Muffle sounds when the player is under water

client.h

@@ -1135,6 +1135,9 @@ typedef struct client_state_s
 
  // used by EntityState5_ReadUpdate
  skeleton_t *engineskeletonobjects;
+
+ // used by underwater sound filter (snd_waterfx)
+ qbool view_underwater;
 }
 client_state_t;
 

snd_main.c

@@ -183,6 +183,7 @@ cvar_t snd_spatialization_prologic_frontangle = {CF_CLIENT | CF_ARCHIVE, "snd_sp
 cvar_t snd_spatialization_occlusion = {CF_CLIENT | CF_ARCHIVE, "snd_spatialization_occlusion", "1", "enable occlusion testing on spatialized sounds, which simply quiets sounds that are blocked by the world; 1 enables PVS method, 2 enables LineOfSight method, 3 enables both"};
 
 // Cvars declared in snd_main.h (shared with other snd_*.c files)
+cvar_t snd_waterfx = {CF_CLIENT | CF_ARCHIVE, "snd_waterfx", "1", "underwater sound filter strength"};
 cvar_t _snd_mixahead = {CF_CLIENT | CF_ARCHIVE, "_snd_mixahead", "0.15", "how much sound to mix ahead of time"};
 cvar_t snd_streaming = {CF_CLIENT | CF_ARCHIVE, "snd_streaming", "1", "enables keeping compressed ogg sound files compressed, decompressing them only as needed, otherwise they will be decompressed completely at load (may use a lot of memory); when set to 2, streaming is performed even if this would waste memory"};
 cvar_t snd_streaming_length = {CF_CLIENT | CF_ARCHIVE, "snd_streaming_length", "1", "decompress sounds completely if they are less than this play time when snd_streaming is 1"};
@@ -812,6 +813,7 @@ void S_Init(void)
  Cvar_RegisterVariable(&ambient_fade);
  Cvar_RegisterVariable(&snd_noextraupdate);
  Cvar_RegisterVariable(&snd_show);
+ Cvar_RegisterVariable(&snd_waterfx);
  Cvar_RegisterVariable(&_snd_mixahead);
  Cvar_RegisterVariable(&snd_swapstereo); // for people with backwards sound wiring
  Cvar_RegisterVariable(&snd_channellayout);
@@ -1850,7 +1852,6 @@ void S_StaticSound (sfx_t *sfx, vec3_t origin, float fvol, float attenuation)
  S_PlaySfxOnChannel (sfx, target_chan, CHANNELFLAG_FORCELOOP, origin, fvol, attenuation, true, 0, 0, 0, 1.0f);
 }
 
-
 /*
 ===================
 S_UpdateAmbientSounds
@@ -1870,7 +1871,10 @@ static void S_UpdateAmbientSounds (void)
  if (cl.worldmodel && cl.worldmodel->brush.AmbientSoundLevelsForPoint)
  cl.worldmodel->brush.AmbientSoundLevelsForPoint(cl.worldmodel, listener_origin, ambientlevels, sizeof(ambientlevels));
 
+
  // Calc ambient sound levels
+ S_SetUnderwaterIntensity();
+
  for (ambient_channel = 0 ; ambient_channel< NUM_AMBIENTS ; ambient_channel++)
  {
  chan = &channels[ambient_channel];

snd_main.h

@@ -125,6 +125,7 @@ extern snd_ringbuffer_t *snd_renderbuffer;
 extern qbool snd_threaded; // enables use of snd_usethreadedmixing, provided that no sound hacks are in effect (like timedemo)
 extern qbool snd_usethreadedmixing; // if true, the main thread does not mix sound, soundtime does not advance, and neither does snd_renderbuffer->endframe, instead the audio thread will call S_MixToBuffer as needed
 
+extern struct cvar_s snd_waterfx;
 extern struct cvar_s _snd_mixahead;
 extern struct cvar_s snd_swapstereo;
 extern struct cvar_s snd_streaming;
@@ -152,6 +153,8 @@ extern qbool simsound;
 // Architecture-independent functions
 // ====================================================================
 
+void S_SetUnderwaterIntensity(void);
+
 void S_MixToBuffer(void *stream, unsigned int frames);
 
 qbool S_LoadSound (struct sfx_s *sfx, qbool complain);

snd_mix.c

@@ -310,6 +310,66 @@ static void S_ConvertPaintBuffer(portable_sampleframe_t *painted_ptr, void *rb_p
 }
 
 
+
+/*
+===============================================================================
+
+UNDERWATER EFFECT
+
+Muffles the intensity of sounds when the player is underwater
+
+===============================================================================
+*/
+
+static struct
+{
+ float intensity;
+ float alpha;
+ float accum[SND_LISTENERS];
+}
+underwater = {0.f, 1.f, {0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f}};
+
+void S_SetUnderwaterIntensity(void)
+{
+ float target = cl.view_underwater ? bound(0.f, snd_waterfx.value, 2.f) : 0.f;
+
+ if (underwater.intensity < target)
+ {
+ underwater.intensity += cl.realframetime * 4.f;
+ underwater.intensity = min(underwater.intensity, target);
+ }
+ else if (underwater.intensity > target)
+ {
+ underwater.intensity -= cl.realframetime * 4.f;
+ underwater.intensity = max(underwater.intensity, target);
+ }
+
+ underwater.alpha = exp(-underwater.intensity * log(12.f));
+}
+
+static void S_UnderwaterFilter(int endtime)
+{
+ int i;
+ int sl;
+
+ if (!underwater.intensity)
+ {
+ if (endtime > 0)
+ for (sl = 0; sl < SND_LISTENERS; sl++)
+ underwater.accum[sl] = paintbuffer[endtime-1].sample[sl];
+ return;
+ }
+
+ for (i = 0; i < endtime; i++)
+ for (sl = 0; sl < SND_LISTENERS; sl++)
+ {
+ underwater.accum[sl] += underwater.alpha * (paintbuffer[i].sample[sl] - underwater.accum[sl]);
+ paintbuffer[i].sample[sl] = underwater.accum[sl];
+ }
+}
+
+
+
 /*
 ===============================================================================
 
@@ -580,6 +640,9 @@ void S_MixToBuffer(void *stream, unsigned int bufferframes)
 
  S_SoftClipPaintBuffer(paintbuffer, totalmixframes, snd_renderbuffer->format.width, snd_renderbuffer->format.channels);
 
+ S_UnderwaterFilter(totalmixframes);
+
+
 #ifdef CONFIG_VIDEO_CAPTURE
  if (!snd_usethreadedmixing)
  S_CaptureAVISound(paintbuffer, totalmixframes);

view.c

@@ -1059,6 +1059,7 @@ void V_CalcViewBlend(void)
  supercontents = CL_PointSuperContents(vieworigin);
  if (supercontents & SUPERCONTENTS_LIQUIDSMASK)
  {
+ cl.view_underwater = true;
  r_refdef.frustumscale_x *= 1 - (((sin(cl.time * 4.7) + 1) * 0.015) * r_waterwarp.value);
  r_refdef.frustumscale_y *= 1 - (((sin(cl.time * 3.0) + 1) * 0.015) * r_waterwarp.value);
  if (supercontents & SUPERCONTENTS_LAVA)
@@ -1083,6 +1084,7 @@ void V_CalcViewBlend(void)
  }
  else
  {
+ cl.view_underwater = false;
  cl.cshifts[CSHIFT_CONTENTS].destcolor[0] = 0;
  cl.cshifts[CSHIFT_CONTENTS].destcolor[1] = 0;
  cl.cshifts[CSHIFT_CONTENTS].destcolor[2] = 0;