fix for empty sounds/animation collections

cmake/copy_resources.cmake

@@ -5,14 +5,14 @@ endif()
 set(CHARACTERS_DIR "${SRC_DIR}/characters")
 set(CHARACTERS_ZIP_SCRIPT "${CHARACTERS_DIR}/zip")
 
-if(EXISTS "${CHARACTERS_ZIP_SCRIPT}")
+if(EXISTS "${CHARACTERS_ZIP_SCRIPT}" AND NOT WIN32)
     execute_process(
             COMMAND "${CHARACTERS_ZIP_SCRIPT}"
             WORKING_DIRECTORY "${CHARACTERS_DIR}"
             RESULT_VARIABLE ZIP_SCRIPT_RESULT
     )
     if(NOT ZIP_SCRIPT_RESULT EQUAL 0)
-        message(FATAL_ERROR "Failed running ${CHARACTERS_ZIP_SCRIPT} (exit code ${ZIP_SCRIPT_RESULT})")
+        message(WARNING "Failed running ${CHARACTERS_ZIP_SCRIPT} (exit code ${ZIP_SCRIPT_RESULT}); continuing with existing archives")
     endif()
 endif()
 
@@ -26,6 +26,25 @@ file(COPY "${SRC_DIR}/" DESTINATION "${DST_DIR}"
 # Copy only .zip archives from resources/characters.
 file(MAKE_DIRECTORY "${DST_DIR}/characters")
 file(GLOB CHARACTER_ZIPS "${CHARACTERS_DIR}/*.zip")
+
+if(NOT CHARACTER_ZIPS)
+    file(GLOB CHARACTER_FILES RELATIVE "${CHARACTERS_DIR}" "${CHARACTERS_DIR}/*")
+    list(FILTER CHARACTER_FILES EXCLUDE REGEX "^zip$")
+    list(FILTER CHARACTER_FILES EXCLUDE REGEX ".*\\.zip$")
+
+    if(CHARACTER_FILES)
+        execute_process(
+                COMMAND "${CMAKE_COMMAND}" -E tar cf "snivy.zip" --format=zip ${CHARACTER_FILES}
+                WORKING_DIRECTORY "${CHARACTERS_DIR}"
+                RESULT_VARIABLE ZIP_GENERATE_RESULT
+        )
+        if(NOT ZIP_GENERATE_RESULT EQUAL 0)
+            message(FATAL_ERROR "Failed generating ${CHARACTERS_DIR}/snivy.zip (exit code ${ZIP_GENERATE_RESULT})")
+        endif()
+        file(GLOB CHARACTER_ZIPS "${CHARACTERS_DIR}/*.zip")
+    endif()
+endif()
+
 if(CHARACTER_ZIPS)
     file(COPY ${CHARACTER_ZIPS} DESTINATION "${DST_DIR}/characters")
 endif()