orbitersim · TheGondos · Oct 3, 2025 · Oct 4, 2025 · Oct 4, 2025
diff --git a/.gitignore b/.gitignore
@@ -24,8 +24,6 @@ Sound/XRSound/**/Release-with-OrbiterRelease/
 .kdev/
 [Bb]uild/
 
-Extern/irrKlang
-
 Doc/**/*.log
 Doc/**/*.pdf
 Doc/**/*.gz
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -211,10 +211,6 @@ option(ORBITER_SANITIZER
 	OFF
 )
 
-if(ORBITER_BUILD_XRSOUND)
-	set(IRRKLANG_DIR "" CACHE PATH "Path to the irrKlang library")
-endif()
-
 if(ORBITER_BUILD_D3D9CLIENT)
 	find_package(DXSDK REQUIRED)
 	set(DXSDK_DIR

diff --git a/Doc/Orbiter User Manual/CREDITS.tex b/Doc/Orbiter User Manual/CREDITS.tex
@@ -22,9 +22,10 @@ \subsection{Source contributions and components}
 Steve Arch: TransX development \url{http://orbiter.quorg.org}
 
 \subsection{Libraries, code, data, algorithms}
-\textbf{IrrKlang}\\
+\textbf{SDL3 and SDL3_mixer}\\
 Audio and sound library\\
-\url{https://www.ambiera.com/irrklang/}\\
+\url{https://github.com/libsdl-org/SDL/}\\
+\url{https://github.com/libsdl-org/SDL_mixer/}\\
 \\
 \textbf{Zlib}\\
 Compression/decompression library\\

diff --git a/Extern/CMakeLists.txt b/Extern/CMakeLists.txt
@@ -6,6 +6,7 @@ endif(NOT DEFINED ORBITER_BINARY_ROOT_DIR)
 
 add_subdirectory(Lua)
 add_subdirectory(zlib)
+add_subdirectory(SDL3)
 
 ## LFS
 add_library(lfs SHARED luafilesystem/src/lfs.c)

diff --git a/Extern/SDL3/CMakeLists.txt b/Extern/SDL3/CMakeLists.txt
@@ -0,0 +1,52 @@
+project(SDL3)
+
+Include(FetchContent)
+
+set(SDL_SHARED ON)
+set(SDL_STATIC OFF)
+#set(SDL_INSTALL ON)
+
+
+FetchContent_Declare(
+        SDL3
+        GIT_REPOSITORY https://github.com/libsdl-org/SDL.git
+#        GIT_TAG release-3.2.24
+		GIT_TAG 8824eace93de228032639f11df262df91a6257a4
+		OVERRIDE_FIND_PACKAGE
+)
+FetchContent_MakeAvailable(SDL3)
+
+set_target_properties(SDL3-shared PROPERTIES
+        ARCHIVE_OUTPUT_DIRECTORY ${ORBITER_BINARY_ROOT_DIR}
+        LIBRARY_OUTPUT_DIRECTORY ${ORBITER_BINARY_ROOT_DIR}
+        RUNTIME_OUTPUT_DIRECTORY ${ORBITER_BINARY_ROOT_DIR}
+)
+
+set_target_properties(SDL3_Headers PROPERTIES
+        ARCHIVE_OUTPUT_DIRECTORY "${ORBITER_INSTALL_SDK_DIR}/include"
+        LIBRARY_OUTPUT_DIRECTORY "${ORBITER_INSTALL_SDK_DIR}/include"
+        RUNTIME_OUTPUT_DIRECTORY "${ORBITER_INSTALL_SDK_DIR}/include"
+)
+
+file(GLOB SDL3_HEADERS "${SDL3_SOURCE_DIR}/include/SDL3/*.h" "${SDL3_BINARY_DIR}/include-revision/SDL3/*.h")
+file(COPY ${SDL3_HEADERS} DESTINATION "${ORBITER_BINARY_SDK_DIR}/include/SDL3")
+
+install(TARGETS SDL3_Headers RUNTIME DESTINATION "${ORBITER_INSTALL_SDK_DIR}/include")
+install(TARGETS SDL3-shared RUNTIME DESTINATION ${ORBITER_INSTALL_ROOT_DIR})
+
+###############
+## SDL_mixer ##
+###############
+
+set(BUILD_SHARED_LIBS ON)
+
+FetchContent_Declare(
+        SDL3_mixer
+        GIT_REPOSITORY https://github.com/libsdl-org/SDL_mixer.git
+        GIT_TAG 5cdf029bae982df1d6c210f915fc151a616d982f
+)
+FetchContent_MakeAvailable(SDL3_mixer)
+
+install(TARGETS SDL3_mixer-shared RUNTIME DESTINATION ${ORBITER_INSTALL_ROOT_DIR})
+file(GLOB SDL3_MIXER_HEADERS "${SDL3_mixer_SOURCE_DIR}/include/SDL3_mixer/*.h")
+file(COPY ${SDL3_MIXER_HEADERS} DESTINATION "${ORBITER_BINARY_SDK_DIR}/include/SDL3_Mixer")
diff --git a/Sound/XRSound/CMakeLists.txt b/Sound/XRSound/CMakeLists.txt
@@ -1,49 +1,7 @@
-## irrKlang
-if(NOT IRRKLANG_DIR)
-	set(IRRKLANG_DIR ${EXTERN_DIR}/irrKlang/${ARCH})
-
-	if(NOT EXISTS ${IRRKLANG_DIR})
-		if(BUILD64)
-			set(IRRKLANG_URL https://www.ambiera.at/downloads/irrKlang-64bit-1.6.0.zip)
-		else()
-			set(IRRKLANG_URL https://www.ambiera.at/downloads/irrKlang-32bit-1.6.0.zip)
-		endif()
-
-		include(FetchContent)
-		FetchContent_Declare(irrKlang
-			URL ${IRRKLANG_URL}
-			SOURCE_DIR ${IRRKLANG_DIR}
-			DOWNLOAD_EXTRACT_TIMESTAMP ON
-		)
-
-		message("Downloading irrKlang from ${IRRKLANG_URL} ...")
-		FetchContent_MakeAvailable(irrKlang)
-
-	else()
-		message("Found existing irrKlang at ${IRRKLANG_DIR}")
-	endif()
-
-elseif(NOT EXISTS ${IRRKLANG_DIR})
-	message(FATAL_ERROR "IRRKLANG_DIR does not exist")
-endif()
-
-if(BUILD64)
-	set(IRRKLANG_BIN_DIR ${IRRKLANG_DIR}/bin/winx64-visualStudio)
-	set(IRRKLANG_LIB_DIR ${IRRKLANG_DIR}/lib/Winx64-visualStudio)
-else()
-	# because of a bug in the 32bit version of irrKlang (it has hidden "__MACOSX" dir),
-	# CMake does not strip the top-level directory
-	string(APPEND IRRKLANG_DIR /irrKlang-1.6.0)
-
-	set(IRRKLANG_BIN_DIR ${IRRKLANG_DIR}/bin/win32-visualStudio)
-	set(IRRKLANG_LIB_DIR ${IRRKLANG_DIR}/lib/Win32-visualStudio)
-endif()
-set(IRRKLANG_LIB ${IRRKLANG_LIB_DIR}/irrKlang.lib)
-
 ## XRSound
 set(ASSET_DIR ${CMAKE_CURRENT_SOURCE_DIR}/assets)
 set(SOLUTION_DIR ${CMAKE_CURRENT_SOURCE_DIR}/src)
-set(IRRKLANG_DLL_DIR ${IRRKLANG_DIR})
+
 # Deploy assets
 file(GLOB config_files ${ASSET_DIR}/XRSound/*.cfg)
 
@@ -55,9 +13,6 @@ add_custom_target(XRSound_assets ALL
 	COMMAND ${CMAKE_COMMAND} -E copy ${ASSET_DIR}/XRSound/ReadMe.txt ${ORBITER_BINARY_ROOT_DIR}/XRSound/
 	COMMAND ${CMAKE_COMMAND} -E copy "${ASSET_DIR}/Doc/XRSound User Manual.pdf" ${ORBITER_BINARY_ROOT_DIR}/Doc/
 	COMMAND ${CMAKE_COMMAND} -E copy ${SOLUTION_DIR}/XRSound.h ${ORBITER_BINARY_SDK_DIR}/XRSound/
-	COMMAND ${CMAKE_COMMAND} -E copy ${IRRKLANG_BIN_DIR}/ikpMP3.dll ${ORBITER_BINARY_ROOT_DIR}
-	COMMAND ${CMAKE_COMMAND} -E copy ${IRRKLANG_BIN_DIR}/ikpFlac.dll ${ORBITER_BINARY_ROOT_DIR}
-	COMMAND ${CMAKE_COMMAND} -E copy ${IRRKLANG_BIN_DIR}/irrKlang.dll ${ORBITER_BINARY_ROOT_DIR}
 	COMMAND ${CMAKE_COMMAND} -E copy_directory ${ASSET_DIR}/XRSound/Default ${ORBITER_BINARY_ROOT_DIR}/XRSound/Default
 )
 
@@ -73,8 +28,5 @@ install(DIRECTORY ${ORBITER_BINARY_ROOT_DIR}/XRSound/Default
 install(FILES "${ORBITER_BINARY_ROOT_DIR}/Doc/XRSound User Manual.pdf"
 	DESTINATION ${ORBITER_INSTALL_DOC_DIR}/
 )
-install(FILES ${ORBITER_BINARY_ROOT_DIR}/ikpMP3.dll ${ORBITER_BINARY_ROOT_DIR}/ikpFlac.dll ${ORBITER_BINARY_ROOT_DIR}/irrKlang.dll
-	DESTINATION ${ORBITER_INSTALL_ROOT_DIR}/
-)
 
 add_subdirectory(src)
diff --git a/Sound/XRSound/LICENSE b/Sound/XRSound/LICENSE
@@ -19,36 +19,3 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-
-=============================================================================
-
-DEPENDENCIES:
-
-1) XRSound uses the irrKlang Sound Engine. 
-See https://www.ambiera.com/irrklang/license.html for details
-about the ikkLang license. Its license as of 31-July-2021 is quoted below:
-
-The irrKlang License
-irrKlang's source codes, documentation and binaries contained within the 
-distributed archive are copyright © Nikolaus Gebhardt / Ambiera 2001-2020.
-
-The contents of the irrKlang distribution archive may not be redistributed,
-reproduced, modified, transmitted, broadcast, published or adapted in any way,
-shape or form, without the prior written consent of the owner, Nikolaus 
-Gebhardt.
-
-The irrKlang.dll, irrKlang.so and libirrklang.dylib files may be 
-redistributed without the author's prior permission in non-commercial
-products, and must remain unmodified except for compressing the file.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS''
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGE.
diff --git a/Sound/XRSound/assets/XRSound/XRSound.cfg b/Sound/XRSound/assets/XRSound/XRSound.cfg
@@ -21,23 +21,15 @@
 #--------------------------------------------------------------------------
 # Space-separated list of sound file extensions supported by XRSound.
 #
-# XRSound uses irrKlang Pro, which supports these sound file formats by default:
+# XRSound uses SDL3_mixer, which supports these sound file formats by default:
 #
 #   RIFF WAVE (*.wav)
 #   Ogg Vorbis (*.ogg)
-#   MPEG-1 Audio Layer 3 (*.mp3)		[via ikpMP3.dll plugin, included]
-#   Free Lossless Audio Codec (*.flac)  [via ikpFlac.dll plugin, included]
-#   Amiga Modules (*.mod)
-#   Impulse Tracker (*.it)
-#   Scream Tracker 3 (*.s3d)
-#   Fast Tracker 2 (*.xm)
+#   MPEG-1 Audio Layer 3 (*.mp3)
 #
-# Additional formats may be supported via plugins; visit 
-# https://www.ambiera.com/irrklang/ for more information.
-#
-# Default = .wav .ogg  .mp3 .flac .mod .it .s3d .xm
+# Default = .wav .ogg .mp3
 #--------------------------------------------------------------------------
-SupportedSoundFileTypes = .wav .ogg .mp3 .flac .mod .it .s3d .xm
+SupportedSoundFileTypes = .wav .ogg .mp3
 
 #--------------------------------------------------------------------------
 # Sets the master volume for all sounds.

diff --git a/Sound/XRSound/src/CMakeLists.txt b/Sound/XRSound/src/CMakeLists.txt
@@ -11,6 +11,7 @@ add_library(XRSound_dll SHARED
 	Resource.rc
 	Utils/ConfigFileParser.cpp
 	Utils/FileList.cpp
+	ISound.cpp
 )
 
 set_target_properties(XRSound_dll PROPERTIES
@@ -22,18 +23,20 @@ set_target_properties(XRSound_dll PROPERTIES
 target_include_directories(XRSound_dll PUBLIC
 	${ORBITER_SOURCE_SDK_INCLUDE_DIR}
 	${CMAKE_CURRENT_SOURCE_DIR}/Utils
-	${IRRKLANG_DIR}/include
 )
 
 target_link_libraries(XRSound_dll
 	${ORBITER_LIB}
 	${ORBITER_SDK_LIB}
-	${IRRKLANG_LIB}
+	SDL3::SDL3-shared
+	SDL3_mixer::SDL3_mixer-shared
 )
 
 add_dependencies(XRSound_dll
 	${OrbiterTgt}
 	Orbitersdk
+	SDL3::SDL3-shared
+	SDL3_mixer::SDL3_mixer-shared
 )
 
 install(TARGETS XRSound_dll

diff --git a/Sound/XRSound/src/DefaultSoundGroupPreSteps.cpp b/Sound/XRSound/src/DefaultSoundGroupPreSteps.cpp
@@ -606,7 +606,7 @@ void MusicDefaultSoundGroupPreStep::clbkPreStep(const double simt, const double
     if (!HasFocus())
         return;
 
-    // To prevent intermittent music stuttering on Orbiter startup when Orbiter hangs for a full second, which starves the irrKLang engine, 
+    // To prevent intermittent music stuttering on Orbiter startup, 
     // don't play any music until two seconds after simulation start.
     if (simt < 2.0)
     {