[PATCH v6 02/10] libcamera: software_isp: Use RGB type to represent gains

[Milan Zamazal]

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>
 
 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