Add imgui stdlib target.

PiperOrigin-RevId: 875686702
Change-Id: Ie8ba8349c70da3313a1896b14a30d076f2068368

cmake/third_party_deps/dear_imgui/CMakeLists.txt

@@ -59,3 +59,15 @@ target_sources(dear_imgui_OpenGL3
     ${dear_imgui_SOURCE_DIR}/backends/imgui_impl_opengl3.h
     ${dear_imgui_SOURCE_DIR}/backends/imgui_impl_opengl3.cpp
 )
+
+# stdlib
+add_library(dear_imgui_stdlib STATIC)
+target_include_directories(dear_imgui_stdlib
+  PUBLIC
+    ${dear_imgui_SOURCE_DIR}
+)
+target_sources(dear_imgui_stdlib
+  PUBLIC
+    ${dear_imgui_SOURCE_DIR}/misc/cpp/imgui_stdlib.h
+    ${dear_imgui_SOURCE_DIR}/misc/cpp/imgui_stdlib.cpp
+)

src/experimental/platform/CMakeLists.txt

@@ -112,6 +112,7 @@ include(third_party_deps/libwebp)
 target_link_libraries(${MUJOCO_PLATFORM_TARGET_NAME}
     dear_imgui
     dear_imgui_SDL2
+    dear_imgui_stdlib
     implot
     webp
     SDL2::SDL2-static

src/experimental/platform/imgui_widgets.h

@@ -26,7 +26,7 @@
 
 #include <imgui.h>
 #include <imgui_internal.h>
-#include "third_party/dear_imgui/misc/cpp/imgui_stdlib.h"
+#include <misc/cpp/imgui_stdlib.h>
 #include <mujoco/mujoco.h>
 #include "experimental/platform/enum_utils.h"