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A point can be generated by various tools. The point tool will
normally generate a free point. If the Shift-key is
pressed, the point can be fixed with an expression in the point
properties dialog. A point will fix to the position of another point,
if this point is shift clicked with the point tool.
If an intersection of two circles or similar objects is clicked, the intersection is automatically created. A confirmation for this automatism to generate intersections is turned off by default. Also by default, a preview of the intersected objects and the intersection is shown. Of course, intersection points are not free, but depend on the two intersected objects.
Points can be bound to circles and lines and other objects like tracks, conic sections and functions (bound points). To generate such a point, click on the object with the point tool. A confirmation for this can be turned on.
Fixed points can still be moved, if the expression refers to the point itself and to no other object (selfreference). Here, @-references do not count. In this case, the position is recomputed using the expression. This is useful to restrict the movement of points.
Points can be kept on a grid by using a grid increment in the dialog, which is larger then 0. For an integer grid, use 1. Alternatively, there are more advanced methods of self referring objects to keep the point on certain sets. Note that points can easily be kept in polygons, since they can be bound to these objects.
Like other objects, free points can be dragged immediately after generation. During the drag, the size and name will display, unless this option is turned off.
Points can also be filled with white background, if their thickness is normal. This is the default. The fill can be disabled in the edit dialog of the point.
Related topics: Points on Objects, Intersections, Special Settings, The Mouse, Object Properties, Self Reference
Next topic: Points on Objects