1 files changed, 106 insertions, 0 deletions
diff --git a/tools/unique.py b/tools/unique.py
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+++ b/tools/unique.py
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+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""
+Usage: python unique.py [-f|--flip] [-x|--cross] image.png
+
+Erase duplicate tiles from an input image.
+-f or --flip counts X/Y mirrored tiles as duplicates.
+-x or --cross erases with a cross instead of a blank tile.
+"""
+
+import sys
+
+import png
+
+def rgb5_pixels(row):
+	yield from (tuple(c // 8 for c in row[x:x+3]) for x in range(0, len(row), 4))
+
+def rgb8_pixels(row):
+	yield from (c * 8 + c // 4 for pixel in row for c in pixel)
+
+def gray_pixels(row):
+	yield from (pixel[0] // 10 for pixel in row)
+
+def rows_to_tiles(rows, width, height):
+	assert len(rows) == height and len(rows[0]) == width
+	yield from (tuple(tuple(row[x:x+8]) for row in rows[y:y+8])
+		for y in range(0, height, 8) for x in range(0, width, 8))
+
+def tiles_to_rows(tiles, width, height):
+	assert width % 8 == 0 and height % 8 == 0
+	width, height = width // 8, height // 8
+	tiles = list(tiles)
+	assert len(tiles) == width * height
+	tile_rows = (tiles[y:y+width] for y in range(0, width * height, width))
+	yield from ([tile[y][x] for tile in tile_row for x in range(8)]
+		for tile_row in tile_rows for y in range(8))
+
+def tile_variants(tile, flip):
+	yield tile
+	if flip:
+		yield tile[::-1]
+		yield tuple(row[::-1] for row in tile)
+		yield tuple(row[::-1] for row in tile[::-1])
+
+def unique_tiles(tiles, flip, cross):
+	if cross:
+		blank = [[(0, 0, 0)] * 8 for _ in range(8)]
+		for y in range(8):
+			blank[y][y] = blank[y][7 - y] = (31, 31, 31)
+		blank = tuple(tuple(row) for row in blank)
+	else:
+		blank = tuple(tuple([(31, 31, 31)] * 8) for _ in range(8))
+	seen = set()
+	for tile in tiles:
+		if any(variant in seen for variant in tile_variants(tile, flip)):
+			yield blank
+		else:
+			yield tile
+			seen.add(tile)
+
+def is_grayscale(colors):
+	return (colors.issubset({(31, 31, 31), (21, 21, 21), (10, 10, 10), (0, 0, 0)}) or
+		colors.issubset({(31, 31, 31), (20, 20, 20), (10, 10, 10), (0, 0, 0)}))
+
+def erase_duplicates(filename, flip, cross):
+	with open(filename, 'rb') as file:
+		width, height, rows = png.Reader(file).asRGBA8()[:3]
+		rows = [list(rgb5_pixels(row)) for row in rows]
+	if width % 8 or height % 8:
+		return False
+	tiles = unique_tiles(rows_to_tiles(rows, width, height), flip, cross)
+	rows = list(tiles_to_rows(tiles, width, height))
+	if is_grayscale({c for row in rows for c in row}):
+		rows = [list(gray_pixels(row)) for row in rows]
+		writer = png.Writer(width, height, greyscale=True, bitdepth=2, compression=9)
+	else:
+		rows = [list(rgb8_pixels(row)) for row in rows]
+		writer = png.Writer(width, height, greyscale=False, bitdepth=8, compression=9)
+	with open(filename, 'wb') as file:
+		writer.write(file, rows)
+	return True
+
+def main():
+	flip = cross = False
+	while True:
+		if len(sys.argv) < 2:
+			print(f'Usage: {sys.argv[0]} [-f|--flip] [-x|--cross] tileset.png', file=sys.stderr)
+			sys.exit(1)
+		elif sys.argv[1] in {'-f', '--flip'}:
+			flip = True
+		elif sys.argv[1] in {'-x', '--cross'}:
+			cross = True
+		elif sys.argv[1] in {'-fx', '-xf'}:
+			flip = cross = True
+		else:
+			break
+		sys.argv.pop(1)
+	for filename in sys.argv[1:]:
+		if not filename.lower().endswith('.png'):
+			print(f'{filename} is not a .png file!', file=sys.stderr)
+		elif not erase_duplicates(filename, flip, cross):
+			print(f'{filename} is not divisible into 8x8 tiles!', file=sys.stderr)
+
+if __name__ == '__main__':
+	main()