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Pages -> a digital PDF (reportlab) or raster pages (Pillow).
Both backends draw the same `layout.Page` operations. The PDF uses the
standard Helvetica / Times / Courier fonts, so it carries a real text layer
like an accounting package's export; the raster uses the URW Type 1 clones of
those fonts that ship inside reportlab (same metrics), so text lands in the
same place.
"""
from __future__ import annotations
import io
import os
import random
from functools import lru_cache
from typing import List, Sequence
from PIL import Image, ImageDraw, ImageFont
from reportlab.pdfgen.canvas import Canvas
from .handwriting import draw_hand
from .layout import PDF_FONTS, Box, Page, Rule, Text, text_width
_RL_FONT_DIR = None
def _rl_font_dir() -> str:
global _RL_FONT_DIR
if _RL_FONT_DIR is None:
import reportlab
_RL_FONT_DIR = os.path.join(os.path.dirname(reportlab.__file__), "fonts")
return _RL_FONT_DIR
_PIL_FONT_FILES = {
"sans": "_a______.pfb", "sans-bold": "_ab_____.pfb",
"serif": "_er_____.pfb", "serif-bold": "_eb_____.pfb",
"mono": "com_____.pfb", "mono-bold": "cob_____.pfb",
"hand": "_ai_____.pfb",
}
@lru_cache(maxsize=256)
def _pil_font(name: str, px: int) -> ImageFont.FreeTypeFont:
path = os.path.join(_rl_font_dir(), _PIL_FONT_FILES.get(name, "_a______.pfb"))
try:
return ImageFont.truetype(path, max(4, px))
except OSError: # pragma: no cover - a reportlab build without the Type 1 files
return ImageFont.truetype(os.path.join(_rl_font_dir(), "Vera.ttf"), max(4, px))
# ---------------------------------------------------------------------------
# PDF
# ---------------------------------------------------------------------------
def render_pdf(pages: Sequence[Page], title: str = "", author: str = "") -> bytes:
"""A deterministic PDF (invariant=1: no timestamp, fixed document id).
The creator string is part of the bytes: keep it, or the published
sha256 sums stop matching."""
buf = io.BytesIO()
c = Canvas(buf, pagesize=(pages[0].width, pages[0].height), invariant=1)
c.setCreator("IPP accuracy benchmark generator")
if title:
c.setTitle(title)
if author:
c.setAuthor(author)
for page in pages:
c.setPageSize((page.width, page.height))
H = page.height
for op in page.ops:
if isinstance(op, Box):
if op.fill is not None:
c.setFillColorRGB(*(v / 255 for v in op.fill))
if op.stroke is not None:
c.setStrokeColorRGB(*(v / 255 for v in op.stroke))
c.setLineWidth(op.width)
c.rect(op.x, H - op.y - op.h, op.w, op.h, fill=1 if op.fill else 0, stroke=1 if op.stroke else 0)
elif isinstance(op, Rule):
c.setStrokeColorRGB(*(v / 255 for v in op.color))
c.setLineWidth(op.width)
c.line(op.x1, H - op.y1, op.x2, H - op.y2)
elif isinstance(op, Text):
c.setFillColorRGB(*(v / 255 for v in op.color))
c.setFont(PDF_FONTS.get(op.font, "Helvetica"), op.size)
c.drawString(op.left, H - op.y, op.text)
c.showPage()
c.save()
return buf.getvalue()
# ---------------------------------------------------------------------------
# Raster
# ---------------------------------------------------------------------------
def render_page_image(page: Page, dpi: int = 200, seed: str = "") -> Image.Image:
k = dpi / 72.0
img = Image.new("RGB", (int(round(page.width * k)), int(round(page.height * k))), "white")
draw = ImageDraw.Draw(img)
for i, op in enumerate(page.ops):
if isinstance(op, Box):
x0, y0 = op.x * k, op.y * k
x1, y1 = (op.x + op.w) * k, (op.y + op.h) * k
draw.rectangle((x0, y0, x1, y1), fill=op.fill, outline=op.stroke,
width=max(1, int(round(op.width * k))) if op.stroke else 0)
elif isinstance(op, Rule):
draw.line((op.x1 * k, op.y1 * k, op.x2 * k, op.y2 * k), fill=op.color,
width=max(1, int(round(op.width * k))))
elif isinstance(op, Text):
if op.hand:
rng = random.Random(f"{seed}:{i}:{op.text}")
draw_hand(img, op.left * k if op.align == "left" else op.x * k, op.y * k, op.text,
op.size * k, op.color, op.hand, rng, align=op.align,
target_width=text_width(op.text, op.font, op.size) * k)
draw = ImageDraw.Draw(img)
else:
font = _pil_font(op.font, int(round(op.size * k)))
draw.text((op.left * k, op.y * k), op.text, font=font, fill=op.color, anchor="ls")
return img
def render_images(pages: Sequence[Page], dpi: int = 200, seed: str = "") -> List[Image.Image]:
return [render_page_image(p, dpi, f"{seed}:{n}") for n, p in enumerate(pages)]
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