SDL_mixer: cmake: remove support for vendoring libmodplug

From 5e668f99e011f668260890c5c68403d7af28232b Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Wed, 12 Oct 2022 03:33:09 +0200
Subject: [PATCH] cmake: remove support for vendoring libmodplug

---
 CMakeLists.txt | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f86ab9f6..7be3d807 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -555,22 +555,7 @@ if(SDL2MIXER_MOD_MODPLUG)
     target_compile_definitions(SDL2_mixer PRIVATE MUSIC_MOD_MODPLUG)
     if(SDL2MIXER_VENDORED)
         message(STATUS "Using vendored libmodplug")
-        sdl_check_project_in_subfolder(external/libmodplug libmodplug SDL2MIXER_VENDORED)
-        set(BUILD_SHARED_LIBS "${SDL2MIXER_MOD_MODPLUG_SHARED}")
-        enable_language(CXX)
-        add_subdirectory(external/libmodplug EXCLUDE_FROM_ALL)
-        target_include_directories(SDL2_mixer PRIVATE external/libmodplug/src)
-        if(NOT TARGET modplug::modplug)
-            add_library(modplug::modplug ALIAS modplug)
-            # <modplug.h> is not escaped properly for windres when using MinGW + "Unix Makefiles" ==> limit it to C sources
-            target_compile_definitions(SDL2_mixer PRIVATE $<$<COMPILE_LANGUAGE:C>:MODPLUG_HEADER=<modplug.h$<ANGLE-R>>)
-        endif()
-        if(SDL2MIXER_MOD_MODPLUG_SHARED OR NOT SDL2MIXER_BUILD_SHARED_LIBS)
-            list(APPEND INSTALL_EXTRA_TARGETS modplug)
-        endif()
-        if(NOT SDL2MIXER_MOD_MODPLUG_SHARED)
-            list(APPEND PC_LIBS -l$<TARGET_FILE_BASE_NAME:modplug>)
-        endif()
+        message(FATAL_ERROR "libmodplug is not vendored.")
     else()
         message(STATUS "Using system libmodplug")
         find_package(modplug REQUIRED)