Add Brazilian Portuguese (pt-BR) translation

.gitignore

@@ -6,3 +6,5 @@
 *.pdf
 *.blg
 **/*.dia~
+figures/.built
+figures-pt-BR/

Makefile

@@ -2,9 +2,46 @@
 # Use as you see fit.
 SOURCE=paper
 
-all: $(SOURCE).tex
-	pdflatex $(SOURCE).tex < /dev/null > /dev/null
-	bibtex $(SOURCE).aux < /dev/null > /dev/null
-	pdflatex $(SOURCE).tex < /dev/null > /dev/null
-	pdflatex $(SOURCE).tex < /dev/null > /dev/null
+DIA_FILES := $(wildcard figures/*.dia)
 
+all: figures $(SOURCE).tex
+	-pdflatex -interaction=nonstopmode $(SOURCE).tex < /dev/null
+	-bibtex $(SOURCE).aux < /dev/null
+	-pdflatex -interaction=nonstopmode $(SOURCE).tex < /dev/null
+	-pdflatex -interaction=nonstopmode $(SOURCE).tex < /dev/null
+
+pt-br: figures-pt-BR paper.pt-BR.tex
+	-pdflatex -interaction=nonstopmode paper.pt-BR.tex < /dev/null
+	-bibtex paper.pt-BR.aux < /dev/null
+	-pdflatex -interaction=nonstopmode paper.pt-BR.tex < /dev/null
+	-pdflatex -interaction=nonstopmode paper.pt-BR.tex < /dev/null
+
+# Convert figures/*.dia to figures/*.pdf using a Debian container (Dia is no
+# longer packaged for macOS). Sentinel file means we only re-run when sources
+# change. Requires Docker.
+figures: figures/.built
+
+figures/.built: $(DIA_FILES) figures/dia2pdf.py
+	docker run --rm -v "$(CURDIR)/figures":/figures -w /figures --platform linux/amd64 \
+		debian:bookworm-slim bash -c 'set -e; \
+			apt-get update -qq > /dev/null && \
+			apt-get install -y -qq --no-install-recommends \
+				dia ghostscript xvfb xauth python3 > /dev/null && \
+			xvfb-run -a python3 dia2pdf.py'
+	touch $@
+
+# Translated figures for the pt-BR build: substitute strings using
+# translations-pt-BR.json, then render to PDF in the same Debian container.
+figures-pt-BR: figures-pt-BR/.built
+
+figures-pt-BR/.built: $(DIA_FILES) figures/translations-pt-BR.json figures/translate-pt-BR.py figures/dia2pdf.py
+	python3 figures/translate-pt-BR.py figures-pt-BR
+	docker run --rm -v "$(CURDIR)/figures":/scripts:ro -v "$(CURDIR)/figures-pt-BR":/work -w /work --platform linux/amd64 \
+		debian:bookworm-slim bash -c 'set -e; \
+			apt-get update -qq > /dev/null && \
+			apt-get install -y -qq --no-install-recommends \
+				dia ghostscript xvfb xauth python3 > /dev/null && \
+			xvfb-run -a python3 /scripts/dia2pdf.py'
+	touch $@
+
+.PHONY: all pt-br figures figures-pt-BR

README.md

@@ -4,6 +4,17 @@ This is the Bitcoin Lightning Network paper.
 
 Paper PDF: [http://lightning.network/lightning-network-paper.pdf](http://lightning.network/lightning-network-paper.pdf)
 
+## Translations
+
+| Language | Source | Status |
+| --- | --- | --- |
+| English (original) | [paper.tex](paper.tex) | Draft v0.5.9.2 |
+| Portuguese (Brazil) | [paper.pt-BR.tex](paper.pt-BR.tex) | Draft v0.5.9.2 |
+
+To compile a translation, run the same recipe as the English version against
+the translated file (e.g. `pdflatex paper.pt-BR.tex` etc.). Figures in
+`figures/` are language-neutral and shared across translations.
+
 #Compiling/Editing
 
 Paper is in LaTeX format. Diagrams are in dia, but may remake the diagrams in

figures/translate-pt-BR.py

@@ -0,0 +1,133 @@
+#!/usr/bin/env python3
+"""Apply translations-pt-BR.json to all figures/*.dia, output translated copies to a target dir.
+
+After substituting strings, recompute obj_bb for each Standard - Text object so that
+text-with-background labels (e.g. "Output X") don't render with stale wider-than-text
+background rectangles from the English source.
+"""
+import gzip
+import json
+import re
+import sys
+from pathlib import Path
+
+HERE = Path(__file__).parent
+
+# Helvetica character widths in 1/1000 em units (Adobe AFM standard).
+# Default 556 for unmapped chars (matches digit/lowercase width).
+HELVETICA = {
+    ' ': 278, '!': 278, '"': 355, '#': 556, '$': 556, '%': 889, '&': 667,
+    "'": 191, '(': 333, ')': 333, '*': 389, '+': 584, ',': 278, '-': 333,
+    '.': 278, '/': 278, ':': 278, ';': 278, '<': 584, '=': 584, '>': 584,
+    '?': 556, '@': 1015, '[': 278, '\\': 278, ']': 278, '^': 469, '_': 556,
+    '`': 333, '{': 334, '|': 260, '}': 334, '~': 584,
+    '0': 556, '1': 556, '2': 556, '3': 556, '4': 556, '5': 556, '6': 556,
+    '7': 556, '8': 556, '9': 556,
+    'A': 667, 'B': 667, 'C': 722, 'D': 722, 'E': 667, 'F': 611, 'G': 778,
+    'H': 722, 'I': 278, 'J': 500, 'K': 667, 'L': 556, 'M': 833, 'N': 722,
+    'O': 778, 'P': 667, 'Q': 778, 'R': 722, 'S': 667, 'T': 611, 'U': 722,
+    'V': 667, 'W': 944, 'X': 667, 'Y': 667, 'Z': 611,
+    'a': 556, 'b': 556, 'c': 500, 'd': 556, 'e': 556, 'f': 278, 'g': 556,
+    'h': 556, 'i': 222, 'j': 222, 'k': 500, 'l': 222, 'm': 833, 'n': 556,
+    'o': 556, 'p': 556, 'q': 556, 'r': 333, 's': 500, 't': 278, 'u': 556,
+    'v': 500, 'w': 722, 'x': 500, 'y': 500, 'z': 500,
+    'á': 556, 'à': 556, 'â': 556, 'ã': 556, 'ä': 556, 'å': 556,
+    'é': 556, 'è': 556, 'ê': 556, 'ë': 556,
+    'í': 278, 'ì': 278, 'î': 278, 'ï': 278,
+    'ó': 556, 'ò': 556, 'ô': 556, 'õ': 556, 'ö': 556,
+    'ú': 556, 'ù': 556, 'û': 556, 'ü': 556,
+    'ñ': 556, 'ç': 500, 'ß': 611,
+    'Á': 667, 'À': 667, 'Â': 667, 'Ã': 667, 'Ä': 667, 'Å': 667,
+    'É': 667, 'È': 667, 'Ê': 667, 'Ë': 667,
+    'Í': 278, 'Ì': 278, 'Î': 278, 'Ï': 278,
+    'Ó': 778, 'Ò': 778, 'Ô': 778, 'Õ': 778, 'Ö': 778,
+    'Ú': 722, 'Ù': 722, 'Û': 722, 'Ü': 722,
+    'Ñ': 722, 'Ç': 722,
+}
+# Empirically derived from the English source's cached obj_bb vs. AFM width sums.
+SCALE = 0.92
+
+
+def text_width_cm(text, font_height_cm):
+    return sum(HELVETICA.get(c, 556) for c in text) * font_height_cm * SCALE / 1000
+
+
+def update_text_object(obj_xml, translations):
+    """Substitute string and recompute obj_bb if it changed."""
+    text_match = re.search(r'<dia:string>#(.*?)#</dia:string>', obj_xml, re.DOTALL)
+    if not text_match:
+        return obj_xml
+    original = text_match.group(1)
+    translated = translations.get(original)
+    if translated is None or translated == original:
+        return obj_xml
+
+    # Substitute the string first
+    obj_xml = obj_xml.replace(
+        f'<dia:string>#{original}#</dia:string>',
+        f'<dia:string>#{translated}#</dia:string>',
+    )
+
+    # Only Standard - Text objects have obj_bb that visibly affects rendering
+    if 'type="Standard - Text"' not in obj_xml:
+        return obj_xml
+
+    pos_m = re.search(r'name="obj_pos">\s*<dia:point val="([-\d.]+),([-\d.]+)"', obj_xml)
+    bb_m = re.search(r'name="obj_bb">\s*<dia:rectangle val="([-\d.]+),([-\d.]+);([-\d.]+),([-\d.]+)"', obj_xml)
+    h_m = re.search(r'name="height">\s*<dia:real val="([-\d.eE]+)"', obj_xml)
+    align_m = re.search(r'name="alignment">\s*<dia:enum val="(\d+)"', obj_xml)
+    if not (pos_m and bb_m and h_m):
+        return obj_xml
+
+    pos_x = float(pos_m.group(1))
+    font_height = float(h_m.group(1))
+    alignment = int(align_m.group(1)) if align_m else 0
+
+    lines = translated.split('\n')
+    width = max(text_width_cm(line, font_height) for line in lines) if lines else 0
+    # Padding to avoid clipping; AFM-derived widths are slightly conservative
+    # for some accented characters and Dia's own metric can be marginally larger.
+    width += 0.15
+
+    if alignment == 0:    # left
+        new_x1, new_x2 = pos_x, pos_x + width
+    elif alignment == 1:  # center
+        new_x1, new_x2 = pos_x - width / 2, pos_x + width / 2
+    else:                 # right
+        new_x1, new_x2 = pos_x - width, pos_x
+
+    # Preserve y range from the cached bb (height handling is more involved
+    # and the y dimension is usually fine for these labels).
+    y1, y2 = bb_m.group(2), bb_m.group(4)
+    new_bb = f'{new_x1:.4f},{y1};{new_x2:.4f},{y2}'
+
+    return re.sub(
+        r'(name="obj_bb">\s*<dia:rectangle val=")[-\d.,;]+(")',
+        rf'\g<1>{new_bb}\g<2>',
+        obj_xml,
+        count=1,
+    )
+
+
+def main():
+    if len(sys.argv) != 2:
+        sys.exit("usage: translate-pt-BR.py <output-dir>")
+
+    out_dir = Path(sys.argv[1])
+    out_dir.mkdir(exist_ok=True)
+
+    translations = json.loads((HERE / "translations-pt-BR.json").read_text(encoding="utf-8"))
+
+    obj_re = re.compile(r'<dia:object\b.*?</dia:object>', re.DOTALL)
+
+    for src in sorted(HERE.glob("*.dia")):
+        content = gzip.decompress(src.read_bytes()).decode("utf-8")
+        translated = obj_re.sub(lambda m: update_text_object(m.group(0), translations), content)
+        (out_dir / src.name).write_bytes(gzip.compress(translated.encode("utf-8")))
+        print(f"  {src.name}")
+
+    print(f"Translated {len(list(HERE.glob('*.dia')))} files into {out_dir}/")
+
+
+if __name__ == "__main__":
+    main()