EFX: Ring modulator fixes

Change from unipolar to bipolar carrier signal in the Ring modulator effect.

1 files changed, 3 insertions, 3 deletions

diff --git a/Alc/effects/modulator.c b/Alc/effects/modulator.c
index 7985f03e..b629b584 100644
--- a/Alc/effects/modulator.c
+++ b/Alc/effects/modulator.c
@@ -63,17 +63,17 @@ DEFINE_ALEFFECTSTATE_VTABLE(ALmodulatorState);
 
 static inline ALfloat Sin(ALsizei index)
 {
-    return sinf(index*(F_TAU/WAVEFORM_FRACONE) - F_PI)*0.5f + 0.5f;
+    return sinf(index * (F_TAU / WAVEFORM_FRACONE));
 }
 
 static inline ALfloat Saw(ALsizei index)
 {
-    return (ALfloat)index / WAVEFORM_FRACONE;
+    return index*(2.0f/WAVEFORM_FRACONE) - 1.0f;
 }
 
 static inline ALfloat Square(ALsizei index)
 {
-    return (ALfloat)((index >> (WAVEFORM_FRACBITS - 1)) & 1);
+    return ((index>>(WAVEFORM_FRACBITS-1))&1)*2.0f - 1.0f;
 }
 
 #define DECL_TEMPLATE(func)                                                   \