From 861d77ea4bc39b609aa6dabc500c03f1716e54b9 Mon Sep 17 00:00:00 2001
From: fed <58637860+fedddddd@users.noreply.github.com>
Date: Tue, 22 Aug 2023 22:04:23 +0200
Subject: [PATCH] Add music volume slider

---
 data/zonetool/localizedstrings/english.json |  3 ++
 src/client/component/sound.cpp              | 37 +++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/data/zonetool/localizedstrings/english.json b/data/zonetool/localizedstrings/english.json
index 19ea2692..a91caf00 100644
--- a/data/zonetool/localizedstrings/english.json
+++ b/data/zonetool/localizedstrings/english.json
@@ -64,6 +64,9 @@
     "LUA_MENU_INTRO": "Intro movie",
     "LUA_MENU_INTRO_DESC": "Show or skip intro movie with companies' logos on startup.",
 
+    "MENU_MUSIC_VOLUME": "Music Volume",
+    "MENU_MUSIC_VOLUME_DESC": "Move the slider to adjust the volume of the music.",
+
     "MENU_SYSINFO_CUSTOMER_SUPPORT_LINK": "Github Page:",
     "MENU_SYSINFO_CUSTOMER_SUPPORT_URL": "https://github.com/fedddddd/h2-mod",
     "MENU_SYSINFO_DONATION_LINK": "Donation link:",
diff --git a/src/client/component/sound.cpp b/src/client/component/sound.cpp
index 03b7d752..6eb8e2a7 100644
--- a/src/client/component/sound.cpp
+++ b/src/client/component/sound.cpp
@@ -13,6 +13,9 @@ namespace sound
 {
 	namespace
 	{
+		game::dvar_t* snd_music_volume = nullptr;
+		game::dvar_t** snd_music_disabled_for_custom_sndtrack = nullptr;
+
 		void com_sprintf_raw_sound_localized_stub(char* buffer, int size, const char* fmt,
 			const char* lang, const char* name, const char* extension)
 		{
@@ -35,6 +38,35 @@ namespace sound
 
 			return snd_is_music_playing_hook.invoke<bool>(a1);
 		}
+
+		float get_snd_volume(game::snd_alias_t* sound, float original_volume)
+		{
+			// original code
+			if (sound->dspBusIndex == *reinterpret_cast<int*>(0x151B9AA40) &&
+				snd_music_disabled_for_custom_sndtrack &&
+				(*snd_music_disabled_for_custom_sndtrack)->current.enabled)
+			{
+				return 0.f;
+			}
+
+			if (sound->dspBusIndex == 11 || sound->volModIndex == 5)
+			{
+				return original_volume * snd_music_volume->current.value;
+			}
+
+			return original_volume;
+		}
+
+		void snd_update_channel_stub(utils::hook::assembler& a)
+		{
+			a.pushad64();
+			a.mov(rcx, qword_ptr(rdi, 0xD0));
+			a.call_aligned(get_snd_volume);
+			a.movaps(xmm1, xmm0);
+			a.popad64();
+
+			a.jmp(0x1407CD8C7);
+		}
 	}
 
 	class component final : public component_interface
@@ -42,12 +74,17 @@ namespace sound
 	public:
 		void post_unpack() override
 		{
+			snd_music_volume = dvars::register_float("snd_musicVolume", 1.f, 0.0f, 1.f, game::DVAR_FLAG_SAVED, "Music volume scale");
+			snd_music_disabled_for_custom_sndtrack = reinterpret_cast<game::dvar_t**>(0x151B818C8);
+
 			// remove raw/sound or raw/language/sound prefix when loading raw sounds
 			utils::hook::call(0x140622FEF, com_sprintf_raw_sound_localized_stub);
 			utils::hook::call(0x14062306C, com_sprintf_raw_sound_stub);
 
 			// fix playing non-existing music crashing
 			snd_is_music_playing_hook.create(0x1407C58A0, snd_is_music_playing_stub);
+
+			utils::hook::jump(0x1407CD8A5, utils::hook::assemble(snd_update_channel_stub), true);
 		}
 	};
 }