Generate your app icon and splash screen with ChatGPT: prompts, store rules and WebViewGold file placement

#!/usr/bin/env python3
"""Turn one AI-generated master icon into the files a WebViewGold project needs.

Usage:
  python3 make_store_icons.py master.png --bg "#0F766E"
  python3 make_store_icons.py master.png --fg symbol.png --bg "#0F766E"

master.png  square artwork with a solid, full-bleed background
--fg        optional: the symbol alone on a transparent background (better adaptive icon)
--bg        the background color of your icon; reuse it as the splash screen color
Requires Pillow: pip install Pillow
"""
import argparse
import math
from pathlib import Path
from PIL import Image, ImageDraw

DENSITIES = {"mdpi": 1, "hdpi": 1.5, "xhdpi": 2, "xxhdpi": 3, "xxxhdpi": 4}
OUT = Path("store-icons")


def flatten(img, bg):
    """Composite on a solid color and drop the alpha channel (App Store requirement)."""
    img = img.convert("RGBA")
    base = Image.new("RGBA", img.size, bg)
    base.alpha_composite(img)
    return base.convert("RGB")


def square(img):
    w, h = img.size
    if w != h:
        print(f"warning: master is {w}x{h}, cropping to a centered square")
        s = min(w, h)
        img = img.crop(((w - s) // 2, (h - s) // 2, (w + s) // 2, (h + s) // 2))
    return img


def save(img, path):
    path.parent.mkdir(parents=True, exist_ok=True)
    img.save(path)
    print("wrote", path, img.size, img.mode)


def adaptive_foreground(symbol, px):
    """108 dp canvas; the bounding box of the symbol must fit the 66 dp safe circle."""
    canvas = Image.new("RGBA", (px, px), (0, 0, 0, 0))
    sym = symbol.convert("RGBA")
    sym = sym.crop(sym.getbbox() or (0, 0, sym.width, sym.height))
    scale = (px * 66 / 108) / math.hypot(sym.width, sym.height)
    sym = sym.resize((max(1, round(sym.width * scale)), max(1, round(sym.height * scale))), Image.LANCZOS)
    canvas.alpha_composite(sym, ((px - sym.width) // 2, (px - sym.height) // 2))
    return canvas


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("master")
    ap.add_argument("--fg", help="symbol on a transparent background")
    ap.add_argument("--bg", default="#FFFFFF")
    a = ap.parse_args()

    master = flatten(square(Image.open(a.master)), a.bg)
    if master.width < 1024:
        print(f"warning: master is only {master.width}px; the App Store needs 1024x1024")

    # iOS: one opaque 1024 px PNG for the AppIcon set
    save(master.resize((1024, 1024), Image.LANCZOS), OUT / "ios" / "AppIcon-1024.png")
    # Google Play listing icon: uploaded in the Play Console, not in the project
    save(master.resize((512, 512), Image.LANCZOS), OUT / "play" / "play-icon-512.png")

    symbol = Image.open(a.fg) if a.fg else None
    for name, f in DENSITIES.items():
        folder = OUT / "android" / f"mipmap-{name}"
        legacy = round(48 * f)
        icon = master.resize((legacy, legacy), Image.LANCZOS)
        save(icon, folder / "ic_launcher.png")
        mask = Image.new("L", (legacy, legacy), 0)
        ImageDraw.Draw(mask).ellipse((0, 0, legacy - 1, legacy - 1), fill=255)
        rnd = icon.convert("RGBA")
        rnd.putalpha(mask)
        save(rnd, folder / "ic_launcher_round.png")
        fg_px = round(108 * f)
        fg = adaptive_foreground(symbol, fg_px) if symbol else master.resize((fg_px, fg_px), Image.LANCZOS)
        save(fg, folder / "ic_launcher_foreground.png")

    # Splash: square GIF with the symbol on your splash background color
    if symbol:
        splash = Image.new("RGB", (1024, 1024), a.bg)
        s = adaptive_foreground(symbol, 1024)
        splash.paste(s, (0, 0), s)
    else:
        splash = master.resize((1024, 1024), Image.LANCZOS)
    save(splash.convert("P", palette=Image.ADAPTIVE), OUT / "splash" / "splash.gif")


if __name__ == "__main__":
    main()