Assets - Analyzing Mission Files

Traffic Department's mission files present a considerable challenge to analyze because they are have an arbitrary design and relate to conceptual ideas in the game that have no conventional format. The original developer could have stored any information in any order they wanted. Luckily for us, the 59 mission files are all the same size (20,080 bytes), which means we can assume that a byte in some position in one file has the same meaning across all the files. We'll study the byte statistics across this sample to determine their purpose. Like the other data assets, we only need to understand what the file is doing so we can incorporate it as-is in our prototype.

Mission File Format

The layout of the TD2192 mission data files

The mission files contain the ship type data for 20 ships along with their mission paths that are directly applied to the map. An unusual point is that the first 19 ships have paths that include 501 points, while the last ship has only 481 points.

Mission File Analyzer in Python

We used a Python script to find the maximum byte values and section breaks across all positions among the 59 mission files. This gave us insight as to the purpose of the sections and byte values.

import os, glob

data = [] 	# Holds all bytes across all files
data_max = []	# Holds max value for each byte position across all files

# LOAD ALL FILES INTO DATA ARRAY
for filename in glob.glob(os.path.join(os.getcwd(),'M*.TD*')):
	filedata = open(filename,'rb')
	byte_index=0
	for line in filedata:
		for byte in line:
			try: data[byte_index].append(byte)
			except: data.append([byte])
			byte_index+=1
	filedata.close()

# CALCULATE DATA_MAX VALUE ARRAY
for bytearray in data: data_max.append(max(bytearray))

# CONVENIENT DISPLAY OF MAX DATA VALUES
def show_data(minlines=0,maxlines=21000):
	offset=0
	for item in data_max:
		if offset >= minlines: print(hex(offset),": ", item)
		offset+=1
		if offset > maxlines: break

# SHOW ALL BREAKS
def show_breaks():
	last_break=0
	this_break=0
	size=0
	for i in range(len(data_max)):
		if data_max[i-1]==0:
			if data_max[i] > 0:
				this_break = i
				size = this_break-last_break-1
				print(hex(this_break), "-- Size:", size)
		last_break = int(this_break)

import os, glob

data = [] # Holds all bytes across all files

data_max = [] # Holds max value for each byte position across all files

# LOAD ALL FILES INTO DATA ARRAY

for filename in glob.glob(os.path.join(os.getcwd(),'M*.TD*')):

filedata = open(filename,'rb')

byte_index=0

for line in filedata:

for byte in line:

try: data[byte_index].append(byte)

except: data.append([byte])

byte_index+=1

filedata.close()

# CALCULATE DATA_MAX VALUE ARRAY

for bytearray in data: data_max.append(max(bytearray))

# CONVENIENT DISPLAY OF MAX DATA VALUES

def show_data(minlines=0,maxlines=21000):

offset=0

for item in data_max:

if offset >= minlines: print(hex(offset),": ", item)

offset+=1

if offset > maxlines: break

# SHOW ALL BREAKS

def show_breaks():

last_break=0

this_break=0

size=0

for i in range(len(data_max)):

if data_max[i-1]==0:

if data_max[i] > 0:

this_break = i

size = this_break-last_break-1

print(hex(this_break), "-- Size:", size)

last_break = int(this_break)

Map and Waypoint Analyzer in Python

We put all our knowledge together and extracted an NPC's mission waypoints and drew it out on the city map with this Python script.

file=open('TD.MAP','rb').read()   # DANGLING FILE DESCRIPTOR
mission=open('M1.TD1','rb').read()  # SECOND PHASE

map=[]

#LOAD UP MAP
for mapx in range(201):
	map.append([])
	for mapy in range(201):
		if file[mapx*201+mapy] == 0x31: map[mapx].append('.')
		elif file[mapx*201+mapy] == 0x32: map[mapx].append('.')
		elif file[mapx*201+mapy] == 0x33: map[mapx].append('.')
		#elif file[mapx*201+mapy] == 0x3B: map[mapx].append('.')
		#elif file[mapx*201+mapy] == 0x3C: map[mapx].append('.')
		#elif file[mapx*201+mapy] == 0x3D: map[mapx].append('.')
		else: map[mapx].append('O')

#LOAD UP SHIP WAYPOINTS  SECOND PHASE
for i in range(500):
	x_pos = mission[0x50+i]
	y_pos = mission[0x50+10000+i]
	map[x_pos][y_pos]='X'

#PRINT OUT MAP
for i in range(201):
	line=''
	for j in range(201):
		line+=map[j][i]
	print(line,end="")

file=open('TD.MAP','rb').read() # DANGLING FILE DESCRIPTOR

mission=open('M1.TD1','rb').read() # SECOND PHASE

map=[]

#LOAD UP MAP

for mapx in range(201):

map.append([])

for mapy in range(201):

if file[mapx*201+mapy] == 0x31: map[mapx].append('.')

elif file[mapx*201+mapy] == 0x32: map[mapx].append('.')

elif file[mapx*201+mapy] == 0x33: map[mapx].append('.')

#elif file[mapx*201+mapy] == 0x3B: map[mapx].append('.')

#elif file[mapx*201+mapy] == 0x3C: map[mapx].append('.')

#elif file[mapx*201+mapy] == 0x3D: map[mapx].append('.')

else: map[mapx].append('O')

#LOAD UP SHIP WAYPOINTS SECOND PHASE

for i in range(500):

x_pos = mission[0x50+i]

y_pos = mission[0x50+10000+i]

map[x_pos][y_pos]='X'

#PRINT OUT MAP

for i in range(201):

line=''

for j in range(201):

line+=map[j][i]

print(line,end="")

Mission Section Offsets

Reading in the correct data is important so we'll rely on the following offsets:

Section	First byte	Last Byte	Notes
Unused	0x0000	0x0027	One mission has a non-zero value in position 0x000A, but the reason isn't clear. This section is apparently unused
Ship types	0x0028	0x003B	One byte used per ship for twenty ships. Valid values are 0x00-0x08 and 0xFF. FF indicates an unused ship.
Unused	0x003C	0x004F	Not used
Ship 1 x-coord	0x0050	0x0244	Ship mission waypoints (501 points)
Ship 2 x-coord	0x0245	0x0439	Ship mission waypoints (501 points)
Ship 3 x-coord	0x043A	0x062E	Ship mission waypoints (501 points)
Ship 4 x-coord	0x062F	0x0823	Ship mission waypoints (501 points)
Ship 5 x-coord	0x0824	0x0A18	Ship mission waypoints (501 points)
Ship 6 x-coord	0x0A19	0x0C0D	Ship mission waypoints (501 points)
Ship 7 x-coord	0x0C0E	0x0E02	Ship mission waypoints (501 points)
Ship 8 x-coord	0x0E03	0x0FF7	Ship mission waypoints (501 points)
Ship 9 x-coord	0x0FF8	0x11EC	Ship mission waypoints (501 points)
Ship 10 x-coord	0x11ED	0x13E1	Ship mission waypoints (501 points)
Ship 11 x-coord	0x13E2	0x15D6	Ship mission waypoints (501 points)
Ship 12 x-coord	0x15D7	0x17CB	Ship mission waypoints (501 points)
Ship 13 x-coord	0x17CC	0x19C0	Ship mission waypoints (501 points)
Ship 14 x-coord	0x19C1	0x1BB5	Ship mission waypoints (501 points)
Ship 15 x-coord	0x1BB6	0x1DAA	Ship mission waypoints (501 points)
Ship 16 x-coord	0x1DAB	0x1F9F	Ship mission waypoints (501 points)
Ship 17 x-coord	0x1FA0	0x2194	Ship mission waypoints (501 points)
Ship 18 x-coord	0x2195	0x2389	Ship mission waypoints (501 points)
Ship 19 x-coord	0x238A	0x257E	Ship mission waypoints (501 points)
Ship 20 x-coord	0x257F	0x275F	Ship mission waypoints (481 points)
Ship 1 y-coord	0x2760	0x2954	Ship mission waypoints (501 points)
Ship 2 y-coord	0x2955	0x2B49	Ship mission waypoints (501 points)
Ship 3 y-coord	0x2B4A	0x2D3E	Ship mission waypoints (501 points)
Ship 4 y-coord	0x2D3F	0x2F33	Ship mission waypoints (501 points)
Ship 5 y-coord	0x2F34	0x3128	Ship mission waypoints (501 points)
Ship 6 y-coord	0x3129	0x331D	Ship mission waypoints (501 points)
Ship 7 y-coord	0x331E	0x3512	Ship mission waypoints (501 points)
Ship 8 y-coord	0x3513	0x3707	Ship mission waypoints (501 points)
Ship 9 y-coord	0x3708	0x38FC	Ship mission waypoints (501 points)
Ship 10 y-coord	0x38FD	0x3AF1	Ship mission waypoints (501 points)
Ship 11 y-coord	0x3AF2	0x3CE6	Ship mission waypoints (501 points)
Ship 12 y-coord	0x3CE7	0x3EDB	Ship mission waypoints (501 points)
Ship 13 y-coord	0x3EDC	0x40D0	Ship mission waypoints (501 points)
Ship 14 y-coord	0x40D1	0x42C5	Ship mission waypoints (501 points)
Ship 15 y-coord	0x42C6	0x44BA	Ship mission waypoints (501 points)
Ship 16 y-coord	0x44BB	0x46AF	Ship mission waypoints (501 points)
Ship 17 y-coord	0x46B0	0x48A4	Ship mission waypoints (501 points)
Ship 18 y-coord	0x48A5	0x4A99	Ship mission waypoints (501 points)
Ship 19 y-coord	0x4A9A	0x4C8E	Ship mission waypoints (501 points)
Ship 20 y-coord	0x4C9F	0x4E6F	Ship mission waypoints (481 points)

Mission File Usage

We'll eventually have to create the NPC ships in our prototype. We'll read in the mission file as-is and pull the 20 ship type headers to create the appropriate ships. Then we'll attach an AI object to each ship that holds the paths.

< Part 12 – Analyzing Dialogue Files	Part 14 – Sound and Music >