Node:Point Data Members, Next:Point Typedefs and Utility Structures, Previous:Point Reference, Up:Point Reference
valarray<real> world_coordinates  Private variable 
The set of four homogeneous coordinates x, y, z, and w that represent
the position of the Point within 3DLDF's global coordinate
system.

valarray<real> projective_coordinates  Private variable 
The set of four homogeneous coordinates x, y, z, and w that represent
the position of the projection of the Point onto a
twodimensional plane for output. The x and y values are used in the
MetaPost code written to out_stream . The z value is used
in the hidden surface algorithm (which is currently rather primitive and
doesn't work very well. see Surface Hiding). The w value can be
!= 1
,
depending on the projection used; the perspective projection is
nonaffine, so w can take on other values.

valarray<real> user_coordinates  Private variable 
A set of four homogeneous coordinates x, y, z, and w.

valarray<real> view_coordinates  Private variable 
A set of four homogeneous coordinates x, y, z, and w.

Transform transform  Private variable 
Contains the product of the transformations applied to the Point .
When apply_transform() is called for the Point , directly
or indirectly, the world_coordinates are updated and
transform is reset to the identity Transform .
See Point Reference; Applying Transformations.

bool on_free_store  Private variable 
Returns on_free_store . This should only be true if
the Point was dynamically allocated on the
free store. Points should only ever be dynamically
allocated by create_new<Point>() , which
uses set_on_free_store() to set on_free_store
to true .
See Point Reference; Constructors and Setting Functions, and
Point Reference; Modifying.

signed short drawdot_value  Private variable 
Used to tell Point::output() what MetaPost drawing command
(drawdot() or undrawdot() ) to write to out_stream
when outputting a Point .
When 
const Color* drawdot_color  Private variable 
Used to tell Point::output() what string to write to out_stream
for the color when outputting a Point .

string pen  Private variable 
Used to tell Point::output() what string to write to out_stream
for the pen when outputting a Point .

valarray<real> projective_extremes  Protected variable 
A set of 6 real values indicating the maximum and minumum x, y,
and
zcoordinates of the Point .
Used for determining whether a Point is projectable with the
parameters of a particular invocation of Picture::output() .
See Picture Reference; Outputting.
Obviously, the maxima and minima
will always be the same for a 
bool do_output  Protected variable 
true by default. Set to false by suppress_output() ,
which is called on a Shape by Picture::output() , if the
Shape is not projectable.
See Picture Reference; Outputting.

string measurement_units  Public static variable 
The unit of measurement for all distances within a Picture ,
"cm" (for centimeters) by default. The x and ycoordinates of
the projected Points are always followed by measurement_units
when they're written to out_stream . Unlike Metafont, units of
measurement cannot be indicated for individual coordinates. Nor can
measurement_unit be changed within a Picture .
When I write an input routine, I plan to make it behave the way Metafont does, however, 3DLDF will probably also convert all of the input values to a standard unit, as Metafont does. 
real CURR_Y  Public static variable 
real CURR_Z  Public static variable 
Default values for the y and zcoordinate of Points , when the
xcoordinate, or the x and ycoordinates only are specified.
Both are 0 by default.
These values only used in the constructor and setting function taking
one required Point A(1); A.show("A:");  A: (1, 0, 0); CURR_Y = 5; A.set(2); A.show("A:");  A: (2, 5, 0); CURR_Z = 12; Point B(3); B.show("B:");  B: (3, 5, 12); Point C; C.show("C:");  C: (0, 0, 0); 