CMake: Support header-only NanoSVG library

Check if the NanoSVG target defines any library locations.
Add a private compile definition to wxcore, instead of adding another setup.h option.

build/cmake/lib/core/CMakeLists.txt

@@ -66,6 +66,9 @@ foreach(lib JPEG PNG TIFF NANOSVG)
         wx_lib_include_directories(wxcore ${${lib}_INCLUDE_DIR})
     endif()
 endforeach()
+if(wxUSE_NANOSVG STREQUAL "sys" AND wxUSE_NANOSVG_EXTERNAL_ENABLE_IMPL)
+    wx_lib_compile_definitions(wxcore wxUSE_NANOSVG_EXTERNAL_ENABLE_IMPL)
+endif()
 
 if(WIN32)
     wx_lib_link_libraries(wxcore PRIVATE winmm)

build/cmake/lib/nanosvg.cmake

@@ -17,4 +17,12 @@ elseif(wxUSE_NANOSVG)
     set(NANOSVG_LIBRARIES NanoSVG::nanosvgrast)
     get_target_property(svg_incl_dir NanoSVG::nanosvg INTERFACE_INCLUDE_DIRECTORIES)
     set(NANOSVG_INCLUDE_DIRS ${svg_incl_dir})
+
+    get_target_property(svg_lib_d NanoSVG::nanosvgrast IMPORTED_LOCATION_DEBUG)
+    get_target_property(svg_lib_r NanoSVG::nanosvgrast IMPORTED_LOCATION_RELEASE)
+    get_target_property(svg_lib   NanoSVG::nanosvgrast IMPORTED_LOCATION)
+    set(wxUSE_NANOSVG_EXTERNAL_ENABLE_IMPL TRUE)
+    if(svg_lib_d OR svg_lib_r OR svg_lib)
+        set(wxUSE_NANOSVG_EXTERNAL_ENABLE_IMPL FALSE)
+    endif()
 endif()

src/generic/bmpsvg.cpp

@@ -57,13 +57,16 @@
     #endif
 #endif
 
+#if !wxUSE_NANOSVG_EXTERNAL || defined(wxUSE_NANOSVG_EXTERNAL_ENABLE_IMPL)
+    #define NANOSVG_IMPLEMENTATION
+    #define NANOSVGRAST_IMPLEMENTATION
+    #define NANOSVG_ALL_COLOR_KEYWORDS
+#endif
+
 #if wxUSE_NANOSVG_EXTERNAL
     #include <nanosvg.h>
     #include <nanosvgrast.h>
 #else
-    #define NANOSVG_IMPLEMENTATION
-    #define NANOSVGRAST_IMPLEMENTATION
-    #define NANOSVG_ALL_COLOR_KEYWORDS
     #include "../../3rdparty/nanosvg/src/nanosvg.h"
     #include "../../3rdparty/nanosvg/src/nanosvgrast.h"
 #endif