Shadow
Implemented by earth.worldwind.draw.Drawables that can be rendered into the cascaded shadow map's depth pass. Parallel to earth.worldwind.draw.SightlineOccluder but specialized for the directional sun-shadow pipeline: the depth-pass program is the same depth-only shader used by the sightline pipeline, but the per-cascade matrices come from DrawableShadow (orthographic) instead of from a perspective sightline frustum.
Implementations are dispatched once per cascade by DrawableShadow.draw. Implementers should call DrawableShadow.loadCasterTranslation (or the matrix variant) to set the per-shape model transform, then issue draw calls for their triangle geometry. Line / point primitives should be skipped — they don't contribute meaningful occlusion volumes and would alias on the shadow map.
Inheritors
Properties
World-space bounding sphere center used to skip cascades whose AABB doesn't intersect this caster. Default null opts out of culling — the caster is dispatched into every cascade. Implementations populate this from their shape's boundingBox.center to gain per-cascade culling.
World-space bounding sphere radius. Only consulted when shadowCasterCenter is non-null.
Functions
Renders this drawable's caster geometry into the currently bound cascade shadow map. Called once per cascade by DrawableShadow. The depth-pass program is already bound and the cascade's MVP base matrix loaded; the implementation only needs to bind its own vertex buffer, set its model translation via DrawableShadow.loadCasterTranslation / DrawableShadow.loadCasterMatrix, and call DrawableShadow.drawShapeStateOccluder (or issue raw draws for non-DrawShapeState geometry).