Super Tetris 2 + Bombliss (PC-98)

This page contains notes for the game Super Tetris 2 + Bombliss (PC-98).

Python 3 script for extracting graphics from RGB.DB and RGB.CNT: (requires Pillow)

#!/usr/bin/env python3

# Super Tetris 2 + Bombliss (PC-98) image unpacker
# by Revenant

import struct, math
from PIL import Image

entries = []

with open("RGB.CNT", 'rb') as cnt:
    while True:
        try:
            name, offset = struct.unpack("16sI", cnt.read(20))
            endpos = name.find(0)
            if endpos >= 0:
                name = name[:endpos]
            name = name.decode('ascii', 'ignore')
            entries.append((name, offset))
        except struct.error:
            break

with open("RGB.DB", 'rb') as db:
    for entry in entries:
        # seek
        db.seek(entry[1], 0)
        
        # get num. of colors
        num_colors = db.read(1)[0]
        colors = [0] * 768
        for i in range(3 * num_colors):
            colors[i] = db.read(1)[0]
            colors[i] |= (colors[i] << 4)
        
        # get image dimensions
        width, height = struct.unpack("II", db.read(8))
        stride = math.ceil(width / 8)
        
        # get bitplanes
        bitplanes = []
        for i in range(4):
            bitplanes.append(db.read(stride * height))
        
        imagedata = []
        for y in range(height):
            for x in range(width):
                offset = (y * stride) + (x // 8)
                mask = 1 << (7 - (x % 8))
                byte = 0
                for p in range(4):
                    if bitplanes[p][offset] & mask:
                        byte |= (1 << p)
                imagedata.append(byte)
        image = Image.frombytes('P', (width, height), bytes(imagedata))
        image.putpalette(bytes(colors))
        image.save(entry[0] + '.png')
        print("%s (%dx%d)" % (entry[0], width, height))