Add a flag to specify when the low-pass filter needs to apply

3 files changed, 54 insertions, 29 deletions

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 07b6d501..8baa5a4f 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -581,23 +581,29 @@ ALvoid CalcNonAttnSourceParams(ALactivesource *src, const ALCcontext *ALContext)
     src->WetMix = SelectSendMixer();
 
     {
-        ALfloat gain = maxf(0.01f, DryGainHF);
+        ALfloat gainhf = maxf(0.01f, DryGainHF);
         ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
         for(c = 0;c < num_channels;c++)
+        {
+            src->Direct.Filters[c] = (gainhf != 1.0f) ? AF_LowPass : AF_None;
             ALfilterState_setParams(
-                &src->Direct.LpFilter[c], ALfilterType_HighShelf, gain,
+                &src->Direct.LpFilter[c], ALfilterType_HighShelf, gainhf,
                 hfscale, 0.0f
             );
+        }
     }
     for(i = 0;i < NumSends;i++)
     {
-        ALfloat gain = maxf(0.01f, WetGainHF[i]);
+        ALfloat gainhf = maxf(0.01f, WetGainHF[i]);
         ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
         for(c = 0;c < num_channels;c++)
+        {
+            src->Send[i].Filters[c] = (gainhf != 1.0f) ? AF_LowPass : AF_None;
             ALfilterState_setParams(
-                &src->Send[i].LpFilter[c], ALfilterType_HighShelf, gain,
+                &src->Send[i].LpFilter[c], ALfilterType_HighShelf, gainhf,
                 hfscale, 0.0f
             );
+        }
     }
 }
 
@@ -1082,19 +1088,21 @@ ALvoid CalcSourceParams(ALactivesource *src, const ALCcontext *ALContext)
     src->WetMix = SelectSendMixer();
 
     {
-        ALfloat gain = maxf(0.01f, DryGainHF);
+        ALfloat gainhf = maxf(0.01f, DryGainHF);
         ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
+        src->Direct.Filters[0] = (gainhf != 1.0f) ? AF_LowPass : AF_None;
         ALfilterState_setParams(
-            &src->Direct.LpFilter[0], ALfilterType_HighShelf, gain,
+            &src->Direct.LpFilter[0], ALfilterType_HighShelf, gainhf,
             hfscale, 0.0f
         );
     }
     for(i = 0;i < NumSends;i++)
     {
-        ALfloat gain = maxf(0.01f, WetGainHF[i]);
+        ALfloat gainhf = maxf(0.01f, WetGainHF[i]);
         ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
+        src->Direct.Filters[0] = (gainhf != 1.0f) ? AF_LowPass : AF_None;
         ALfilterState_setParams(
-            &src->Send[i].LpFilter[0], ALfilterType_HighShelf, gain,
+            &src->Send[i].LpFilter[0], ALfilterType_HighShelf, gainhf,
             hfscale, 0.0f
         );
     }
diff --git a/Alc/mixer.c b/Alc/mixer.c
index fc3fecbd..ac433e35 100644
--- a/Alc/mixer.c
+++ b/Alc/mixer.c
@@ -84,12 +84,21 @@ static void SilenceData(ALfloat *dst, ALuint samples)
 }
 
 
-static void DoFilter(ALfilterState *filter, ALfloat *restrict dst, const ALfloat *restrict src,
-                     ALuint numsamples)
+static void DoFilters(ALfilterState *lpfilter, ALfloat *restrict dst, const ALfloat *restrict src,
+                      ALuint numsamples, enum ActiveFilters type)
 {
     ALuint i;
-    for(i = 0;i < numsamples;i++)
-        dst[i] = ALfilterState_processSingle(filter, src[i]);
+    switch(type)
+    {
+        case AF_None:
+            memcpy(dst, src, numsamples * sizeof(ALfloat));
+            break;
+
+        case AF_LowPass:
+            for(i = 0;i < numsamples;i++)
+                dst[i] = ALfilterState_processSingle(lpfilter, src[i]);
+            break;
+    }
 }
 
 
@@ -323,8 +332,8 @@ ALvoid MixSource(ALactivesource *src, ALCdevice *Device, ALuint SamplesToDo)
             {
                 DirectParams *directparms = &src->Direct;
 
-                DoFilter(&directparms->LpFilter[chan], SrcData, ResampledData,
-                         DstBufferSize);
+                DoFilters(&directparms->LpFilter[chan], SrcData, ResampledData,
+                          DstBufferSize, directparms->Filters[chan]);
                 src->DryMix(directparms, SrcData, chan, OutPos, DstBufferSize);
             }
 
@@ -334,8 +343,8 @@ ALvoid MixSource(ALactivesource *src, ALCdevice *Device, ALuint SamplesToDo)
                 if(!sendparms->OutBuffer)
                     continue;
 
-                DoFilter(&sendparms->LpFilter[chan], SrcData, ResampledData,
-                         DstBufferSize);
+                DoFilters(&sendparms->LpFilter[chan], SrcData, ResampledData,
+                          DstBufferSize, sendparms->Filters[chan]);
                 src->WetMix(sendparms, SrcData, OutPos, DstBufferSize);
             }
         }
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index 36e81e0b..dd13a293 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -39,6 +39,11 @@
 extern "C" {
 #endif
 
+enum ActiveFilters {
+    AF_None = 0,
+    AF_LowPass = 1,
+};
+
 typedef struct HrtfState {
     alignas(16) ALfloat History[SRC_HISTORY_LENGTH];
     alignas(16) ALfloat Values[HRIR_LENGTH][2];
@@ -54,6 +59,16 @@ typedef struct HrtfParams {
 typedef struct DirectParams {
     ALfloat (*OutBuffer)[BUFFERSIZE];
 
+    enum ActiveFilters Filters[MAX_INPUT_CHANNELS];
+    ALfilterState LpFilter[MAX_INPUT_CHANNELS];
+
+    /* If not 'moving', gain/coefficients are set directly without fading. */
+    ALboolean Moving;
+    /* Stepping counter for gain/coefficient fading. */
+    ALuint Counter;
+    /* History/coefficient offset. */
+    ALuint Offset;
+
     union {
         struct {
             HrtfParams Params[MAX_INPUT_CHANNELS];
@@ -72,19 +87,17 @@ typedef struct DirectParams {
             ALfloat Target[MAX_INPUT_CHANNELS][MaxChannels];
         } Gains;
     } Mix;
-    /* If not 'moving', gain/coefficients are set directly without fading. */
-    ALboolean Moving;
-    /* Stepping counter for gain/coefficient fading. */
-    ALuint Counter;
-    /* History/coefficient offset. */
-    ALuint Offset;
-
-    ALfilterState LpFilter[MAX_INPUT_CHANNELS];
 } DirectParams;
 
 typedef struct SendParams {
     ALfloat (*OutBuffer)[BUFFERSIZE];
 
+    enum ActiveFilters Filters[MAX_INPUT_CHANNELS];
+    ALfilterState LpFilter[MAX_INPUT_CHANNELS];
+
+    ALboolean Moving;
+    ALuint Counter;
+
     /* Gain control, which applies to all input channels to a single (mono)
      * output buffer. */
     struct {
@@ -92,11 +105,6 @@ typedef struct SendParams {
         ALfloat Step;
         ALfloat Target;
     } Gain;
-
-    ALboolean Moving;
-    ALuint Counter;
-
-    ALfilterState LpFilter[MAX_INPUT_CHANNELS];
 } SendParams;