drawShapeStateOccluder

Renders the filled-triangle primitives of a DrawShapeState into the sightline depth cube. Shared between DrawableShape (interleaved attributes, passes its own DrawShapeState.vertexStride) and DrawableMesh (positions packed tightly in their own buffer, stride 0). Line-mode primitives within an otherwise filled state are skipped, and the state's DrawShapeState.enableCullFace preference is respected.