accel: Add per-axis accel scale helpers

src/Makefile.am

@@ -32,6 +32,8 @@ iio_sensor_proxy_SOURCES =			\
 	accel-mount-matrix.c			\
 	accel-attributes.h			\
 	accel-attributes.c			\
+	accel-scale.h				\
+	accel-scale.c				\
 	$(BUILT_SOURCES)
 
 iio_sensor_proxy_CPPFLAGS =			\

src/accel-scale.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020 Bastien Nocera <hadess@hadess.net>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3 as published by
+ * the Free Software Foundation.
+ *
+ */
+
+#include <glib.h>
+
+#include "accel-scale.h"
+
+void
+reset_accel_scale (AccelScale *scale)
+{
+	set_accel_scale (scale, 1.0);
+}
+
+void
+set_accel_scale (AccelScale *scale,
+		 double     value)
+{
+	g_return_if_fail (scale != NULL);
+	g_return_if_fail (value != 0.0);
+
+	scale->x = scale->y = scale->z = value;
+}
+
+void
+copy_accel_scale (AccelScale *target,
+		  AccelScale  source)
+{
+	g_return_if_fail (target != NULL);
+
+	target->x = source.x;
+	target->y = source.y;
+	target->z = source.z;
+}

src/accel-scale.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2020 Bastien Nocera <hadess@hadess.net>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3 as published by
+ * the Free Software Foundation.
+ *
+ */
+
+#pragma once
+
+typedef struct {
+	double x;
+	double y;
+	double z;
+} AccelScale;
+
+void reset_accel_scale (AccelScale *scale);
+void set_accel_scale (AccelScale *scale, double value);
+void copy_accel_scale (AccelScale *target, AccelScale source);