From 3e0c4b531435eb1a0b04653721d65285488b1487 Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Sun, 11 Apr 2021 20:03:21 +0200
Subject: [PATCH] Stream music files from disk with FMOD, instead of preloading
 the entire file into memory and playing from there. Added a helper function
 to COM_ to assist with this. This removes the noticeable delay when loading
 into a level, and simplifies the music playback code as well.

---
 engine/Quake/bgmusic.c | 32 +++++---------------------------
 engine/Quake/common.c  | 28 ++++++++++++++++++++++++----
 engine/Quake/common.h  |  1 +
 3 files changed, 30 insertions(+), 31 deletions(-)

diff --git a/engine/Quake/bgmusic.c b/engine/Quake/bgmusic.c
index 8a9f9c6..f1f1306 100644
--- a/engine/Quake/bgmusic.c
+++ b/engine/Quake/bgmusic.c
@@ -42,7 +42,6 @@ extern FMOD_SYSTEM *fmod_system;
 FMOD_CHANNELGROUP *bgm_channelGroup = NULL;
 FMOD_CHANNEL *bgm_channel = NULL;
 FMOD_SOUND *bgm_sound = NULL;
-byte *bgm_data = NULL;
 
 static const char *extensions[] =
 {
@@ -136,9 +135,7 @@ void BGM_Shutdown (void)
 
 static qboolean BGM_PlayStream(const char *filename)
 {
-	FILE *f;
-	int len;
-	FMOD_CREATESOUNDEXINFO exinfo;
+	char netpath[MAX_OSPATH];
 	FMOD_RESULT result;
 
 	if (!fmod_system || !bgm_channelGroup)
@@ -147,28 +144,13 @@ static qboolean BGM_PlayStream(const char *filename)
 		return false;
 	}
 
-	len = COM_FOpenFile(filename, &f, NULL);
-	fclose(f);
-	if (len < 1)
+	if (!COM_FullFilePath(filename, netpath, sizeof(netpath)))
 	{
 		Con_Printf("Could not open BGM file %s, file not found\n", filename);
 		return false;
 	}
 
-	bgm_data = COM_LoadMallocFile(filename, NULL);	// TODO is there really no better way to pre-cache this data than with malloc?
-	if (!bgm_data)
-	{
-		Con_Printf("Failed to load BGM file %s\n", filename);
-		return false;
-	}
-
-	Con_DPrintf("BGM_PlayStream: Successfully loaded %s\n", filename);
-
-	memset(&exinfo, 0, sizeof(FMOD_CREATESOUNDEXINFO));
-	exinfo.cbsize = sizeof(FMOD_CREATESOUNDEXINFO);
-	exinfo.length = len;
-
-	result = FMOD_System_CreateSound(fmod_system, (const char*)bgm_data, FMOD_OPENMEMORY | FMOD_2D, &exinfo, &bgm_sound);
+	result = FMOD_System_CreateSound(fmod_system, netpath, FMOD_CREATESTREAM | FMOD_2D, NULL, &bgm_sound);
 	if (result != FMOD_OK || !bgm_sound)
 	{
 		Con_Printf("Failed to create FMOD sound: %s\n", FMOD_ErrorString(result));
@@ -176,6 +158,8 @@ static qboolean BGM_PlayStream(const char *filename)
 		return false;
 	}
 
+	Con_DPrintf("BGM_PlayStream: Successfully loaded %s\n", filename);
+
 	result = FMOD_System_PlaySound(fmod_system, bgm_sound, bgm_channelGroup, false, &bgm_channel);
 	if (result != FMOD_OK || !bgm_channel)
 	{
@@ -298,12 +282,6 @@ void BGM_Stop(void)
 		FMOD_Sound_Release(bgm_sound);
 		bgm_sound = NULL;
 	}
-
-	if (bgm_data)
-	{
-		free(bgm_data);
-		bgm_data = NULL;
-	}
 }
 
 void BGM_Pause (void)
diff --git a/engine/Quake/common.c b/engine/Quake/common.c
index a449001..313f7b0 100644
--- a/engine/Quake/common.c
+++ b/engine/Quake/common.c
@@ -1604,11 +1604,9 @@ If neither of file or handle is set, this
 can be used for detecting a file's presence.
 ===========
 */
-static int COM_FindFile (const char *filename, int *handle, FILE **file,
-							unsigned int *path_id)
+static int COM_FindFile2(const char *filename, int *handle, FILE **file, unsigned int *path_id, char *netpath, size_t size)
 {
 	searchpath_t	*search;
-	char		netpath[MAX_OSPATH];
 	pack_t		*pak;
 	int		i, findtime;
 
@@ -1616,6 +1614,7 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 		Sys_Error ("COM_FindFile: both handle and file set");
 
 	file_from_pak = 0;
+	memset(netpath, 0, size);
 
 //
 // search through the path, one element at a time
@@ -1661,7 +1660,7 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 					continue;
 			}
 
-			q_snprintf (netpath, sizeof(netpath), "%s/%s",search->filename, filename);
+			q_snprintf (netpath, size, "%s/%s",search->filename, filename);
 			findtime = Sys_FileTime (netpath);
 			if (findtime == -1)
 				continue;
@@ -1703,6 +1702,11 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 	return com_filesize;
 }
 
+static int COM_FindFile(const char *filename, int *handle, FILE **file, unsigned int *path_id)
+{
+	char netpath[MAX_OSPATH];
+	return COM_FindFile2(filename, handle, file, path_id, netpath, sizeof(netpath));
+}
 
 /*
 ===========
@@ -1762,6 +1766,22 @@ void COM_CloseFile (int h)
 	Sys_FileClose (h);
 }
 
+/*
+================
+COM_FullFilePath
+
+Get the full canonical file path of the requested file on disk.
+If it is inside a pak file, this returns false.
+================
+*/
+qboolean COM_FullFilePath(const char *filename, char *netpath, size_t size)
+{
+	int ret = COM_FindFile2(filename, NULL, NULL, NULL, netpath, size);
+	if (ret < 0 || !*netpath || file_from_pak)
+		return false;
+
+	return true;
+}
 
 /*
 ============
diff --git a/engine/Quake/common.h b/engine/Quake/common.h
index eff6b64..b7b9afb 100644
--- a/engine/Quake/common.h
+++ b/engine/Quake/common.h
@@ -233,6 +233,7 @@ int COM_OpenFile (const char *filename, int *handle, unsigned int *path_id);
 int COM_FOpenFile (const char *filename, FILE **file, unsigned int *path_id);
 qboolean COM_FileExists (const char *filename, unsigned int *path_id);
 void COM_CloseFile (int h);
+qboolean COM_FullFilePath(const char *filename, char *netpath, size_t size);
 
 // these procedures open a file using COM_FindFile and loads it into a proper
 // buffer. the buffer is allocated with a total size of com_filesize + 1. the