumR <= sumG / 4 ? 4.0 : static_cast<double>(sumG) / sumR,
> +               1.0,
> +               sumB <= sumG / 4 ? 4.0 : static_cast<double>(sumG) / sumB,
> +       } };
>  
> -       RGB<double> rgbGains{ { 1 / gains.red, 1 / gains.green, 1 / gains.blue } };
> +       RGB<double> rgbGains{ { 1 / gains.r(), 1 / gains.g(), 1 / gains.b() } };
>         context.activeState.awb.temperatureK = estimateCCT(rgbGains);
>  
>         LOG(IPASoftAwb, Debug)
> -               << "gain R/B: " << gains.red << "/" << gains.blue
> -               << "; temperature: " << context.activeState.awb.temperatureK;
> +               << "gain R/B: " << gains << "; temperature: "
> +               << context.activeState.awb.temperatureK;
>  }
>  
>  REGISTER_IPA_ALGORITHM(Awb, "Awb")
> diff --git a/src/ipa/simple/algorithms/lut.cpp b/src/ipa/simple/algorithms/lut.cpp
> index d75ff710..1d392737 100644
> --- a/src/ipa/simple/algorithms/lut.cpp
> +++ b/src/ipa/simple/algorithms/lut.cpp
> @@ -103,16 +103,10 @@ void Lut::prepare(IPAContext &context,
>                 const double div = static_cast<double>(DebayerParams::kRGBLookupSize) /
>                                    gammaTableSize;
>                 /* Apply gamma after gain! */
> -               unsigned int idx;
> -               idx = std::min({ static_cast<unsigned int>(i * gains.red / div),
> -                                gammaTableSize - 1 });
> -               params->red[i] = gammaTable[idx];
> -               idx = std::min({ static_cast<unsigned int>(i * gains.green / div),
> -                                gammaTableSize - 1 });
> -               params->green[i] = gammaTable[idx];
> -               idx = std::min({ static_cast<unsigned int>(i * gains.blue / div),
> -                                gammaTableSize - 1 });
> -               params->blue[i] = gammaTable[idx];
> +               const RGB<double> lutGains = (gains * i / div).min(gammaTableSize - 1);
> +               params->red[i] = gammaTable[static_cast<unsigned int>(lutGains.r())];
> +               params->green[i] = gammaTable[static_cast<unsigned int>(lutGains.g())];
> +               params->blue[i] = gammaTable[static_cast<unsigned int>(lutGains.b())];
>         }
>  }
>  
> diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h
> index 607af45a..df0552db 100644
> --- a/src/ipa/simple/ipa_context.h
> +++ b/src/ipa/simple/ipa_context.h
> @@ -14,6 +14,7 @@
>  #include <libcamera/controls.h>
>  
>  #include <libipa/fc_queue.h>
> +#include <libipa/vector.h>

Since Fixes: fa93d40035db ("libipa: Drop Vector class"), this now needs
to be 

#include "libcamera/internal/vector.h".

With that:


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

>  
>  namespace libcamera {
>  
> @@ -36,11 +37,7 @@ struct IPAActiveState {
>         } blc;
>  
>         struct {
> -               struct {
> -                       double red;
> -                       double green;
> -                       double blue;
> -               } gains;
> +               RGB<double> gains;
>                 unsigned int temperatureK;
>         } awb;
>  
> -- 
> 2.48.1
>