OpenSoure_Repos/TheAlgorithms-C-Plus-Plus
1
0
Fork 0
mirror of https://hub.njuu.cf/TheAlgorithms/C-Plus-Plus.git synced 2023-10-11 13:05:55 +08:00
Code Issues Packages Projects Releases Wiki Activity

Update graham_scan_functions.hpp

Browse Source
This commit is contained in:
Lajat5 2021-11-08 23:10:06 +05:30 committed by GitHub
parent d502cfe371
commit f2f6923496
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 9 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
geometry/graham_scan_functions.hpp
View File

@ -1,8 +1,8 @@
/****************************************************************************** /******************************************************************************
* @file * @file
* @brief Implementation of the [Convex * @brief Implementation of the [Convex
*Hull](https://en.wikipedia.org/wiki/Convex_hull) implementation using [Graham * Hull](https://en.wikipedia.org/wiki/Convex_hull) implementation using [Graham
*Scan](https://en.wikipedia.org/wiki/Graham_scan) * Scan](https://en.wikipedia.org/wiki/Graham_scan)
* @details * @details
* In geometry, the convex hull or convex envelope or convex closure of a shape * In geometry, the convex hull or convex envelope or convex closure of a shape
* is the smallest convex set that contains it. The convex hull may be defined * is the smallest convex set that contains it. The convex hull may be defined
@ -22,18 +22,18 @@
* points be sorting them with respect to the bottom-most point. Once the points * points be sorting them with respect to the bottom-most point. Once the points
* are sorted, they form a simple closed path. * are sorted, they form a simple closed path.
* The sorting criteria is to use the orientation to compare angles without * The sorting criteria is to use the orientation to compare angles without
*actually computing them (See the compare() function below) because computation * actually computing them (See the compare() function below) because computation
*of actual angles would be inefficient since trigonometric functions are not * of actual angles would be inefficient since trigonometric functions are not
*simple to evaluate. * simple to evaluate.
* *
* Accept or Reject Points * Accept or Reject Points
* Once we have the closed path, the next step is to traverse the path and * Once we have the closed path, the next step is to traverse the path and
* remove concave points on this path using orientation. The first two points in * remove concave points on this path using orientation. The first two points in
* sorted array are always part of Convex Hull. For remaining points, we keep * sorted array are always part of Convex Hull. For remaining points, we keep
*track of recent three points, and find the angle formed by them. Let the three * track of recent three points, and find the angle formed by them. Let the three
*points be prev(p), curr(c) and next(n). If orientation of these points * points be prev(p), curr(c) and next(n). If orientation of these points
*(considering them in same order) is not counterclockwise, we discard c, * (considering them in same order) is not counterclockwise, we discard c,
*otherwise we keep it. * otherwise we keep it.
* *
* @author [Lajat Manekar](https://github.com/Lazeeez) * @author [Lajat Manekar](https://github.com/Lazeeez)
* *