Fix drop in volume when shooting into a Brains power screen.

If too many of these sounds are started in one frame (for example if the
player shoots with the super shotgun into the power screen of a Brain)
things get too loud and OpenAL is forced to scale the volume of several
other sounds and the background music down. That leads to a noticable
and annoying drop in the overall volume.

Work around that by limiting the number of sounds started. 16 was
choosen by empirical testing.

src/client/cl_main.c

@@ -92,6 +92,11 @@ centity_t cl_entities[MAX_EDICTS];
 
 entity_state_t cl_parse_entities[MAX_PARSE_ENTITIES];
 
+/*Evil hack against too many power screen and power
+  shield impact sounds. For example if the player
+  fires his shotgun onto a Brain. */
+int num_power_sounds;
+
 extern cvar_t *allow_download;
 extern cvar_t *allow_download_players;
 extern cvar_t *allow_download_models;
@@ -733,6 +738,9 @@ CL_Frame(int packetdelta, int renderdelta, int timedelta, qboolean packetframe,
 		cls.netchan.last_received = Sys_Milliseconds();
 	}
 
+	// Reset power shield / power screen sound counter.
+	num_power_sounds = 0;
+
 	if (!cl_timedemo->value)
 	{
 		// Don't throttle too much when connecting / loading.

src/client/cl_tempentities.c

@@ -24,7 +24,9 @@
  * =======================================================================
  */
 
+#include <SDL2/SDL_scancode.h>
 #include "header/client.h"
+#include "sound/header/local.h"
 
 typedef enum
 {
@@ -716,7 +718,23 @@ CL_ParseTEnt(void)
 				CL_ParticleEffect(pos, dir, 0xb0, 40);
 			}
 
+			num_power_sounds++;
+
+			/* If too many of these sounds are started in one frame (for
+			 * example if the player shoots with the super shotgun into
+			 * the power screen of a Brain) things get too loud and OpenAL
+			 * is forced to scale the volume of several other sounds and
+			 * the background music down. That leads to a noticable and
+			 * annoying drop in the overall volume.
+			 *
+			 * Work around that by limiting the number of sounds started.
+			 * 16 was choosen by empirical testing.
+			 */
+			if (sound_started == SS_OAL && num_power_sounds < 16)
+			{
 				S_StartSound(pos, 0, 0, cl_sfx_lashit, 1, ATTN_NORM, 0);
+			}
+
 			break;
 
 		case TE_SHOTGUN: /* bullet hitting wall */

src/client/header/client.h

@@ -249,6 +249,11 @@ typedef struct
 
 extern client_static_t	cls;
 
+/*Evil hack against too many power screen and power
+  shield impact sounds. For example if the player
+  fires his shotgun onto a Brain. */
+extern int num_power_sounds;
+
 /* cvars */
 extern	cvar_t	*gl_stereo_separation;
 extern	cvar_t	*gl_stereo_convergence;