Module backend_init 

Grouped construction inputs for the render backends, plus the requirements derivation that trims scene-scoped features when a world has no 3D content. GraphicsSystem init assembles a BackendInit from the drained world assets, calls resolve_requirements(), and hands it to the backend constructor selected at compile time (Metal / DirectX / Vulkan). Every backend receives the same struct; each reads the fields its feature set consumes.

Structs

BackendInit

Everything a backend constructor needs, assembled once by GraphicsSystem init after the world’s assets have been drained and settings resolved.

MediaPayloads

Decoded image payloads: texture pools, glyph atlases, and the serialised IBL / grading payloads (None = the backend binds identity fallbacks).

PostSettings

Post-process and display settings resolved from PostProcessConfig (plus the user’s persisted overrides, the quality-preset ceiling, and the launch’s render requests). Every Option here is an init-time gate: None allocates nothing.

RenderRequirements

What the world’s content requires of the renderer. Derived from the assembled scene + fx data, backend-agnostic, so all three backends make identical trimming decisions.

SceneData

Static scene geometry and the draw lists built over it.

ShaderBytes

Compiled shader payloads. Each backend loads the format its toolchain produced (metallib / DXBC / SPIR-V).

ShadowParams

Shadow-mapping knobs from GraphicsConfig. map_size == 0 disables the shadow pipeline and cascade array entirely.

SwapchainConfig

The swapchain-level configuration a backend bakes into its window / surface at construction: the ring depth and the HDR-output request that together fix the drawable pixel format and frames-in-flight sizing. A live world swap (RenderBackend::reload_world) can only reuse the existing window when these are unchanged; a difference forces a full backend rebuild (a new window). Kept small + Eq so the swap decision is one comparison.

WorldFx

World-authored effect content drained from components. Empty / None means the backend builds no pipelines or pools for that feature.