ipa: rpi: awb: Make it possible to set the colour temperature directlyHEADmaster

ColourTemperature is now exported as a writable control so that
applications can set it directly. The AWB algorithm class now requires
a method to be provided to perform this operation. The method should
clamp the passed value to the calibrated range known to the algorithm.

The default range is set very wide to cover all conceivable future AWB
calibrations. It will always be clamped before use.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Tested-by: Stefan Klug <stefan.klug@ideasonboard.com>

4 files changed, 40 insertions, 0 deletions

diff --git a/src/ipa/rpi/common/ipa_base.cpp b/src/ipa/rpi/common/ipa_base.cpp
index 45e2a1d7..0c8aee69 100644
--- a/src/ipa/rpi/common/ipa_base.cpp
+++ b/src/ipa/rpi/common/ipa_base.cpp
@@ -81,6 +81,7 @@ const ControlInfoMap::Map ipaColourControls{
 	{ &controls::AwbEnable, ControlInfo(false, true) },
 	{ &controls::AwbMode, ControlInfo(controls::AwbModeValues) },
 	{ &controls::ColourGains, ControlInfo(0.0f, 32.0f) },
+	{ &controls::ColourTemperature, ControlInfo(100, 100000) },
 	{ &controls::Saturation, ControlInfo(0.0f, 32.0f, 1.0f) },
 };
 
@@ -1011,6 +1012,25 @@ void IpaBase::applyControls(const ControlList &controls)
 			break;
 		}
 
+		case controls::COLOUR_TEMPERATURE: {
+			/* Silently ignore this control for a mono sensor. */
+			if (monoSensor_)
+				break;
+
+			auto temperatureK = ctrl.second.get<int32_t>();
+			RPiController::AwbAlgorithm *awb = dynamic_cast<RPiController::AwbAlgorithm *>(
+				controller_.getAlgorithm("awb"));
+			if (!awb) {
+				LOG(IPARPI, Warning)
+					<< "Could not set COLOUR_TEMPERATURE - no AWB algorithm";
+				break;
+			}
+
+			awb->setColourTemperature(temperatureK);
+			/* This metadata will get reported back automatically. */
+			break;
+		}
+
 		case controls::BRIGHTNESS: {
 			RPiController::ContrastAlgorithm *contrast = dynamic_cast<RPiController::ContrastAlgorithm *>(
 				controller_.getAlgorithm("contrast"));
diff --git a/src/ipa/rpi/controller/awb_algorithm.h b/src/ipa/rpi/controller/awb_algorithm.h
index 1779b050..d941ed4e 100644
--- a/src/ipa/rpi/controller/awb_algorithm.h
+++ b/src/ipa/rpi/controller/awb_algorithm.h
@@ -19,6 +19,7 @@ public:
 	virtual void initialValues(double &gainR, double &gainB) = 0;
 	virtual void setMode(std::string const &modeName) = 0;
 	virtual void setManualGains(double manualR, double manualB) = 0;
+	virtual void setColourTemperature(double temperatureK) = 0;
 	virtual void enableAuto() = 0;
 	virtual void disableAuto() = 0;
 };
diff --git a/src/ipa/rpi/controller/rpi/awb.cpp b/src/ipa/rpi/controller/rpi/awb.cpp
index c277a176..8479ae40 100644
--- a/src/ipa/rpi/controller/rpi/awb.cpp
+++ b/src/ipa/rpi/controller/rpi/awb.cpp
@@ -293,6 +293,24 @@ void Awb::setManualGains(double manualR, double manualB)
 	}
 }
 
+void Awb::setColourTemperature(double temperatureK)
+{
+	if (!config_.bayes) {
+		LOG(RPiAwb, Warning) << "AWB uncalibrated - cannot set colour temperature";
+		return;
+	}
+
+	temperatureK = config_.ctR.domain().clamp(temperatureK);
+	manualR_ = 1 / config_.ctR.eval(temperatureK);
+	manualB_ = 1 / config_.ctB.eval(temperatureK);
+
+	syncResults_.temperatureK = temperatureK;
+	syncResults_.gainR = manualR_;
+	syncResults_.gainG = 1.0;
+	syncResults_.gainB = manualB_;
+	prevSyncResults_ = syncResults_;
+}
+
 void Awb::switchMode([[maybe_unused]] CameraMode const &cameraMode,
 		     Metadata *metadata)
 {
diff --git a/src/ipa/rpi/controller/rpi/awb.h b/src/ipa/rpi/controller/rpi/awb.h
index 5d628b47..86640f8f 100644
--- a/src/ipa/rpi/controller/rpi/awb.h
+++ b/src/ipa/rpi/controller/rpi/awb.h
@@ -105,6 +105,7 @@ public:
 	void initialValues(double &gainR, double &gainB) override;
 	void setMode(std::string const &name) override;
 	void setManualGains(double manualR, double manualB) override;
+	void setColourTemperature(double temperatureK) override;
 	void enableAuto() override;
 	void disableAuto() override;
 	void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;