build: assemble dist/udt with fonts and wallpaper

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/build b/build
index 9097679..4a6c1d0 100755
--- a/build
+++ b/build
@@ -11,9 +11,13 @@ current wallpaper next to theme.txt. Everything is staged in a temporary
 directory and swapped in at the end, so a failed run leaves the previous
 dist/udt/ untouched. Never touches /boot: root copies dist/udt/ there.
 """
+import os
 import re
+import shutil
 import struct
+import subprocess
 import sys
+import tempfile
 import zlib
 from pathlib import Path
 
@@ -28,6 +32,13 @@ FONTS = {
     "inconsolata-18.pf2": ("Inconsolata Nerd Font Mono", 18,
                            "Inconsolata Nerd Font Mono Regular 18"),
 }
+RENDERED = REPO / "theme.txt"
+BUILD = REPO / "dist"
+OUT = BUILD / "udt"
+FONT_CACHE = BUILD / "fonts"  # fonts do not follow the scheme, so built once
+WALLPAPER = Path.home() / ".cache/udt/wpaper"
+PANEL_ALPHA = 0xd9  # ~85%, enough to read text over any wallpaper
+MAX_SIDE = 2560  # widest mode in use; GRUB crops, a bigger image only costs /boot
 
 
 def die(msg):
@@ -83,6 +94,75 @@ def unpng(data):
     return w, h, px
 
 
+def run(*cmd):
+    p = subprocess.run(cmd, capture_output=True, text=True)
+    if p.returncode:
+        die(f"{cmd[0]} failed:\n{p.stderr.strip()}")
+    return p.stdout
+
+
+def pf2_name(path):
+    """The NAME section of a .pf2, which is what theme.txt refers to."""
+    data = path.read_bytes()
+    pos = 0
+    while pos < len(data):
+        tag, n = struct.unpack(">4sI", data[pos:pos + 8])
+        if tag == b"NAME":
+            return data[pos + 8:pos + 8 + n].rstrip(b"\0").decode()
+        pos += 8 + n
+    die(f"{path.name} has no NAME section")
+
+
+def font(fname, pattern, size, name):
+    """A cached .pf2, built from the TTF fontconfig resolves the pattern to."""
+    cached = FONT_CACHE / fname
+    if cached.exists():
+        return cached
+    family = pattern.split(":")[0]
+    # fc-match never fails: a missing family comes back as a fallback font.
+    if family not in run("fc-match", "-f", "%{family}", pattern).split(","):
+        die(f"font {family!r} is not installed")
+    ttf = run("fc-match", "-f", "%{file}", pattern)
+    FONT_CACHE.mkdir(parents=True, exist_ok=True)
+    tmp = cached.with_suffix(".tmp")
+    run("grub-mkfont", "-s", str(size), "-o", str(tmp), ttf)
+    if pf2_name(tmp) != name:
+        die(f"{fname} is named {pf2_name(tmp)!r}, theme.txt expects {name!r}")
+    tmp.rename(cached)
+    return cached
+
+
+def os_name():
+    for line in Path("/etc/os-release").read_text().splitlines():
+        if line.startswith("NAME="):
+            return line[5:].strip('"')
+    return "GNU/Linux"
+
+
+def assemble(stage, text, c, wallpaper, fonts):
+    (stage / "theme.txt").write_text(text.replace("%TITLE%", os_name()))
+    slices = {
+        "panel.png": (8, 8, (*c["bg_alt"], PANEL_ALPHA)),
+        # The selected item: a 4px accent bar on the left, surface behind.
+        "select_w.png": (4, 1, (*c["accent"], 255)),
+        "select_c.png": (1, 1, (*c["surface"], 255)),
+        "select_e.png": (8, 1, (*c["surface"], 255)),
+    }
+    for s in ("nw", "n", "ne", "w", "c", "e", "sw", "s", "se"):
+        slices[f"terminal_box_{s}.png"] = (1, 1, (*c["bg_deep"], 255))
+    for fname, (w, h, rgba) in slices.items():
+        (stage / fname).write_bytes(png(w, h, rgba))
+    for f in fonts:
+        shutil.copy(f, stage / f.name)
+    # [0]: first frame only. Baseline JPEG, alpha flattened: GRUB reads
+    # neither progressive JPEG nor webp, and has no use for transparency here.
+    bg = "#%02x%02x%02x" % c["bg_deep"]
+    run("magick", f"{wallpaper}[0]", "-auto-orient",
+        "-background", bg, "-alpha", "remove",
+        "-resize", f"{MAX_SIDE}x{MAX_SIDE}>", "-strip",
+        "-interlace", "none", "-quality", "90", str(stage / "background.jpg"))
+
+
 def selftest():
     w, h, px = unpng(png(3, 2, (0x12, 0x34, 0x56, 0xd9)))
     assert (w, h, px) == (3, 2, {(0x12, 0x34, 0x56, 0xd9)}), (w, h, px)
@@ -105,6 +185,28 @@ def selftest():
 def main():
     if sys.argv[1:] == ["--selftest"]:
         return selftest()
+    for tool in ("magick", "grub-mkfont", "fc-match"):
+        if not shutil.which(tool):
+            die(f"{tool} not found")
+    if not RENDERED.exists():
+        die("theme.txt missing; run udt-palette first")
+    text = RENDERED.read_text()
+    c = read_colours(text)
+    try:
+        wallpaper = WALLPAPER.resolve(strict=True)
+    except FileNotFoundError:
+        die(f"no wallpaper at {WALLPAPER}")
+    fonts = [font(f, *spec) for f, spec in FONTS.items()]
+    BUILD.mkdir(exist_ok=True)
+    stage = Path(tempfile.mkdtemp(dir=BUILD, prefix=".udt-"))
+    try:
+        assemble(stage, text, c, wallpaper, fonts)
+        os.chmod(stage, 0o755)  # mkdtemp makes it 0700; root copies it as is
+        shutil.rmtree(OUT, ignore_errors=True)
+        stage.rename(OUT)
+    finally:
+        shutil.rmtree(stage, ignore_errors=True)
+    print(f"build: {OUT}")
 
 
 if __name__ == "__main__":