Used in
Path::output()
for writing the x and y values of theprojective_coordinates
ofPoints
toout_stream
. See Path Reference; Outputting. This is a low-level function that ordinary users should never have to invoke directly.
Writes the MetaPost code for drawing or undrawing a
Point
toout_stream
. Called byPicture::output()
, when aShape
on thePicture
is aPoint
. See Picture Reference; Outputting.
Sets
do_output
tofalse
, which causes aPoint
not to be output. This function is called inPicture::output()
, when aPoint
cannot be projected. See Picture Reference; Outputting.
Resets
do_output
totrue
, so that aPoint
can potentially be output, ifPicture::output()
is called again for thePicture
thePoint
is on. This function is called inPicture::output()
. See Picture Reference; Outputting.
vector<shape*>
extract (const Focus& f, const unsigned short proj, real factor)Attempts to project the
Point
using the arguments passed toPicture::output()
, which calls this function. Ifextract()
succeeds, it returns avector<shape*>
containing only thePoint
. Otherwise, it returns an emptyvector<shape*>
.
Sets “extreme” values for x, y, and z in
projective_coordinates
. This is, of course, trivial forPoints
, because they only have one x, y and z-coordinate. So the maxima and minima for each coordinate are always the same.
const
function: real get_minimum_z (void)const
function: real get_maximum_z (void)const
function: real get_mean_z (void)These functions return the minimum, maximum, and mean z-value of the
Point
.get_minimum_z()
returnsprojective_extremes[4]
,get_maximum_z()
returnsprojective_extremes[5]
, andget_mean_z()
returns(projective_extremes[4] + projective_extremes[5]) / 2
. However, since aPoint
has only one z-coordinate (fromworld_coordinates
), these values will all be the same.These functions are pure virtual functions in
Shape
, and are called onPoints
through pointers toShape
. Therefore, they must be consistent with the versions for other types derived fromShape
. See Shape Reference; Outputting.