From 509dd6e20b1bfa8f42966da1ea421a0b7057485c Mon Sep 17 00:00:00 2001 From: Qiang Yu Date: Sun, 18 Jun 2017 00:37:39 +0800 Subject: [PATCH] u_math: add ushort_to_float/float_to_ushort v2: - return 0 for NaN too Signed-off-by: Qiang Yu Reviewed-by: Roland Scheidegger --- src/util/u_math.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/src/util/u_math.h b/src/util/u_math.h index e7dbbe5..5e712da 100644 --- a/src/util/u_math.h +++ b/src/util/u_math.h @@ -389,6 +389,37 @@ float_to_ubyte(float f) } } +/** + * Convert ushort to float in [0, 1]. + */ +static inline float +ushort_to_float(ushort us) +{ + return (float) us * (1.0f / 65535.0f); +} + + +/** + * Convert float in [0,1] to ushort in [0,65535] with clamping. + */ +static inline ushort +float_to_ushort(float f) +{ + /* return 0 for NaN too */ + if (!(f > 0.0f)) { + return (ushort) 0; + } + else if (f >= 1.0f) { + return (ushort) 65535; + } + else { + union fi tmp; + tmp.f = f; + tmp.f = tmp.f * (65535.0f/65536.0f) + 128.0f; + return (ushort) tmp.i; + } +} + static inline float byte_to_float_tex(int8_t b) { -- 2.7.4