libcamera: Use CameraConfiguration::orientation

Replace the usage of CameraConfiguration::transform with the newly
introduced CameraConfiguration::orientation.

Rework and rename the CameraSensor::validateTransform(transform) to
CameraSensor::computeTransform(orientation), that given the desired
image orientation computes the Transform that pipeline handlers should
apply to the sensor to obtain it.

Port all pipeline handlers to use the newly introduced function.

This commit breaks existing applications as it removes the public
CameraConfiguration::transform in favour of
CameraConfiguration::orientation.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

11 files changed, 66 insertions, 86 deletions

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index a4536c72..ae35792d 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -24,7 +24,6 @@
 #include <libcamera/orientation.h>
 #include <libcamera/request.h>
 #include <libcamera/stream.h>
-#include <libcamera/transform.h>
 
 namespace libcamera {
 
@@ -94,7 +93,6 @@ public:
 	std::size_t size() const;
 
 	std::optional<SensorConfiguration> sensorConfig;
-	Transform transform;
 	Orientation orientation;
 
 protected:
diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
index 0b2ece31..bcdb2d83 100644
--- a/include/libcamera/internal/camera_sensor.h
+++ b/include/libcamera/internal/camera_sensor.h
@@ -33,6 +33,8 @@ class SensorConfiguration;
 
 struct CameraSensorProperties;
 
+enum class Orientation;
+
 class CameraSensor : protected Loggable
 {
 public:
@@ -76,7 +78,7 @@ public:
 
 	CameraLens *focusLens() { return focusLens_.get(); }
 
-	Transform validateTransform(Transform *transform) const;
+	Transform computeTransform(Orientation *orientation) const;
 
 protected:
 	std::string logPrefix() const override;
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 59ee3c40..0ad1a4b5 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -291,8 +291,7 @@ bool SensorConfiguration::isValid() const
  * \brief Create an empty camera configuration
  */
 CameraConfiguration::CameraConfiguration()
-	: transform(Transform::Identity), orientation(Orientation::Rotate0),
-	  config_({})
+	: orientation(Orientation::Rotate0), config_({})
 {
 }
 
@@ -541,19 +540,6 @@ CameraConfiguration::Status CameraConfiguration::validateColorSpaces(ColorSpaceF
  */
 
 /**
- * \var CameraConfiguration::transform
- * \brief User-specified transform to be applied to the image
- *
- * The transform is a user-specified 2D plane transform that will be applied
- * to the camera images by the processing pipeline before being handed to
- * the application.
- *
- * The usual 2D plane transforms are allowed here (horizontal/vertical
- * flips, multiple of 90-degree rotations etc.), but the validate() function
- * may adjust this field at its discretion if the selection is not supported.
- */
-
-/**
  * \var CameraConfiguration::orientation
  * \brief The desired orientation of the images produced by the camera
  *
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 521a1997..f175f8b5 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -16,6 +16,7 @@
 #include <string.h>
 
 #include <libcamera/camera.h>
+#include <libcamera/orientation.h>
 #include <libcamera/property_ids.h>
 
 #include <libcamera/base/utils.h>
@@ -466,7 +467,7 @@ int CameraSensor::initProperties()
 
 		/*
 		 * Cache the Transform associated with the camera mounting
-		 * rotation for later use in validateTransform().
+		 * rotation for later use in computeTransform().
 		 */
 		bool success;
 		rotationTransform_ = transformFromRotation(propertyValue, &success);
@@ -1109,69 +1110,64 @@ void CameraSensor::updateControlInfo()
  */
 
 /**
- * \brief Validate a transform request against the sensor capabilities
- * \param[inout] transform The requested transformation, updated to match
- * the sensor capabilities
+ * \brief Compute the Transform that gives the requested \a orientation
+ * \param[inout] orientation The desired image orientation
  *
- * The input \a transform is the transform that the caller wants, and it is
- * adjusted according to the capabilities of the sensor to represent the
- * "nearest" transform that can actually be delivered.
+ * This function computes the Transform that the pipeline handler should apply
+ * to the CameraSensor to obtain the requested \a orientation.
  *
- * The returned Transform is the transform applied to the sensor in order to
- * produce the input \a transform, It is also validated against the sensor's
- * ability to perform horizontal and vertical flips.
+ * The intended caller of this function is the validate() implementation of
+ * pipeline handlers, that pass in the application requested
+ * CameraConfiguration::orientation and obtain a Transform to apply to the
+ * camera sensor, likely at configure() time.
  *
- * For example, if the requested \a transform is Transform::Identity and the
- * sensor rotation is 180 degrees, the output transform will be
- * Transform::Rot180 to correct the images so that they appear to have
- * Transform::Identity, but only if the sensor can apply horizontal and vertical
- * flips.
+ * If the requested \a orientation cannot be obtained, the \a orientation
+ * parameter is adjusted to report the current image orientation and
+ * Transform::Identity is returned.
  *
- * \return A Transform instance that represents which transformation has been
- * applied to the camera sensor
+ * If the requested \a orientation can be obtained, the function computes a
+ * Transform and does not adjust \a orientation.
+ *
+ * Pipeline handlers are expected to verify if \a orientation has been
+ * adjusted by this function and set the CameraConfiguration::status to
+ * Adjusted accordingly.
+ *
+ * \return A Transform instance that applied to the CameraSensor produces images
+ * with \a orientation
  */
-Transform CameraSensor::validateTransform(Transform *transform) const
+Transform CameraSensor::computeTransform(Orientation *orientation) const
 {
+	Orientation mountingOrientation = transformToOrientation(rotationTransform_);
+
 	/*
-	 * Combine the requested transform to compensate the sensor mounting
-	 * rotation.
+	 * If we cannot do any flips we cannot change the native camera mounting
+	 * orientation.
 	 */
-	Transform combined = rotationTransform_ * *transform;
+	if (!supportFlips_) {
+		*orientation = mountingOrientation;
+		return Transform::Identity;
+	}
 
 	/*
-	 * We combine the platform and user transform, but must "adjust away"
-	 * any combined result that includes a transposition, as we can't do
-	 * those. In this case, flipping only the transpose bit is helpful to
-	 * applications - they either get the transform they requested, or have
-	 * to do a simple transpose themselves (they don't have to worry about
-	 * the other possible cases).
+	 * Now compute the required transform to obtain 'orientation' starting
+	 * from the mounting rotation.
+	 *
+	 * As a note:
+	 * 	orientation / mountingOrientation = transform
+	 * 	mountingOrientation * transform = orientation
 	 */
-	if (!!(combined & Transform::Transpose)) {
-		/*
-		 * Flipping the transpose bit in "transform" flips it in the
-		 * combined result too (as it's the last thing that happens),
-		 * which is of course clearing it.
-		 */
-		*transform ^= Transform::Transpose;
-		combined &= ~Transform::Transpose;
-	}
+	Transform transform = *orientation / mountingOrientation;
 
 	/*
-	 * We also check if the sensor doesn't do h/vflips at all, in which
-	 * case we clear them, and the application will have to do everything.
+	 * If transform contains any Transpose we cannot do it, so adjust
+	 * 'orientation' to report the image native orientation and return Identity.
 	 */
-	if (!supportFlips_ && !!combined) {
-		/*
-		 * If the sensor can do no transforms, then combined must be
-		 * changed to the identity. The only user transform that gives
-		 * rise to this is the inverse of the rotation. (Recall that
-		 * combined = rotationTransform * transform.)
-		 */
-		*transform = -rotationTransform_;
-		combined = Transform::Identity;
+	if (!!(transform & Transform::Transpose)) {
+		*orientation = mountingOrientation;
+		return Transform::Identity;
 	}
 
-	return combined;
+	return transform;
 }
 
 std::string CameraSensor::logPrefix() const
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index a81c817a..fa4bd0bb 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -187,9 +187,9 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 	 * rotation and store the final combined transform that configure() will
 	 * need to apply to the sensor to save us working it out again.
 	 */
-	Transform requestedTransform = transform;
-	combinedTransform_ = data_->cio2_.sensor()->validateTransform(&transform);
-	if (transform != requestedTransform)
+	Orientation requestedOrientation = orientation;
+	combinedTransform_ = data_->cio2_.sensor()->computeTransform(&orientation);
+	if (orientation != requestedOrientation)
 		status = Adjusted;
 
 	/* Cap the number of entries to the available streams. */
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 6efa79f2..586b46d6 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -481,9 +481,9 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 		status = Adjusted;
 	}
 
-	Transform requestedTransform = transform;
-	Transform combined = sensor->validateTransform(&transform);
-	if (transform != requestedTransform)
+	Orientation requestedOrientation = orientation;
+	combinedTransform_ = data_->sensor_->computeTransform(&orientation);
+	if (orientation != requestedOrientation)
 		status = Adjusted;
 
 	/*
@@ -595,8 +595,6 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 	if (sensorFormat_.size.isNull())
 		sensorFormat_.size = sensor->resolution();
 
-	combinedTransform_ = combined;
-
 	return status;
 }
 
diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
index 7c88b87e..ee222d06 100644
--- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
+++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
@@ -174,9 +174,9 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
 	 * rotation and store the final combined transform that configure() will
 	 * need to apply to the sensor to save us working it out again.
 	 */
-	Transform requestedTransform = transform;
-	combinedTransform_ = data_->sensor_->validateTransform(&transform);
-	if (transform != requestedTransform)
+	Orientation requestedOrientation = orientation;
+	combinedTransform_ = data_->sensor_->computeTransform(&orientation);
+	if (orientation != requestedOrientation)
 		status = Adjusted;
 
 	rawStreams_.clear();
@@ -1234,7 +1234,8 @@ int CameraData::configureIPA(const CameraConfiguration *config, ipa::RPi::Config
 	}
 
 	/* Always send the user transform to the IPA. */
-	params.transform = static_cast<unsigned int>(config->transform);
+	Transform transform = config->orientation / Orientation::Rotate0;
+	params.transform = static_cast<unsigned int>(transform);
 
 	/* Ready the IPA - it must know about the sensor resolution. */
 	ret = ipa_->configure(sensorInfo_, params, result);
diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index 05ba76bc..911051b2 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -889,9 +889,9 @@ CameraConfiguration::Status SimpleCameraConfiguration::validate()
 	if (config_.empty())
 		return Invalid;
 
-	Transform requestedTransform = transform;
-	combinedTransform_ = sensor->validateTransform(&transform);
-	if (transform != requestedTransform)
+	Orientation requestedOrientation = orientation;
+	combinedTransform_ = sensor->computeTransform(&orientation);
+	if (orientation != requestedOrientation)
 		status = Adjusted;
 
 	/* Cap the number of entries to the available streams. */
diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
index 38f48a5d..ed9c7f88 100644
--- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
@@ -111,8 +111,8 @@ CameraConfiguration::Status UVCCameraConfiguration::validate()
 	if (config_.empty())
 		return Invalid;
 
-	if (transform != Transform::Identity) {
-		transform = Transform::Identity;
+	if (orientation != Orientation::Rotate0) {
+		orientation = Orientation::Rotate0;
 		status = Adjusted;
 	}
 
diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
index 00e6f4c6..5536941a 100644
--- a/src/libcamera/pipeline/vimc/vimc.cpp
+++ b/src/libcamera/pipeline/vimc/vimc.cpp
@@ -128,8 +128,8 @@ CameraConfiguration::Status VimcCameraConfiguration::validate()
 	if (config_.empty())
 		return Invalid;
 
-	if (transform != Transform::Identity) {
-		transform = Transform::Identity;
+	if (orientation != Orientation::Rotate0) {
+		orientation = Orientation::Rotate0;
 		status = Adjusted;
 	}
 
diff --git a/src/py/libcamera/py_main.cpp b/src/py/libcamera/py_main.cpp
index aa35f0a2..bce08218 100644
--- a/src/py/libcamera/py_main.cpp
+++ b/src/py/libcamera/py_main.cpp
@@ -329,7 +329,6 @@ PYBIND11_MODULE(_libcamera, m)
 		.def_property_readonly("size", &CameraConfiguration::size)
 		.def_property_readonly("empty", &CameraConfiguration::empty)
 		.def_readwrite("sensor_config", &CameraConfiguration::sensorConfig)
-		.def_readwrite("transform", &CameraConfiguration::transform);
 		.def_readwrite("orientation", &CameraConfiguration::orientation);
 
 	pyCameraConfigurationStatus