Add an option to disable specific EFX effect types

Alc/ALc.c

@@ -309,6 +309,37 @@ static void InitAL(void)
                            strcasecmp(str, "yes") == 0 ||
                            strcasecmp(str, "on") == 0 ||
                            atoi(str) != 0);
+
+        str = GetConfigValue(NULL, "excludefx", "");
+        if(str[0])
+        {
+            const struct {
+                const char *name;
+                int type;
+            } EffectList[] = {
+                { "reverb", REVERB },
+                { NULL, 0 }
+            };
+            int n;
+            size_t len;
+            const char *next = str;
+
+            do {
+                str = next;
+                next = strchr(str, ',');
+
+                if(!str[0] || next == str)
+                    continue;
+
+                len = (next ? ((size_t)(next-str)) : strlen(str));
+                for(n = 0;EffectList[n].name;n++)
+                {
+                    if(len == strlen(EffectList[n].name) &&
+                       strncmp(EffectList[n].name, str, len) == 0)
+                        DisabledEffects[EffectList[n].type] = AL_TRUE;
+                }
+            } while(next++);
+        }
     }
 }
 

OpenAL32/Include/alEffect.h

@@ -38,6 +38,13 @@ extern "C" {
 #define AL_REVERB_DECAY_HFLIMIT                            0x000D
 
 
+enum {
+    REVERB = 0,
+    MAX_EFFECTS
+};
+extern ALboolean DisabledEffects[MAX_EFFECTS];
+
+
 typedef struct ALeffect_struct
 {
     // Effect type (AL_EFFECT_NULL, ...)

OpenAL32/alEffect.c

@@ -29,6 +29,10 @@
 #include "alThunk.h"
 #include "alError.h"
 
+
+ALboolean DisabledEffects[MAX_EFFECTS];
+
+
 static ALeffect *g_EffectList;
 static ALuint    g_EffectCount;
 
@@ -165,8 +169,10 @@ ALvoid AL_APIENTRY alEffecti(ALuint effect, ALenum param, ALint iValue)
 
         if(param == AL_EFFECT_TYPE)
         {
-            if(iValue == AL_EFFECT_NULL ||
-               iValue == AL_EFFECT_REVERB)
+            ALboolean isOk = (iValue == AL_EFFECT_NULL ||
+                (iValue == AL_EFFECT_REVERB && !DisabledEffects[REVERB]));
+
+            if(isOk)
                 InitEffectParams(ALEffect, iValue);
             else
                 alSetError(AL_INVALID_VALUE);

alsoftrc.sample

@@ -61,6 +61,12 @@ drivers =  # Sets the backend driver list order, comma-seperated. Unknown
            # Default is:
            # alsa,oss,solaris,dsound,winmm,wave
 
+excludefx =  # Sets which effects to exclude, preventing apps from using them.
+             # This can help for apps that try to use effects which are too CPU
+             # intensive for the system to handle. Available effects are:
+             # reverb
+             # Default is empty (all available effects enabled)
+
 [alsa]  # ALSA backend stuff
 device = default  # Sets the device name for the default playback device.
                   # Default is default