+//parameter ix: index of mesh bed leveling point in X-axis
+//parameter iy: index of mesh bed leveling point in Y-axis
+//parameter meas_points: number of mesh bed leveling points in one axis; currently designed and tested for values 3 and 7
+//parameter zigzag: false if ix is considered 0 on left side of bed and ix rises with rising X coordinate; true if ix is considered 0 on the right side of heatbed for odd iy values (zig zag mesh bed leveling movements)
+//function returns true if point is considered valid (typicaly in safe distance from magnet or another object which inflences PINDA measurements)