Add and use a method for fast float rounding

Unlike fastf2i, this keeps the result as a float instead of converting to
integer.

2 files changed, 2 insertions, 1 deletions

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 81914850..9d7fcdd5 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -1663,7 +1663,7 @@ static void ApplyDither(ALfloat (*restrict Samples)[BUFFERSIZE], ALuint *dither_
             ALuint rng0 = dither_rng(&seed);
             ALuint rng1 = dither_rng(&seed);
             val += (ALfloat)(rng0*(1.0/UINT_MAX) - rng1*(1.0/UINT_MAX));
-            samples[i] = fastf2i(val) * invscale;
+            samples[i] = fast_roundf(val) * invscale;
         }
     }
     *dither_seed = seed;
diff --git a/Alc/helpers.c b/Alc/helpers.c
index 7bcb3f4a..e54f3fb2 100644
--- a/Alc/helpers.c
+++ b/Alc/helpers.c
@@ -125,6 +125,7 @@ extern inline ALuint NextPowerOf2(ALuint value);
 extern inline size_t RoundUp(size_t value, size_t r);
 extern inline ALint fastf2i(ALfloat f);
 extern inline int float2int(float f);
+extern inline float fast_roundf(float f);
 #ifndef __GNUC__
 #if defined(HAVE_BITSCANFORWARD64_INTRINSIC)
 extern inline int msvc64_ctz64(ALuint64 v);