[libcamera-devel] [PATCH v4 04/10] libcamera: controls: Add default to ControlRange

[Jacopo Mondi]

Augment the the ControlRange class to store the control default value.

This is particularly relevant for v4l2 controls used to create
Camera properties, which are constructed using immutable video device
properties, whose value won't change at runtime.

Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 include/libcamera/controls.h |  5 ++++-
 src/libcamera/controls.cpp   | 17 +++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index b1b73367e874..458b84e8fa8c 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -114,10 +114,12 @@ class ControlRange
 {
 public:
 	explicit ControlRange(const ControlValue &min = 0,
-			      const ControlValue &max = 0);
+			      const ControlValue &max = 0,
+			      const ControlValue &def = 0);
 
 	const ControlValue &min() const { return min_; }
 	const ControlValue &max() const { return max_; }
+	const ControlValue &def() const { return def_; }
 
 	std::string toString() const;
 
@@ -134,6 +136,7 @@ public:
 private:
 	ControlValue min_;
 	ControlValue max_;
+	ControlValue def_;
 };
 
 using ControlIdMap = std::unordered_map<unsigned int, const ControlId *>;
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 7d8a0e97ee3a..1678d3cba4f3 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -353,14 +353,21 @@ Control<int64_t>::Control(unsigned int id, const char *name)
  * pipeline handlers to describe the controls they support.
  */
 
+/**
+ * \var ControlRange::def_
+ * \brief The control default value
+ */
+
 /**
  * \brief Construct a ControlRange with minimum and maximum range parameters
  * \param[in] min The control minimum value
  * \param[in] max The control maximum value
+ * \param[in] def The control default value
  */
 ControlRange::ControlRange(const ControlValue &min,
-			   const ControlValue &max)
-	: min_(min), max_(max)
+			   const ControlValue &max,
+			   const ControlValue &def)
+	: min_(min), max_(max), def_(def)
 {
 }
 
@@ -376,6 +383,12 @@ ControlRange::ControlRange(const ControlValue &min,
  * \return A ControlValue with the maximum value for the control
  */
 
+/**
+ * \fn ControlRange::def()
+ * \brief Retrieve the default value of the control
+ * \return A ControlValue with the default value for the control
+ */
+
 /**
  * \brief Provide a string representation of the ControlRange
  */
-- 
2.24.0