phonon: Source:get/setAbsorption;

src/api/l_audio_source.c

@@ -119,6 +119,44 @@ static int l_lovrSourceSetPose(lua_State *L) {
   return 0;
 }
 
+static int l_lovrSourceGetAbsorption(lua_State* L) {
+  Source* source = luax_checktype(L, 1, Source);
+  float absorption[3];
+  lovrSourceGetAbsorption(source, absorption);
+  if (absorption[0] == 0.f && absorption[1] == 0.f && absorption[2] == 0.f) {
+    lua_pushnil(L);
+    return 1;
+  }
+  lua_pushnumber(L, absorption[0]);
+  lua_pushnumber(L, absorption[1]);
+  lua_pushnumber(L, absorption[2]);
+  return 3;
+}
+
+static int l_lovrSourceSetAbsorption(lua_State* L) {
+  Source* source = luax_checktype(L, 1, Source);
+  float absorption[3] = { 0.f };
+  switch (lua_type(L, 2)) {
+    case LUA_TNONE:
+    case LUA_TNIL:
+      break;
+    case LUA_TBOOLEAN:
+      if (lua_toboolean(L, 2)) {
+        absorption[0] = .0002f;
+        absorption[1] = .0017f;
+        absorption[2] = .0182f;
+      }
+      break;
+    default:
+      absorption[0] = luax_checkfloat(L, 2);
+      absorption[1] = luax_checkfloat(L, 3);
+      absorption[2] = luax_checkfloat(L, 4);
+      break;
+  }
+  lovrSourceSetAbsorption(source, absorption);
+  return 0;
+}
+
 static int l_lovrSourceGetFalloff(lua_State* L) {
   Source* source = luax_checktype(L, 1, Source);
   float falloff = lovrSourceGetFalloff(source);
@@ -165,6 +203,8 @@ const luaL_Reg lovrSource[] = {
   { "isSpatial", l_lovrSourceIsSpatial },
   { "getPose", l_lovrSourceGetPose },
   { "setPose", l_lovrSourceSetPose },
+  { "getAbsorption", l_lovrSourceGetAbsorption },
+  { "setAbsorption", l_lovrSourceSetAbsorption },
   { "getFalloff", l_lovrSourceGetFalloff },
   { "setFalloff", l_lovrSourceSetFalloff },
   { NULL, NULL }

src/modules/audio/audio.c

@@ -34,6 +34,7 @@ struct Source {
   float volume;
   float position[4];
   float orientation[4];
+  float absorption[3];
   float falloff;
   bool playing;
   bool looping;
@@ -484,6 +485,14 @@ void lovrSourceSetPose(Source *source, float position[4], float orientation[4])
   ma_mutex_unlock(&state.lock);
 }
 
+void lovrSourceGetAbsorption(Source* source, float absorption[3]) {
+  memcpy(absorption, source->absorption, sizeof(source->absorption));
+}
+
+void lovrSourceSetAbsorption(Source* source, float absorption[3]) {
+  memcpy(source->absorption, absorption, sizeof(source->absorption));
+}
+
 float lovrSourceGetFalloff(Source* source) {
   return source->falloff;
 }

src/modules/audio/audio.h

@@ -56,6 +56,8 @@ void lovrSourceSetTime(Source* source, double time, TimeUnit units);
 bool lovrSourceIsSpatial(Source* source);
 void lovrSourceGetPose(Source* source, float position[4], float orientation[4]);
 void lovrSourceSetPose(Source* source, float position[4], float orientation[4]);
+void lovrSourceGetAbsorption(Source* source, float absorption[3]);
+void lovrSourceSetAbsorption(Source* source, float absorption[3]);
 float lovrSourceGetFalloff(Source* source);
 void lovrSourceSetFalloff(Source* source, float falloff);
 intptr_t* lovrSourceGetSpatializerMemoField(Source* source);

src/modules/audio/spatializer_phonon.c

@@ -129,6 +129,8 @@ uint32_t phonon_apply(Source* source, const float* input, float* output, uint32_
   quat_rotate(orientation, up);
   quat_rotate(orientation, right);
 
+  float absorption[3];
+  lovrSourceGetAbsorption(source, absorption);
   float falloff = lovrSourceGetFalloff(source);
 
   IPLSource iplSource = {
@@ -140,7 +142,8 @@ uint32_t phonon_apply(Source* source, const float* input, float* output, uint32_
     .directivity.dipolePower = 0.f,
     .distanceAttenuationModel.type = IPL_DISTANCEATTENUATION_INVERSEDISTANCE,
     .distanceAttenuationModel.minDistance = falloff,
-    .airAbsorptionModel.type = IPL_AIRABSORPTION_DEFAULT
+    .airAbsorptionModel.type = IPL_AIRABSORPTION_EXPONENTIAL,
+    .airAbsorptionModel.coefficients = { absorption[0], absorption[1], absorption[2] }
   };
 
   IPLDirectOcclusionMode occlusionMode = IPL_DIRECTOCCLUSION_NONE;
@@ -149,8 +152,8 @@ uint32_t phonon_apply(Source* source, const float* input, float* output, uint32_
 
   IPLDirectSoundEffectOptions options = {
     .applyDistanceAttenuation = falloff > 0.f ? IPL_TRUE : IPL_FALSE,
-    .applyAirAbsorption = IPL_TRUE,
     .applyDirectivity = IPL_TRUE,
+    .applyAirAbsorption = (absorption[0] > 0.f || absorption[1] > 0.f || absorption[2] > 0.f) ? IPL_TRUE : IPL_FALSE,
     .directOcclusionMode = occlusionMode
   };