clean_mayavi_mesh.py

#!/usr/bin/env python3
import re
import sys
import math
from optparse import OptionParser

line_re = re.compile(r'''^(?P<x>\d+\.\d+)\s+(?P<y>\d+\.\d+)\s+L''')

bb_re=re.compile(r'''^%%BoundingBox:''')

linestyle_re = re.compile(r'''^\d+\s+setlinecap\s+\d+\s+setlinejoin\s*\n$''')

class PostscriptError(Exception):
    """Exception for malformed Postscript."""
    pass

def find_bounding_box(ps, margin=10):
    '''Find the ends of all the lines in the mesh and set the bounding box
    to slightly larger than their hull'''

    bb=[float('inf'),float('inf'),-float('inf'),-float('inf')]

    for line in ps:
        m=line_re.match(line)
        if m:
            x=float(m.group("x"))
            y=float(m.group("y"))

            bb[0]=min(bb[0],x)
            bb[2]=max(bb[2],x)
            bb[1]=min(bb[1],y)
            bb[3]=max(bb[3],y)


    bb[0]=int(math.floor(bb[0])-margin)
    bb[1]=int(math.floor(bb[1])-margin)
    bb[2]=int(math.ceil(bb[2])+margin)
    bb[3]=int(math.ceil(bb[3])+margin)

    return bb

def set_bounding_box(ps, margin):

    bb=find_bounding_box(ps, margin)

    for i in range(len(ps)):
        
        if (bb_re.match(ps[i])):
            ps[i]="%%BoundingBox: "+" ".join(map(str,bb))+"\n"

            # Once we find the bounding box, we can stop.
            return

    raise PostscriptError("No bounding box in input file.")

def set_linestyle(ps):

    for i in range(len(ps)):
        
        if (linestyle_re.match(ps[i])):
            ps[i]="1 setlinecap 1 setlinejoin\n"
            return

    raise PostscriptError("No line style parameters in input file.")

def process_file(inname, outname, options):

    ps=open(inname,'r').readlines()

    set_bounding_box(ps,options.margin)
    set_linestyle(ps)

    open(outname,"w").writelines(ps)


if __name__=='__main__':
    optparser=OptionParser(usage='''usage: %prog [options] <input_filename> <output_filename>

    This program cleans up vector eps mesh images output by Mayavi2.

    The input file should be an eps file output by the "save scene as"
    "Vector PS/EPS/PDF/TeX" option in Mayavi2.''',
                    add_help_option=True)

    optparser.add_option("--margin",
                         action="store",
                         type="int",
                         dest="margin",
                         default=10,
                         help="margin around the mesh in points. Default is 10.")
    
    optparser.set_defaults(dir=".", project="")

    (options, argv) = optparser.parse_args()

    try:
        infile=argv[0]
        outfile=argv[1]
    except IndexError:
        optparser.print_help()
        sys.exit(1)

    process_file(infile, outfile, options)