Databases
StackOverflow2013
Postsdbo
POCreate waypoints on a polygon with JS
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POCreate waypoints on a polygon with JS
    primarykey
    data
    text
    <p>This is more a mathematical than a JS problem, but I hope you can help me.</p> <p>I'm trying to create waypoints around a polygon. It should be able to walk <strong>on</strong> a line. I need to observe the following cases (<em>true</em> means the way isn't possible):</p> <p><img src="https://i.stack.imgur.com/kf1VH.jpg" alt="polygon"> &nbsp; In my script, I have problems to observe case 2 and case 7 at the same time. The polygon is an array with 5 objects (points) in them. A and B are the points for the red line. Here you can find my <a href="http://jsfiddle.net/bwe5a/3/" rel="nofollow noreferrer">jsFiddle</a>. &nbsp;</p> <pre><code>// check if point is in polygon var intersectLinePolygon = function(A, B, poly){ var result = false; for (var i = 0; i &lt; poly.length; i++){ var C = { 'x':poly[i].x, 'y':poly[i].y }; var D = {}; // if it's not the last point, take the next if (i != poly.length-1){ D.x = poly[i+1].x; D.y = poly[i+1].y; } // if it's the last point, take the first else { D.x = poly[0].x; D.y = poly[0].y; } if (intersectLineLine(A, B, C, D)){ result = true; } } return result; }; // check if there is an intersection between two lines var intersectLineLine = function(A, B, C, D){ if ( (B.x == C.x &amp;&amp; B.y == C.y) || (B.x == D.x &amp;&amp; B.y == D.y) || (A.x == C.x &amp;&amp; A.y == C.y) || (A.x == D.x &amp;&amp; A.y == D.y) ){ return false; } else { return (ccw(A,C,D) != ccw(B,C,D) &amp;&amp; ccw(A,B,C) != ccw(A,B,D)); } }; // helper function for intersectLineLine var ccw = function(A, B, C){ return ((C.y-A.y)*(B.x-A.x) &gt; (B.y-A.y)*(C.x-A.x)); }; </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. UStomatentobi
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POCreate waypoints on a polygon with JS
      1. USRobin
      1. VTFavorite
    2. VO
      singulars
      1. POCreate waypoints on a polygon with JS
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIn short, you need an algorithm to test if a segment intersects a non-convex polygon?
      singulars
      1. POCreate waypoints on a polygon with JS
      1. USleonbloy
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload