From 412cec73de3e127bbfba9f91c9586089217621df Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Fri, 12 Aug 2011 15:42:36 -0700
Subject: [PATCH] Avoid a temporary throw-away buffer for mixing null output

---
 Alc/ALu.c  | 35 +++++++++++++++++++----------------
 Alc/null.c | 20 +-------------------
 2 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 1ba71129..fd9b5334 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -1101,23 +1101,26 @@ ALvoid aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size)
             }
         }
 
-        switch(device->FmtType)
+        if(buffer)
         {
-            case DevFmtByte:
-                Write_ALbyte(device, buffer, SamplesToDo);
-                break;
-            case DevFmtUByte:
-                Write_ALubyte(device, buffer, SamplesToDo);
-                break;
-            case DevFmtShort:
-                Write_ALshort(device, buffer, SamplesToDo);
-                break;
-            case DevFmtUShort:
-                Write_ALushort(device, buffer, SamplesToDo);
-                break;
-            case DevFmtFloat:
-                Write_ALfloat(device, buffer, SamplesToDo);
-                break;
+            switch(device->FmtType)
+            {
+                case DevFmtByte:
+                    Write_ALbyte(device, buffer, SamplesToDo);
+                    break;
+                case DevFmtUByte:
+                    Write_ALubyte(device, buffer, SamplesToDo);
+                    break;
+                case DevFmtShort:
+                    Write_ALshort(device, buffer, SamplesToDo);
+                    break;
+                case DevFmtUShort:
+                    Write_ALushort(device, buffer, SamplesToDo);
+                    break;
+                case DevFmtFloat:
+                    Write_ALfloat(device, buffer, SamplesToDo);
+                    break;
+            }
         }
 
         size -= SamplesToDo;
diff --git a/Alc/null.c b/Alc/null.c
index 1a3072e8..1f83df34 100644
--- a/Alc/null.c
+++ b/Alc/null.c
@@ -27,9 +27,6 @@
 
 
 typedef struct {
-    ALvoid *buffer;
-    ALuint size;
-
     volatile int killNow;
     ALvoid *thread;
 } null_data;
@@ -68,7 +65,7 @@ static ALuint NullProc(ALvoid *ptr)
 
         while(avail-done >= Device->UpdateSize)
         {
-            aluMixData(Device, data->buffer, Device->UpdateSize);
+            aluMixData(Device, NULL, Device->UpdateSize);
             done += Device->UpdateSize;
         }
     }
@@ -104,23 +101,11 @@ static ALCboolean null_reset_playback(ALCdevice *device)
 {
     null_data *data = (null_data*)device->ExtraData;
 
-    data->size = device->UpdateSize * FrameSizeFromDevFmt(device->FmtChans,
-                                                          device->FmtType);
-    data->buffer = malloc(data->size);
-    if(!data->buffer)
-    {
-        ERR("Buffer malloc failed\n");
-        return ALC_FALSE;
-    }
     SetDefaultWFXChannelOrder(device);
 
     data->thread = StartThread(NullProc, device);
     if(data->thread == NULL)
-    {
-        free(data->buffer);
-        data->buffer = NULL;
         return ALC_FALSE;
-    }
 
     return ALC_TRUE;
 }
@@ -137,9 +122,6 @@ static void null_stop_playback(ALCdevice *device)
     data->thread = NULL;
 
     data->killNow = 0;
-
-    free(data->buffer);
-    data->buffer = NULL;
 }