Article Outline
Python pil example 'avecta'
Functions in program:
def levelsdump(fn,tg,tf,numbers=True):def leveldump(fn,count,d,tg,tf,numbers):def floortile(d,tf):def hex(d):def unpack_txt(b):def unpack_4bit(g, tw, th, stride, rows):def palette_color(x):
Modules used in program:
import PIL.ImageDrawimport PIL.ImageFontimport PIL.Image
python avecta
Python pil example: avecta
# Avecta I: Ebora is an Atari ST game published in STart Magazine, September 1989
#
# Information here:
# https://www.atarimagazines.com/startv4n2/avecta.html
#
# This program parses its data files, and generates maps from it.
# The file formats can be deduced from the program.
# Some of the data is described in comments.
import PIL.Image
import PIL.ImageFont
import PIL.ImageDraw
info = True
prg = open("AVECTA.PRG","rb").read()
grafxdat = open("GRAFX.DAT","rb").read()
filldat = open("FILL.DAT","rb").read()
font = PIL.ImageFont.truetype("ProggyTiny.ttf",16)
# Font available here: https://proggyfonts.net/download/
palette = [
0x000,
0x700,
0x007,
0x520,
0x560,
0x050,
0x741,
0x444,
0x770,
0x077,
0x641,
0x111, #0x000,
0x707,
0x765,
0x505,
0x777,
]
pattern = []
pattern_color_remap = [
0x0,0xF,0x2,0x3,
0x4,0x6,0x6,0x5,
0x7,0x9,0x9,0xB,
0xC,0xD,0xE,0xD,
] # 1,4,5,7,8,A,C,F are known. 0,2,3,6,9,B,D,E are unused/unknown.
# fill patterns derived from GFA Basic DEFFILL
fill_patterns = [
[0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,], # 0
[0xFFFF,0xBBBB,0xFFFF,0xEEEE,0xFFFF,0xBBBB,0xFFFF,0xEEEE,0xFFFF,0xBBBB,0xFFFF,0xEEEE,0xFFFF,0xBBBB,0xFFFF,0xEEEE,], # 1
[0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,0xFFFF,0xAAAA,], # 2
[0x7777,0xAAAA,0xDDDD,0xAAAA,0x7777,0xAAAA,0xDDDD,0xAAAA,0x7777,0xAAAA,0xDDDD,0xAAAA,0x7777,0xAAAA,0xDDDD,0xAAAA,], # 3
[0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,0x5555,0xAAAA,], # 4
[0x5555,0x2222,0x5555,0x8888,0x5555,0x2222,0x5555,0x8888,0x5555,0x2222,0x5555,0x8888,0x5555,0x2222,0x5555,0x8888,], # 5
[0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,0x5555,0x0000,], # 6
[0x1111,0x0000,0x4444,0x0000,0x1111,0x0000,0x4444,0x0000,0x1111,0x0000,0x4444,0x0000,0x1111,0x0000,0x4444,0x0000,], # 7
[0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,], # 8
[0x0000,0x7F7F,0x7F7F,0x7F7F,0x0000,0xF7F7,0xF7F7,0xF7F7,0x0000,0x7F7F,0x7F7F,0x7F7F,0x0000,0xF7F7,0xF7F7,0xF7F7,], # 9
[0xDFDF,0xBFBF,0x7F7F,0xBEBE,0xDDDD,0xEBEB,0xF7F7,0xEFEF,0xDFDF,0xBFBF,0x7F7F,0xBEBE,0xDDDD,0xEBEB,0xF7F7,0xEFEF,], # 10
[0xFFFF,0xFFFF,0xEFEF,0xD7D7,0xFFFF,0xFFFF,0xFEFE,0x7D7D,0xFFFF,0xFFFF,0xEFEF,0xD7D7,0xFFFF,0xFFFF,0xFEFE,0x7D7D,], # 11
[0xFDFD,0xFDFD,0x5555,0xAFAF,0xDFDF,0xDFDF,0x5555,0xFAFA,0xFDFD,0xFDFD,0x5555,0xAFAF,0xDFDF,0xDFDF,0x5555,0xFAFA,], # 12
[0xBFBF,0x7F7F,0xFFFF,0xF7F7,0xFBFB,0xFDFD,0xFFFF,0xDFDF,0xBFBF,0x7F7F,0xFFFF,0xF7F7,0xFBFB,0xFDFD,0xFFFF,0xDFDF,], # 13
[0x99F9,0x3939,0x2727,0xE7E7,0x7E7E,0x724E,0xF3CC,0x9FFF,0x99F9,0x3939,0x2727,0xE7E7,0x7E7E,0x724E,0xF3CC,0x9FFF,], # 14
[0xFFFF,0xFFFF,0xFBFF,0xFFFF,0xFFEF,0xFFFF,0x7FFF,0xFFFF,0xFFFF,0xFFFF,0xFBFF,0xFFFF,0xFFEF,0xFFFF,0x7FFF,0xFFFF,], # 15
[0x0707,0x9393,0x3939,0x7070,0xE0E0,0xC9C9,0x9C9C,0x0E0E,0x0707,0x9393,0x3939,0x7070,0xE0E0,0xC9C9,0x9C9C,0x0E0E,], # 16
[0x5555,0xFFFF,0x7777,0xEBEB,0xDDDD,0xBEBE,0x7777,0xFFFF,0x5555,0xFFFF,0x7777,0xEBEB,0xDDDD,0xBEBE,0x7777,0xFFFF,], # 17
[0xF7F7,0xFFFF,0x5555,0xFFFF,0xF7F7,0xFFFF,0x7777,0xFFFF,0xF7F7,0xFFFF,0x5555,0xFFFF,0xF7F7,0xFFFF,0x7777,0xFFFF,], # 18
[0x8888,0x6767,0x0707,0x0707,0x8888,0x7676,0x7070,0x7070,0x8888,0x6767,0x0707,0x0707,0x8888,0x7676,0x7070,0x7070,], # 19
[0x7F7F,0x7F7F,0xBEBE,0xC1C1,0xF7F7,0xF7F7,0xEBEB,0x1C1C,0x7F7F,0x7F7F,0xBEBE,0xC1C1,0xF7F7,0xF7F7,0xEBEB,0x1C1C,], # 20
[0x7E7E,0xBDBD,0xDBDB,0xE7E7,0xF9F9,0xFEFE,0x7F7F,0x7F7F,0x7E7E,0xBDBD,0xDBDB,0xE7E7,0xF9F9,0xFEFE,0x7F7F,0x7F7F,], # 21
[0x0F0F,0x0F0F,0x0F0F,0x0F0F,0xF0F0,0xF0F0,0xF0F0,0xF0F0,0x0F0F,0x0F0F,0x0F0F,0x0F0F,0xF0F0,0xF0F0,0xF0F0,0xF0F0,], # 22
[0xF7F7,0xE3E3,0xC1C1,0x8080,0x0000,0x8080,0xC1C1,0xE3E3,0xF7F7,0xE3E3,0xC1C1,0x8080,0x0000,0x8080,0xC1C1,0xE3E3,], # 23
]
for i in range(0,24):
dst = PIL.Image.new("RGBA",(16,16),(255,255,255,0))
dp = dst.load()
for y in range(16):
a = fill_patterns[i][y]
for x in range(16):
if ((a >> x) & 1) != 0:
dp[x,y] = (0,0,0,255)
pattern.append(dst)
def palette_color(x):
p = palette[x]
a = 0 if x == 0 else 255
return (
(((p>>8)&7) * 255) // 7,
(((p>>4)&7) * 255) // 7,
(((p>>0)&7) * 255) // 7,
a )
def unpack_4bit(g, tw, th, stride, rows):
def read16(x):
return (g[x+0] << 8) | g[x+1]
cols = ((len(g) // stride) + rows - 1) // rows
img = PIL.Image.new("RGB",(cols*tw,rows*th),(255,0,255))
tiles = []
for c in range(cols):
for r in range(rows):
od = ((c * rows) + r) * stride
ox = c * tw
oy = r * th
tile = PIL.Image.new("RGBA",(tw,th),(255,0,255,0))
pixels = tile.load()
for y in range(th):
for x in range(tw):
if (od + 8) >= len(g):
continue
p = 0
for plane in range(3,-1,-1):
#for plane in range(4):
m = read16(od+(plane*2))
p = (p << 1) | ((m >> (15-x)) & 1)
pixels[x,y] = palette_color(p)
od = od + 8
img.paste(tile,(ox,oy))
tiles.append(tile)
return (img, tiles)
def unpack_txt(b):
s = ""
addr = 0
ss = ""
def emit(x):
e = ""
if len(x) > 0:
e += "%04X: " % addr
e += ss + "\n"
return e
for i in range(len(b)):
c = b[i]
if c == 0:
s += emit(ss)
ss = ""
addr = i+1
else:
pc = "*"
if c >= 0x20 and c < 128:
pc = chr(c)
ss += pc
s += emit(ss)
return s
def hex(d):
s = ""
for v in d:
s += " %02X" % v
if len(s) > 0:
s = s[1:]
return s
def floortile(d,tf):
if d[0] == 0xFF: # background tile
return tf[d[1]]
elif d[0] == 0x02: # pattern fill tile (colours are remapped instead of direct?)
t = PIL.Image.new("RGBA",(16,16),palette_color(pattern_color_remap[d[2]]))
p = pattern[d[1]]
t.paste(p,(0,0),p)
return t
return tf[0] # ?
def leveldump(fn,count,d,tg,tf,numbers):
def read16(n):
return (d[n+0] << 8) | d[n+1]
# skip empty data
if all(v==0 for v in d):
return
# not empty:
iw = 256 if info else 16
ih = 0 if info else 0
img = PIL.Image.new("RGBA",(16*16+iw,8*16+ih),(0,0,0,0))
# floor
ft1 = floortile(d[0x10:0x13],tf)
ft2 = floortile(d[0x13:0x16],tf)
fl = [[0]*9 for x in range(16)]
coord0 = d[0]
c0 = coord0
for i in range(1,16):
# draw the walls (a cycle of nybble coordinates drawing straight lines)
c1 = d[i]
x = c0 & 15
y = c0 >> 4
xt = c1 & 15
yt = c1 >> 4
while (x != xt) or (y != yt):
fl[x][y] = 1
if x < xt:
x += 1
if x > xt:
x -= 1
if y < yt:
y += 1
if y > yt:
y -= 1
if (c1 == coord0):
break # wall ends when it meets the starting coordinate
c0 = c1
for y in range(0,8):
for x in range(0,16):
# fill the interior
if fl[x][y] != 0:
continue
x0c = 0
x1c = 0
y0c = 0
y1c = 0
for i in range(0,x):
if fl[i][y] == 1:
x0c += 1
for i in range(x+1,16):
if fl[i][y] == 1:
x1c += 1
for i in range(0,y):
if fl[x][i] == 1:
y0c += 1
for i in range(y+1,8):
if fl[x][i] == 1:
y1c += 1
if x0c < 1 or x1c < 1 or y0c < 1 or y1c < 1:
continue
fl[x][y] = 2
for y in range(0,8):
# draw floor
for x in range(0,16):
if fl[x][y] == 2:
img.paste(ft2,(x*16,y*16))
if fl[x][y] == 1:
img.paste(ft1,(x*16,y*16))
# items
color = [
# every item has 9 data bytes:
# 0 - tile
# 1 - ?
# 2 - door text?
# 3 - exit room number
# 4 - book/sign text?
# 5 - FF solid, FE locked, 01 filled, 00 empty ?
# 6 - X coordinate
# 7 - Y coordinate
# 8 - always 01 ?
(255,255, 0),(255,255,255),(255,255,255),
( 0,255, 0),(255,255,255),(255, 0, 0),
(200,128,128),(128,200,128),( 0,255,255) ]
draw = PIL.ImageDraw.Draw(img,"RGBA")
for i in range(14):
item = d[31+(i*9):31+(i*9)+9]
if all(v==0 for v in item):
continue
it = item[0]
ix = item[6]
iy = item[7]
img.paste(tg[it],(ix*16,iy*16),tg[it])
if info:
#s = ("%2d: " % i) + hex(item)
#draw.text(((16*16)+8,(i*9)+1),s,font=font)
draw.text(((16*16)+8,(i*9)+1),"%2d:"%i,font=font)
for j in range(9):
draw.text(((16*16)+26+(j*20),(i*9)+1),hex(item[j:j+1]),fill=color[j],font=font)
if numbers:
draw.rectangle((ix*16+2,iy*16+3,ix*16+13,iy*16+11),fill=(0,0,0,64))
draw.text((ix*16+2,iy*16+3),"%2d"%i,font=font)
if (item[8] == 0): # hidden
draw.rectangle((ix*16,iy*16,ix*16+15,iy*16+15),outline=color[8])
fn = fn + "." + ("%02X" % count)
if info:
ip = 16*16+iw-50
draw.text((ip, 5),hex([count]),fill=color[3],font=font)
# wall tile
draw.text((ip,14),hex(d[0x10:0x13]),font=font,fill=(128,128,128))
# floor tile
draw.text((ip,23),hex(d[0x13:0x16]),font=font,fill=(128,128,128))
# 9 more mystery bytes, the last one seems to indicate darkness
# but the rest probably have to do with NPCs or enemies?
draw.text((ip,32),hex(d[0x16:0x19]),font=font)
draw.text((ip,41),hex(d[0x19:0x1C]),font=font)
draw.text((ip,50),hex(d[0x1C:0x1F]),font=font)
else:
pos = (0,0)
for x in range(16):
for y in range(8):
if fl[x][y] == 1:
if pos[0] < x:
pos = (x,y)
if not numbers:
pos = (pos[0]-1,pos[1]+1) # shift for world map which always has a black border
draw.text(((pos[0]+1)*16+1,pos[1]*16+0),"%02X"%count,font=font,fill=(0,255,0))
if info:
img.save("info/" + fn + ".png")
else:
img.save("out/" + fn + ".png")
print((fn + " ($%4X)" % (count * 157)))
return
def levelsdump(fn,tg,tf,numbers=True):
dat = open(fn,"rb").read()
start = 0
stride = 157 # each room is 157 bytes
extra = 0
count = 0
while (start + stride + extra) <= len(dat):
leveldump(fn,count,dat[start:start+stride+extra],tg,tf,numbers)
count += 1
start += stride
if count >= 0x50:
# there is extra data at the end of the file, unknown purpose
break
return
palimg = PIL.Image.new("RGB",(128,128))
paldrw = PIL.ImageDraw.Draw(palimg,"RGBA")
for y in range(0,4):
for x in range(0,4):
ci = x+(y*4)
c = palette_color(ci)
paldrw.rectangle((x*32,y*32,x*32+31,y*32+31),fill=c)
paldrw.rectangle((x*32,y*32,x*32+ 7,y*32+ 8),fill=(0,0,0,128))
paldrw.text((x*32+1,y*32-1),"%X"%ci)
palimg.save("palette.png")
(grafxpng, grafxt) = unpack_4bit(grafxdat,16,16,(8*16)+2,16)
(fillpng, fillt) = unpack_4bit(filldat, 16,16,(8*16)+2,16)
grafxpng.save("GRAFX.DAT.png")
fillpng.save("FILL.DAT.png")
open("AVECTA.PRG.txt","wt").write(unpack_txt(prg))
levelsdump("CAVE.DAT",grafxt,fillt)
levelsdump("TROND.DAT",grafxt,fillt)
levelsdump("DEMON.DAT",grafxt,fillt)
# These three seem to differ only by their "mystery" bytes.
# Not sure when they are used by the game.
# Presumably they alter which characers/NPCs appear in various rooms.
#levelsdump("DCAVE.DAT",grafxt,fillt)
#levelsdump("DTROND.DAT",grafxt,fillt)
#levelsdump("DDEMON.DAT",grafxt,fillt)
levelsdump("OUTSIDE.DAT",fillt[20:],fillt,numbers=False)
Python links
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