tornavis/source/blender/blenlib/BLI_convexhull_2d.h

55 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup bli
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* A.M. Andrew's monotone chain 2D convex hull algorithm.
*
* \param points: An array of 2D points presorted by increasing x and y-coords.
* \param n: The number of points in points.
* \param r_points: An array of the convex hull vertex indices (max is n).
* \returns the number of points in r_points.
*/
int BLI_convexhull_2d_sorted(const float (*points)[2], int n, int r_points[]);
/**
* A.M. Andrew's monotone chain 2D convex hull algorithm.
*
* \param points: An array of 2D points.
* \param n: The number of points in points.
* \param r_points: An array of the convex hull vertex indices (max is n).
* _must_ be allocated as `n * 2` because of how its used internally,
* even though the final result will be no more than \a n in size.
* \returns the number of points in r_points.
*/
int BLI_convexhull_2d(const float (*points)[2], int n, int r_points[]);
/**
* \return The best angle for fitting the convex hull to an axis aligned bounding box.
*
* Intended to be used with #BLI_convexhull_2d
*
* \param points_hull: Ordered hull points
* (result of #BLI_convexhull_2d mapped to a contiguous array).
*
* \note we could return the index of the best edge too if its needed.
*/
float BLI_convexhull_aabb_fit_hull_2d(const float (*points_hull)[2], unsigned int n);
/**
* Wrap #BLI_convexhull_aabb_fit_hull_2d and do the convex hull calculation.
*
* \param points: arbitrary 2d points.
*/
float BLI_convexhull_aabb_fit_points_2d(const float (*points)[2], unsigned int n);
#ifdef __cplusplus
}
#endif