paths2json/paths2json.txt

#!/usr/bin/env python3
# GTA SA IPL to JSON parser, Python 3.2 (Windows 2000) or up
# Also compatible with Linux and others

# Arguments: <input.ipl> <output.json>
# Example: ipl2json.py nodes14.ipl nodes14.json

# You can get the ipl files from GTA3.IMG

# Thanks to: https://gtamods.com/wiki/Paths_(GTA_SA)

# --------------------------------------------------------------------------

# MIT License

# Copyright (c) 2024

# 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.

import sys
import os
import json

def read(fh,tp):
	signed = True
	if tp[0] == "u":
		tp = tp[1:]
		signed = False
	
	if tp.startswith("int"):
		tp = tp[3:]
		tp = int(int(tp) / 8)
		return int.from_bytes(fh.read(tp),byteorder="little",signed=signed)
	
	if tp != "float":
		raise Exception("Invalid format: " +tp)
	
	return float.from_bytes(fh.read(4),byteorder="little",signed=signed)

ipl = open(sys.argv[1],"rb")
# HEADER
output = {}
output["node_count"] = read(ipl,"uint32")
output["veh_node_count"] = read(ipl,"uint32")
output["ped_node_count"] = read(ipl,"uint32")
output["navi_node_count"] = read(ipl,"uint32")
output["link_count"] = read(ipl,"uint32")

# Some helpers for seeking file
offset_node_links = 20 + (28 * output["node_count"]) + (14 * output["navi_node_count"])
offset_navi_links = offset_node_links + (4 * output["link_count"]) + 768
offset_link_lengths = offset_navi_links + (2 * output["link_count"])
offset_path_intersection = offset_link_lengths + output["link_count"]

def access_bit(data, num):
    base = int(num // 8)
    shift = int(num % 8)
    return (data[base] >> shift) & 0x1

# SECTION 1 - PATH NODES
output["path_nodes"] = {}
node_index = 0
while node_index < output["node_count"]:
	node = {}
	node["mem_address"] = read(ipl,"uint32") # useless (unused)
	node["unknown0"] = read(ipl,"uint32") # useless
	node["pos"] = {}
	node["pos"]["x"] = read(ipl,"int16")
	node["pos"]["y"] = read(ipl,"int16")
	node["pos"]["z"] = read(ipl,"int16")
	node["unknown1"] = read(ipl,"int16") # useless
	node["link_id"] = read(ipl,"uint16") # useless (links are stored in node)
	node["area_id"] = read(ipl,"uint16") # useless-ish (in file name)
	node["node_id"] = read(ipl,"uint16") # useless (nodes are indiced by their ID)
	node["path_width"] = read(ipl,"uint8")
	node["node_type"] = read(ipl,"uint8")
	node["flags"] = []
	flags = ipl.read(4)
	for i in range(32): node["flags"].append(access_bit(flags,i))
	node["link_count"] = node["flags"][0] + node["flags"][1] + node["flags"][2] + node["flags"][3]
	
	# Reading links (section 3)
	node["links"] = []
	link_i = 0
	oldoffset = ipl.tell()
	offset = offset_node_links + (4 * node["link_id"])
	ipl.seek(offset)
	while link_i < node["link_count"]:
		link = {}
		link["area_id"] = read(ipl,"uint16")
		link["node_id"] = read(ipl,"uint16")
		link["navi_area_id"] = 0
		link["navi_node_id"] = 0
		link["length"] = 0
		link["flags"] = []
		node["links"].append(link)
		link_i += 1
	ipl.seek(oldoffset)
	
	# Reading navi links (section 5)
	link_i = 0
	oldoffset = ipl.tell()
	offset = offset_navi_links + (2 * node["link_id"])
	ipl.seek(offset)
	while link_i < node["link_count"]:
		data = ipl.read(2)
		node_id = ""
		area_id = ""
		for i in range(10): node_id = str(access_bit(data,i)) + node_id
		for i in range(10,16): area_id = str(access_bit(data,i)) + area_id
		node["links"][link_i]["navi_node_id"] = int(node_id,2)
		node["links"][link_i]["navi_area_id"] = int(area_id,2)
		link_i += 1
	ipl.seek(oldoffset)
	
	# Reading link lengths (section 6)
	link_i = 0
	oldoffset = ipl.tell()
	offset = offset_link_lengths + node["link_id"]
	ipl.seek(offset)
	while link_i < node["link_count"]:
		node["links"][link_i]["length"] = read(ipl,"uint8")
		link_i += 1
	ipl.seek(oldoffset)
	
	# Reading path intersection flags (section 7)
	link_i = 0
	oldoffset = ipl.tell()
	offset = offset_path_intersection + (node["link_id"] * 2)
	ipl.seek(offset)
	while link_i < node["link_count"]:
		node["links"][link_i]["flags"].append(read(ipl,"uint8"))
		node["links"][link_i]["flags"].append(read(ipl,"uint8"))
		link_i += 1
	ipl.seek(oldoffset)
	
	output["path_nodes"][node["node_id"]] = node
	node_index += 1

# SECTION 2 - NAVI NODES
output["navi_nodes"] = {}
node_index = 0
while node_index < output["navi_node_count"]:
	node = {}
	node["pos"] = {}
	node["pos"]["x"] = read(ipl,"int16")
	node["pos"]["y"] = read(ipl,"int16")
	node["area_id"] = read(ipl,"uint16") # useless-ish (in file name)
	node["node_id"] = read(ipl,"uint16") # useless (nodes are indiced by their ID)
	node["dir"] = {}
	node["dir"]["x"] = read(ipl,"int8")
	node["dir"]["y"] = read(ipl,"int8")
	node["flags"] = []
	flags = ipl.read(4)
	for i in range(32): node["flags"].append(access_bit(flags,i))
	node["lane_left_count"] = node["flags"][8] + node["flags"][9] + node["flags"][10]
	node["lane_right_count"] = node["flags"][11] + node["flags"][12] + node["flags"][13]
	output["navi_nodes"][node["node_id"]] = node
	
	node_index += 1

ipl.close()
outf = open(sys.argv[2],"w")
outf.write(json.dumps(output,sort_keys=True,indent=2)) # Put indent to None instead of 2 for smaller output (less readable)
outf.close()