Add shorthand macro F16() for defining numeric constants

1 files changed, 9 insertions, 0 deletions

diff --git a/libfixmath/fix16.h b/libfixmath/fix16.h
index 3b41d2c..6f3599b 100644
--- a/libfixmath/fix16.h
+++ b/libfixmath/fix16.h
@@ -75,7 +75,16 @@ static inline fix16_t fix16_from_dbl(double a)
 	return (fix16_t)temp;

 }

 

+/* Macro for defining fix16_t constant values.

+   The functions above can't be used from e.g. global variable initializers,

+   and their names are quite long also. This macro is useful for constants

+   springled alongside code, e.g. F16(1.234).

 

+   Note that the argument is evaluated multiple times, and also otherwise

+   you should only use this for constant values. For runtime-conversions,

+   use the functions above.

+*/

+#define F16(x) ((fix16_t)(((x) >= 0) ? ((x) * 65536.0 + 0.5) : ((x) * 65536.0 - 0.5)))

 

 static inline fix16_t fix16_abs(fix16_t x)

 	{ return (x < 0 ? -x : x); }