GPBDMI - Set Back Data Mapping Index

Purpose

Use GPBDMI to insert a Set Back Data Mapping Index structure element into the open structure following the element pointer, or to replace the element pointed at by the element pointer with a Set Back Data Mapping Index structure element, depending upon the edit mode.

During traversal, the back data mapping index specifies the entry in the data mapping table used to perform data mapping on subsequent primitives that support data mapping.

If the face distinguish mode (GPFDMO) is 1=NONE , then the graPHIGS API uses the current data mapping index for data mapping on the front and back facing portions of area primitives. If the face distinguish mode is 2=COLOR_SURFACE_PROPERTIES , then the graPHIGS API uses the specified back data mapping index for data mapping on only back facing portions of area primitives.

The data mapping table is zero based. Entry zero always contains a data mapping entry of 1=DM_METHOD_COLOR Use GPQWDT to determine the number of definable data mapping table entries.

The traversal default back data mapping index is zero. If the specified index is not supported on the workstation, then the graPHIGS API uses a default index of zero.

Parameters