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| -rw-r--r-- | contrib/chem/chem.pic | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/contrib/chem/chem.pic b/contrib/chem/chem.pic new file mode 100644 index 0000000..33e932c --- /dev/null +++ b/contrib/chem/chem.pic @@ -0,0 +1,89 @@ +# macros for chem + +# Copyright (C) 2006-2020 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 +} +# Local Variables: +# mode: Nroff +# End: |