Tool for extracting palettes from Amiga AGI games' executables. My first Python program, yay :-)

svn-id: r28035

tools/palex.py

@@ -0,0 +1,106 @@
+#!/usr/bin/python
+# Amiga AGI game palette extractor.
+# Extracts palette from an Amiga AGI game's executable file.
+# Initial version written during summer of 2007 by Buddha^.
+# Unoptimized.
+import struct, sys, os.path
+
+# Constants
+maxComponentValue     = 0x0F
+colorsPerPalette      = 16
+componentsPerColor    = 3
+bytesPerComponent     = 2
+bytesPerColor         = componentsPerColor    * bytesPerComponent
+paletteComponentCount = colorsPerPalette      * componentsPerColor
+paletteByteCount      = paletteComponentCount * bytesPerComponent
+black                 = tuple([0 for x in range(componentsPerColor)])
+white                 = tuple([maxComponentValue for x in range(componentsPerColor)])
+componentPrintFormat  = "0x%1X"
+
+def is12BitColor(color):
+	"""Is color 12-bit (i.e. 4 bits per color component)?"""
+	return color == filter(lambda component: 0 <= component <= maxComponentValue, color)
+
+def printColor(color, tabulate = True, printLastComma = True, newLine = True):
+	"""Prints color with optional start tabulation, comma in the end and a newline"""
+	result = ""
+	if tabulate:
+		result = result + "\t"
+	for component in color[:-1]:
+		result = result + ((componentPrintFormat + ", ") % component)
+	result = result + (componentPrintFormat % color[-1])
+	if printLastComma:
+		result = result + ","
+	if newLine:
+		print result
+	else:
+		print result,
+
+def printPalette(palette, arrayName):
+	"""Prints out palette as a C-style array"""
+	print "/** A 16-color, 12-bit RGB palette from an Amiga AGI game. */"
+	print "static const unsigned char " + arrayName + "[] = {"
+	for color in palette[:-1]:
+		printColor(color)
+	printColor(palette[-1], printLastComma = False)
+	print("};")
+
+def isAmigaPalette(palette):
+	"""Test if the given palette is an Amiga-style palette"""
+	# Palette must be of correct size
+	if len(palette) != colorsPerPalette:
+		return False
+	
+	# First palette color must be black, last color white
+	if palette[0] != black or palette[-1] != white:
+		return False
+	
+	# All colors must be 12-bit (i.e. 4 bits per color component)
+	for color in palette:
+		if not is12BitColor(color):
+			return False
+	
+	# All colors must be unique
+	if len(set(palette)) != colorsPerPalette:
+		return False
+	
+	return True
+
+# The main program starts here
+if len(sys.argv) <= 2 or sys.argv[1] == "-h" or sys.argv[1] == "--help":
+	quit("Usage: " + os.path.basename(sys.argv[0]) + " FILE ARRAYNAME\n" \
+		"  Searches FILE for an Amiga AGI game palette\n" \
+		"  and prints out any found candidates as C-array style arrays with the name ARRAYNAME.");
+
+# Open file and read it into memory
+file = open(sys.argv[1], 'rb')
+data = file.read()
+foundPalettes = []
+palette = [black for x in range(colorsPerPalette)]
+# Search through the whole file
+for searchPosition in range(len(data) - paletteByteCount + 1):
+	# Parse possible palette from byte data
+	for colorNum in range(colorsPerPalette):
+		paletteStart = searchPosition + colorNum * bytesPerColor
+		paletteEnd   = paletteStart + bytesPerColor
+		# Parse color components as unsigned 16-bit big endian integers
+		color = struct.unpack('>' + 'H' * componentsPerColor, data[paletteStart:paletteEnd]);
+		palette[colorNum] = color;
+
+	# Save good candidates to a list
+	if isAmigaPalette(palette):
+		foundPalettes.append(tuple(palette));
+
+# Close file
+file.close()
+
+# Remove duplicates from found palettes list
+uniqueFoundPalettes = set(foundPalettes)
+
+# Print out the found unique palettes
+if len(uniqueFoundPalettes) > 0:
+	for palette in uniqueFoundPalettes:
+		printPalette(palette, sys.argv[2])
+else:
+	print "Didn't find any Amiga AGI game palettes in file " + sys.argv[1]
+	print "Heuristic isn't perfect though, so caveat emptor"