Used in
Path::output()for writing the x and y values of theprojective_coordinatesofPointstoout_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
Pointtoout_stream. Called byPicture::output(), when aShapeon thePictureis aPoint. See Picture Reference; Outputting.
Sets
do_outputtofalse, which causes aPointnot to be output. This function is called inPicture::output(), when aPointcannot be projected. See Picture Reference; Outputting.
Resets
do_outputtotrue, so that aPointcan potentially be output, ifPicture::output()is called again for thePicturethePointis 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
Pointusing 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 aPointhas only one z-coordinate (fromworld_coordinates), these values will all be the same.These functions are pure virtual functions in
Shape, and are called onPointsthrough pointers toShape. Therefore, they must be consistent with the versions for other types derived fromShape. See Shape Reference; Outputting.