Fix 'simplify' static libpng

Author: AaronVanGeffen

CMakeLists.txt

@@ -106,10 +106,14 @@ if (ENABLE_LIBPNG)
     target_compile_definitions(sawyer PRIVATE CS_ENABLE_LIBPNG)
     find_package(PNG REQUIRED)
 
-    if (TARGET PNG::PNG)
-        target_link_libraries(sawyer PRIVATE PNG::PNG)
+    if (MSVC AND (${VCPKG_TARGET_TRIPLET} MATCHES "-static$"))
+        merge_static_libraries(sawyer ${PNG::PNG})
     else ()
-        target_link_libraries(sawyer PRIVATE png)
+        if (TARGET PNG::PNG)
+            target_link_libraries(sawyer PRIVATE PNG::PNG)
+        else ()
+            target_link_libraries(sawyer PRIVATE png)
+        endif ()
     endif ()
 endif ()