> <\body> \<#8F91\>\<#56FE\>\<#5F62\>\<#5BF9\>\<#8C61\>> Any of the modes which allows for the insertion of new objects (points, lines, polygons, etc.) also allows you to directly edit existing objects. More precisely, as soon as you go over an existing object with your mouse, then the control points for that object will be highlighted automatically. Several editing operations are supported: <\description> When your mouse is sufficiently close to a control point, then it will be possible to drag and drop the control point to somewhere else using the left mouse button. For objects with an arbitrary number of control points, such as broken lines, polygons, splines and closed splines, it is possible to insert new points on existing edges. In order to do so, move the mouse pointer on the edge where you want to insert a new point; the two neighbouring control points should be highlighted. Then insert a new point drag and move it around using drag and drop for the first mouse button. Using the middle mouse button, it is possible to remove control points (and eventually the object itself). Using the middle mouse button while simultaneously pressing the shift key removes the entire object which is currently highlighted. While editing, it should also be noticed that attempts to automatically the mouse pointer to control points or edges of existing objects, as well as to intersection points of two curves and points on the grid. This makes it possible to quickly draw complex pictures which are exact, and not merely exact up to one or more pixels (and ugly when magnified or printed). Around boxes with text or mathematical formulas, there are also eight invisible control points to which will attempt to snap the mouse pointer. This makes it easier to draw diagrams as in figure below. Graphical objects are drawn in a specific which has the effect that certain objects may be hidden by other objects. Using and , you may move the currently highlighted object closer to or farther away from the eye for this stacking order. In a similar vein, certain control points may become unaccessible, because hidden by closer control points. In that case, you may use to cycle through all possibilities for the current cursor position. <\big-figure||gr-frame|>|gr-geometry||gr-grid||gr-grid-old||1>|gr-edit-grid-aspect|||>|gr-edit-grid||gr-edit-grid-old||1>|gr-text-at-halign|center|gr-arrow-end|\|gr-auto-crop|true|>>|>>|>>|>>|>>|>>|||>>|||>>|||>>|||>>|||>>|||>>|||>>|||||>>>>> Example of a diagram which was drawn by using snapping to the eight control points around each box with a mathematical formula. Notice also that we cropped the graphics to its actual size. >