Give up on fetching libjpeg-turbo ourselves, rely on find_package and user providing it at build time

CMakeLists.txt

@@ -21,6 +21,15 @@ option(DUSK_BUILD_WARNINGS "If off, compiler warnings will be suppressed")
 option(DUSK_SELECTED_OPT "If on, selected parts of the project will be compiled with optimizations on Debug, intending to make the game run at 30 FPS. Note for MSVC: you will need to remove '/RTC1' from your debug flags in CMake.")
 option(DUSK_MOVIE_SUPPORT "If on, compile against libjpeg-turbo to enable THP file decoding" ON)
 
+find_package(libjpeg-turbo)
+set(DUSK_MOVIE_SUPPORT_REAL ${DUSK_MOVIE_SUPPORT})
+if (DUSK_MOVIE_SUPPORT AND NOT libjpeg-turbo_FOUND)
+    message(WARNING "libjpeg-turbo not found but DUSK_MOVIE_SUPPORT set, movie playback will not be available!")
+    set(DUSK_MOVIE_SUPPORT_REAL OFF)
+endif ()
+
+message(WARNING "FOUND: ${libjpeg-turbo_FOUND}")
+
 if (CMAKE_SYSTEM_NAME STREQUAL Linux)
     # -Wno-multichar: Multi-character constants ('ABCD') are implementation-defined but all compilers
     #   (CW, GCC, Clang, MSVC) encode them identically in big-endian order.
@@ -54,10 +63,6 @@ endif ()
 
 include(FetchContent)
 
-if (DUSK_MOVIE_SUPPORT)
-    include(ExternalProject)
-endif ()
-
 message(STATUS "dusk: Fetching cxxopts")
 FetchContent_Declare(
   cxxopts
@@ -67,9 +72,6 @@ FetchContent_Declare(
 
 FetchContent_MakeAvailable(cxxopts)
 
-if (DUSK_MOVIE_SUPPORT)
-    include(cmake/libjpeg.cmake)
-endif ()
 include(files.cmake)
 
 # TODO: version handling for res includes
@@ -116,8 +118,8 @@ add_library(game SHARED ${DOLZEL_FILES} ${Z2AUDIOLIB_FILES} ${SSYSTEM_FILES} ${J
         src/dusk/imgui/ImGuiAudio.cpp)
 
 target_link_libraries(game PRIVATE game_debug cxxopts::cxxopts)
-if (DUSK_MOVIE_SUPPORT)
-    target_link_libraries(game PRIVATE libjpeg-turbo-lib)
+if (DUSK_MOVIE_SUPPORT_REAL)
+    target_link_libraries(game PRIVATE libjpeg-turbo::turbojpeg-static)
     target_compile_definitions(game PRIVATE MOVIE_SUPPORT=1)
 endif ()
 target_compile_definitions(game PRIVATE TARGET_PC AVOID_UB=1 VERSION=0 NDEBUG=1 NDEBUG_DEFINED=1 DEBUG_DEFINED=0

cmake/libjpeg.cmake

@@ -1,12 +0,0 @@
-ExternalProject_Add(
-    libjpeg-turbo
-    URL https://github.com/libjpeg-turbo/libjpeg-turbo/archive/refs/tags/3.1.90.tar.gz
-    URL_HASH SHA256=076ef1431f2803a91f07e0f92433d4dcf39bc9113226c4f46ba3d3d54f514c9d
-    DOWNLOAD_EXTRACT_TIMESTAMP TRUE
-    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
-)
-
-ExternalProject_Get_Property(libjpeg-turbo INSTALL_DIR)
-add_library(libjpeg-turbo-lib STATIC IMPORTED GLOBAL)
-set_target_properties(libjpeg-turbo-lib PROPERTIES IMPORTED_LOCATION ${INSTALL_DIR}/lib/turbojpeg-static.lib)
-target_include_directories(libjpeg-turbo-lib INTERFACE ${INSTALL_DIR}/include)