Multiply the history offset in the filtering funcitons

1 files changed, 2 insertions, 36 deletions

diff --git a/OpenAL32/Include/alFilter.h b/OpenAL32/Include/alFilter.h
index 927b7fc4..fc91bb16 100644
--- a/OpenAL32/Include/alFilter.h
+++ b/OpenAL32/Include/alFilter.h
@@ -16,28 +16,10 @@ typedef struct {
     ALfloat history[1];
 #endif
 } FILTER;
-/*
-static __inline ALfloat lpFilter4P(FILTER *iir, ALuint offset, ALfloat input)
-{
-    ALfloat *history = &iir->history[offset];
-    ALfloat a = iir->coeff;
-    ALfloat output = input;
-
-    output = output + (history[0]-output)*a;
-    history[0] = output;
-    output = output + (history[1]-output)*a;
-    history[1] = output;
-    output = output + (history[2]-output)*a;
-    history[2] = output;
-    output = output + (history[3]-output)*a;
-    history[3] = output;
 
-    return output;
-}
-*/
 static __inline ALfloat lpFilter2P(FILTER *iir, ALuint offset, ALfloat input)
 {
-    ALfloat *history = &iir->history[offset];
+    ALfloat *history = &iir->history[offset*2];
     ALfloat a = iir->coeff;
     ALfloat output = input;
 
@@ -48,7 +30,6 @@ static __inline ALfloat lpFilter2P(FILTER *iir, ALuint offset, ALfloat input)
 
     return output;
 }
-
 static __inline ALfloat lpFilter1P(FILTER *iir, ALuint offset, ALfloat input)
 {
     ALfloat *history = &iir->history[offset];
@@ -60,24 +41,10 @@ static __inline ALfloat lpFilter1P(FILTER *iir, ALuint offset, ALfloat input)
 
     return output;
 }
-/*
-static __inline ALfloat lpFilter4PC(const FILTER *iir, ALuint offset, ALfloat input)
-{
-    const ALfloat *history = &iir->history[offset];
-    ALfloat a = iir->coeff;
-    ALfloat output = input;
-
-    output = output + (history[0]-output)*a;
-    output = output + (history[1]-output)*a;
-    output = output + (history[2]-output)*a;
-    output = output + (history[3]-output)*a;
 
-    return output;
-}
-*/
 static __inline ALfloat lpFilter2PC(const FILTER *iir, ALuint offset, ALfloat input)
 {
-    const ALfloat *history = &iir->history[offset];
+    const ALfloat *history = &iir->history[offset*2];
     ALfloat a = iir->coeff;
     ALfloat output = input;
 
@@ -86,7 +53,6 @@ static __inline ALfloat lpFilter2PC(const FILTER *iir, ALuint offset, ALfloat in
 
     return output;
 }
-
 static __inline ALfloat lpFilter1PC(FILTER *iir, ALuint offset, ALfloat input)
 {
     const ALfloat *history = &iir->history[offset];