Add AL_FILTER_LOWPASS support

Direct filters only, since auxiliary sends and slots aren't available yet

4 files changed, 86 insertions, 1 deletions

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 23367e00..7397af8f 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -369,10 +369,19 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
             PanningFB = 0.5f;
         }
 
+        //7. Apply filter gains and filters
+        switch(ALSource->DirectFilter.filter)
+        {
+            case AL_FILTER_LOWPASS:
+                DryMix *= ALSource->DirectFilter.Gain;
+                DryGainHF *= ALSource->DirectFilter.GainHF;
+                break;
+        }
+
         *drygainhf = DryGainHF;
         *wetgainhf = WetGainHF;
 
-        //7. Convert pannings into channel volumes
+        //8. Convert pannings into channel volumes
         switch(OutputFormat)
         {
             case AL_FORMAT_MONO8:
diff --git a/OpenAL32/Include/alFilter.h b/OpenAL32/Include/alFilter.h
index b1a61d59..038304e8 100644
--- a/OpenAL32/Include/alFilter.h
+++ b/OpenAL32/Include/alFilter.h
@@ -14,11 +14,18 @@ extern "C" {
 #define AL_FILTER_HIGHPASS                                 0x0002
 #define AL_FILTER_BANDPASS                                 0x0003
 
+#define AL_LOWPASS_GAIN                                    0x0001
+#define AL_LOWPASS_GAINHF                                  0x0002
+
+
 typedef struct ALfilter_struct
 {
     // Filter type (AL_FILTER_NULL, ...)
     ALenum type;
 
+    ALfloat Gain;
+    ALfloat GainHF;
+
     // Index to itself
     ALuint filter;
 
diff --git a/OpenAL32/alExtension.c b/OpenAL32/alExtension.c
index e38dcb7b..54371ff4 100644
--- a/OpenAL32/alExtension.c
+++ b/OpenAL32/alExtension.c
@@ -255,6 +255,10 @@ static ALenums enumeration[]={
     { (ALchar *)"AL_FILTER_HIGHPASS",                   AL_FILTER_HIGHPASS                  },
     { (ALchar *)"AL_FILTER_BANDPASS",                   AL_FILTER_BANDPASS                  },
 
+    // Filter params
+    { (ALchar *)"AL_LOWPASS_GAIN",                      AL_LOWPASS_GAIN                     },
+    { (ALchar *)"AL_LOWPASS_GAINHF",                    AL_LOWPASS_GAINHF                   },
+
     // Effect types
     { (ALchar *)"AL_EFFECT_TYPE",                       AL_EFFECT_TYPE                      },
     { (ALchar *)"AL_EFFECT_NULL",                       AL_EFFECT_NULL                      },
diff --git a/OpenAL32/alFilter.c b/OpenAL32/alFilter.c
index 0167462f..719ccc0a 100644
--- a/OpenAL32/alFilter.c
+++ b/OpenAL32/alFilter.c
@@ -160,8 +160,18 @@ AL_API ALvoid AL_APIENTRY alFilteri(ALuint filter, ALenum param, ALint iValue)
 
     if (alIsFilter(filter))
     {
+        ALfilter *ALFilter = (ALfilter*)ALTHUNK_LOOKUPENTRY(filter);
+
         switch(param)
         {
+        case AL_FILTER_TYPE:
+            if(iValue == AL_FILTER_NULL ||
+               iValue == AL_FILTER_LOWPASS)
+                InitFilterParams(ALFilter, iValue);
+            else
+                alSetError(AL_INVALID_VALUE);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -186,6 +196,10 @@ AL_API ALvoid AL_APIENTRY alFilteriv(ALuint filter, ALenum param, ALint *piValue
     {
         switch(param)
         {
+        case AL_FILTER_TYPE:
+            alFilteri(filter, param, piValues[0]);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -208,8 +222,30 @@ AL_API ALvoid AL_APIENTRY alFilterf(ALuint filter, ALenum param, ALfloat flValue
 
     if (alIsFilter(filter))
     {
+        ALfilter *ALFilter = (ALfilter*)ALTHUNK_LOOKUPENTRY(filter);
+
         switch(param)
         {
+        case AL_LOWPASS_GAIN:
+            if(ALFilter->type == AL_FILTER_LOWPASS)
+            {
+                if(flValue >= 0.0f && flValue <= 1.0f)
+                    ALFilter->Gain = flValue;
+            }
+            else
+                alSetError(AL_INVALID_ENUM);
+            break;
+
+        case AL_LOWPASS_GAINHF:
+            if(ALFilter->type == AL_FILTER_LOWPASS)
+            {
+                if(flValue >= 0.0f && flValue <= 1.0f)
+                    ALFilter->GainHF = flValue;
+            }
+            else
+                alSetError(AL_INVALID_ENUM);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -234,6 +270,11 @@ AL_API ALvoid AL_APIENTRY alFilterfv(ALuint filter, ALenum param, ALfloat *pflVa
     {
         switch(param)
         {
+        case AL_LOWPASS_GAIN:
+        case AL_LOWPASS_GAINHF:
+            alFilterf(filter, param, pflValues[0]);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -304,8 +345,24 @@ AL_API ALvoid AL_APIENTRY alGetFilterf(ALuint filter, ALenum param, ALfloat *pfl
 
     if (alIsFilter(filter))
     {
+        ALfilter *ALFilter = (ALfilter*)ALTHUNK_LOOKUPENTRY(filter);
+
         switch(param)
         {
+        case AL_LOWPASS_GAIN:
+            if(ALFilter->type == AL_FILTER_LOWPASS)
+                *pflValue = ALFilter->Gain;
+            else
+                alSetError(AL_INVALID_ENUM);
+            break;
+
+        case AL_LOWPASS_GAINHF:
+            if(ALFilter->type == AL_FILTER_LOWPASS)
+                *pflValue = ALFilter->GainHF;
+            else
+                alSetError(AL_INVALID_ENUM);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -330,6 +387,11 @@ AL_API ALvoid AL_APIENTRY alGetFilterfv(ALuint filter, ALenum param, ALfloat *pf
     {
         switch(param)
         {
+        case AL_LOWPASS_GAIN:
+        case AL_LOWPASS_GAINHF:
+            alGetFilterf(filter, param, pflValues);
+            break;
+
         default:
             alSetError(AL_INVALID_ENUM);
             break;
@@ -365,4 +427,7 @@ ALvoid ReleaseALFilters(ALvoid)
 static void InitFilterParams(ALfilter *filter, ALenum type)
 {
     filter->type = type;
+
+    filter->Gain = 1.0;
+    filter->GainHF = 1.0;
 }