Definition

1. For any spatial index related organization SIRO,

   1. The column_width of SIRO shall be a positive number.

   2. The row_width of SIRO shall be a positive number.

   3. For each branch of the organization, the corresponding <Spatial Index Data> link object shall define a region in the spatial index, such that

      1. The column_index of the <Spatial Index Data> link object shall be between 1 and the column_count defined by SIRO.

      2. The row_index of the <Spatial Index Data> link object shall be between 1 and the row_count defined by SIRO.

      3. Each primitive within the branch shall have a spatial extent overlapping that defined by the <Spatial Index Data> link object of the branch.

2. Consider an instance SRA, which is either a <Spatial Index Related Features> instance or a <Spatial Index Related Geometry> instance.

   1. If SRA's strict_organizing_principle = SE_TRUE, for each branch of SRA, each primitive within the branch shall have a spatial extent fully contained within that defined by the <Spatial Index Data> link object corresponding to the branch. (If SRA's strict_organizing_principle = SE_FALSE, no guarantees exist as to how accurately the instances of the component tree rooted at SRA were placed into their "sorted bins" (the branches of SRA), apart from that specified by 1.)

   2. If SRA is a <Spatial Index Related Features> instance, and the same <Feature Representation> instance belongs to more than one of its branches, the unique_descendants and strict_organizing_principle flags of SRA shall be set to SE_FALSE.

   3. If SRA is a <Spatial Index Related Geometry> instance, and the same <Geometry Representation> instance belongs to more than one of its branches, the unique_descendants and strict_organizing_principle flags of SRA shall be set to SE_FALSE.

Rationale

1. Each branch of a spatial index related organization is intended to organize instances that fall within the specified spatial-index for that branch.

2. The strict_organizing_principle flag of <Spatial Index Related Features> and <Spatial Index Related Geometry> was designed to allow the use of spatial index related organization, even when a few primitives cross the boundaries of the organizing principle.

Example

1. See the <Spatial Index Related Geometry> class, example 1.

2. See the <Spatial Index Related Features> class, example 1.

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