[gnuastro-commits] master b0ffbef: book: update gal_polygon_clip definition

[Mohammad Akhlaghi]

branch: master
commit b0ffbef4788bf09ce0fc43da341c0377d0c8b551
Author: Pedram Ashofteh Ardakani <pedramardakani@pm.me>
Commit: Pedram Ashofteh Ardakani <pedramardakani@pm.me>

    book: update gal_polygon_clip definition
    
    Until now, the gal_polygon_clip had a small definition in the
    manual. However, it was defined pretty well in the lib/polygon.c file.
    
    With this commit, I have relocated the detailed definition to the Gnuastro
    manual. Now, developers can read more about it in the manual itself,
    without the need to visit the lib/polygon.c file for a better understanding
    of gal_polygon_clip innerworkings.
---
 doc/gnuastro.texi | 27 ++++++++++++++++++++++++++-
 lib/polygon.c     | 30 ++----------------------------
 2 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/doc/gnuastro.texi b/doc/gnuastro.texi
index 9e4d168..7fa39e1 100644
--- a/doc/gnuastro.texi
+++ b/doc/gnuastro.texi
@@ -29114,13 +29114,38 @@ Note that the polygon vertices have to be sorted 
before calling this function.
 Arrange the vertices of the sorted polygon in place, to be in a 
counter-clockwise direction.
 If the input polygon already has a counter-clockwise direction it won't touch 
the input.
 The return value is @code{1} on successful execution.
-This function is just a wrapper over @code{gal_polygon_is_counterclockwise}, 
and will reverse the order of the vertices when necessary necessary.
+This function is just a wrapper over @code{gal_polygon_is_counterclockwise}, 
and will reverse the order of the vertices when necessary.
 @end deftypefun
 
 @deftypefun void gal_polygon_clip (double @code{*s}, size_t @code{n}, double 
@code{*c}, size_t @code{m}, double @code{*o}, size_t @code{*numcrn})
 Clip (find the overlap of) two polygons.
 This function uses the 
@url{https://en.wikipedia.org/wiki/Sutherland%E2%80%93Hodgman_algorithm, 
Sutherland-Hodgman} polygon clipping algorithm.
 Note that the vertices of both polygons have to be sorted in an 
anti-clock-wise manner.
+
+The Pseudocode from Wikipedia:
+@verbatim
+List outputList = subjectPolygon;
+for (Edge clipEdge in clipPolygon) do
+  List inputList = outputList;
+  outputList.clear();
+  Point S = inputList.last;
+  for (Point E in inputList) do
+     if (E inside clipEdge) then
+        if (S not inside clipEdge) then
+           outputList.add(ComputeIntersection(S,E,clipEdge));
+        end if
+        outputList.add(E);
+     else if (S inside clipEdge) then
+        outputList.add(ComputeIntersection(S,E,clipEdge));
+     end if
+     S = E;
+  done
+done
+@end verbatim
+
+The difference is that we are not using lists, but arrays to keep polygon 
vertices.
+The two polygons are called Subject @code{s} and Clip @code{c} with @code{n} 
and @code{m} vertices respectively.
+The output is stored in @code{o} and the number of elements in the output are 
stored in what @code{*numcrn} (for number of corners) points to.
 @end deftypefun
 
 @deftypefun void gal_polygon_vertices_sort (double @code{*vertices}, size_t 
@code{n}, size_t @code{*ordinds})
diff --git a/lib/polygon.c b/lib/polygon.c
index 7566f1c..6655a05 100644
--- a/lib/polygon.c
+++ b/lib/polygon.c
@@ -6,6 +6,7 @@ Original author:
      Mohammad Akhlaghi <mohammad@akhlaghi.org>
 Contributing author(s):
      Sachin Kumar Singh <sachinkumarsingh092@gmail.com>
+     Pedram Ashofteh Ardakani <pedramardakani@pm.me>
 Copyright (C) 2015-2021, Free Software Foundation, Inc.
 
 Gnuastro is free software: you can redistribute it and/or modify it
@@ -529,34 +530,7 @@ seginfintersection(double *Aa, double *Ab, double *Ba, 
double *Bb,
 
 
 
-/* Clip (find the overlap of) two polygons. This function uses the
-   Sutherland-Hodgman polygon clipping psudocode from Wikipedia:
-
-   List outputList = subjectPolygon;
-   for (Edge clipEdge in clipPolygon) do
-     List inputList = outputList;
-     outputList.clear();
-     Point S = inputList.last;
-     for (Point E in inputList) do
-        if (E inside clipEdge) then
-           if (S not inside clipEdge) then
-              outputList.add(ComputeIntersection(S,E,clipEdge));
-           end if
-           outputList.add(E);
-        else if (S inside clipEdge) then
-           outputList.add(ComputeIntersection(S,E,clipEdge));
-        end if
-        S = E;
-     done
-   done
-
-   The difference is that we are not using lists, but arrays to keep
-   polygon vertices. The two polygons are called Subject ('s') and
-   Clip ('c') with 'n' and 'm' vertices respectively.
-
-   The output is stored in 'o' and the number of elements in the
-   output are stored in what '*numcrn' (for number of corners) points
-   to.*/
+/* Clip (find the overlap of) two polygons. */
 void
 gal_polygon_clip(double *s, size_t n, double *c, size_t m,
                  double *o, size_t *numcrn)