CPLofBB

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - CPL/Closed Polygon Lists
Introduced first in SolidGeometry 2.7, Creation date: 2015-09-29, Last change: 2025-09-14

returns a CPL around a 2D Bounding Contour BB

Description

Used for creating a surrounding BB for a CPL.

See Also: BBofCPL , BBofVL , SGofBB , VLFLofBB , BBofSG

Example Illustration

Syntax

CPL=CPLofBB(BB,[d])

Input Parameter

`BB`:		Bounding Box or CPL
`d`:		distance around the bounding box; default is 1

Output Parameter

CPL: Closed Polygon Liste

Examples


CPLofBB(CPLslicer(SGsample(7),9))

Copyright 2015-2025 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, CPLofBB, generates a Closed Polygon List (CPL) around a 2D Bounding Box (BB). It is part of the SolidGeometry library and was developed by Tim Lueth.

Input Parameters

BB: This is the Bounding Box or a Closed Polygon List (CPL) that the function will process.
d: This is the distance around the bounding box. If not specified, it defaults to 1.

Output

CPL: The function returns a Closed Polygon List that represents a bounding contour around the input BB.

Algorithm Steps

Initialize the distance d to 1. If a second argument is provided and is not empty, set d to this value.
Check if BB is a cell array:
- If true, create a cell array CPL of the same size as BB.
- Iterate over each element in BB, recursively calling CPLofBB for each element and storing the result in CPL.
If BB is not a cell array:
- Check if BB has two columns:
  - If true, treat BB as a polygon list PL and compute its bounding box using BBofVL.
  - Set a flag cpl to true.
- Construct the CPL by expanding the bounding box by d in all directions.
- Close the polygon by appending the first point to the end of the list.
If no output is requested:
- Open a new figure with grid and axis enabled.
- Plot the CPL in red with a line width of 4.
- If cpl is true, plot the original polygon list PL in blue with markers.

Algorithm explaination created using ChatGPT on 2025-08-19 01:24. (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