diff -r 000000000000 -r 007bbb709982 cylindertransport.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cylindertransport.py	Sun Apr 02 23:59:00 2017 +0200
@@ -0,0 +1,133 @@
+from math import sqrt
+from PIL import Image, ImageDraw, ImageFont
+import argparse, sys
+
+# pfad zu den TTF files (arial.ttf)
+FONTBASE = "/usr/share/fonts/truetype/msttcorefonts/"
+
+SPACE_MIN = 10 # minimum offset between bottles
+
+# Durchmesser, Laenge, Volumen und Gewicht der verfuegbaren Tauchflaschen
+CYLINDER = {
+	"03"	: [100, 515, 3,  4.7],
+	"05"	: [140, 466, 5,	 5.7],
+	"07"	: [140, 605, 7,  8.8],
+	"08"	: [171, 490, 8,  10.4],
+	"10"	: [171, 595, 10, 12.4],
+	"12S"	: [204, 550, 12, 15.4],
+	"12L"	: [171, 690, 12, 14.5],
+	"15"	: [204, 640, 15, 18.1],
+}
+
+PIPES = [
+	["DN8", 13.5],
+	["DN10", 17.2],
+	["DN15", 21.3],
+	["DN20", 26.9],
+	["DN25", 33.7],
+	["DN32", 42.4],
+	["DN40", 48.3],
+	["DN50", 60.3],
+	["DN65", 76.1],
+	["DN80", 88.9],
+	["DN100", 114.3],
+	["DN125", 139.7],
+	["DN150", 168.3],
+]
+
+
+
+def offset(r1, r2):
+	o = (2*sqrt(r1*r2))
+	#print "offset %i" % o
+	return o
+
+def calc_min(r1, r2):
+	# stupider annaehreungsversuch, bis sich die beiden Tauchflaschen r1 und r2 nicht mehr beruehren
+	#print "r1=%.0f r2=%.0f" % (r1, r2)
+	for p in PIPES:
+		i = p[1] / 2
+		if i>r1 or i>r2:
+			print "spacer radius > r1 or r2, abort"
+			return None
+		x1 = offset(r1, i)
+		x2 = offset(r2, i)
+		x = (x1 + x2) - (r1+r2) 
+		if x >= SPACE_MIN:
+			print "%s Pipe (%.1fmm), Cylinder spacing: %imm" % (p[0], p[1], x)
+			return [r1, i, r2, p[0]]
+	return None
+
+def circ(draw, x, r, txt = "", txtfactor = 1.0):
+	draw.arc([x-r, 0, x + r, 2 * r], 0, 360, 'white')
+	if txt != "":
+		font = ImageFont.truetype(FONTBASE+"arial.ttf", int(24*txtfactor))
+		tox, toy = draw.textsize(txt, font=font)
+		draw.text((x-tox/2, r-toy/2), txt, font=font, fill='#ffffff')
+
+
+def draw_bottles(draw, args):
+	bottles = args.cylinders
+	SPACE_MIN = args.space_min
+
+	spacerY1 = 200
+	spacerY2 = 220
+	# first bottle spacer
+	r1 = CYLINDER[bottles[0]][0] / 2
+	r2 = CYLINDER[bottles[1]][0] / 2
+	x = 20 + r1 # start offset x
+	r1, r2, r3, dn  = calc_min(r1, r2)
+	circ(draw, x, r2, dn, 0.5)
+	x = x + offset(r2, r3)
+
+	for i in range(0, len(bottles)-1):
+		r1 = CYLINDER[bottles[i]][0] / 2
+		r2 = CYLINDER[bottles[i+1]][0] / 2
+		r1, r2, r3, dn  = calc_min(r1, r2)
+		# draw bottle
+		circ(draw, x, r1, "Tank "+bottles[i])
+		sx1 = x+r1
+		x = x + offset(r1, r2)
+		# draw right spacer
+		circ(draw, x, r2, dn, 0.5)
+		x = x + offset(r2, r3)
+		sx2 = x-r3
+		if i == (len(bottles)-2):
+			# draw last bottle
+			circ(draw, x, r3, "Tank "+bottles[i+1])
+			x = x + offset(r2, r3)
+		# draw the space between bottles
+		draw.line((sx1, spacerY1, sx1, spacerY2), fill='#ffffff')
+		draw.line((sx2, spacerY1, sx2, spacerY2), fill='#ffffff')
+		txt = "%imm" % (sx2-sx1)
+		font = ImageFont.truetype(FONTBASE+"arial.ttf", 12)
+		tox, toy = draw.textsize(txt, font=font)
+		draw.text((sx1+(sx2-sx1)/2-(tox/2), spacerY2+toy/2), txt, font=font, fill='#ffffff')
+
+	# last bottle spacer
+	circ(draw, x, r2, dn, 0.5)
+
+def getimage(args):
+	image = Image.new('1', (1000, 250)) #create new image, 1000x500 pixels, 1 bit per pixel
+	draw = ImageDraw.Draw(image)
+	draw_bottles(draw, args)
+	return image
+
+if __name__ == "__main__":
+	parser = argparse.ArgumentParser(description="Calculate spacer pipes for pressure cylinder transport\n" +
+		"Known cylinder types:\n" + ", ".join(sorted(CYLINDER.keys())) )
+	parser.add_argument('cylinders', metavar='cylinder', type=str, nargs='+',
+                    help='cylinder types')
+	parser.add_argument('--space', dest='space_min', type=int,
+                    default=SPACE_MIN,
+                    help='minimum space between cylinders (mm)')
+
+	args = parser.parse_args()
+
+	for test in args.cylinders:
+		if not test in CYLINDER.keys():
+			print "Cylinder type '%s' is unknown" % test
+			sys.exit(1)
+
+	image = getimage(args)
+	image.show()
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