1 files changed, 60 insertions, 0 deletions
diff --git a/test/math_util.c b/test/math_util.c
new file mode 100644
index 0000000000..bfc0345655
--- /dev/null
+++ b/test/math_util.c
@@ -0,0 +1,60 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Test motion sense code.
+ */
+
+#include <math.h>
+
+#include "math_util.h"
+#include "motion_sense.h"
+#include "test_util.h"
+
+/*****************************************************************************/
+/* Mock functions */
+
+/* Need to define accelerometer init and read functions just to compile. */
+int accel_init(enum accel_id id)
+{
+	return EC_SUCCESS;
+}
+
+int accel_read(enum accel_id id, int *x_acc, int *y_acc, int *z_acc)
+{
+	return EC_SUCCESS;
+}
+
+/*****************************************************************************/
+/* Test utilities */
+
+/* Macro to compare two floats and check if they are equal within diff. */
+#define IS_FLOAT_EQUAL(a, b, diff) ((a) >= ((b) - diff) && (a) <= ((b) + diff))
+
+#define ACOS_TOLERANCE_DEG 0.5f
+#define RAD_TO_DEG (180.0f / 3.1415926f)
+
+static int test_acos(void)
+{
+	float a, b;
+	float test;
+
+	/* Test a handful of values. */
+	for (test = -1.0; test <= 1.0; test += 0.01) {
+		a = arc_cos(test);
+		b = acos(test) * RAD_TO_DEG;
+		TEST_ASSERT(IS_FLOAT_EQUAL(a, b, ACOS_TOLERANCE_DEG));
+	}
+
+	return EC_SUCCESS;
+}
+
+
+void run_test(void)
+{
+	test_reset();
+
+	RUN_TEST(test_acos);
+
+	test_print_result();
+}