From 3e5a7870c17c2c4a16574002f5e2dac45fbf6acc Mon Sep 17 00:00:00 2001
From: OPNA2608 <opna2608@protonmail.com>
Date: Sun, 15 Dec 2024 18:34:13 +0100
Subject: [PATCH] SDL_mixer: Fix mod support

mikmod flags are gathered via libmikmod-config, which isn't in PATH anymore due to strictDeps.

modplug, an alternative library for mod support, is found via pkg-config, and libopenmpt-modplug
is a compatibility library emulating modplug's API via the actively-maintained libopenmpt library.
---
 pkgs/by-name/sd/SDL_mixer/package.nix | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/pkgs/by-name/sd/SDL_mixer/package.nix b/pkgs/by-name/sd/SDL_mixer/package.nix
index d1c96b7c0e11..e42592d5bc58 100644
--- a/pkgs/by-name/sd/SDL_mixer/package.nix
+++ b/pkgs/by-name/sd/SDL_mixer/package.nix
@@ -4,7 +4,7 @@
   fetchpatch,
   fetchurl,
   fluidsynth,
-  libmikmod,
+  libopenmpt-modplug,
   libogg,
   libvorbis,
   pkg-config,
@@ -63,6 +63,12 @@ stdenv.mkDerivation (finalAttrs: {
     })
   ];
 
+  # Fix location of modplug header
+  postPatch = ''
+    substituteInPlace music_modplug.h \
+      --replace-fail '#include "modplug.h"' '#include <libmodplug/modplug.h>'
+  '';
+
   nativeBuildInputs = [
     SDL
     pkg-config
@@ -72,7 +78,7 @@ stdenv.mkDerivation (finalAttrs: {
   buildInputs = [
     SDL
     fluidsynth
-    libmikmod
+    libopenmpt-modplug
     libogg
     libvorbis
     smpeg
@@ -81,6 +87,7 @@ stdenv.mkDerivation (finalAttrs: {
   configureFlags = [
     (lib.enableFeature false "music-ogg-shared")
     (lib.enableFeature false "music-mod-shared")
+    (lib.enableFeature true "music-mod-modplug")
     (lib.enableFeature enableNativeMidi "music-native-midi-gpl")
     (lib.enableFeature enableSdltest "sdltest")
     (lib.enableFeature enableSmpegtest "smpegtest")