[libcamera-devel] [PATCH v6 05/10] ipa: af_hill_climbing: Add "Windows" metering mode

[Daniel Semkowicz]

Add support for setting user defined auto focus window in the
AfHillClimbing. This enables usage of AfMetering and AfWindows controls.
Each time, there is a need for changing the window configuration in the
ISP, the signal is emitted. Platform layer that wants to use
the "Windows" metering mode, needs to connect to this signal
and configure the ISP on each emission.

Currently only one window is supported.

Signed-off-by: Daniel Semkowicz <dse at thaumatec.com>
---
 .../libipa/algorithms/af_hill_climbing.cpp    | 62 +++++++++++++++++--
 src/ipa/libipa/algorithms/af_hill_climbing.h  | 10 +++
 2 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/src/ipa/libipa/algorithms/af_hill_climbing.cpp b/src/ipa/libipa/algorithms/af_hill_climbing.cpp
index 244b8803..0fb17df3 100644
--- a/src/ipa/libipa/algorithms/af_hill_climbing.cpp
+++ b/src/ipa/libipa/algorithms/af_hill_climbing.cpp
@@ -63,9 +63,8 @@ LOG_DEFINE_CATEGORY(Af)
  * movement range rather than coarse search result.
  * \todo Implement setRange.
  * \todo Implement setSpeed.
- * \todo Implement setMeteringMode.
- * \todo Implement setWindows.
  * \todo Implement the AfPauseDeferred mode.
+ * \todo Implement support for multiple AF windows.
  */
 
 /**
@@ -99,6 +98,27 @@ int AfHillClimbing::init(int32_t minFocusPosition, int32_t maxFocusPosition,
 	return 0;
 }
 
+/**
+ * \brief Configure the AfHillClimbing with sensor information
+ * \param[in] outputSize Camera sensor output size
+ *
+ * This method should be called in the libcamera::ipa::Algorithm::configure()
+ * method of the platform layer.
+ */
+void AfHillClimbing::configure(const Size &outputSize)
+{
+	/*
+	 * Default AF window of 3/4 size of the camera sensor output,
+	 * placed at the center
+	 */
+	defaultWindow_ = Rectangle(static_cast<int>(outputSize.width / 8),
+				   static_cast<int>(outputSize.height / 8),
+				   3 * outputSize.width / 4,
+				   3 * outputSize.height / 4);
+
+	windowUpdateRequested.emit(defaultWindow_);
+}
+
 /**
  * \brief Run the auto focus algorithm loop
  * \param[in] currentContrast New value of contrast measured for current frame
@@ -185,6 +205,14 @@ void AfHillClimbing::skipFrames(uint32_t n)
 		framesToSkip_ = n;
 }
 
+/**
+ * \var AfHillClimbing::windowUpdateRequested
+ * \brief Signal emitted when change in AF window was requested
+ *
+ * Platform layer supporting AF windows should connect to this signal
+ * and configure the ISP with new window on each emition.
+ */
+
 void AfHillClimbing::setMode(controls::AfModeEnum mode)
 {
 	if (mode == mode_)
@@ -210,14 +238,36 @@ void AfHillClimbing::setSpeed([[maybe_unused]] controls::AfSpeedEnum speed)
 	LOG(Af, Error) << "setSpeed() not implemented!";
 }
 
-void AfHillClimbing::setMeteringMode([[maybe_unused]] controls::AfMeteringEnum metering)
+void AfHillClimbing::setMeteringMode(controls::AfMeteringEnum metering)
 {
-	LOG(Af, Error) << "setMeteringMode() not implemented!";
+	if (metering == meteringMode_)
+		return;
+
+	meteringMode_ = metering;
+
+	switch (metering) {
+	case controls::AfMeteringAuto:
+		windowUpdateRequested.emit(defaultWindow_);
+		break;
+	case controls::AfMeteringWindows:
+		windowUpdateRequested.emit(userWindow_);
+		break;
+	}
 }
 
-void AfHillClimbing::setWindows([[maybe_unused]] Span<const Rectangle> windows)
+void AfHillClimbing::setWindows(Span<const Rectangle> windows)
 {
-	LOG(Af, Error) << "setWindows() not implemented!";
+	if (windows.size() != 1) {
+		LOG(Af, Error) << "Only one AF window is supported";
+		return;
+	}
+
+	LOG(Af, Debug) << "setWindows: " << windows[0];
+
+	userWindow_ = windows[0];
+
+	if (meteringMode_ == controls::AfMeteringWindows)
+		windowUpdateRequested.emit(userWindow_);
 }
 
 void AfHillClimbing::setTrigger(controls::AfTriggerEnum trigger)
diff --git a/src/ipa/libipa/algorithms/af_hill_climbing.h b/src/ipa/libipa/algorithms/af_hill_climbing.h
index 2147939b..0f7c65db 100644
--- a/src/ipa/libipa/algorithms/af_hill_climbing.h
+++ b/src/ipa/libipa/algorithms/af_hill_climbing.h
@@ -10,6 +10,7 @@
 #pragma once
 
 #include <libcamera/base/log.h>
+#include <libcamera/base/signal.h>
 
 #include "af.h"
 
@@ -26,12 +27,15 @@ class AfHillClimbing : public Af
 public:
 	int init(int32_t minFocusPosition, int32_t maxFocusPosition,
 		 const YamlObject &tuningData);
+	void configure(const Size &outputSize);
 	int32_t process(double currentContrast);
 	void skipFrames(uint32_t n);
 
 	controls::AfStateEnum state() override { return state_; }
 	controls::AfPauseStateEnum pauseState() override { return pauseState_; }
 
+	Signal<const Rectangle &> windowUpdateRequested;
+
 private:
 	void setMode(controls::AfModeEnum mode) override;
 	void setRange(controls::AfRangeEnum range) override;
@@ -54,6 +58,7 @@ private:
 	controls::AfModeEnum mode_ = controls::AfModeManual;
 	controls::AfStateEnum state_ = controls::AfStateIdle;
 	controls::AfPauseStateEnum pauseState_ = controls::AfPauseStateRunning;
+	controls::AfMeteringEnum meteringMode_ = controls::AfMeteringAuto;
 
 	/* Current focus lens position. */
 	int32_t lensPosition_ = 0;
@@ -84,6 +89,11 @@ private:
 
 	/* Max ratio of variance change, 0.0 < maxChange_ < 1.0. */
 	double maxChange_;
+
+	/* Default AF window. */
+	Rectangle defaultWindow_;
+	/* AF window set by user using AF_WINDOWS control. */
+	Rectangle userWindow_;
 };
 
 } /* namespace ipa::algorithms */
-- 
2.39.2