Convert Halfbrick Jetpack Joyride texture files (*.tex) to png

convert.py

import os
import glob
import struct
from PIL import Image

def check_file_header(file_path):
    headers = [
        b'\x54\x45\x58\x01\x00\x00\x00\x01\x04\x02\x04\x03\x04\x04\x04\x01\x00\x00\x00\x00',
        b'\x54\x45\x58\x01\x06\x00\x00\x00\x08\x02\x08\x03\x08\x04\x08\x01\x00\x00\x00\x00',
        b'\x54\x45\x58\x01\x00\x00\x00\x03\x08\x01\x08\x04\x08\x03\x08\x02\x00\x00\x00\x00',
        b'\x54\x45\x58\x01\x00\x00\x00\x00\x08\x02\x08\x03\x08\x04\x00\x00\x00\x00\x00\x00',
        b'\x54\x45\x58\x01\x00\x00\x00\x01\x05\x02\x05\x03\x05\x04\x01\x01\x00\x00\x00\x00'
    ]

    with open(file_path, 'rb') as file:
        file_data = file.read(len(headers[0]))
        for i, header in enumerate(headers):
            if file_data == header:
                return i  # Return the index of the matching header
    return -1  # Return -1 if no header matches

def extract_image_to_png_4_bits(file_path, output_path, image_offset=0x34):
    """Extract raw image data and save as PNG."""
    with open(file_path, 'rb') as file:
        # Read dimensions (assumes width and height are stored as 16-bit shorts at a fixed offset)
        file.seek(0x14)
        width, height = struct.unpack('<HH', file.read(4))

        # Read raw image data starting at the image_offset
        file.seek(image_offset)
        data = file.read(width * height * 2)  # 16 bits (2 bytes) per pixel

    # Convert raw data to an image (ARGB format)
    image = Image.new('RGBA', (width, height))
    pixels = image.load()

    for y in range(height):
        for x in range(width):
            pixel_offset = (y * width + x) * 2
            if pixel_offset + 1 >= len(data):
                break
            pixel = struct.unpack('<H', data[pixel_offset:pixel_offset + 2])[0]
            red = (pixel & 0xF000) >> 12
            green = (pixel & 0x0F00) >> 8
            blue = (pixel & 0x00F0) >> 4
            alpha = (pixel & 0x000F)

            # Scale 4-bit color channels (0–15) to 8-bit (0–255)
            pixels[x, y] = (
                red * 17,  # Scale 0–15 to 0–255
                green * 17,
                blue * 17,
                alpha * 17
            )

    # Ensure the output directory exists
    os.makedirs(os.path.dirname(output_path), exist_ok=True)

    # Save the image as PNG
    image.save(output_path)
    print(f"[INFO] Saved {output_path}")

def extract_image_to_png_8_bits(file_path, output_path, image_offset=0x34):
    """Extract raw image data and save as PNG."""
    with open(file_path, 'rb') as file:
        # Read dimensions (assumes width and height are stored as 16-bit shorts at a fixed offset)
        file.seek(0x14)
        width, height = struct.unpack('<HH', file.read(4))

        # Read raw image data starting at the image_offset
        file.seek(image_offset)
        data = file.read(width * height * 4)  # 32 bits (4 bytes) per pixel (8 bits per channel)

    # Convert raw data to an image (RGBA format)
    image = Image.new('RGBA', (width, height))
    pixels = image.load()

    for y in range(height):
        for x in range(width):
            pixel_offset = (y * width + x) * 4  # 4 bytes per pixel (RGBA)
            if pixel_offset + 3 >= len(data):
                break
            # Unpack the 4 bytes (RGBA)
            pixel = struct.unpack('<4B', data[pixel_offset:pixel_offset + 4])
            red, green, blue, alpha = pixel

            # Assign directly (no need to scale, since each channel is already 8-bit)
            pixels[x, y] = (red, green, blue, alpha)

    # Ensure the output directory exists
    os.makedirs(os.path.dirname(output_path), exist_ok=True)

    # Save the image as PNG
    image.save(output_path)
    print(f"[INFO] Saved {output_path}")

def parse_directory_and_convert(directory, output_base_dir):
    pattern = os.path.join(directory, '**', '*.tex')
    tex_files = glob.glob(pattern, recursive=True)

    for file_path in tex_files:
        header_index = check_file_header(file_path)
        relative_path = os.path.relpath(file_path, directory)
        output_path = os.path.join(output_base_dir, relative_path + '.png')
        if header_index == 0:
            extract_image_to_png_4_bits(file_path, output_path)
        elif header_index == 2:
            extract_image_to_png_8_bits(file_path, output_path)

if __name__ == "__main__":
    input_directory = './textures'
    output_directory = './textures_png'
    parse_directory_and_convert(input_directory, output_directory)

Currently only support 2 types of texture (header type 0 and header type 2). As of Jetpack Joyride apk version 1.93.2, this works fine for most important textures except level backgrounds (header type 1). However, we can use the apk version 1.48.1 to get access to those background textures, since back then they were still type 2 textures.