char *cxPyrActiveNext(cxPyramid *pyr, long curLayer, long dstLayer, char *flg)
integer function cxPyrActiveNext( pyr, curLayer, dstLayer, flg ) integer pyr integer curLayer integer dstLayer character*1 flg(*)
- Input pyramid structure for which computations are to be performed.
- Input layer of currently active elements (1-based value).
- Input layer of next active elements (1-based value).
- Input byte array indicating which elements are currently active in layer curLayer.
Position i of the returned byte array holds a 0 if element i of the layer is inactive, a 1 if the element is active and contained within only one parent element, or a 2 if the element is active and contained within more than one parent element.
cxPyrActiveNext is useful in circumstances where a subset of the elements at a given level are to be manipulated, and the caller wishes to identify the subordinate elements to manipulate at a lower level. This is the approved way of determining the pyramid elements which should be manipulated or displayed in any pyramid-based module (the alternative method of displaying all elements available at a given level is not correct).
The returned indicator array is considered to be owned by the caller of cxPyrActiveNext and should be freed (with free(3C)) after use.
Other routines exist to determine the active elements at a specified layer and to return a variable-length array of only the active elements.cxPyramid(3E), cxPyrActive(3E), cxPyrActiveListNext(3E), cxPyrActiveList(3E).
Last modified: Mon Nov 6 16:33:42 GMT 2000
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