Add sound volume when unfocused setting (#14083)

This adds a new setting to set sound volume multiplier when Minetest window is unfocused/inactive (sound_volume_unfocused, located in Settings > Graphics and Audio > Audio > Volume when unfocused).

If the window is not focused, the sound volume will be multiplied by sound_volume_unfocused setting. The sound volume will be set back to sound_volume again when the window is focused.

builtin/settingtypes.txt

@@ -623,6 +623,9 @@ bloom_radius (Bloom Radius) float 1 0.1 8
 #    Requires the sound system to be enabled.
 sound_volume (Volume) float 0.8 0.0 1.0
 
+#    Volume multiplier when the window is unfocused.
+sound_volume_unfocused (Volume when unfocused) float 0.3 0.0 1.0
+
 #    Whether to mute sounds. You can unmute sounds at any time, unless the
 #    sound system is disabled (enable_sound=false).
 #    In-game, you can toggle the mute state with the mute key or by using the

src/client/game.cpp

@@ -3209,19 +3209,7 @@ void Game::updateSound(f32 dtime)
 			camera->getDirection(),
 			camera->getCameraNode()->getUpVector());
 
-	bool mute_sound = g_settings->getBool("mute_sound");
-	if (mute_sound) {
-		sound_manager->setListenerGain(0.0f);
-	} else {
-		// Check if volume is in the proper range, else fix it.
-		float old_volume = g_settings->getFloat("sound_volume");
-		float new_volume = rangelim(old_volume, 0.0f, 1.0f);
-		sound_manager->setListenerGain(new_volume);
-
-		if (old_volume != new_volume) {
-			g_settings->setFloat("sound_volume", new_volume);
-		}
-	}
+	sound_volume_control(sound_manager.get(), device->isWindowActive());
 
 	// Tell the sound maker whether to make footstep sounds
 	soundmaker->makes_footstep_sound = player->makes_footstep_sound;

src/client/sound.cpp

@@ -22,6 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "filesys.h"
 #include "log.h"
 #include "porting.h"
+#include "settings.h"
 #include "util/numeric.h"
 #include <algorithm>
 #include <string>
@@ -95,3 +96,26 @@ void ISoundManager::freeId(sound_handle_t id, u32 num_owners)
 	else
 		it->second -= num_owners;
 }
+
+void sound_volume_control(ISoundManager *sound_mgr, bool is_window_active)
+{
+	bool mute_sound = g_settings->getBool("mute_sound");
+	if (mute_sound) {
+		sound_mgr->setListenerGain(0.0f);
+	} else {
+		// Check if volume is in the proper range, else fix it.
+		float old_volume = g_settings->getFloat("sound_volume");
+		float new_volume = rangelim(old_volume, 0.0f, 1.0f);
+
+		if (old_volume != new_volume) {
+			g_settings->setFloat("sound_volume", new_volume);
+		}
+
+		if (!is_window_active) {
+			new_volume *= g_settings->getFloat("sound_volume_unfocused");
+			new_volume = rangelim(new_volume, 0.0f, 1.0f);
+		}
+
+		sound_mgr->setListenerGain(new_volume);
+	}
+}

src/client/sound.h

@@ -184,3 +184,9 @@ class DummySoundManager final : public ISoundManager
 	void fadeSound(sound_handle_t sound, f32 step, f32 target_gain) override {}
 	void updateSoundPosVel(sound_handle_t sound, const v3f &pos, const v3f &vel) override {}
 };
+
+/**
+ * A helper function to control sound volume based on some values: sound volume
+ * settings, mute sound setting, and window activity.
+ */
+void sound_volume_control(ISoundManager *sound_mgr, bool is_window_active);

src/defaultsettings.cpp

@@ -40,6 +40,7 @@ void set_default_settings()
 	settings->setDefault("address", "");
 	settings->setDefault("enable_sound", "true");
 	settings->setDefault("sound_volume", "0.8");
+	settings->setDefault("sound_volume_unfocused", "0.3");
 	settings->setDefault("mute_sound", "false");
 	settings->setDefault("enable_mesh_cache", "false");
 	settings->setDefault("mesh_generation_interval", "0");

src/gui/guiEngine.cpp

@@ -23,7 +23,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <ICameraSceneNode.h>
 #include "client/renderingengine.h"
 #include "scripting_mainmenu.h"
-#include "util/numeric.h"
 #include "config.h"
 #include "version.h"
 #include "porting.h"
@@ -296,6 +295,7 @@ void GUIEngine::run()
 		driver->endScene();
 
 		IrrlichtDevice *device = m_rendering_engine->get_raw_device();
+
 		u32 frametime_min = 1000 / (device->isWindowFocused()
 			? g_settings->getFloat("fps_max")
 			: g_settings->getFloat("fps_max_unfocused"));
@@ -310,6 +310,8 @@ void GUIEngine::run()
 
 		m_script->step();
 
+		sound_volume_control(m_sound_manager.get(), device->isWindowActive());
+
 		m_sound_manager->step(dtime);
 
 #ifdef __ANDROID__