libipa: camera_sensor_helper: Reorganize gain constants

To prepare for other gain models than the linear model, store the gain
constants in a union with per-model members. Due to the lack of
designated initializer support in gcc with C++17, initializing a single
complex structure that includes a union will be difficult. Split the
gain model type to a separate variable to work around this issue.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/ipa/libipa/camera_sensor_helper.h b/src/ipa/libipa/camera_sensor_helper.h
index 26adfcb5..6b96520b 100644
--- a/src/ipa/libipa/camera_sensor_helper.h
+++ b/src/ipa/libipa/camera_sensor_helper.h
@@ -34,15 +34,19 @@ protected:
 		AnalogueGainExponential,
 	};
 
-	struct AnalogueGainConstants {
-		AnalogueGainType type;
+	struct AnalogueGainLinearConstants {
 		int16_t m0;
 		int16_t c0;
 		int16_t m1;
 		int16_t c1;
 	};
 
-	AnalogueGainConstants analogueGainConstants_;
+	union AnalogueGainConstants {
+		AnalogueGainLinearConstants linear;
+	};
+
+	AnalogueGainType gainType_;
+	AnalogueGainConstants gainConstants_;
 
 private:
 	LIBCAMERA_DISABLE_COPY_AND_MOVE(CameraSensorHelper)