Map save/reload stream lua function problem

[Dexter]

Hi,

I'm trying to get lua examples for Map's Save and Reload functions working. If you try the example from https://www.ultraengine.com/learn/Map_Save?lang=lua , sol complains about args (with a StreamBuffer at least). It's not clear to me what to feed it for in-memory stuff.

I assume it's outdated because it's trying to call this

scene:Save(stream, "game.sav")

 

But save and reload do not take a string whatsoever as a second arg in lua docs. I assume changing the examples to do something like this is the way?

 

local buffer = CreateBuffer(1024)
local stream = CreateBufferStream(buffer)

-- Create a scene
local scene = CreateMap()

-- .... 

-- Save the starting scene to an in memory buffer
scene:Save(stream)

This appears to work, but it's unclear to me how to do the next two things:

1. seek to beginning of stream: I tried this `stream = CreateStreamBuffer(stream)`. an API to seek to beginning of oft-reused buffers for cute tricks would be nice though

2. Actually reload a map from memory? `Map:Reload(Stream)` complains about args as well when trying a stream arg, it appears only the unary string function exists.

I understand I can work around it with disk like so, maybe the old API was shorthand for this. But I'd like to avoid all disk I/O for reasons

scene:Save('foo.sav')

-- Main loop
while not window:Closed() and not window:KeyDown(KEY_ESCAPE) do
    -- Reload the starting scene when space key is pressed
    if window:KeyHit(KEY_SPACE) then
        scene:Reload('foo.sav')
    end
    world:Update()
    world:Render(framebuffer)
end

 

If something like "`scene:Reload(stream, LOAD_DEFAULT)`" worked again that would be the money. Appreciate any input

[Josh]

I do not know why the example in the documentation is wrong. I fixed it, thank you for pointing that out:
https://github.com/UltraEngine/Documentation/blob/master/Lua/Map_Save.md

It will take a few hours to re-cache in the docs system, but the link there will take you straight to the source content.

[Dexter]

Is there currently a way to do it in memory only?

[Josh]

Yeah, it should work if you use CreateBufferStream to create a stream. This command does not require a buffer as an argument, and it is better not to provide one.

Then, before saving or loading call stream:Seek(0) to make sure the file position is at the beginning of the file.