Module lights 

Converts drained DirectionalLight, PointLight, SpotLight, and RectAreaLight asset components into the GPU data the renderer consumes: the fixed LightUniforms uniform (directional lights, ambient, and the legacy point array the raymarch / fog / probe paths read), the GpuLight storage buffer the clustered forward pass iterates, the per-slice spot shadow projections, and the rect area-light extents.

Structs

LightData

The per-scene GPU light data: the storage buffer the clustered forward pass iterates, plus the side tables it indexes into. Kept together because GpuLight.shadow_index indexes spot_shadows and GpuLight.data_index indexes area_lights – invariants that would be easy to break if the three were built independently.

Functions

build_light_data

Packs point, spot, and rect area lights into the GpuLight storage buffer and assigns their side-table slots. All three share the MAX_LOCAL_LIGHTS budget (not the 8-entry LightUniforms array); extras past the cap are dropped with a warning. Unused fields stay at their neutral GpuLight::ZERO values, so a point light carries no cone, shadow, or area data.

build_light_uniforms

local_lights is the buffer build_light_data produced; its length is the authoritative num_local_lights the forward pass iterates.

directional_light_data

The LightUniforms directional slots and their count for lights, padded with zeroed entries. Shared by the init-time build below and the live crate::backend::RenderBackend::update_directional_lights seam, so a sun edited at runtime packs exactly as a relaunch would pack it.

sun_color

The intensity-weighted colour of the sun sun_direction names, white when the world declares no directional light.

sun_direction

The direction the cascade shadow projection and the fog ray-march follow: the first declared directional light, or the neutral sun a world with none falls back to. Backends cache this at init and re-derive it when the light set changes.