src/classes/sigma.classes.edgequad.js
function(r) {
      var width = (
        Math.sqrt(
          Math.pow(r.x2 - r.x1, 2) +
          Math.pow(r.y2 - r.y1, 2)
        )
      );

      return {
        x: r.x1 - (r.y2 - r.y1) * r.height / width,
        y: r.y1 + (r.x2 - r.x1) * r.height / width
      };
    }
function(r) {
      var width = (
        Math.sqrt(
          Math.pow(r.x2 - r.x1, 2) +
          Math.pow(r.y2 - r.y1, 2)
        )
      );

      return {
        x: r.x1 - (r.y2 - r.y1) * r.height / width,
        y: r.y1 + (r.x2 - r.x1) * r.height / width
      };
    }
function ( r ) { var width = ( Math . sqrt ( Math . pow ( r . x2 - r . x1 , 2 ) + Math . pow ( r . y2 - r . y1 , 2 ) ) ) ; return { x : r . x1 - ( r . y2 - r . y1 ) * r . height / width , y : r . y1 + ( r . x2 - r . x1 ) * r . height / width } ; }
Get coordinates of a rectangle's lower left corner from its top points.

@param  {object} A rectangle defined by two points (x1, y1) and (x2, y2).
@return {object} Coordinates of the corner (x, y).
Get coordinates of a rectangle s lower left corner from its top points .