A simple Python program that can read DOOM.Hexen IWAD and PWAD files and render them as SVG see examples at http://jason.sperske.com/wad/

MIT-LICENSE

MIT License

Copyright (c) 2018 Jason Sperske

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

WADParser.py

#!/usr/bin/env python3

import struct
import re

class Wad(object):
    """Encapsulates the data found inside a WAD file"""

    def __init__(self, wadFile):
        """Each WAD files contains definitions for global attributes as well as map level attributes"""
        self.levels = []
        self.wad_format = 'DOOM' #Assume DOOM format unless 'BEHAVIOR' 
        with open(wadFile, "rb") as f:
            header_size = 12
            self.wad_type = f.read(4)[0]
            self.num_lumps = struct.unpack("<I", f.read(4))[0]
            data = f.read(struct.unpack("<I", f.read(4))[0] - header_size)

            current_level = Level(None) #The first few records of a WAD are not associated with a level

            lump = f.read(16) #Each offset is is part of a packet 16 bytes
            while len(lump) == 16:
                filepos = struct.unpack("<I", lump[0:4])[0] - header_size
                size = struct.unpack("<I", lump[4:8])[0]
                name = lump[8:16].decode('UTF-8').rstrip('\0')
                print(name)
                if(re.match('E\dM\d|MAP\d\d', name)):
                    #Level nodes are named things like E1M1 or MAP01
                    if(current_level.is_valid()):
                        self.levels.append(current_level)
                    
                    current_level = Level(name)
                elif name == 'BEHAVIOR':
                    #This node only appears in Hexen formated WADs
                    self.wad_format = 'HEXEN'
                else:
                    current_level.lumps[name] = data[filepos:filepos+size]

                lump = f.read(16)
            if(current_level.is_valid()):
                self.levels.append(current_level)

        for level in self.levels:
            level.load(self.wad_format)

class Level(object):
    """Represents a level inside a WAD which is a collection of lumps"""
    def __init__(self, name):
        self.name = name
        self.lumps = dict()
        self.vertices = []
        self.lower_left = None
        self.upper_right = None
        self.shift = None
        self.lines = []

    def is_valid(self):
        return self.name is not None and 'VERTEXES' in self.lumps and 'LINEDEFS' in self.lumps

    def normalize(self, point, padding=5):
        return (self.shift[0]+point[0]+padding,self.shift[1]+point[1]+padding)

    def load(self, wad_format):
        for vertex in packets_of_size(4, self.lumps['VERTEXES']):
            x,y = struct.unpack('<hh', vertex[0:4])
            self.vertices.append((x,y))

        self.lower_left = (min((v[0] for v in self.vertices)), min((v[1] for v in self.vertices)))
        self.upper_right = (max((v[0] for v in self.vertices)), max((v[1] for v in self.vertices)))

        self.shift = (0-self.lower_left[0],0-self.lower_left[1])
        
        packet_size = 16 if wad_format is 'HEXEN' else 14
        for data in packets_of_size(packet_size, self.lumps['LINEDEFS']):
            self.lines.append(Line(data))

    def save_svg(self):
        """ Scale the drawing to fit inside a 1024x1024 canvas (iPhones don't like really large SVGs even if they have the same detail) """
        import svgwrite
        view_box_size = self.normalize(self.upper_right, 10)
        if view_box_size[0] > view_box_size[1]:
            canvas_size = (1024, int(1024*(float(view_box_size[1])/view_box_size[0])))
        else:
            canvas_size = (int(1024*(float(view_box_size[0])/view_box_size[1])), 1024)

        dwg = svgwrite.Drawing(self.name+'.svg', profile='tiny', size=canvas_size , viewBox=('0 0 %d %d' % view_box_size))
        for line in self.lines:
            a = self.normalize(self.vertices[line.a])
            b = self.normalize(self.vertices[line.b])
            if line.is_one_sided():
                dwg.add(dwg.line(a, b, stroke='#333', stroke_width=10))
            else:
                dwg.add(dwg.line(a, b, stroke='#999', stroke_width=3))

        dwg.save()

class Line(object):
    """Represents a Linedef inside a WAD"""
    def __init__(self,data):
        self.a, self.b = struct.unpack('<hh', data[0:4])
        self.left_side, self.right_side = struct.unpack('<hh', data[-4:])

    def is_one_sided(self):
        return self.left_side == -1 or self.right_side == -1

def packets_of_size(n, data):
    size = len(data)
    index = 0
    while index < size:
        yield data[index : index+n]
        index = index + n
    return

if __name__ == "__main__":
    import sys

    if len(sys.argv) > 1:
        wad = Wad(sys.argv[1])
        for level in wad.levels:
            level.save_svg()
    else:
        print('You need to pass a WAD file as the only argument')

ohh of course! Why didn't I think to try that. Thank you!