libcamera: ipa: simple: Introduce a general correction matrix

Let's introduce IPAActiveState::combinedMatrix that is separate from
IPAActiveState::ccm and represents the overall correction matrix, not
only the sensor colour correction matrix.

IPAActiveState::ccm still includes everything; this is changed in the
followup patch.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/ipa/simple/algorithms/ccm.cpp

@@ -104,6 +104,7 @@ void Ccm::prepare(IPAContext &context, const uint32_t frame,
 	if (saturation)
 		applySaturation(ccm, saturation.value());
 
+	context.activeState.combinedMatrix = ccm;
 	context.activeState.ccm = ccm;
 	frameContext.saturation = saturation;
 	context.activeState.matrixChanged = true;

src/ipa/simple/algorithms/lut.cpp

@@ -131,7 +131,7 @@ void Lut::prepare(IPAContext &context,
 		Matrix<float, 3, 3> gainMatrix = { { gains.r(), 0, 0,
 						     0, gains.g(), 0,
 						     0, 0, gains.b() } };
-		auto matrix = context.activeState.ccm * gainMatrix;
+		auto matrix = context.activeState.combinedMatrix * gainMatrix;
 		auto &red = params->redCcm;
 		auto &green = params->greenCcm;
 		auto &blue = params->blueCcm;

src/ipa/simple/ipa_context.h

@@ -63,6 +63,7 @@ struct IPAActiveState {
 	} gamma;
 
 	Matrix<float, 3, 3> ccm;
+	Matrix<float, 3, 3> combinedMatrix;
 	bool matrixChanged = false;
 
 	struct {