Python GTA: SA Path Reader

sapaths.py

from struct import unpack
from cStringIO import StringIO


class SAPath():
    def __init__(self, node):
        self.path = StringIO(open(node, "rb").read())
        self.header = {}
        self.pathnodes = []
        self.navinodes = []
        self.links = []
        self.navilinks = []
        self.linklengths = []
        self._offset = 20

        # headers
        self.header['nodes'] = unpack('I', self.path.read(4))[0]
        self.header['vehnodes'] = unpack('I', self.path.read(4))[0]
        self.header['pednodes'] = unpack('I', self.path.read(4))[0]
        self.header['navinodes'] = unpack('I', self.path.read(4))[0]
        self.header['links'] = unpack('I', self.path.read(4))[0]

    def Headers(self):
        return self.header

    def Paths(self):
        if len(self.pathnodes) != self.header['nodes']:
            self.path.seek(self._offset, 0)
            for i in range(self.header['nodes']):
                self.pathnodes.append({})
                self.pathnodes[i]['mem'] = unpack('I', self.path.read(4))[0]
                self.pathnodes[i]['zero'] = unpack('I', self.path.read(4))[0]
                self.pathnodes[i]['x'] = float(unpack('h', self.path.read(2))[0]) / 8
                self.pathnodes[i]['y'] = float(unpack('h', self.path.read(2))[0]) / 8
                self.pathnodes[i]['z'] = float(unpack('h', self.path.read(2))[0]) / 8
                self.pathnodes[i]['unknown'] = unpack('h', self.path.read(2))[0]
                self.pathnodes[i]['link'] = unpack('h', self.path.read(2))[0]
                self.pathnodes[i]['area'] = unpack('h', self.path.read(2))[0]
                self.pathnodes[i]['node'] = unpack('h', self.path.read(2))[0]
                self.pathnodes[i]['width'] = unpack('b', self.path.read(1))[0] / 8
                self.pathnodes[i]['type'] = unpack('b', self.path.read(1))[0]
                self.pathnodes[i]['flags'] = unpack('I', self.path.read(4))[0]
        return self.pathnodes

    def NaviNodes(self):
        if len(self.navinodes) != self.header['navinodes']:
            self.path.seek(self._offset + (self.header['nodes'] * 28), 0)
            for i in range(self.header['navinodes']):
                self.navinodes.append({})
                self.navinodes[i]['x'] = float(unpack('h', self.path.read(2))[0]) / 8
                self.navinodes[i]['y'] = float(unpack('h', self.path.read(2))[0]) / 8
                self.navinodes[i]['area'] = unpack('h', self.path.read(2))[0]
                self.navinodes[i]['node'] = unpack('h', self.path.read(2))[0]
                self.navinodes[i]['disx'] = float(unpack('b', self.path.read(1))[0]) / 8
                self.navinodes[i]['disy'] = float(unpack('b', self.path.read(1))[0]) / 8
                self.navinodes[i]['flags'] = unpack('I', self.path.read(4))[0]
        return self.navinodes

    def Links(self):
        if len(self.links) != self.header['links']:
            self.path.seek(self._offset + (self.header['nodes'] * 28) + (self.header['navinodes'] * 14), 0)
            for i in range(self.header['links']):
                self.links.append({})
                self.links[i]['area'] = unpack('h', self.path.read(2))[0]
                self.links[i]['node'] = unpack('h', self.path.read(2))[0]
        return self.links

    def NaviLinks(self):
        if len(self.navilinks) != self.header['links']:
            self.path.seek(self._offset + (self.header['nodes'] * 28) + (self.header['navinodes'] * 14) + (
            self.header['links'] * 4) + 768, 0)
            for i in range(self.header['links']):
                b = unpack('H', self.path.read(2))[0]

                self.navilinks.append({})
                self.navilinks[i]['area'] = (b >> 10) & 0x3F
                self.navilinks[i]['navinode'] = b & 0x3FF

        return self.navilinks

    def LinkLengths(self):
        if len(self.linklengths) != self.header['links']:
            self.path.seek(self._offset + (self.header['nodes'] * 28) + (self.header['navinodes'] * 14) + (
            self.header['links'] * 4) + 768 + (self.header['links'] * 2), 0)
            for i in range(self.header['links']):
                self.linklengths.append(unpack('b', self.path.read(1))[0])
        return self.linklengths

    def Close(self):
        self.path.close()