Content

These are blobs that contain arbitrary binary data like images, audio, models, voxels, etc. They are always referenced by resources via a field with the keen::ContentHash type. Content assets are not parsed by EML, but instead provided as raw binary data as a Buffer object. There are also some helper modules like the image module to work with specific content types.

Accessing Content

To access content assets, you first need a keen::ContentHash value that references the content asset you want to access. You can find these values in resource data structures. But you can also just use the guid of a content asset if you know it.

Now, to actually get the content asset, you can use the game.assets.get_content function like this:

local content_hash = some_resource.data.textureHash  -- Assume this is a keen::ContentHash value
local content_asset = game.assets.get_content(content_hash)

print("Guid: " .. content_asset.guid)
print("Size: " .. content_asset.size)
print("Data: " .. tostring(content_asset:read_data()))

This function returns a Content object that contains some metadata about the content asset (like its guid and size) and a method to read the actual binary data as a read-only Buffer object.

Note: The Content object can be assigned everywhere where a Guid or keen::ContentHash is expected, so you can pass it directly to functions and fields that expect these types without having to extract the guid manually.

Content Object

A content object contains some metadata about the content asset such as its guid and size but also a method to read the actual binary data. Calling the read_data method will return a read-only Buffer object that contains the binary data of the content asset.

In comparison to resources, content assets are immutable since content hashes are unique, so the data for a given content hash is always the same and never changes. Because of that, you will have to instead create new content assets and update the old references.

Creating Content

To create new content assets, you can use the game.assets.create_content function. This function takes a Buffer object containing the binary data of the content asset and returns a new Content object that can be assigned to resource fields.

local buf = ... -- Assume this is a Buffer object containing the binary data of the content asset
local content_asset = game.assets.create_content(buf)

print("Guid: " .. content_asset.guid)
print("Size: " .. content_asset.size)

Binary Format

Every content asset is stored differently depending on the context where it is used. For example, image content are referenced in keen::UiTextureResource which has information about the format, size, etc. of the image data. Without it, its very hard to interpret the raw binary data of a content asset.

Currently, EML does only provide the image module as a helper to work with image content assets. That is, because most content formats have not been figured out just yet. So you will have to reverse engineer the binary formats on your own if you want to work with other content types. When doing so, i highly suggest exporting the binary data with the export capability and inspecting it with external tools such as ImHex for binary analysis. Be aware that this requires some knowledge about binary formats and reverse engineering, so it may not be suitable for everyone.