Files
dungeoncraft/tools/cut_icons.py
T

73 lines
2.7 KiB
Python

#!/usr/bin/env python3
"""Cut a generated sheet of icons (a grid on a flat magenta background) into transparent icons
for the high-res atlas: every cell keyed (only nearly pure magenta goes, so violet glows stay),
cropped to its icon, centred in a square with a small margin and scaled down without fringes,
the alpha made hard.
Usage:
cut_icons.py raw.png out_prefix --grid ROWSxCOLS [--count N] [--margin 0.06]
Writes out_prefix-64.png and out_prefix-128.png: the icons side by side in reading order, and
out_prefix-preview.png (on a grey background, 2x). Needs Pillow.
"""
import argparse
from PIL import Image
def keyed(p):
r, g, b = p[:3]
return r > 170 and b > 170 and g < 90 and abs(r - b) < 70
def main():
ap = argparse.ArgumentParser()
ap.add_argument("raw")
ap.add_argument("out")
ap.add_argument("--grid", required=True)
ap.add_argument("--count", type=int, default=0)
ap.add_argument("--margin", type=float, default=0.06)
a = ap.parse_args()
rows, cols = (int(v) for v in a.grid.split("x"))
n = a.count or rows * cols
img = Image.open(a.raw).convert("RGBA")
px = img.load()
for y in range(img.height):
for x in range(img.width):
if keyed(px[x, y]):
px[x, y] = (0, 0, 0, 0)
icons = []
for i in range(n):
r, c = divmod(i, cols)
cell = img.crop((c * img.width // cols, r * img.height // rows, (c + 1) * img.width // cols, (r + 1) * img.height // rows))
box = cell.getchannel("A").point(lambda v: 255 if v > 0 else 0).getbbox() or (0, 0, cell.width, cell.height)
icon = cell.crop(box)
side = int(max(icon.size) * (1 + 2 * a.margin))
sq = Image.new("RGBA", (side, side), (0, 0, 0, 0))
sq.paste(icon, ((side - icon.width) // 2, (side - icon.height) // 2))
icons.append(sq)
for size in (64, 128):
strip = Image.new("RGBA", (size * n, size), (0, 0, 0, 0))
for k, sq in enumerate(icons):
small = sq.resize((size, size), Image.BOX)
sp = small.load()
for y in range(size):
for x in range(size):
r, g, b, al = sp[x, y]
if al < 110:
sp[x, y] = (0, 0, 0, 0)
else:
f = 255 / al
sp[x, y] = (min(255, int(r * f)), min(255, int(g * f)), min(255, int(b * f)), 255)
strip.paste(small, (k * size, 0))
strip.save(f"{a.out}-{size}.png")
prev = Image.new("RGBA", (64 * n, 64), (80, 76, 84, 255))
prev.alpha_composite(Image.open(f"{a.out}-64.png"))
prev.resize((prev.width * 2, prev.height * 2), Image.NEAREST).save(f"{a.out}-preview.png")
print(f"{a.out}: {n} icons")
if __name__ == "__main__":
main()