test_gcxgc.c

This contains examples on how to use yac_gcxgc_vec

// Copyright (c) 2024 The YAC Authors
//
// SPDX-License-Identifier: BSD-3-Clause
 
#include "test_cxc.h"
 
static void test_gcxgc(double lon_a, double lat_a, double lon_b, double lat_b,
                      double lon_c, double lat_c, double lon_d, double lat_d,
                      double lon_ref_p, double lat_ref_p,
                      double lon_ref_q, double lat_ref_q, int ref_ret_val);
 
int main (void) {
 
   enum {
      p_between_ab = 1,
      q_between_ab = 2,
      p_between_cd = 4,
      q_between_cd = 8,
      circles_are_identically = 16
   };
 
   double lon_middle_ab, lat_middle_ab, lon_middle_cd, lat_middle_cd;
 
   // simple example
 
   test_gcxgc(-10,   0, // point a
               10,   0, // point b
                0,  10, // point c
                0, -10, // point d
                0,   0, // reference point p
              180,   0, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   // d at north pole
 
   test_gcxgc(-10,   0, // point a
               10,   0, // point b
                0, -20, // point c
                0,  90, // point d
                0,   0, // reference point p
              180,   0, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   // edge_a == edge_b
 
   test_gcxgc(-10,   0, // point a
               10,   0, // point b
              -10,   0, // point c
               10,   0, // point d
              -10,   0, // reference point p
               10,   0, // reference point q
              p_between_ab + p_between_cd + q_between_ab + q_between_cd +
              circles_are_identically); // reference return value
 
   // both circles on the same plane but no intersection
 
   get_edge_middle_point(
     YAC_GREAT_CIRCLE_EDGE, -45, 45, 0, 0, &lon_middle_ab, &lat_middle_ab);
   get_edge_middle_point(
     YAC_GREAT_CIRCLE_EDGE, 225, 45, 135, -45, &lon_middle_cd, &lat_middle_cd);
   test_gcxgc(-45,  45,                     // point a
                0,   0,                     // point b
              225,  45,                     // point c
              135, -45,                     // point d
              lon_middle_ab, lat_middle_ab, // reference point p
              lon_middle_cd, lat_middle_cd, // reference point q
              p_between_ab + q_between_cd +
              circles_are_identically); // reference return value
 
   // normal case + some cyclic stuff
 
   test_gcxgc(  45,   3, // point a
                45, -10, // point b
               -45,   0, // point c
              -135, -45, // point d
                45,  45, // reference point p
              -135, -45, // reference point q
              q_between_cd); // reference return value
 
   // normal case + some heavier cyclic stuff
 
   test_gcxgc(  67.5,  40, // point a
                67.5, -13, // point b
                 405,   0, // point c
                 450,   0, // point d
              -112.5,   0, // reference point p
                67.5,   0, // reference point q
              q_between_ab + q_between_cd); // reference return value
 
 
   // normal case + some heavier cyclic stuff + shifted end of edge b
 
   test_gcxgc(  67.5,  40, // point a
                67.5, -13, // point b
                  45,   0, // point c
                 450,   0, // point d
              -112.5,   0, // reference point p
                67.5,   0, // reference point q
              q_between_ab + q_between_cd); // reference return value
 
  // one of the two edge has length zero and is not on the other plane
 
   test_gcxgc( 10,  10, // point a
               10,  10, // point b
              -10, -10, // point c
               10,  11, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
   test_gcxgc(-10, -10, // point a
               10,  11, // point b
               10,  10, // point c
               10,  10, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
  // one of the two edge has length zero, is not on the other edge, but on the other plane
 
   test_gcxgc( 10,   10, // point a
               10,   10, // point b
              -10,  -10, // point c
                0,    0, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_ab); // reference return value
 
   test_gcxgc(-10,  -10, // point a
                0,    0, // point b
               10,   10, // point c
               10,   10, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_cd); // reference return value
 
   test_gcxgc( 10,   10, // point a
               10,   10, // point b
              190,  -10, // point c
              170,   10, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_ab + q_between_cd); // reference return value
 
   test_gcxgc(190,  -10, // point a
              170,   10, // point b
               10,   10, // point c
               10,   10, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_cd + q_between_ab); // reference return value
 
  // one of the two edge has length zero and touches the other edge
 
   test_gcxgc( 10,  10, // point a
               10,  10, // point b
              -10, -10, // point c
               10,  10, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   test_gcxgc( 10,  10, // point a
               10,  10, // point b
              -10, -10, // point c
               10,  10, // point d
               10,   10, // reference point p
               190, -10, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
  // one of the two edge has length zero and is on the other edge
 
   test_gcxgc(  0,   0, // point a
                0,   0, // point b
              -10, -10, // point c
               10,  10, // point d
                0,   0, // reference point p
              180,   0, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   test_gcxgc(-10, -10, // point a
               10,  10, // point b
                0,   0, // point c
                0,   0, // point d
                0,   0, // reference point p
              180,   0, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   // both edges have length zero and do not match
 
   test_gcxgc(-10, -10, // point a
              -10, -10, // point b
               10,  10, // point c
               10,  10, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
   test_gcxgc( 10,  10, // point a
               10,  10, // point b
              -10, -10, // point c
              -10, -10, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
   // both edges have length zero and do not match, but are directly opposite
   // of each other
 
   test_gcxgc(-10, -10, // point a
              -10, -10, // point b
              170,  10, // point c
              170,  10, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
   test_gcxgc(170,  10, // point a
              170,  10, // point b
              -10, -10, // point c
              -10, -10, // point d
               -1,  -1, // reference point p
               -1,  -1, // reference point q
              -1); // reference return value
 
   // both edges have length zero and match
 
   test_gcxgc(-10, -10, // point a
              -10, -10, // point b
              -10, -10, // point c
              -10, -10, // point d
              -10, -10, // reference point p
              170,  10, // reference point q
              p_between_ab + p_between_cd); // reference return value
 
   return TEST_EXIT_CODE;
}
 
static void test_gcxgc(double lon_a, double lat_a, double lon_b, double lat_b,
                       double lon_c, double lat_c, double lon_d, double lat_d,
                       double lon_ref_p, double lat_ref_p,
                       double lon_ref_q, double lat_ref_q, int ref_ret_val) {
 
   test_cxc(lon_a, lat_a, lon_b, lat_b, lon_c, lat_c, lon_d, lat_d,
            YAC_GREAT_CIRCLE_EDGE, YAC_GREAT_CIRCLE_EDGE,
            lon_ref_p, lat_ref_p, lon_ref_q, lat_ref_q, ref_ret_val);
}