.\" A macro package for simple two-dimensional figures
.\"
.\" The main macros are as follows:
.\"
.\" .ptbeg x_min x_max y_min y_max
.\"   Begins a figure.
.\"
.\" .ptend
.\"   Ends the current figure.
.\"
.\" .ptdef name x y
.\"   Define a point with the given name at (x, y).
.\"
.\" .ptput name
.\"   Draw the point with the given name.
.\"
.\" .ptlink src dst
.\"   Draw a line between points named src and dst.
.\"
.\" .ptrect llx urx
.\"   Draw a rectangle with the given opposite vertices.
.\"
.\" .ptcir cen rad
.\"   Draw a rectangle with the given center and radius.
.\"
.\" .pttext pos text
.\"   Print the given text at the given position.
.\"
.\" .ptclr line point fill
.\"   Set point, line, and fill colours.
.\"
.nr ptcir 50		\" Point circle radius in basic unit
.nr ptlnsz 24		\" Line point size
.ds ptfont 1		\" Font for writing point name
.nr ptsize 10		\" Size for writing point name
.nr ptfill 1
.nr ptbox 1
.ds ptclr.pt "#135
.ds ptclr.ln "#725
.ds ptclr.fl "#fff
.de ptbeg
.	br
.	nr ptxmin 0\\$1
.	nr ptxmax 0\\$2
.	nr ptxwid 0\\n[ptxmax]-\\n[ptxmin]
.	nr ptymin 0\\$3
.	nr ptymax 0\\$4
.	nr ptywid 0\\n[ptymax]-\\n[ptymin]
.	nr ptwd \\n(.l-\\n(.i
.	nr ptht \\n[ptywid]*\\n[ptwd]/\\n[ptxwid]
.	nr ptxoff \\n(.i
.	nr ptyoff \\n(.d+\\n[ptht]
.	ne \\n[ptht]u
.	ev ptenv
.	nf
..
.de ptend
.	ps \\n[ptlnsz]
.	if \\n[ptbox] \
\v'|\\n[ptyoff]u'\h'|\\n[ptxoff]u'\D'p \\n[ptwd]u 0 0 -\\n[ptht]u -\\n[ptwd]u 0'
.	ps
.	sp |\\n[ptyoff]u
.	ev
..
.de ptclr
.	if \\n(.$>0 .if !'-'\\$1' .ds ptclr.ln "\\$1
.	if \\n(.$>1 .if !'-'\\$2' .ds ptclr.pt "\\$2
.	if \\n(.$>2 .if !'-'\\$3' .ds ptclr.fl "\\$3
..
.de ptdef
.	nr pt.\\$1.x \\$2
.	nr pt.\\$1.y \\$3
.	nr pt.\\$1.xu \\n[ptxoff]+((\\$2-\\n[ptxmin])*\\n[ptwd]/\\n[ptxwid])
.	nr pt.\\$1.yu \\n[ptyoff]-((\\$3-\\n[ptymin])*\\n[ptht]/\\n[ptywid])
.	ds pt.\\$1.s "\\$1
.	if \\n(.$>3 .ds pt.\\$1.s "\\$4
..
.de ptvert
.	cl \\*[ptclr.pt]
\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u-(\\n[ptcir]u/2u)'\D'C \\n[ptcir]u'
.	cl
.	sp -1
..
.de ptdesc
.	ptvert \\$1
.	ft \\*[ptfont]
.	ps \\n[ptsize]
\v'|\\n[pt.\\$1.yu]u+1v\\$4'\h'|\\n[pt.\\$1.xu]u-(\w'\\$2'u/2u)\\$3'\\$2
.	ft
.	ps
.	sp -1
..
.de ptput
.	ptdesc "\\$1" "\\*[pt.\\$1.s]" \\$2 \\$3
..
.de ptdot
.	nr _xu \\n[ptxoff]+((\\$2-\\n[ptxmin])*\\n[ptwd]/\\n[ptxwid])
.	nr _yu \\n[ptyoff]-((\\$3-\\n[ptymin])*\\n[ptht]/\\n[ptywid])
.	ft \\*[ptfont]
.	ps \\n[ptsize]
\v'|\\n[_yu]u+1v\\$3'\h'|\\n[xu]u-(\\n[ptcir]u/2u)'
.	ft
.	ps
.	sp -1
.	cl \\*[ptclr.pt]
\v'|\\n[_yu]u'\h'|\\n[_xu]u-(\\n[ptcir]u/2u)'\D'C \\n[ptcir]u'
.	cl
.	sp -1
..
.de ptline
.	nr ptxdiff (\\n[pt.\\$2.xu]-\\n[pt.\\$1.xu])
.	nr ptydiff (\\n[pt.\\$2.yu]-\\n[pt.\\$1.yu])
.	cl \\*[ptclr.ln]
.	ps \\n[ptlnsz]
\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u'\D'l \\n[ptxdiff]u \\n[ptydiff]u'
.	ps
.	cl
.	sp -1
..
.de ptlink
.	ptline \\$1 \\$2
.	if \\n(.$>2 .ptline \\$2 \\$3
.	if \\n(.$>3 .ptline \\$3 \\$4
.	if \\n(.$>4 .ptline \\$4 \\$5
.	if \\n(.$>5 .ptline \\$5 \\$6
.	if \\n(.$>6 .ptline \\$6 \\$7
.	if \\n(.$>7 .ptline \\$7 \\$8
.	if \\n(.$>8 .ptline \\$8 \\$9
.	if \\n(.$>9 .ptline \\$9 \\$(10
.	if \\n(.$>10 .ptline \\$(10 \\$(11
..
.de ptput*
.	if \\n(.$>0 .ptput \\$1
.	if \\n(.$>1 .ptput \\$2
.	if \\n(.$>2 .ptput \\$3
.	if \\n(.$>3 .ptput \\$4
.	if \\n(.$>4 .ptput \\$5
.	if \\n(.$>5 .ptput \\$6
.	if \\n(.$>6 .ptput \\$7
.	if \\n(.$>7 .ptput \\$8
.	if \\n(.$>8 .ptput \\$9
.	if \\n(.$>9 .ptput \\$(10
.	if \\n(.$>10 .ptput \\$(11
..
.de ptseg
.	ptlink \\$1 \\$2
.	ptvert \\$1
.	ptvert \\$2
..
.de ptrect
.	nr ptxdiff (\\n[pt.\\$2.xu]-\\n[pt.\\$1.xu])
.	nr ptydiff (\\n[pt.\\$2.yu]-\\n[pt.\\$1.yu])
.	ps \\n[ptlnsz]
.	if \\n[ptfill] \{\
\m[\\*[ptclr.fl]]\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u'\D'P \\n[ptxdiff]u 0u 0u \\n[ptydiff]u -\\n[ptxdiff]u 0u'\m[]
.		sp -1
.	\}
\m[\\*[ptclr.ln]]\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u'\D'p \\n[ptxdiff]u 0u 0u \\n[ptydiff]u -\\n[ptxdiff]u 0u'\m[]
.	sp -1
.	ps
..
.de ptcir
.	nr ptcirrad \\n[ptwd]/\\n[ptxwid]
.	if \\n(.$>1 .nr ptcirrad \\n[ptcirrad]*(\\$2)
.	ps \\n[ptlnsz]
\m[\\*[ptclr.fl]]\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u-(\\n[ptcirrad]u/2u)'\D'C \\n[ptcirrad]u'\m[]
\m[\\*[ptclr.ln]]\v'|\\n[pt.\\$1.yu]u'\h'|\\n[pt.\\$1.xu]u-(\\n[ptcirrad]u/2u)'\D'c \\n[ptcirrad]u'\m[]
.	ps
..
.de pttext
.	ft \\*[ptfont]
.	ps \\n[ptsize]
\v'|\\n[pt.\\$1.yu]u\\$3'\h'|\\n[pt.\\$1.xu]u\\$4'\\$2
.	sp -1
.	ft
.	ps
..