add layer and param

1 files changed, 21 insertions, 0 deletions

diff --git a/io/init.lua b/io/init.lua
index 1288bd4..2fa38e6 100644
--- a/io/init.lua
+++ b/io/init.lua
@@ -5,3 +5,24 @@ function nerv.ParamFile:write_chunkdata(metadata, writer)
     end
     return self:_write_chunkdata(table.tostring(metadata), writer)
 end
+
+function nerv.ParamFile:write_param(param)
+    local id = param.id
+    local type = param.__typename
+    if id == nil then
+        nerv_error("id of param %s must be specified", type)
+    end
+    self:write_chunkdata({id = id,
+                            type = type,
+                            info = param:get_info()}, param)
+end
+
+function nerv.ParamFile:read_param(id)
+    local metadata = self.metadata[id]
+    if metadata == nil then
+        nerv_error("param with id %s does not exist", id)
+    end
+    local param = assert(loadstring("return " .. metadata.type .. "(" .. id .. ")"))()
+    param:set_info(metadata.info)
+    param:read(self:get_chunkdata(id))
+end