Enable MuJoCo Studio build and packaging on macos.

Also:
- Packages MuJoCo Studio as MuJoCoStudio.app in the MuJoCo.dmg.
- Fixes a Filament compile issue.
- Patches libwebp to fix compile error related to universal builds and forces
  it to build as static.
- Removes the separate, obsolete "build_studio" step.
PiperOrigin-RevId: 934564785
Change-Id: I50c83283b5e138062e37d53926a5a77fdf99dbfa

cmake/libwebp-apple-float16.patch

@@ -0,0 +1,8 @@
+diff --git a/cmake/cpu.cmake b/cmake/cpu.cmake
+--- a/cmake/cpu.cmake
++++ b/cmake/cpu.cmake
+@@ -121,3 +121,3 @@
+     # Explicitly disable SIMD.
+-    if(SIMD_DISABLE_FLAGS)
++    if(SIMD_DISABLE_FLAGS AND NOT APPLE)
+       list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)

cmake/third_party_deps/filament.cmake

@@ -32,6 +32,11 @@ else()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -include cstring -include optional")
 endif()
 
+# Filament generates deprecated warnings on MacOS.
+if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=deprecated-declarations")
+endif()
+
 set(FILAMENT_ENABLE_EXPERIMENTAL_GCC_SUPPORT ON)
 set(FILAMENT_SKIP_SDL2 ON)
 set(FILAMENT_USE_EXTERNAL_ABSL ON)

cmake/third_party_deps/libwebp.cmake

@@ -20,9 +20,21 @@ mark_as_advanced(MUJOCO_DEP_VERSION_libwebp)
 
 include(FindOrFetch)
 
+set(LIBWEBP_PATCH_COMMAND
+  git apply --reject --whitespace=fix ${mujoco_SOURCE_DIR}/cmake/libwebp-apple-float16.patch
+)
+
+set(BUILD_SHARED_LIBS_OLD ${BUILD_SHARED_LIBS})
+set(BUILD_SHARED_LIBS OFF)
+
 fetchpackage(
     PACKAGE_NAME  libwebp
     GIT_REPO      https://github.com/webmproject/libwebp.git
     GIT_TAG       ${MUJOCO_DEP_VERSION_libwebp}
     TARGETS       webp
+    PATCH_COMMAND ${LIBWEBP_PATCH_COMMAND}
 )
+
+set(BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS_OLD})
+
+

python/mujoco/CMakeLists.txt

@@ -89,6 +89,7 @@ if(NOT TARGET mujoco)
           ${MUJOCO_FRAMEWORK}/mujoco.framework/Versions/A/libmujoco.3.10.0.dylib
       )
       target_compile_options(mujoco INTERFACE -F${MUJOCO_FRAMEWORK})
+      set(MUJOCO_INCLUDE "${MUJOCO_FRAMEWORK}/mujoco.framework/Versions/A/Headers")
     endif()
   endif()
 
@@ -132,8 +133,12 @@ endif()
 
 # =================== MUJOCO PLATFORM STATIC LIBRARY ==========================
 if(NOT TARGET mujoco::platform)
+  set(MUJOCO_PLATFORM_HINTS ${MUJOCO_LIBRARY_DIR})
+  if(MUJOCO_FRAMEWORK)
+    list(APPEND MUJOCO_PLATFORM_HINTS "${MUJOCO_FRAMEWORK}/mujoco.framework/Versions/A")
+  endif()
   find_library(
-    MUJOCO_PLATFORM_LIBRARY mujoco_platform HINTS ${MUJOCO_LIBRARY_DIR}
+    MUJOCO_PLATFORM_LIBRARY mujoco_platform HINTS ${MUJOCO_PLATFORM_HINTS}
   )
   if(MUJOCO_PLATFORM_LIBRARY)
     message(STATUS "Found mujoco_platform library at ${MUJOCO_PLATFORM_LIBRARY}")
@@ -141,8 +146,9 @@ if(NOT TARGET mujoco::platform)
     set_target_properties(mujoco_platform PROPERTIES IMPORTED_LOCATION "${MUJOCO_PLATFORM_LIBRARY}")
     add_library(mujoco::platform ALIAS mujoco_platform)
 
+    set(PLATFORM_INCLUDES "${MUJOCO_INCLUDE}" "${MUJOCO_INCLUDE}/mujoco" "${MUJOCO_INCLUDE}/SDL2")
     set_target_properties(mujoco_platform PROPERTIES
-      INTERFACE_INCLUDE_DIRECTORIES "${MUJOCO_INCLUDE};${MUJOCO_INCLUDE}/mujoco;${MUJOCO_INCLUDE}/SDL2"
+      INTERFACE_INCLUDE_DIRECTORIES "${PLATFORM_INCLUDES}"
     )
     target_compile_features(mujoco_platform INTERFACE cxx_std_20)
 
@@ -177,7 +183,7 @@ if(NOT TARGET mujoco::platform)
       zstd
       z
     )
-      find_library(DEP_PATH_${dep_lib} ${dep_lib} HINTS ${MUJOCO_LIBRARY_DIR})
+      find_library(DEP_PATH_${dep_lib} ${dep_lib} HINTS ${MUJOCO_PLATFORM_HINTS})
       if(DEP_PATH_${dep_lib})
         add_library(mujoco::dep::${dep_lib} STATIC IMPORTED GLOBAL)
         set_target_properties(mujoco::dep::${dep_lib} PROPERTIES
@@ -191,6 +197,22 @@ if(NOT TARGET mujoco::platform)
     if(UNIX AND NOT APPLE)
       list(APPEND PLATFORM_DEPS pthread dl rt)
     endif()
+    if(APPLE)
+      list(APPEND PLATFORM_DEPS
+        "-framework Cocoa"
+        "-framework IOKit"
+        "-framework Carbon"
+        "-framework ForceFeedback"
+        "-framework CoreVideo"
+        "-framework CoreAudio"
+        "-framework AudioToolbox"
+        "-framework Metal"
+        "-framework GameController"
+        "-framework CoreHaptics"
+        "-framework AVFoundation"
+        "-framework QuartzCore"
+      )
+    endif()
 
     set_target_properties(mujoco_platform PROPERTIES INTERFACE_LINK_LIBRARIES "${PLATFORM_DEPS}")
   endif()
@@ -494,6 +516,10 @@ target_link_libraries(
           structs_wrappers
 )
 
+if(APPLE)
+  set_target_properties(_structs PROPERTIES INTERPROCEDURAL_OPTIMIZATION FALSE)
+endif()
+
 if(NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/specs.cc.inc)
   add_custom_command(
     OUTPUT specs.cc.inc

python/mujoco/experimental/studio/CMakeLists.txt

@@ -83,3 +83,26 @@ if(UNIX AND NOT APPLE)
     target_link_options(${target} PRIVATE "-Wl,--allow-multiple-definition")
   endforeach()
 endif()
+
+if(APPLE)
+  set(STUDIO_PY_MODULES
+      parser
+      native_viewer_cc
+      renderer
+      ux
+      sim
+      dear_imgui
+      implot
+  )
+  foreach(target ${STUDIO_PY_MODULES})
+    if(TARGET ${target})
+      add_custom_command(
+        TARGET ${target}
+        POST_BUILD
+        COMMAND
+          install_name_tool -add_rpath @loader_path/../../ $<TARGET_FILE:${target}>
+      )
+    endif()
+  endforeach()
+endif()
+

src/experimental/studio/CMakeLists.txt

@@ -54,24 +54,31 @@ function(configure_studio_target TARGET_NAME)
             mujoco::platform
     )
 
-    file(MAKE_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets)
+    get_target_property(IS_BUNDLE ${TARGET_NAME} MACOSX_BUNDLE)
+    if(IS_BUNDLE)
+        set(STUDIO_ASSETS_DIR $<TARGET_FILE_DIR:${TARGET_NAME}>/../Resources/assets)
+    else()
+        set(STUDIO_ASSETS_DIR ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets)
+    endif()
 
     add_custom_command(
         TARGET ${TARGET_NAME}
         POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${STUDIO_ASSETS_DIR}
         COMMAND ${CMAKE_COMMAND}
             -E copy
                 ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/../_deps/opensans-src/fonts/ttf/OpenSans-Regular.ttf
-                ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets
+                ${STUDIO_ASSETS_DIR}
         COMMENT "Copying OpenSans-Regular.ttf assets to build directory"
     )
     add_custom_command(
         TARGET ${TARGET_NAME}
         POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${STUDIO_ASSETS_DIR}
         COMMAND ${CMAKE_COMMAND}
             -E copy
                 ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/../_deps/font_awesome-src/fonts/fontawesome-webfont.ttf
-                ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets
+                ${STUDIO_ASSETS_DIR}
         COMMENT "Copying fontawesome-webfont.ttf to build directory"
     )
 
@@ -80,10 +87,11 @@ function(configure_studio_target TARGET_NAME)
         add_custom_command(
             TARGET ${TARGET_NAME}
             POST_BUILD
+            COMMAND ${CMAKE_COMMAND} -E make_directory ${STUDIO_ASSETS_DIR}
             COMMAND ${CMAKE_COMMAND}
                 -E copy_directory
                     ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/../src/render/filament/assets
-                    ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets
+                    ${STUDIO_ASSETS_DIR}
             COMMENT "Copying Filament assets to build directory"
         )
     endif()
@@ -92,6 +100,13 @@ endfunction()
 # Desktop Studio target.
 if(NOT EMSCRIPTEN)
     add_executable(mujoco_studio)
+    if(APPLE AND MUJOCO_BUILD_MACOS_FRAMEWORKS)
+        set_target_properties(mujoco_studio PROPERTIES
+            MACOSX_BUNDLE TRUE
+            INSTALL_RPATH "@executable_path/../Frameworks;@executable_path/../../.."
+            BUILD_WITH_INSTALL_RPATH TRUE
+        )
+    endif()
     target_sources(mujoco_studio PRIVATE main.cc)
     configure_studio_target(mujoco_studio)
     install(
@@ -99,10 +114,13 @@ if(NOT EMSCRIPTEN)
       RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT studio
       BUNDLE DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT studio
     )
-    install(
+    get_target_property(IS_BUNDLE mujoco_studio MACOSX_BUNDLE)
-      DIRECTORY "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets"
+    if(NOT IS_BUNDLE)
-      DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT studio
+        install(
-    )
+          DIRECTORY "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets"
+          DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT studio
+        )
+    endif()
 endif()
 
 # WASM Live target.

src/experimental/studio/main.cc

@@ -42,6 +42,10 @@ std::string Resolve(std::string_view path) {
   if (exe_dir.empty()) {
     return std::string("assets/") + std::string(subpath);
   }
+  std::filesystem::path resources_dir = exe_dir.parent_path() / "Resources";
+  if (std::filesystem::exists(resources_dir / "assets")) {
+    return (resources_dir / "assets" / subpath).string();
+  }
   return (exe_dir / "assets" / subpath).string();
 }