Somewhat finalized AddDatafile and AddDownloadableResource

Ready-to-distribute datafiles can now be produced by the build chain. This
is already done for shatter.dat, content.dat, and start.dat

1 files changed, 36 insertions, 1 deletions

diff --git a/cmake/modules/AddDownloadableResource.cmake b/cmake/modules/AddDownloadableResource.cmake
index bbef5b7..d0374ad 100644
--- a/cmake/modules/AddDownloadableResource.cmake
+++ b/cmake/modules/AddDownloadableResource.cmake
@@ -1,4 +1,35 @@
-# TODO: Document this and how it interacts with AddDatafile.
+# Adds a target that downloads an archive containing binary files that should be part of game distribution but are not
+# part of the version control system. For example:
+#
+#     add_downloadable_resource(
+#         resource_shatter
+#         ARCHIVE shatter.tar.xz
+#         DIRECTORY shatter.d
+#         BASE_URL https://ftp.ignore.pl/starshatter/resource/latest
+#         SHA1 bbed14649213a45499e0a158142f19fd619a54af
+#     )
+#
+# Will download 'shatter.tar.xz' from 'https://ftp.ignore.pl/starshatter/resouce/latest' and unpack it into 'shatter.d'
+# subdirectory under respective binary directory. The archive will be validated for correctness with SHA1.
+#
+# Selected options provide default arguments:
+#  * ARCHIVE defaults to '<target_name>.tar.xz'
+#  * DIRECTORY defaults to '<target_name>.d'
+#  * BASE_URL defaults to 'https://ftp.ignore.pl/starshatter/resource/latest'
+#
+# Targets are designed to be used with AddDatafile targets via their RESOURCES option:
+#
+#     add_downloadable_resource(resource_shatter ...)
+#     add_datafile(
+#         shatter
+#         RESOURCES resource_shatter
+#     )
+#
+# This will automatically make the datafile generated by 'shatter' target to include files downloaded by
+# 'resource_shatter'.
+#
+# Downloaded archives are not cleaned by default to avoid unnecessarily long build times. Instead they need to be
+# cleaned explicitly either by removing them manually or by running 'clean_downloaded_<target_name>' target.
 
 set(ADD_DOWNLOADABLE_RESOURCE_SCRIPT ${CMAKE_CURRENT_LIST_DIR}/download_resource.cmake.in)
 function(add_downloadable_resource)
@@ -46,4 +77,8 @@ function(add_downloadable_resource)
 			${CMAKE_COMMAND} -E tar xf ${RESOURCE_ARCHIVE}
 		)
 	add_custom_target(${RESOURCE_TARGET} DEPENDS ${RESOURCE_DIRECTORY})
+	set_property(
+		TARGET ${RESOURCE_TARGET}
+		PROPERTY RESOURCE_DIRECTORY ${RESOURCE_DIRECTORY}
+		)
 endfunction()