2.5.9 BrtColSpan
The BrtColSpan structure specifies the index of the first and last columns (1) that contain data for a single segment of the containing BrtRowHdr (section 2.4.761) structure. Each BrtRowHdr structure is divided into 16 segments; each segment contains 1,024 contiguous columns (1) where the column field of each Cell (section 2.5.10) record in the segment results in the same value for the following formula (section 2.2.2) via integer division:
column / 1024
A BrtColSpan structure exists only if a Cell record exists for one or more columns (1) within the segment.
The following packet diagram specifies this structure.
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colMic |
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colLast |
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colMic (4 bytes): A Col (section 2.5.23) structure that specifies the column (1) index of the first cell logically contained in this segment. The value of this field MUST be less than 0x00004000 (16384), MUST be equal to the smallest value of the column field of the Cell records logically contained in this segment, and MUST be a value that satisfies the following condition under integer division:
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colMic / 1024 = colLast / 1024
colLast (4 bytes): A Col structure that specifies the column (1) index of the last cell logically contained in this segment. The value of this field MUST be greater than or equal to the value of colMic, MUST be less than 0x00004000 (16384), MUST be equal to the largest value of the column field of the Cell records logically contained in this segment, and MUST be a value that satisfies the following condition under integer division:
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colLast / 1024 = colMic / 1024