Created
March 25, 2019 13:51
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Returns the array of 32 compass points and heading.
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/** | |
* Returns the array of 32 compass points and heading. | |
* See details here: | |
* https://en.wikipedia.org/wiki/Points_of_the_compass#32_cardinal_points | |
* | |
* @return {array} | |
* | |
* Example of return : | |
* [ | |
* { abbreviation : 'N', azimuth : 0.00 , | |
* { abbreviation : 'NbE', azimuth : 11.25 }, | |
* { abbreviation : 'NNE', azimuth : 22.50 }, | |
* ... | |
* { abbreviation : 'NbW', azimuth : 348.75 } | |
* ] | |
*/ | |
function Point(abbr, azimuth) { | |
this.abbreviation = abbr; | |
this.azimuth = azimuth; | |
} | |
function createCompassPoints() { | |
let res = new Array(33) | |
var sides = ['N', 'E', 'S', 'W'] | |
sides.forEach((val, idx) => res[idx * 8] = val) | |
function rec_travel(start_str, finish_str, start_pos, finish_pos) { | |
let medium_pos = (finish_pos + start_pos) / 2; | |
if (!Number.isInteger(medium_pos)) | |
return; | |
let medium_str = start_str + finish_str; | |
if (medium_str.length > 3) { | |
let main_idx = (finish_pos - start_pos > 0 ? Math.ceil : Math.trunc)(medium_pos / 8) % 4; | |
medium_str = start_str + 'b' + sides[main_idx]; | |
} | |
if (!res[medium_pos]) { | |
res[medium_pos] = medium_str; | |
} | |
rec_travel(start_str, res[medium_pos], start_pos, medium_pos) | |
rec_travel(finish_str, res[medium_pos], finish_pos, medium_pos) | |
} | |
rec_travel('N', 'N', 0, 32); | |
return res.map((abbr, idx) => new Point(abbr, 11.25 * idx)); | |
} |
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