protocol GPUResourceHost

Registers a face and returns the id to stamp into GlyphInstance.

Idempotent per face, which is a stronger claim than per path: the host opens the file and keys on what it contained, so two names for one file are one id, and a file whose bytes changed is correctly a new one. Nil if the file will not load.

The size is 26.6 fixed point — pixels times 64 — because a Float is not something two processes can compare for equality and agree on, and FreeType wants it quantised anyway. rasterFlags is a FontRasterFlags.raw; unknown bits are refused, not ignored.

Face 0 of path at pixelSize, hinted the renderer's default way — what a caller that just wants a font file at a size should use.

Rounds the size to 26.6 here rather than making every caller do it, which is the point: there is exactly one conversion from "pixels a human typed" to "the number the renderer keys on", and it lives here.

Registers an image, decoded from path, capped to maxPixelSize (0 = native) and quarter-turned by turn, returning a handle with the id and the decoded size.

Blocks. For anything an app needs before its first frame — an icon, a brand mark — where a placeholder would be worse than a stall.

The turn is asked of the host rather than done by the caller because one of the two hosts is a compositor the caller cannot decode for — see ImageTurn. Most callers want none and should use the two-argument convenience below.

Registers an image from encoded bytes (PNG, JPEG, …) rather than a path, for one that was downloaded, generated, or unpacked and never touched the filesystem.

Identity is the content, so registering the same bytes twice is one texture without the caller keeping a key. Prefer registerImage(path:) whenever there is a path: under a compositor this one sends the file through shared memory, where a path sends a path.

Blocks, like its sibling.

The overwhelmingly common case: no turn.

A convenience rather than a defaulted argument because a protocol requirement cannot carry one, and every caller but a viewer's rotate button wants a picture the way it is stored.

The same registration off the calling thread, with completion run on the main queue.

A protocol requirement rather than a helper because the two hosts split the work differently and only they know where. Locally, the decode belongs on a worker and the upload must be back on the main thread — it touches the device. Remotely the whole thing is one call, and there is no main-thread half at all.

Off-thread registration for a host that has no main-thread half — a remote one, where the call is already a round trip and touches nothing local. Editor overrides this, because it does.

Drops one reference to a registered image. key is the cacheKey from the handle, not the bare path — the same file at two decode sizes is two textures.