nesstNSStoBin.py

# load NESST session data and create binary data 
# makes it easier to process and only need to hit save. not save each part or name each part

# python nesstNSStoBin.py session.nss data\output 
# will create 
# data\output.chr
# data\output.map
# data\output.pal
# data\output.msb


import os
import sys 

#write a byte array directly
def writeByteArray(name,output):
	outfile = open(basename + name,"wb")
	outfile.write(output)
	outfile.close()

#decode nss rle packed data
def decodeTo(input):
	output = bytearray()
	prev = 0
	x = 0
	xlen = len(input)
	while(x<xlen-1):
		if input[x]=='[':
			x+=1
			value = 0
			# keep going until we hit ]
			while(input[x]!=']'):
				value = value<<4 | int(input[x],16) 
				x+=1
			# unpack 
			while(value>1):
				output.append(prev)
				value-=1
			x+=1
		else:
			value = int(input[x],16)<<4 
			value |= int(input[x+1],16) 
			prev = value
			output.append(prev)
			x+=2
	return output

# main 
if __name__ == '__main__':

	if len(sys.argv)==1:
		print("input.nss <basename>")
		exit()

	inname = sys.argv[1]
	finput = open(inname, "r")
	# we set the name to default incase we don't get an arg 
	basename = "default"

	if len(sys.argv)>=2:
		if sys.argv[2]!=None:
			basename = sys.argv[2]

	# set some default values 
	# shouldn't be needed 
	nameWidth = 0
	nameHeight = 0
	gridX = 64
	gridY = 64

	for line in finput:
		args = line.split("=")
		if args[0]=="VarNameW":
			nameWidth = int(args[1])
		elif args[0]=="VarNameH":
			nameHeight = int(args[1])
		elif args[0]=="VarSpriteGridX":
			gridX = int(args[1])
		elif args[0]=="VarSpriteGridY":
			gridY = int(args[1])
		elif args[0]=="CHRMain":
			chrs = decodeTo(args[1])
			writeByteArray(".chr",chrs)
		elif args[0]=="NameTable":
			nameTable = decodeTo(args[1])
		elif args[0]=="AttrTable":
			attrTable = decodeTo(args[1])
		elif args[0]=="Palette":
			pal = decodeTo(args[1])
			writeByteArray(".pal",pal)
		elif args[0]=="MetaSprites":
			metaSpr = decodeTo(args[1])

			# process meta sprites here

			outfile = open(basename +".msb","wb")
			outfile.write(gridX.to_bytes(1,byteorder='little'))
			outfile.write(gridY.to_bytes(1,byteorder='little'))
			outfile.write(metaSpr)
			outfile.close()

	finput.close()

	# make meta-tiles when we have attr and map 
	# for now just save 
	print("Map:" + str(nameWidth) + " * " + str(nameHeight))
	outfile = open(basename + ".map","wb")
	outfile.write(nameTable)
	outfile.write(attrTable)

	outfile.write(nameWidth.to_bytes(2,byteorder='little'))
	outfile.write(nameHeight.to_bytes(2,byteorder='little'))
	outfile.close()