CPL2cw

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - CPL/Closed Polygon Lists
Introduced first in SolidGeometry 5.5, Creation date: 2024-11-14, Last change: 2025-09-15

changes the orientation of all nested CPLs to cw

Description

Because of some unclear changes between the polyshape class, this function is required to compare

See Also: , CPL2ccw , CPLinvert

Example Illustration

Syntax

CPLN=CPL2cw(CPL)

Input Parameter

CPL: CPL with nested CPLS

Output Parameter

CPLN: CPL with nested CPLS all in cw

Examples


SGfigure; CPLplotcwccw(CPLsample(44))
SGfigure; CPLplotcwccw(CPL2cw(CPLsample(44)))
SGfigure; CPLplotcwccw(CPLCPL2ccwinvert(CPLsample(4)))
SGfigure; CPLplotcwccw(CPLinvert(CPLsample(44)))

Copyright 2024-2025 Tim C. Lueth. All rights reserved. The code is the property of Tim C. Lueth and may not be redistributed or modified without explicit written permission. This software may be used free of charge for academic research and teaching purposes only. Commercial use, redistribution, modification, or reverse engineering is strictly prohibited. Access to source code is restricted and granted only under specific agreements. For licensing inquiries or commercial use, please contact: Tim C. Lueth

Algorithm (Workflow)

This function, CPL2cw, is designed to change the orientation of all nested closed polygon lists (CPLs) to clockwise (cw). It is part of the SolidGeometry library and was introduced in version 5.5.

Input Parameters

CPL: A matrix representing a closed polygon list with nested CPLs. Each row in the matrix represents a vertex of the polygon, with the first column containing the x-coordinates and the second column containing the y-coordinates.

Output Results

CPLN: A matrix similar to the input CPL, but with all nested CPLs oriented in a clockwise direction.

Algorithm Steps

The function begins by calling the poly2cw function, which takes the x and y coordinates of the CPL and returns them oriented in a clockwise direction. The output is stored in variables x and y.
The function then constructs the output matrix CPLN by combining the x and y vectors into a two-column matrix.
If no output argument is specified (i.e., nargout==0), the function will plot the resulting CPLN using the SGfigure and CPLplotcolors functions. The plot is displayed with a red star marker and line style ('r*-').

Example Usage

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

CPL2cw(CPLsample(44))

This will convert the orientation of the CPL sample with ID 44 to clockwise.

Algorithm explaination created using ChatGPT on 2025-08-18 22:41. (Please note: No guarantee for the correctness of this explanation)

Last html export of this page out of FM database by TL: 2025-09-21