Algorithm (Workflow)

This function, CPLregions, is designed to sort a Closed Polygon Line (CPL) with respect to regions. It is part of the SolidGeometry library and was introduced in version 5.1. The function primarily relies on another function, CPLsortinout, to perform its operations.

Input Parameters

• CPL: A Closed Polygon Line, which is the main input to the function.

Output Results

• CPLN: The sorted Closed Polygon Line, organized into regions.
• PiL: A list containing the parent index of CPLN and the region level, where 0 indicates an outside region.

Algorithm Steps

1. The function first checks if the input CPL is empty. If it is, the function returns empty arrays for both CPLN and PiL.
2. If CPL is not empty, the function calls CPLsortinout to sort the CPL into regions. The sorted CPL is stored in CPLN.
3. If the number of output arguments requested is greater than one, the function calls CPLsortinout again to obtain the parent index list PiL.
4. If no output arguments are requested, the function visualizes the CPL using SGfigure, CPLplotcolors, and textCPL functions.

Example Usage

The function can be called with a sample CPL as follows:

CPLregions(CPLsample(27));