Version 5.0 The LEDA User Manual

geo scene
void
int
GW.get scene with name(string nm)
GW.activate(geo scene sc)
GW.get z order(geo scene sc)
returns the scene with name nm or nil if there is no
scene with name nm.
makes scene sc the active scene of GW .
returns the z-coordinate of sc.
int GW.set z order(geo scene sc, int n)
sets the z-coordinate of sc to n and returns its previous
value.
In front of the scenes of a GeoWin object a so-called ”user layer” can store some geometric
objects illustrating scenes. The following functions let you add some of these objects.
void GW.add user layer segment(const segment& s)
void GW.add user layer circle(const circle& c)
void GW.add user layer point(const point& p)
adds segment s to the segments of the user layer.
adds circle c to the circles of the user layer.
adds point p to the points of the user layer.
void GW.add user layer rectangle(const rectangle& r)
void GW.remove user layer objects( )
adds rectangle r to the rectangles of the user layer.
removes all objects of the user layer.
void
GW.set draw user layer fcn(void (∗fcn)(GeoWin∗))
this function can be used for additional user-defined
redraw after drawing the objects of the user layer.
void GW.set postscript user layer fcn(void (∗fcn)(GeoWin∗, ps file& ))
geo scene GW.get active scene( )
returns the active scene of GW .
bool
GW.is active(geo scene sc)
returns true if sc is an active scene in a GeoWin.
The following get and set operations can be used for retrieving and changing scene parameters.
All set operations return the previous value.
string
GW.get name(geo scene sc)
returns the name of scene sc.