From 67ea4d0c2ef566a615600c77ed32dcd621319261 Mon Sep 17 00:00:00 2001
From: Mathieu Schroeter <mathieu@schroetersa.ch>
Date: Mon, 11 Dec 2017 18:42:49 +0100
Subject: [PATCH] Look music for user dir, fallback to the game dir

Then it's possible to overload the original musicis by providing yours in
the user directory (in music subdir).
---
 src/event.cxx | 28 ++++++++++++++++++++--------
 src/misc.cxx  | 24 ++++++++++++++++++++----
 src/misc.h    |  6 +++++-
 src/sound.cxx |  9 ++++-----
 4 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/src/event.cxx b/src/event.cxx
index 22ff6f4..315a1ab 100644
--- a/src/event.cxx
+++ b/src/event.cxx
@@ -3362,18 +3362,29 @@ CEvent::ChangePhase (Uint32 phase)
       music = m_pDecor->GetMusic ();
       if (music > 0)
       {
-        const std::string exts[] = {"ogg", "mid"};
+        static const std::string exts[] = {"ogg", "mid"};
+        static const Location    locs[] = {LOCATION_USER, LOCATION_BASE};
+        std::string              absolute;
 
-        filename = string_format (
-          "music/music%.3d.%s", music - 1,
-          exts[g_restoreMidi ? 1 : 0].c_str ());
-        if (!FileExists (filename))
+        // Look for music in the user directory, then in the game directory.
+        for (size_t i = 0; i < countof (locs); ++i)
+        {
           filename = string_format (
             "music/music%.3d.%s", music - 1,
-            exts[g_restoreMidi ? 0 : 1].c_str ());
+            exts[g_restoreMidi ? 1 : 0].c_str ());
+          if (!FileExists (filename, absolute, locs[i]))
+            filename = string_format (
+              "music/music%.3d.%s", music - 1,
+              exts[g_restoreMidi ? 0 : 1].c_str ());
+
+          if (FileExists (filename, absolute, locs[i]))
+            break;
+
+          absolute = "";
+        }
 
         m_pSound->StopMusic ();
-        m_pSound->PlayMusic (filename);
+        m_pSound->PlayMusic (absolute);
       }
     }
   }
@@ -4403,7 +4414,8 @@ CEvent::StartMovie (const std::string & pFilename)
   if (!m_bMovie)
     return false;
 
-  if (!FileExists (pFilename))
+  std::string absolute;
+  if (!FileExists (pFilename, absolute))
     return false;
 
   HideMouse (true);
diff --git a/src/misc.cxx b/src/misc.cxx
index de244e9..3884ec7 100644
--- a/src/misc.cxx
+++ b/src/misc.cxx
@@ -157,12 +157,28 @@ AddUserPath (std::string & pFilename)
 }
 
 bool
-FileExists (const std::string & filename)
+FileExists (
+  const std::string & filename, std::string & absolute, enum Location location)
 {
-  const auto path = GetBaseDir () + filename;
-  FILE *     file;
+  absolute = filename;
+  FILE * file;
 
-  file = fopen (path.c_str (), "rb");
+  switch (location)
+  {
+  case LOCATION_BASE:
+    absolute = GetBaseDir () + filename;
+    break;
+
+  case LOCATION_USER:
+    AddUserPath (absolute);
+    break;
+
+  default:
+  case LOCATION_ABSOLUTE:
+    break;
+  }
+
+  file = fopen (absolute.c_str (), "rb");
   if (file == nullptr)
     return false;
 
diff --git a/src/misc.h b/src/misc.h
index db50f86..d1a5c98 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -37,7 +37,11 @@ std::string GetBaseDir ();
 std::string GetShareDir ();
 std::string GetLocale ();
 extern void AddUserPath (std::string & pFilename);
-bool        FileExists (const std::string & filename);
+
+enum Location { LOCATION_ABSOLUTE, LOCATION_BASE, LOCATION_USER };
+bool FileExists (
+  const std::string & filename, std::string & absolute,
+  Location location = LOCATION_BASE);
 
 template <typename... Args>
 std::string
diff --git a/src/sound.cxx b/src/sound.cxx
index 6e0790b..2969914 100644
--- a/src/sound.cxx
+++ b/src/sound.cxx
@@ -326,20 +326,19 @@ CSound::PlayImage (Sounds channel, Point pos, Sint32 rank)
 bool
 CSound::PlayMusic (const std::string & lpszMIDIFilename)
 {
-  std::string path = GetBaseDir ();
-
   if (m_midiVolume == 0)
     return true;
 
+  if (lpszMIDIFilename.empty ())
+    return false;
+
   Mix_VolumeMusic (MIX_MAX_VOLUME * 100 * m_midiVolume / 20 / 100);
   m_lastMidiVolume = m_midiVolume;
 
-  path += lpszMIDIFilename;
-
   if (m_pMusic)
     Mix_FreeMusic (m_pMusic);
 
-  m_pMusic = Mix_LoadMUS (path.c_str ());
+  m_pMusic = Mix_LoadMUS (lpszMIDIFilename.c_str ());
   if (!m_pMusic)
   {
     printf ("%s\n", Mix_GetError ());