Refine desktop onboarding and NSIS branding

apps/desktop/scripts/png_to_bmp.py

@@ -123,15 +123,16 @@ def parse_png(path: Path):
   return width, height, image
 
 
-def resize_with_letterbox(image, width, height, target_w, target_h, background):
-  if width == target_w and height == target_h:
+def resize_with_letterbox(image, width, height, target_w, target_h, background, scale_factor=1.0):
+  if width == target_w and height == target_h and abs(scale_factor - 1.0) < 1e-6:
     return image, width, height
 
   bg_r, bg_g, bg_b = background
-  scale = min(target_w / width, target_h / height)
-  scale = max(scale, 1 / max(width, height))  # avoid zero
-  scaled_w = max(1, int(round(width * scale)))
-  scaled_h = max(1, int(round(height * scale)))
+  base_scale = min(target_w / width, target_h / height)
+  base_scale *= scale_factor
+  base_scale = max(base_scale, 1 / max(width, height))  # avoid zero / collapse
+  scaled_w = max(1, int(round(width * base_scale)))
+  scaled_h = max(1, int(round(height * base_scale)))
 
   output = bytearray(target_w * target_h * 4)
   # Fill background
@@ -142,9 +143,9 @@ def resize_with_letterbox(image, width, height, target_w, target_h, background):
   offset_y = (target_h - scaled_h) // 2
 
   for y in range(scaled_h):
-    src_y = min(height - 1, int(round(y / scale)))
+    src_y = min(height - 1, int(round(y / base_scale)))
     for x in range(scaled_w):
-      src_x = min(width - 1, int(round(x / scale)))
+      src_x = min(width - 1, int(round(x / base_scale)))
       src_idx = (src_y * width + src_x) * 4
       dst_idx = ((y + offset_y) * target_w + (x + offset_x)) * 4
       output[dst_idx : dst_idx + 4] = image[src_idx : src_idx + 4]
@@ -206,6 +207,12 @@ def main():
   parser.add_argument("output", type=Path)
   parser.add_argument("--width", type=int, help="Target width (px)")
   parser.add_argument("--height", type=int, help="Target height (px)")
+  parser.add_argument(
+    "--scale",
+    type=float,
+    default=1.0,
+    help="Optional multiplier applied to the fitted image size (e.g. 0.7 adds padding).",
+  )
   parser.add_argument(
     "--background",
     type=str,
@@ -218,7 +225,9 @@ def main():
     width, height, image = parse_png(args.input)
     if args.width and args.height:
       bg = tuple(int(args.background[i : i + 2], 16) for i in (0, 2, 4))
-      image, width, height = resize_with_letterbox(image, width, height, args.width, args.height, bg)
+      image, width, height = resize_with_letterbox(
+        image, width, height, args.width, args.height, bg, max(args.scale, 0.05)
+      )
     rgb = blend_to_rgb(image)
     write_bmp(args.output, width, height, rgb)
   except Exception as exc:  # noqa: BLE001
@@ -228,4 +237,3 @@ def main():
 
 if __name__ == "__main__":
   main()
-

apps/desktop/scripts/pngs_to_ico.py

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""
+Utility to build an .ico file from a list of PNGs of different sizes.
+
+Uses only Python's standard library so it can run in restricted environments.
+"""
+
+from __future__ import annotations
+
+import argparse
+import struct
+from pathlib import Path
+
+
+PNG_SIGNATURE = b"\x89PNG\r\n\x1a\n"
+
+
+def read_png_dimensions(data: bytes) -> tuple[int, int]:
+  if not data.startswith(PNG_SIGNATURE):
+    raise ValueError("All inputs must be PNG files.")
+  width, height = struct.unpack(">II", data[16:24])
+  return width, height
+
+
+def build_icon(png_paths: list[Path], output: Path) -> None:
+  png_data = [p.read_bytes() for p in png_paths]
+  entries = []
+  offset = 6 + 16 * len(png_data)  # icon header + entries
+
+  for data in png_data:
+    width, height = read_png_dimensions(data)
+    entry = {
+      "width": width if width < 256 else 0,
+      "height": height if height < 256 else 0,
+      "colors": 0,
+      "reserved": 0,
+      "planes": 1,
+      "bit_count": 32,
+      "size": len(data),
+      "offset": offset,
+      "data": data,
+    }
+    entries.append(entry)
+    offset += entry["size"]
+
+  header = struct.pack("<HHH", 0, 1, len(entries))
+  table = bytearray()
+  for entry in entries:
+    table.extend(
+      struct.pack(
+        "<BBBBHHII",
+        entry["width"],
+        entry["height"],
+        entry["colors"],
+        entry["reserved"],
+        entry["planes"],
+        entry["bit_count"],
+        entry["size"],
+        entry["offset"],
+      )
+    )
+
+  payload = header + table + b"".join(entry["data"] for entry in entries)
+  output.write_bytes(payload)
+
+
+def main() -> None:
+  parser = argparse.ArgumentParser(description=__doc__)
+  parser.add_argument("output", type=Path)
+  parser.add_argument("inputs", nargs="+", type=Path)
+  args = parser.parse_args()
+
+  if not args.inputs:
+    raise SystemExit("Provide at least one PNG input.")
+
+  build_icon(args.inputs, args.output)
+
+
+if __name__ == "__main__":
+  main()