[PATCH 3/6] ipa: rkisp1: Use centralised libipa helpers

[Daniel Scally]

Use the centralised libipa helpers instead of open-coding common
functions.

Signed-off-by: Daniel Scally <dan.scally at ideasonboard.com>
---
 src/ipa/rkisp1/algorithms/awb.cpp | 20 +++-----------------
 src/ipa/rkisp1/algorithms/awb.h   |  2 --
 2 files changed, 3 insertions(+), 19 deletions(-)

diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
index b3c00bef..623c4eb2 100644
--- a/src/ipa/rkisp1/algorithms/awb.cpp
+++ b/src/ipa/rkisp1/algorithms/awb.cpp
@@ -16,6 +16,8 @@
 
 #include <libcamera/ipa/core_ipa_interface.h>
 
+#include "libipa/helpers.h"
+
 /**
  * \file awb.h
  */
@@ -178,22 +180,6 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,
 	}
 }
 
-uint32_t Awb::estimateCCT(double red, double green, double blue)
-{
-	/* Convert the RGB values to CIE tristimulus values (XYZ) */
-	double X = (-0.14282) * (red) + (1.54924) * (green) + (-0.95641) * (blue);
-	double Y = (-0.32466) * (red) + (1.57837) * (green) + (-0.73191) * (blue);
-	double Z = (-0.68202) * (red) + (0.77073) * (green) + (0.56332) * (blue);
-
-	/* Calculate the normalized chromaticity values */
-	double x = X / (X + Y + Z);
-	double y = Y / (X + Y + Z);
-
-	/* Calculate CCT */
-	double n = (x - 0.3320) / (0.1858 - y);
-	return 449 * n * n * n + 3525 * n * n + 6823.3 * n + 5520.33;
-}
-
 /**
  * \copydoc libcamera::ipa::Algorithm::process
  */
@@ -279,7 +265,7 @@ void Awb::process(IPAContext &context,
 	    blueMean < kMeanMinThreshold)
 		return;
 
-	activeState.awb.temperatureK = estimateCCT(redMean, greenMean, blueMean);
+	activeState.awb.temperatureK = ipa::estimateCCT(redMean, greenMean, blueMean);
 
 	/* Metadata shall contain the up to date measurement */
 	metadata.set(controls::ColourTemperature, activeState.awb.temperatureK);
diff --git a/src/ipa/rkisp1/algorithms/awb.h b/src/ipa/rkisp1/algorithms/awb.h
index b3b2c0bb..6ac3a5c3 100644
--- a/src/ipa/rkisp1/algorithms/awb.h
+++ b/src/ipa/rkisp1/algorithms/awb.h
@@ -32,8 +32,6 @@ public:
 		     ControlList &metadata) override;
 
 private:
-	uint32_t estimateCCT(double red, double green, double blue);
-
 	bool rgbMode_;
 };
 
-- 
2.30.2