From b623b861ee0532793537bdd256424dcca1f2b0b1 Mon Sep 17 00:00:00 2001
From: alemuntoni <alemuntoni@users.noreply.github.com>
Date: Thu, 12 Sep 2024 14:44:13 +0200
Subject: [PATCH] build io_3mf plugin only if lib3mf target is found

---
 src/meshlabplugins/io_3mf/CMakeLists.txt | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/meshlabplugins/io_3mf/CMakeLists.txt b/src/meshlabplugins/io_3mf/CMakeLists.txt
index 9b76f7323..eb6a2578f 100644
--- a/src/meshlabplugins/io_3mf/CMakeLists.txt
+++ b/src/meshlabplugins/io_3mf/CMakeLists.txt
@@ -21,14 +21,19 @@
 #                                                                           #
 #############################################################################
 
-set(HEADERS
-	io_3mf.h
-	)
+# Only build if we have lib3mf
+if(TARGET external-lib3mf)
+    set(HEADERS io_3mf.h)
 
-set(SOURCES
-	io_3mf.cpp
-	)
+    set(SOURCES io_3mf.cpp)
 
-add_meshlab_plugin(io_3mf ${SOURCES} ${HEADERS})
+    add_meshlab_plugin(io_3mf ${SOURCES} ${HEADERS})
 
-target_link_libraries(io_3mf PUBLIC external-lib3mf)
+    target_link_libraries(io_3mf PUBLIC external-lib3mf)
+
+else()
+    message(
+        STATUS
+        "Skipping io_3mf - missing lib3mf in external directory."
+    )
+endif()