Current File : //usr/local/share/groff/current/pic/chem.pic
# macros for chem
# Source file position: <groff-source>/contrib/chem/chem.pic
# Installed position: <prefix>/share/groff/<version>/pic
# Copyright (C) 2006-2018 Free Software Foundation, Inc.
# Written by Brian Kernighan <http://cm.bell-labs.com/cm/cs/who/bwk>,
# modified by Bernd Warken <groff-bernd.warken-72@web.de>.
# This file is part of 'chem', which is part of 'groff'.
# 'groff' is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License (GPL) version 2 as
# published by the Free Software Foundation.
# 'groff' is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
# The license text for GPL2 is available in the internet at
# <http://www.gnu.org/licenses/gpl-2.0.html>.
########################################################################
pi = 3.141592654
deg = 57.29578
# cr = 0.08 # radius of invis circle at ring vertices (see cr[vh])
# crh = 0.16; crw = 0.12 # ht & wid of invis ellipse around atoms at ring vertices
# dav = 0.015 # vertical shift up for atoms in atom macro
# atom(text, wid, ht, carbon position, crh, crw, dav)
define atom { [
T: $1 wid $2 ht $3-2*$7
C: ellipse invis ht $5 wid $6 at T.w + ($4,$7)
L: ellipse invis ht $5 wid $6 at T.w + (cwid/2,$7)
R: ellipse invis ht $5 wid $6 at T.e + (-cwid/2,$7)
] }
# bond(length, angle in degrees, whatever)
define bond {
line $3 by ($1) * sin(($2)/deg), ($1) * cos(($2)/deg)
}
# fancy bonds: r, theta, from/at
define doublebond {
line $3 invis by ($1) * sin(($2)/deg), ($1) * cos(($2)/deg)
V1: last line.start; V2: last line.end; dx = V2.x-V1.x; dy = V2.y-V1.y
norm = sqrt(dx*dx + dy*dy)
ny = dx * .02 / norm
nx = -dy * .02 / norm
line from V1 + (nx,ny) to V2 + (nx,ny)
line from V1 - (nx,ny) to V2 - (nx,ny)
move to V2
}
define triplebond {
line $3 invis by ($1) * sin(($2)/deg), ($1) * cos(($2)/deg)
V1: last line.start; V2: last line.end; dx = V2.x-V1.x; dy = V2.y-V1.y
norm = sqrt(dx*dx + dy*dy)
ny = dx * .025 / norm
nx = -dy * .025 / norm
line from V1 + (nx,ny) to V2 + (nx,ny)
line from V1 - (nx,ny) to V2 - (nx,ny)
line from V1 to V2
move to V2
}
define backbond {
line $3 invis by ($1) * sin(($2)/deg), ($1) * cos(($2)/deg)
V1: last line.start; V2: last line.end; dx = V2.x-V1.x; dy = V2.y-V1.y
norm = sqrt(dx*dx + dy*dy)
n = norm / .025
ny = dx * .02 / norm
nx = -dy * .02 / norm
for i = 1 to n-1 do {
XZ: i/n <V1,V2>
line from XZ + (nx,ny) to XZ - (nx,ny)
}
move to V2
}
define frontbond {
line $3 invis by ($1) * sin(($2)/deg), ($1) * cos(($2)/deg)
V1: last line.start; V2: last line.end; dx = V2.x-V1.x; dy = V2.y-V1.y
ah = arrowht; aw = arrowwid; ahead = arrowhead
arrowht = sqrt(dx*dx + dy*dy)
arrowwid = 0.05
arrowhead = 7
line <- from V1 to V2
arrowht = ah; arrowwid = aw; arrowhead = ahead
}
### Emacs settings
# Local Variables:
# mode: Nroff
# End:
Mini Shell