#!/usr/bin/env python

# convert a file of gnuplot commands to a gif file.
# Unfortunately, gif output is not available in gnuplot, so gnuplot is
# used to write the plot image to another format (pbm or png), then the
# Python Image Library is used to convert it to gif.
#
# Updated July 19, 2006, BB

import sys, os
import Image

helpmsg = """Usage: gnu2gif.py plotfile [-x xsize -y ysize -c color -f font]
size = 1 means use default size (640x480)
color can be 1 (use color) or zero (black and white)
font can be s,m,l (small, medium, large)
Defaults: x,ysize=1 (640x480), color=1, font=m
Examples:
gnu2gif.py plotfile -c 0 -f s
   gives default size (640x480), monochrome, with small font
gnu2gif.py plotfile -x 1.2 -y 0.8
   gives 1.2*640, 0.8*480 = size 768x384
input plot001 gives output plot001.gif
"""

#  default size is 640 x 480 (for size_x = size_y = 1.0)
#  Alter size variables to reflect proportion of default size
# e.g. -x 1.2 -y 0.8 gives 768 x 384 pixels (total image, not plot interior)
size_x = 1.0
size_y = 1.0
color  = 1   # set to 1 = use color; set to zero = use black & white
font = 'medium'  # 'small', 'medium' or 'large'

def processargs(arglist):
    " eg. processargs [-d database -uuser -ppassword -t table_name] "
    D = {}
    while 1:
        if len(arglist) < 1:
            return D
        
        a = arglist[0]
        if a[0] == '-':
            if len(a) == 2:
                if len(arglist) < 2:
                    return D
                D[a] = arglist[1]
                arglist = arglist[2:]
            elif len(a) > 2:
                flag = a[0:2]
                val = a[2:]
                D[flag] = val
                arglist = arglist[1:]
        else:
            if 'noflag' in D:
                D['noflag'].append(a)
            else:
                D['noflag'] = [a]
            arglist = arglist[1:]

def exit():
    print helpmsg
    sys.exit(0)

if __name__ == '__main__':

    nargs = len(sys.argv[1:])
    if nargs == 0:
        exit()

    # process the arguments
    argdict = processargs(sys.argv[1:])
    if 'noflag' not in argdict: exit()
    else: inplot = argdict['noflag'][0]  # noflag is a list
    if not os.path.exists(inplot):
        print "Unable to find %s" % inplot
        sys.exit()
    if '-x' in argdict: size_x = float(argdict['-x'])
    if '-y' in argdict: size_y = float(argdict['-y'])
    if '-c' in argdict: color  = int(argdict['-c'])
    if '-f' in argdict:
        f = argdict['-f'].lower()
        if   f[0] == 's': font = 'small'
        elif f[0] == 'm': font = 'medium'
        elif f[0] == 'l': font = 'large'

    base,ext = os.path.splitext(inplot)
    outplot = base + ".gif"
                
    if color > 0:  cbw = 'color'
    else: cbw = 'monochrome'

    # png looks better, but not available on Irix(?)
    if sys.platform[:4] == 'irix':
        platform = 'irix'
        filetype = "pbm"
    else:
        platform = 'linux'
        filetype = "png"
        
    # create the gnuplot file that will write out an image
    tmpname = 'tmp66tg65.' + filetype
    f = open(tmpname, 'w')
    f.write("set size %f,%f\n" % (size_x, size_y))
    f.write("set terminal %s %s %s\n" % (filetype, cbw, font))
    f.write("set output '%s'\n" % (tmpname))
    f.close()

    cmd = 'gnuplot %s %s' % (tmpname,inplot)
    os.system(cmd)  # call gnuplot

    # convert the temporary file to gif format
    Image.open(tmpname).save(outplot)
    print "output written to %s" % outplot
    os.remove(tmpname)