generate_splash_header.py

import sys
import os
from pathlib import Path

def main():
    if len(sys.argv) < 2:
        print("Usage: python3 generate_splash_header.py <path_to_splash.bin>")
        sys.exit(1)

    input_path = Path(sys.argv[1])
    if not input_path.exists():
        print(f"Error: {input_path} not found.")
        sys.exit(1)

    output_path = Path("firmware_arduino/splash.h")
    
    print(f"Reading {input_path}...")
    with open(input_path, "rb") as f:
        data = f.read()

    print(f"Size: {len(data)} bytes")
    
    # RLE Compression (PackBits variant)
    compressed_data = bytearray()
    i = 0
    while i < len(data):
        # Look for run of identical bytes
        run_len = 1
        while i + run_len < len(data) and run_len < 128 and data[i + run_len] == data[i]:
            run_len += 1
        
        if run_len > 1:
            # Repeat run
            # Flag: 128 + (run_len - 1) -> 129..255
            # Actually, let's map 2..129 to 128..255?
            # 128 + (run_len - 2)
            # If run_len is 2, flag is 128.
            # If run_len is 129, flag is 255.
            # Max run length 129.
            compressed_data.append(128 + (run_len - 2))
            compressed_data.append(data[i])
            i += run_len
        else:
            # Literal run
            # Look ahead for repeats to stop literal run
            lit_len = 0
            while i + lit_len < len(data) and lit_len < 128:
                # Check if next 2 bytes are identical (start of a run)
                if i + lit_len + 1 < len(data) and data[i + lit_len] == data[i + lit_len + 1]:
                    break
                lit_len += 1
            
            # Flag: 0..127 -> 1..128 literals
            compressed_data.append(lit_len - 1)
            for k in range(lit_len):
                compressed_data.append(data[i + k])
            i += lit_len

    print(f"Compressed Size: {len(compressed_data)} bytes ({(len(compressed_data)/len(data))*100:.1f}%)")
    
    # Generate C header
    print(f"Writing to {output_path}...")
    with open(output_path, "w") as f:
        f.write("#ifndef SPLASH_H\n")
        f.write("#define SPLASH_H\n\n")
        f.write("#include <Arduino.h>\n\n")
        f.write("// Generated splash screen data (RLE Compressed)\n")
        f.write(f"const uint8_t splash_data[{len(compressed_data)}] PROGMEM = {{\n")
        
        # Write hex data
        for i, byte in enumerate(compressed_data):
            if i % 16 == 0:
                f.write("  ")
            f.write(f"0x{byte:02X}, ")
            if (i + 1) % 16 == 0:
                f.write("\n")
        
        f.write("\n};\n\n")
        f.write("#endif\n")

    print("Done! Now include \"splash.h\" in your Arduino sketch.")

if __name__ == "__main__":
    main()