- separated the game-dependent music lookup parts from the core player.

src/sound/music/music.cpp

@@ -72,6 +72,7 @@
 // MACROS ------------------------------------------------------------------
 
 
+
 // EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
 
 extern float S_GetMusicVolume (const char *music);
@@ -86,11 +87,26 @@ static FPlayList PlayList;
 float	relative_volume = 1.f;
 float	saved_relative_volume = 1.0f;	// this could be used to implement an ACS FadeMusic function
 
+static FileReader DefaultOpenMusic(const char* fn)
+{
+	// This is the minimum needed to make the music system functional.
+	FileReader fr;
+	fr.OpenFile(fn);
+	return fr;
+}
+static MusicCallbacks mus_cb = { nullptr, DefaultOpenMusic };
+
 
 // PUBLIC DATA DEFINITIONS -------------------------------------------------
 
 // CODE --------------------------------------------------------------------
 
+void S_SetMusicCallbacks(MusicCallbacks* cb)
+{
+	mus_cb = *cb;
+	if (mus_cb.OpenMusic == nullptr) mus_cb.OpenMusic = DefaultOpenMusic;	// without this we are dead in the water.
+}
+
 //==========================================================================
 //
 // 
@@ -293,33 +309,24 @@ bool S_StartMusic (const char *m_id)
 //
 // S_ChangeMusic
 //
-// Starts playing a music, possibly looping.
+// initiates playback of a song
 //
-// [RH] If music is a MOD, starts it at position order. If name is of the
-// format ",CD,<track>,[cd id]" song is a CD track, and if [cd id] is
-// specified, it will only be played if the specified CD is in a drive.
 //==========================================================================
 
-bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
+bool S_ChangeMusic(const char* musicname, int order, bool looping, bool force)
 {
 	if (nomusic) return false;	// skip the entire procedure if music is globally disabled.
+
 	if (!force && PlayList.GetNumSongs())
 	{ // Don't change if a playlist is active
 		return false;
 	}
-
-	// allow specifying "*" as a placeholder to play the level's default music.
-	if (musicname != nullptr && !strcmp(musicname, "*"))
+	// Do game specific lookup.
+	FString musicname_;
+	if (mus_cb.LookupFileName)
 	{
-		if (gamestate == GS_LEVEL || gamestate == GS_TITLELEVEL)
-		{
-			musicname = primaryLevel->Music;
-			order = primaryLevel->musicorder;
-		}
-		else
-		{
-			musicname = nullptr;
-		}
+		musicname_ = mus_cb.LookupFileName(musicname, order);
+		musicname = musicname_.GetChars();
 	}
 
 	if (musicname == nullptr || musicname[0] == 0)
@@ -330,35 +337,10 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 		mus_playing.LastSong = "";
 		return true;
 	}
-	if (*musicname == '/') musicname++;
-
-	FString DEH_Music;
-	if (musicname[0] == '$')
-	{
-		// handle dehacked replacement.
-		// Any music name defined this way needs to be prefixed with 'D_' because
-		// Doom.exe does not contain the prefix so these strings don't either.
-		const char * mus_string = GStrings[musicname+1];
-		if (mus_string != nullptr)
-		{
-			DEH_Music << "D_" << mus_string;
-			musicname = DEH_Music;
-		}
-	}
-
-	FName *aliasp = MusicAliases.CheckKey(musicname);
-	if (aliasp != nullptr)
-	{
-		if (*aliasp == NAME_None)
-		{
-			return true;	// flagged to be ignored
-		}
-		musicname = aliasp->GetChars();
-	}
 
 	if (!mus_playing.name.IsEmpty() &&
 		mus_playing.handle != nullptr &&
-		stricmp (mus_playing.name, musicname) == 0 &&
+		stricmp(mus_playing.name, musicname) == 0 &&
 		ZMusic_IsLooping(mus_playing.handle) == zmusic_bool(looping))
 	{
 		if (order != mus_playing.baseorder)
@@ -380,20 +362,10 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 		return true;
 	}
 
-	if (strnicmp (musicname, ",CD,", 4) == 0)
-	{
-		static bool warned = false;
-		if (!warned)
-			Printf(TEXTCOLOR_RED "CD Audio no longer supported\n");
-		warned = true;
-		return false;
-	}
-	else
-	{
 	int lumpnum = -1;
 	int length = 0;
 	ZMusic_MusicStream handle = nullptr;
-		MidiDeviceSetting *devp = MidiDevices.CheckKey(musicname);
+	MidiDeviceSetting* devp = MidiDevices.CheckKey(musicname);
 
 	// Strip off any leading file:// component.
 	if (strncmp(musicname, "file://", 7) == 0)
@@ -401,34 +373,12 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 		musicname += 7;
 	}
 
-		FileReader reader;
-		if (!FileExists (musicname))
-		{
-			if ((lumpnum = fileSystem.CheckNumForFullName (musicname, true, ns_music)) == -1)
-			{
-				Printf ("Music \"%s\" not found\n", musicname);
-				return false;
-			}
-			if (handle == nullptr)
-			{
-				if (fileSystem.FileLength (lumpnum) == 0)
-				{
-					return false;
-				}
-				reader = fileSystem.ReopenFileReader(lumpnum);
-			}
-		}
-		else
-		{
-			// Load an external file.
-			if (!reader.OpenFile(musicname))
-			{
-				return false;
-			}
-		}
+	// opening the music must be done by the game because it's different depending on the game's file system use.
+	FileReader reader = mus_cb.OpenMusic(musicname);
+	if (!reader.isOpen()) return false;
 
 	// shutdown old music
-		S_StopMusic (true);
+	S_StopMusic(true);
 
 	// Just record it if volume is 0 or music was disabled
 	if (snd_musicvolume <= 0)
@@ -448,13 +398,12 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 	else
 	{
 		auto mreader = GetMusicReader(reader);	// this passes the file reader to the newly created wrapper.
-			mus_playing.handle = ZMusic_OpenSong(mreader, devp? (EMidiDevice)devp->device : MDEV_DEFAULT, devp? devp->args.GetChars() : "");
+		mus_playing.handle = ZMusic_OpenSong(mreader, devp ? (EMidiDevice)devp->device : MDEV_DEFAULT, devp ? devp->args.GetChars() : "");
 		if (mus_playing.handle == nullptr)
 		{
 			Printf("Unable to load %s: %s\n", mus_playing.name.GetChars(), ZMusic_GetLastError());
 		}
 	}
-	}
 
 	mus_playing.loop = looping;
 	mus_playing.name = musicname;
@@ -475,6 +424,7 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 	return false;
 }
 
+
 //==========================================================================
 //
 // S_RestartMusic

src/sound/music/s_music.h

@@ -7,6 +7,15 @@
 #include "name.h"
 #include <zmusic.h>
 
+class FileReader;
+
+struct MusicCallbacks
+{
+	FString(*LookupFileName)(const char* fn, int &order);
+	FileReader(*OpenMusic)(const char* fn);
+};
+void S_SetMusicCallbacks(MusicCallbacks* cb);
+
 void S_CreateStream();
 void S_PauseStream(bool pause);
 void S_StopStream();
@@ -22,6 +31,8 @@ void S_ResetMusic ();
 bool S_StartMusic (const char *music_name);
 
 // Start music using <music_name>, and set whether looping
+bool S_SetupMusic(const char* musicname, int order, bool looping, FileReader(*OpenMusic)(const char* filename));
+
 bool S_ChangeMusic (const char *music_name, int order=0, bool looping=true, bool force=false);
 
 void S_RestartMusic ();

src/sound/s_doomsound.cpp

@@ -97,6 +97,105 @@ public:
 	void PrintSoundList();
 };
 
+//==========================================================================
+//
+// LookupMusic
+//
+// resolves aliases and special names
+//
+//==========================================================================
+
+static FString LookupMusic(const char* musicname, int& order)
+{
+	if (strnicmp(musicname, ",CD,", 4) == 0)
+	{
+		static bool warned = false;
+		if (!warned)
+			Printf(TEXTCOLOR_RED "CD Audio no longer supported\n");
+		warned = true;
+		return "";
+	}
+
+	// allow specifying "*" as a placeholder to play the level's default music.
+	if (musicname != nullptr && !strcmp(musicname, "*"))
+	{
+		if (gamestate == GS_LEVEL || gamestate == GS_TITLELEVEL)
+		{
+			musicname = primaryLevel->Music.GetChars();
+			order = primaryLevel->musicorder;
+		}
+		else
+		{
+			musicname = nullptr;
+		}
+	}
+
+	if (musicname == nullptr || musicname[0] == 0)
+	{
+		// got nothing, return nothing.
+		return "";
+	}
+	if (*musicname == '/') musicname++;
+
+	FString DEH_Music;
+	if (musicname[0] == '$')
+	{
+		// handle dehacked replacement.
+		// Any music name defined this way needs to be prefixed with 'D_' because
+		// Doom.exe does not contain the prefix so these strings don't either.
+		const char* mus_string = GStrings[musicname + 1];
+		if (mus_string != nullptr)
+		{
+			DEH_Music << "D_" << mus_string;
+			musicname = DEH_Music;
+		}
+	}
+
+	FName* aliasp = MusicAliases.CheckKey(musicname);
+	if (aliasp != nullptr)
+	{
+		if (*aliasp == NAME_None)
+		{
+			order = -1;
+			return "";	// flagged to be ignored
+		}
+		musicname = aliasp->GetChars();
+	}
+	return musicname;
+}
+
+//==========================================================================
+//
+// OpenMusic
+//
+// opens a FileReader for the music - used as a callback to keep
+// implementation details out of the core player.
+//
+//==========================================================================
+
+static FileReader OpenMusic(const char* musicname)
+{
+	FileReader reader;
+	if (!FileExists(musicname))
+	{
+		int lumpnum;
+		if ((lumpnum = fileSystem.CheckNumForFullName(musicname, true, ns_music)) == -1)
+		{
+			Printf("Music \"%s\" not found\n", musicname);
+		}
+		else if (fileSystem.FileLength(lumpnum) != 0)
+		{
+			reader = fileSystem.ReopenFileReader(lumpnum);
+		}
+	}
+	else
+	{
+		// Load an external file.
+		reader.OpenFile(musicname);
+	}
+	return reader;
+}
+
 //==========================================================================
 //
 // S_Init
@@ -107,6 +206,10 @@ public:
 
 void S_Init()
 {
+	// Hook up the music player with the engine specific customizations.
+	static MusicCallbacks cb = { LookupMusic, OpenMusic };
+	S_SetMusicCallbacks(&cb);
+
 	// Must be up before I_InitSound.
 	if (!soundEngine)
 	{
@@ -1438,3 +1541,5 @@ ADD_STAT (sound)
 {
 	return GSnd->GatherStats ();
 }
+
+