[libcamera-devel] [PATCH v2 3/5] libcamera: raspberrypi: Set camera flips correctly from user transform

[David Plowman]

The Raspberry Pi pipeline handler allows all transforms except those
involving a transpose. The user transform is combined with any
inherent rotation of the camera, and the camera's H and V flip bits
are set accordingly.
---
 .../pipeline/raspberrypi/raspberrypi.cpp      | 20 +++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index 236aa5c..9d183e3 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -324,6 +324,8 @@ public:
 	uint32_t expectedSequence_;
 	bool sensorMetadata_;
 
+	Transform transform_;
+
 	/*
 	 * All the functions in this class are called from a single calling
 	 * thread. So, we do not need to have any mutex to protect access to any
@@ -400,8 +402,9 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
 	if (config_.empty())
 		return Invalid;
 
-	if (transform != Transform::Identity) {
-		transform = Transform::Identity;
+	/* We cannot do Transforms with a transpose in them. */
+	if (!!(transform & Transform::Transpose)) {
+		transform = transform ^ Transform::Transpose;
 		status = Adjusted;
 	}
 
@@ -610,6 +613,9 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
 	for (auto const stream : data->streams_)
 		stream->reset();
 
+	/* We will want to know the transform requested by the application. */
+	data->transform_ = config->transform;
+
 	Size maxSize, sensorSize;
 	unsigned int maxIndex = 0;
 	bool rawStream = false;
@@ -1174,8 +1180,14 @@ int RPiCameraData::configureIPA()
 		/* Configure the H/V flip controls based on the sensor rotation. */
 		ControlList ctrls(unicam_[Unicam::Image].dev()->controls());
 		int32_t rotation = sensor_->properties().get(properties::Rotation);
-		ctrls.set(V4L2_CID_HFLIP, static_cast<int32_t>(!!rotation));
-		ctrls.set(V4L2_CID_VFLIP, static_cast<int32_t>(!!rotation));
+		bool success;
+		Transform combined = transform_ * transformFromRotation(rotation, &success);
+		if (!success) {
+			LOG(RPI, Error) << "Invalid rotation: " << rotation;
+			return -EINVAL;
+		}
+		ctrls.set(V4L2_CID_HFLIP, static_cast<int32_t>(!!(combined & Transform::HFlip)));
+		ctrls.set(V4L2_CID_VFLIP, static_cast<int32_t>(!!(combined & Transform::VFlip)));
 		unicam_[Unicam::Image].dev()->setControls(&ctrls);
 	}
 
-- 
2.20.1