From 93b584ff8419f76d934e0a6e9cbc55cf907ea259 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Mon, 11 Jan 2010 06:19:54 -0800
Subject: Add a cosine resampler

---
 Alc/ALu.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'Alc')

diff --git a/Alc/ALu.c b/Alc/ALu.c
index f9a9ff2e..fbac9db2 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -870,6 +870,11 @@ static __inline ALfloat lerp(ALfloat val1, ALfloat val2, ALint frac)
 {
     return val1 + ((val2-val1)*(frac * (1.0f/(1<<FRACTIONBITS))));
 }
+static __inline ALfloat cos_lerp(ALfloat val1, ALfloat val2, ALint frac)
+{
+    ALfloat mult = (1.0f-cos(frac * (1.0f/(1<<FRACTIONBITS)) * M_PI)) * 0.5f;
+    return val1 + ((val2-val1)*mult);
+}
 
 static void MixSomeSources(ALCcontext *ALContext, float (*DryBuffer)[OUTPUTCHANNELS], ALuint SamplesToDo)
 {
@@ -1106,6 +1111,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
@@ -1153,6 +1160,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
@@ -1171,6 +1180,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
@@ -1190,6 +1201,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
@@ -1210,6 +1223,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
@@ -1230,6 +1245,8 @@ another_source:
                 break;
                 case LINEAR: DO_MIX(lerp);
                 break;
+                case COSINE: DO_MIX(cos_lerp);
+                break;
                 case RESAMPLER_MAX:
                 break;
             }
-- 
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