6 Konvexe Bereiche

Konvexe Bereiche are not drawing elements, they are just part of a set of tools used to modify drawing elements and for which you need to focus only on those control points or this part of the drawing that are within some bounded area defined as a union of convex zones. For instance, convex zones can be used to move around some of the control points of drawing elements, or to trim a drawing element.

Konvexe Bereiche sind keine Elemente, die gezeichnet werden, sie sind nur ein Teil eines Satzes von Werkzeugen zum Zeichnen Elemente modifizieren und für die Sie sich konzentrieren nur auf die Kontrollpunkte oder diesem Teil der Zeichnung sind die innerhalb Einige begrenzten Bereich als eine Vereinigung von konvexen Zonen definiert. Zum Beispiel konvexen Zonen verwendet zu bewegen einige der Kontrollpunkte werden Zeichnungselemente oder eine Zeichnung Element trimmen.

Konvexe Bereiche can be defined for each drawing separately, however they are not part of the drawing document, and as such, they are lost when you close a drawing board.

Konvexe Bereiche können für jede Zeichnung getrennt definiert werden, trotzdem sind sie nicht Teil der Zeichnung, und als solche gehen sie verloren, wenn ein Zeichenbrett geschlossen wird.

As far as extensible Bezier curves are concerned, a simpler and less powerful alternative to convex zones, when you want to act on several control points at a time, is to use the GLOBAL/LOCAL edit point mode

Soweit erweiterbare Bezierkurven betrifft, ein einfacheres und weniger leistungsstarke Alternative zu konvexen Zonen, wenn Sie an mehreren handeln wollen Kontrollpunkte in einer Zeit, ist die GLOBAL / LOCAL Schnittmarke Modus verwenden (See (Globaler/lokaler Punktbearbeitungsmodus)actions_globallocalmode.)

Konvexe Bereiche are visible and can be used only when the convex zone palette is visible, and are hidden otherwise. To use convex zones, first make the convex zone pallette visible by clicking on in the main toolbar).

Konvexe Bereiche sind sichtbar und können nur verwendet werden, wenn die „konvexe Zone Palette“ sichtbar ist, und ansonsten sind verborgen. Um konvexe Bereiche verwenden, erste machen die konvexe Zone Palette sichtbar, indem Sie auf in der Haupt-Symbolleiste).

Ein konvexer Bereich wird als Schnitt einer oder mehrerer Halbebenen definiert, jede Halbebene ist wiederum durch zwei Kontrollpunkte definiert:

1. A point P1 on its boundary line.
2. A point P2 such that its boundary line is orthogonal to vector P1 P2 and that Halbebene contains P2.

Each Halbebene that compose a convex zone is viewed with its border line and with a Halbebene sign like this:

Die Umrandung eines konvexen Bereichs wird blau dargestellt. When the convex zone is selected the first and second control point are viewed as the Halbebene sign and as a small square in magenta color. When the convex zone is not selected, only the Halbebene sign is visible, and it is viewed in grey colour wie folgt:

When you edit convex zones, there is a number of things that jPicEdt prevents you from doing:

• You cannot create or move P2 too close to P1, because this would cause undetermination of the Halbebene.
• You cannot move a Halbebene to a position where it would be useless, that is to say to a position where the convex zone defined by the other Halbebenes would be entirely contained in this Halbebene. If you don’t want this Halbebene any longer suppress it with the convex zone edit tool (see Convex zone edition)
• Finally, you are also prevented to move Halbebenes in a way that would result in an empty convex zone, as such a convex zone would be of no use.

Each button can display a tooltip if the mouse hovers around it more than two seconds.

6.1 Auswahl eines konvexen Bereichs

Die Auswahl eines konvexen Bereichs wird mit dem entsprechenden Auswahl-Werkzeug durchgeführt (See Auswahl eines konvexen Bereichs). The convexe-zone-selection and the selection (of drawing elements) are two different selections.

Menu commands, or keyboard shortcuts such as „Select all“, „Suppress“, „F2“ and suchlikes selection-dependent actions, may act either on the drawing element selection, or on the convexe-zone selection, but never on both of them.

The following rules apply:

• All drawing tools act only on the drawing element selection.
• All convexe-zone tools act only on the convexe-zone selection.
• Ambiguous selection dependent actions act on the drawing elements selection when the convexe-zone palette is not visible.
• When the convexe-zone palette is visible then what happens depends on the Use convex zone selection tool state:
  • If the tool is active, then ambiguous selection dependent actions act on the convexe-zone selection.
  • Otherwise, they act on the drawing elements selection.

An alternative to the „Use convexe-zone selection“ tool is to use the same shortcuts with Strg-U prefix. For instance the sequence Strg-u Strg-C will copy a control zone, Strg-U Strg-X will cut it, Strg-U Strg-V will paste it, Strg-U Strg-A will select all control zones, etc. … The sequence Strg-U Strg-G has no effect, it just relaxes the Strg-U prefix.

6.2 Bearbeiten konvexer Bereiche

Wenn das Werkzeug zur Auswahl eines konvexen Bereichs aktiviert ist, können konvexe Bereiche wie folgt bearbeitet werden:

• Verschieben des konvexen Bereichs: When the mouse is in the vicinity of the boundary of a selected convex zone it shows as a spider , if you click and keep mouse click button down while move the mouse (which is known as dragging), you can translate this convex zone. With the Strg modifier you translate all the selected convex zones, and not only the one for which the mouse is in the vicinity of a boundary line. With the Strg+Alt modifier you translate all the existing convexe-zones. Note that translating convex zone(s) does not have any effect on the underlying drawing.
• Verschieben einer Halbebene: When the mouse is in the vicinity of the first control point of a Halbebene that is part of a convexe-zone, then mouse shows as a small arrow. If you click and keep mouse button down then you can translate the half plane (that it to say both control points are translated together). With the Strg modifier, the first control point is constrained to move along the half plane boundary line, this has no effect on the Halbebene itself, but it is useful if you want to rotate the Halbebene around the first control point in the aftermath.
• Rotating a Halbebene: When the mouse is in the vicinity of the second control point of a Halbebene that is part of a convexe-zone, then mouse shows as a small arrow. If you click and keep mouse button down then you translate only the second control point, which has the effect of rotating the Halbebene around the first control point. Remember that you cannot bring the second control point too close to the first one to prevent Halbebene undetermination.

When the convex zone edition tool

is active you can add or remove Halbebenes to a convex zone as follows:

• Selecting target convex zone: Once the convexe-zone edition tool has been activated in the convexe-zone palette, the first step is to select a single target convex zone to act upon. To select the target convex zone click on its boundary or on any of the Halbebene signs. This step is not needed if the target convex zone zone is already selected and there are no other selected convex zones.
• Select Halbebenes for removal: Once a convex zone is selected you can remove Halbebenes: just click on one of the control point of the Halbebene to be selected for removal: the Halbebene sign will appear in green. Umschalter+click on a control point of the same Halbebene point will unselect it. Umschalter+click on a control point of another Halbebene will add it to the seleciton for removal. You may also select several Halbebenes for removal by dragging a lasso around every convex zone control point whose owner Halbebene is to be selected.
• Removing Halbebenes: Simply click on any of Halbebenes that have been selected in to be removed to remove all of them from the selected convex zone.
• Adding Halbebenes: Hold the Strg modifier, then add a plane by click a first time to set the first control point, and a second time to set the second control point. Click-Right to cancel. Remember you cannot add a Halbebene that would make the convex zone empty.

6.3 Negating a Convex zone

If you select a convex zone then click-right and choose Negate in the context menu, the convex zone, that is an intersection of Halbebenes, is transformed to the union of complementary Halbebenes.

Negation can be applied to a selection of several convex zones, so that it is reversible by negating a second time. In other words negating twice has almost no effect. almost is there just because, if in the process of negation some empty convex zones are created, they are suppressed. For instance if you select two convexes zones, with the first one containing the second one, negating twice will suppress the inner convex zone.

6.4 Convex zone Tools

When using any of the convex zone edition tools, you can go by at any time to the standard convex zone SELECT tool ( ), by a single right-click.

Following is a list of all available convexe-zone tools as well as their associated icon on the convex zone palette. Some convexe-zone tools support a set of alternate functions: these are triggered by a specific combination of modifiers (Control+Shift, Control+Alt or Control+Alt+Shift, as indicated), and allows you to release or enforce one or more geometrical constraints (the same combinations are used as in SELECT mode, except for the Strg modifier which makes no sense here). Modifiers may be pressed or released at any time during the convexe-zone tool process.

6.4.1 Convexe zone tool pannel

Icon	Tool	Number of control points	Editing sequence	Alternate functions
	Convex zone Selection	Keine	Click on any convex zone boundary or Halbebene signs, to select the whole convex zone. (See Convex zone selection for details).	Umschalter: the same sequence as for selecting a convex zone can be used to unselect it, or to add another convex zone to the convexe-zone-selection
	Convex zone Edition	Keine	Click on any convex zone boundary or Halbebene signs to select the whole convex zone. Remove any Halbebene from the convex zone by clicking on the corresponding Halbebene sign. (See Convex zone edition for details).	Strg modifier to add Halbebenes to the convex zone.
	Rectangular convex zone.	2	First corner, opposite corner. Sides are kept parallel to the grid axes.	Strg: nail the center of the rectangle to its first point position. Strg+Alt: release the constraint on sides. (Hold the modifiers whenever you want to alter the side’s orientation, then release it and move the mouse to scale the rectangle). Umschalter: rectangle is negated. (see Negation). Strg+Umschalter: nail center and negate. Strg+Alt+Umschalter: releasing the constaint on side orientation and negate.
	Extensible convex zone.	Variable	First control point of first Halbebene, second control point of first Halbebene, first control point of second Halbebene, and so one. Terminate with a right-click.	Keine
	Band-shaped convex zone.	2	First side, Second side. Sides are kept parallel to the grid axes. Band direction is orthogonal to the line passing through first and second points.	Strg: nail the center of the band the first point position. Strg+Alt: release the constraint on sides parallel to grid axes. Umschalter: negate (see Negation) Strg+Umschalter: nail center and negate. Strg+Alt+Umschalter: release the constaint on sides orientation and negate.
	U-shaped convex zone.	3	First corner, Second corner, Top of U. Sides are kept parallel to the grid axes.	Strg: nail the center of the bottom side of U to the first point position. Strg+Alt: release the constraint on sides parallel to grid axes. Umschalter: negate (see Negation) Strg+Umschalter: das Zentrum fixieren und nail center and negate. Strg+Alt+Umschalter: release the constraint on sides orientation and negate.
	Halbebene convex zone.	2	First control-point Second control point. Sides are kept parallel to the grid axes.	Strg+Alt: release the constraint on sides parallel to grid axes. Hold the modifiers whenever you want to alter the side’s orientation, then release it and move the mouse to scale the rectangle). Umschalter: negate (see Negation) Strg+Alt+Umschalter: release the constraint on sides orientation and negate.*
	Translate all drawing elements control points within the selected convex zone.	Keine	Click at one of the convex zone (by clicking on its border line, or on one of its control point), and drag the mouse, i.e. keep click button down as moving the mouse. All the drawing element control points that are within the considered convex zone zone will be translated accordingly as well as the considered convex zone. Note that for extensible Bezier curve control points that are not subdivision points; but for which the corresponding subdivision point is within the selected convex zone are also translated.	With Strg modifier, all selected convex zone, instead of just the one you drag upon are used for translation. With the Strg+Alt modifier all the existing convex zones are considered.
	Trim all drawing elements.	Keine	The intersection of the union of all existing convex zones, and of of all the seelcted drawing elements is erased. This can involve conversion of some element types (for instance rectangle) to extensible Bezier curves.	Keine
	Use convex zone selection.	Keine	Toggling this button on and off allows you to decide selection dependent action like „Cut&Paste“, or „Select all“ act on the drawing element selection, or on the convexe-zone selection. (See Use convex zone selection for details)	Keine

For all convex zones, when the „Convex zone Select“ tool state is active, pressing F2 will open a properties-panel for the first convex zone in the convexe-zone selection. This in particular allows you to edit convexe-zone control points coordinates by hand, or to change the angle of the vector P1 P2 w.r.t. horizontal by hand.