From bd5cc52c5c2d542bf992ac834871ca9a961407ea Mon Sep 17 00:00:00 2001
From: Robert Mader <robert.mader@collabora.com>
Date: Sun, 31 Mar 2024 13:21:19 +0200
Subject: [PATCH] libcamera: add camera rotation property on nodes

Like the location, the orientation is a static property of libcamera
devices. While the rotation is already exposed as buffer transform,
knowing the property can be handy for applications in various ways.

See also: cd8ac5c1a ("libcamera: add camera location property on nodes")
---
 spa/include/spa/utils/keys.h               |  2 ++
 spa/plugins/libcamera/libcamera-device.cpp | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/spa/include/spa/utils/keys.h b/spa/include/spa/utils/keys.h
index 2f007ade3..48b94c50a 100644
--- a/spa/include/spa/utils/keys.h
+++ b/spa/include/spa/utils/keys.h
@@ -78,6 +78,8 @@ extern "C" {
 									  *  used in open() */
 #define SPA_KEY_API_LIBCAMERA_LOCATION	"api.libcamera.location"	/**< location of the camera:
 									  * "front", "back" or "external" */
+#define SPA_KEY_API_LIBCAMERA_ROTATION	"api.libcamera.rotation"	/**< rotation of the camera:
+									  * "0", "90", "180" or "270" */
 
 /** info from libcamera_capability */
 #define SPA_KEY_API_LIBCAMERA_CAP_DRIVER	"api.libcamera.cap.driver"	/**< driver from capbility */
diff --git a/spa/plugins/libcamera/libcamera-device.cpp b/spa/plugins/libcamera/libcamera-device.cpp
index b25a4eb72..1692fcbea 100644
--- a/spa/plugins/libcamera/libcamera-device.cpp
+++ b/spa/plugins/libcamera/libcamera-device.cpp
@@ -97,6 +97,26 @@ static const char *cameraLoc(const Camera *camera)
 	return nullptr;
 }
 
+static const char *cameraRot(const Camera *camera)
+{
+	const ControlList &props = camera->properties();
+
+	if (auto rotation = props.get(properties::Rotation)) {
+		switch (rotation.value()) {
+		case 90:
+			return "90";
+		case 180:
+			return "180";
+		case 270:
+			return "270";
+		default:
+			return "0";
+		}
+	}
+
+	return nullptr;
+}
+
 static int emit_info(struct impl *impl, bool full)
 {
 	struct spa_dict_item items[10];
@@ -120,6 +140,8 @@ static int emit_info(struct impl *impl, bool full)
 
 	if (auto location = cameraLoc(impl->camera.get()))
 		ADD_ITEM(SPA_KEY_API_LIBCAMERA_LOCATION, location);
+	if (auto rotation = cameraRot(impl->camera.get()))
+		ADD_ITEM(SPA_KEY_API_LIBCAMERA_ROTATION, rotation);
 
 	const auto model = cameraModel(impl->camera.get());
 	ADD_ITEM(SPA_KEY_DEVICE_PRODUCT_NAME, model.c_str());