Add pc/ — PyInstaller build scripts, .ico icon, and README

pc/generate_icon.py

@@ -0,0 +1,35 @@
+"""Generate kanjin.ico from a solid-colour PNG embedded in an ICO container."""
+import struct
+import zlib
+from pathlib import Path
+
+
+def _png_chunk(chunk_type, data):
+    c = chunk_type + data
+    crc = struct.pack(">I", zlib.crc32(c) & 0xFFFFFFFF)
+    return struct.pack(">I", len(data)) + c + crc
+
+
+def solid_png_bytes(width, height, r, g, b):
+    header = b"\x89PNG\r\n\x1a\n"
+    ihdr = _png_chunk(b"IHDR", struct.pack(">IIBBBBB", width, height, 8, 2, 0, 0, 0))
+    raw = bytearray()
+    for _ in range(height):
+        raw.append(0)
+        raw.extend(bytes([r, g, b]) * width)
+    idat = _png_chunk(b"IDAT", zlib.compress(bytes(raw)))
+    iend = _png_chunk(b"IEND", b"")
+    return header + ihdr + idat + iend
+
+
+def make_ico(png_data):
+    header = struct.pack("<HHH", 0, 1, 1)
+    entry = struct.pack("<BBBBHHII", 0, 0, 0, 0, 1, 32, len(png_data), 22)
+    return header + entry + png_data
+
+
+if __name__ == "__main__":
+    dst = Path(__file__).parent / "kanjin.ico"
+    png = solid_png_bytes(256, 256, 0x1A, 0x1A, 0x2E)
+    dst.write_bytes(make_ico(png))
+    print(f"Created {dst.name}")