"""Gera icicle.png (59x222), o sprite do projetil de gelo do Blutfest no lugar do original (proofmart, sem licenca clara).
Desenho proprio do FredyGames, dedicado ao dominio publico (CC0 1.0). Uso: python make_icicle.py icicle.png (precisa do Pillow)."""
import sys
from PIL import Image, ImageDraw

S = 4
W, H = 59, 222
w, h = W * S, H * S
# Silhueta: larga no alto, afinando ate a ponta de baixo, com uma leve curva.
left, right = [], []
for i in range(0, 101):
    t = i / 100
    y = 6 + t * (H - 12)
    half = (24 * (1 - t) ** 0.85 + 1.2) * (1 + 0.06 * ((i * 7) % 5 - 2) / 2 * (1 - t))
    cx = 29.5 + 3 * t - 4 * t * t
    left.append(((cx - half) * S, y * S))
    right.append(((cx + half) * S, y * S))
poly = left + right[::-1]
mask = Image.new("L", (w, h), 0)
ImageDraw.Draw(mask).polygon(poly, fill=255)

body = Image.new("RGBA", (w, h), (0, 0, 0, 0))
px = body.load()
mp = mask.load()
for y in range(h):
    t = y / h
    for x in range(w):
        if mp[x, y]:
            u = (x / w - 0.5) * 2
            shade = 0.55 + 0.35 * (1 - abs(u + 0.25)) - 0.25 * t
            r = int(120 + 110 * shade)
            g = int(170 + 70 * shade)
            b = int(215 + 38 * shade)
            px[x, y] = (min(r, 255), min(g, 255), min(b, 255), 235)
d = ImageDraw.Draw(body)
# Brilhos
d.polygon([(22 * S, 22 * S), (28 * S, 22 * S), (31 * S, 130 * S), (27 * S, 130 * S)], fill=(255, 255, 255, 190))
d.polygon([(36 * S, 34 * S), (39 * S, 34 * S), (36 * S, 95 * S), (34 * S, 95 * S)], fill=(235, 248, 255, 150))
body.putalpha(Image.eval(mask, lambda v: v).point(lambda v: v))
# Contorno
edge = Image.new("RGBA", (w, h), (0, 0, 0, 0))
ImageDraw.Draw(edge).line(poly + [poly[0]], fill=(70, 110, 170, 255), width=2 * S, joint="curve")
edge.putalpha(Image.composite(edge.getchannel("A"), Image.new("L", (w, h), 0), mask.point(lambda v: 255)))
out = Image.alpha_composite(body, edge).resize((W, H), Image.LANCZOS)
out.save(sys.argv[1], optimize=True)