feat(export): PDF 内嵌函数图像矢量图

- 抽取 render.py 共享几何:新增 PlotGeometry + compute_geometry,render_svg
  改为薄序列化层,SVG 输出与重构前逐字节一致(8 组用例回归验证)
- 新增 app/plot/render_reportlab.py:消费共享几何产出 reportlab 矢量 Drawing
  (网格/坐标轴 Line、曲线 PolyLine、刻度/标签 String、ylabel Group 旋转),
  复用 STSong-Light 渲染中文,按页面内容宽 renderScale 缩放
- pdf.py _block_function_plot 改为内嵌矢量图(解析/渲染失败或超预算回退占位,
  单图失败不阻断整篇);mermaid 仍占位
- 抽取 FunctionPlotBudget + format_plot_diagnostic 到 _common.py,html/pdf 共用
- 文档同步:PDF 已内嵌函数图像,DOCX 仍占位(栅格化范围外)

Co-Authored-By: Claude Code <noreply@anthropic.com>
This commit is contained in:
yxx
2026-09-06 21:26:54 +08:00
co-authored by Claude Code
parent 4fc26a11e1
commit f1ac414866
9 changed files with 490 additions and 137 deletions
+171 -95
View File
@@ -1,7 +1,11 @@
"""Function Plot → 静态 SVG 渲染。
"""Function Plot → 静态 SVG 渲染 + 共享几何计算
只输出纯几何与 <text> 的 SVG(无 script/foreignObject/内联事件),可安全内嵌 HTML。
所有文本与颜色都经过转义/校验,不把用户输入直接拼进标记。
几何计算(范围解析、采样、刻度、非有限点分段)统一收敛到 ``compute_geometry``
返回像素坐标的 ``PlotGeometry````render_svg`` 只做 SVG 序列化,reportlab 后端
``render_reportlab.py``)消费同一份几何,保证 PDF 与 SVG 视觉一致。
"""
from __future__ import annotations
@@ -9,7 +13,7 @@ from __future__ import annotations
import html
import math
import re
from typing import Callable
from dataclasses import dataclass
from app.plot.model import FunctionPlot, StaticRenderResult
from app.plot.parser import PlotParseError, evaluate, parse_expression
@@ -102,17 +106,51 @@ def _compute_range(
return lo - pad, hi + pad
def _polyline(
def _sx(x: float, xmin: float, xmax: float) -> float:
"""数据 x → 像素 x(SVG y-down 约定,原点左上)。"""
return _MARGIN + (x - xmin) / (xmax - xmin) * (_WIDTH - 2 * _MARGIN)
def _sy(y: float, ymin: float, ymax: float) -> float:
"""数据 y → 像素 y(SVG y-down 约定,原点左上)。"""
return _HEIGHT - _MARGIN - (y - ymin) / (ymax - ymin) * (_HEIGHT - 2 * _MARGIN)
@dataclass
class PlotGeometry:
"""已解析的几何:范围、轴位置、刻度、曲线像素点段、标签与 warnings。
像素坐标统一为 SVG y-down 约定;reportlab 后端(y-up)自行翻转 y。
"""
width: int
height: int
xmin: float
xmax: float
ymin: float
ymax: float
x_axis_y: float # 数据空间里 x 轴所在 y(过原点则 0,否则贴边)
y_axis_x: float # 数据空间里 y 轴所在 x(过原点则 0,否则贴边)
xticks: list[float]
yticks: list[float]
polylines: list[list[list[tuple[float, float]]]] # 按表达式分组:段 → 像素点
colors: list[str] # 与 polylines 对齐
xlabel: str | None
ylabel: str | None
grid: bool
warnings: list[str]
def _sample_segments(
tree: object,
xmin: float,
xmax: float,
sx: Callable[[float], float],
sy: Callable[[float], float],
color: str,
) -> str:
"""采样并把非有限点处断开成多段 polyline,避免画穿渐近线。"""
segments: list[str] = []
points: list[str] = []
ymin: float,
ymax: float,
) -> list[list[tuple[float, float]]]:
"""采样并映射为像素点段;非有限点处断段,避免画穿渐近线。"""
segments: list[list[tuple[float, float]]] = []
points: list[tuple[float, float]] = []
for i in range(_SAMPLES + 1):
x = xmin + (xmax - xmin) * i / _SAMPLES
try:
@@ -121,85 +159,25 @@ def _polyline(
y = math.nan
if not isinstance(y, (int, float)) or not math.isfinite(y):
if points:
segments.append(f'<polyline points="{" ".join(points)}" fill="none" stroke="{color}"/>')
segments.append(points)
points = []
continue
px = sx(x)
py = sy(y)
px = _sx(x, xmin, xmax)
py = _sy(y, ymin, ymax)
# 映射后的坐标必须有限:显式 range 下极端 y 值可能让像素坐标溢出为 inf
if not (math.isfinite(px) and math.isfinite(py)):
if points:
segments.append(f'<polyline points="{" ".join(points)}" fill="none" stroke="{color}"/>')
segments.append(points)
points = []
continue
points.append(f"{px:.2f},{py:.2f}")
points.append((px, py))
if points:
segments.append(f'<polyline points="{" ".join(points)}" fill="none" stroke="{color}"/>')
return "".join(segments)
segments.append(points)
return segments
def _grid(
xmin: float,
xmax: float,
ymin: float,
ymax: float,
sx: Callable[[float], float],
sy: Callable[[float], float],
) -> str:
parts: list[str] = []
for x in _ticks(xmin, xmax, _nice_step(xmax - xmin)):
parts.append(f'<line x1="{sx(x):.2f}" y1="{sy(ymin):.2f}" x2="{sx(x):.2f}" y2="{sy(ymax):.2f}" stroke="#eaeef2"/>')
for y in _ticks(ymin, ymax, _nice_step(ymax - ymin)):
parts.append(f'<line x1="{sx(xmin):.2f}" y1="{sy(y):.2f}" x2="{sx(xmax):.2f}" y2="{sy(y):.2f}" stroke="#eaeef2"/>')
return "".join(parts)
def _axes(
xmin: float,
xmax: float,
ymin: float,
ymax: float,
sx: Callable[[float], float],
sy: Callable[[float], float],
) -> str:
parts: list[str] = []
# 坐标轴:过原点则画在原点,否则贴边,保证始终有参照系
x_axis_y = 0.0 if ymin <= 0 <= ymax else ymin
y_axis_x = 0.0 if xmin <= 0 <= xmax else xmin
parts.append(
f'<line x1="{sx(xmin):.2f}" y1="{sy(x_axis_y):.2f}" x2="{sx(xmax):.2f}" y2="{sy(x_axis_y):.2f}" stroke="#57606a"/>'
)
parts.append(
f'<line x1="{sx(y_axis_x):.2f}" y1="{sy(ymin):.2f}" x2="{sx(y_axis_x):.2f}" y2="{sy(ymax):.2f}" stroke="#57606a"/>'
)
# x 轴刻度数字(画在轴下方)
for x in _ticks(xmin, xmax, _nice_step(xmax - xmin)):
parts.append(
f'<text x="{sx(x):.2f}" y="{sy(x_axis_y) + 14:.2f}" text-anchor="middle" font-size="10" fill="#57606a">{html.escape(_fmt_num(x))}</text>'
)
# y 轴刻度数字(画在轴左侧)
for y in _ticks(ymin, ymax, _nice_step(ymax - ymin)):
parts.append(
f'<text x="{sx(y_axis_x) - 6:.2f}" y="{sy(y) + 3:.2f}" text-anchor="end" font-size="10" fill="#57606a">{html.escape(_fmt_num(y))}</text>'
)
return "".join(parts)
def _labels(plot: FunctionPlot, sx: Callable[[float], float], sy: Callable[[float], float]) -> str:
parts: list[str] = []
if plot.axes.xlabel:
parts.append(
f'<text x="{(_WIDTH / 2):.2f}" y="{_HEIGHT - 10:.2f}" text-anchor="middle" font-size="12" fill="#1f2328">{html.escape(plot.axes.xlabel)}</text>'
)
if plot.axes.ylabel:
parts.append(
f'<text x="16" y="{(_HEIGHT / 2):.2f}" text-anchor="middle" font-size="12" fill="#1f2328" transform="rotate(-90 16 {_HEIGHT / 2:.2f})">{html.escape(plot.axes.ylabel)}</text>'
)
return "".join(parts)
def render_svg(plot: FunctionPlot) -> StaticRenderResult:
"""把已解析的 FunctionPlot 渲染为内嵌 SVG。"""
def compute_geometry(plot: FunctionPlot) -> PlotGeometry:
"""解析并计算几何,供 SVG 与 reportlab 后端复用。"""
warnings: list[str] = []
xmin, xmax = plot.domain
if not _valid_span(xmin, xmax):
@@ -232,27 +210,125 @@ def render_svg(plot: FunctionPlot) -> StaticRenderResult:
warnings.append("y 范围跨度无法表示,回退到 [-10, 10]")
ymin, ymax = -10.0, 10.0
def sx(x: float) -> float:
return _MARGIN + (x - xmin) / (xmax - xmin) * (_WIDTH - 2 * _MARGIN)
x_axis_y = 0.0 if ymin <= 0 <= ymax else ymin
y_axis_x = 0.0 if xmin <= 0 <= xmax else xmin
xticks = _ticks(xmin, xmax, _nice_step(xmax - xmin))
yticks = _ticks(ymin, ymax, _nice_step(ymax - ymin))
def sy(y: float) -> float:
return _HEIGHT - _MARGIN - (y - ymin) / (ymax - ymin) * (_HEIGHT - 2 * _MARGIN)
parts: list[str] = [
f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 {_WIDTH} {_HEIGHT}" role="img">'
]
if plot.axes.grid:
parts.append(_grid(xmin, xmax, ymin, ymax, sx, sy))
parts.append(_axes(xmin, xmax, ymin, ymax, sx, sy))
polylines: list[list[list[tuple[float, float]]]] = []
colors: list[str] = []
for i, (expr, tree) in enumerate(fns):
color = _safe_color(expr.color, _PALETTE[i % len(_PALETTE)])
parts.append(_polyline(tree, xmin, xmax, sx, sy, color))
parts.append(_labels(plot, sx, sy))
colors.append(color)
polylines.append(_sample_segments(tree, xmin, xmax, ymin, ymax))
return PlotGeometry(
width=_WIDTH,
height=_HEIGHT,
xmin=xmin,
xmax=xmax,
ymin=ymin,
ymax=ymax,
x_axis_y=x_axis_y,
y_axis_x=y_axis_x,
xticks=xticks,
yticks=yticks,
polylines=polylines,
colors=colors,
xlabel=plot.axes.xlabel,
ylabel=plot.axes.ylabel,
grid=plot.axes.grid,
warnings=warnings,
)
# --- SVG 序列化(与 compute_geometry 共用,保证字节级稳定) ---
def _grid_svg(geo: PlotGeometry) -> str:
sx = lambda x: _sx(x, geo.xmin, geo.xmax)
sy = lambda y: _sy(y, geo.ymin, geo.ymax)
parts: list[str] = []
for x in geo.xticks:
parts.append(
f'<line x1="{sx(x):.2f}" y1="{sy(geo.ymin):.2f}" x2="{sx(x):.2f}" '
f'y2="{sy(geo.ymax):.2f}" stroke="#eaeef2"/>'
)
for y in geo.yticks:
parts.append(
f'<line x1="{sx(geo.xmin):.2f}" y1="{sy(y):.2f}" x2="{sx(geo.xmax):.2f}" '
f'y2="{sy(y):.2f}" stroke="#eaeef2"/>'
)
return "".join(parts)
def _axes_svg(geo: PlotGeometry) -> str:
sx = lambda x: _sx(x, geo.xmin, geo.xmax)
sy = lambda y: _sy(y, geo.ymin, geo.ymax)
parts: list[str] = []
# 坐标轴:过原点则画在原点,否则贴边,保证始终有参照系
parts.append(
f'<line x1="{sx(geo.xmin):.2f}" y1="{sy(geo.x_axis_y):.2f}" x2="{sx(geo.xmax):.2f}" '
f'y2="{sy(geo.x_axis_y):.2f}" stroke="#57606a"/>'
)
parts.append(
f'<line x1="{sx(geo.y_axis_x):.2f}" y1="{sy(geo.ymin):.2f}" x2="{sx(geo.y_axis_x):.2f}" '
f'y2="{sy(geo.ymax):.2f}" stroke="#57606a"/>'
)
# x 轴刻度数字(画在轴下方)
for x in geo.xticks:
parts.append(
f'<text x="{sx(x):.2f}" y="{sy(geo.x_axis_y) + 14:.2f}" text-anchor="middle" '
f'font-size="10" fill="#57606a">{html.escape(_fmt_num(x))}</text>'
)
# y 轴刻度数字(画在轴左侧)
for y in geo.yticks:
parts.append(
f'<text x="{sx(geo.y_axis_x) - 6:.2f}" y="{sy(y) + 3:.2f}" text-anchor="end" '
f'font-size="10" fill="#57606a">{html.escape(_fmt_num(y))}</text>'
)
return "".join(parts)
def _polylines_svg(geo: PlotGeometry) -> str:
parts: list[str] = []
for segments, color in zip(geo.polylines, geo.colors):
for seg in segments:
points = " ".join(f"{px:.2f},{py:.2f}" for px, py in seg)
parts.append(f'<polyline points="{points}" fill="none" stroke="{color}"/>')
return "".join(parts)
def _labels_svg(geo: PlotGeometry) -> str:
parts: list[str] = []
if geo.xlabel:
parts.append(
f'<text x="{geo.width / 2:.2f}" y="{geo.height - 10:.2f}" text-anchor="middle" '
f'font-size="12" fill="#1f2328">{html.escape(geo.xlabel)}</text>'
)
if geo.ylabel:
parts.append(
f'<text x="16" y="{geo.height / 2:.2f}" text-anchor="middle" font-size="12" '
f'fill="#1f2328" transform="rotate(-90 16 {geo.height / 2:.2f})">'
f'{html.escape(geo.ylabel)}</text>'
)
return "".join(parts)
def render_svg(plot: FunctionPlot) -> StaticRenderResult:
"""把已解析的 FunctionPlot 渲染为内嵌 SVG。"""
geo = compute_geometry(plot)
parts: list[str] = [
f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 {geo.width} {geo.height}" role="img">'
]
if geo.grid:
parts.append(_grid_svg(geo))
parts.append(_axes_svg(geo))
parts.append(_polylines_svg(geo))
parts.append(_labels_svg(geo))
parts.append("</svg>")
return StaticRenderResult(
content="".join(parts),
width=_WIDTH,
height=_HEIGHT,
warnings=warnings,
width=geo.width,
height=geo.height,
warnings=geo.warnings,
)
+116
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@@ -0,0 +1,116 @@
"""Function Plot → reportlab 矢量 Drawing(供 PDF 内嵌)。
消费 ``render.compute_geometry`` 的共享几何,产出 ``reportlab.graphics.shapes.Drawing``
网格/坐标轴用 ``Line``、曲线用 ``PolyLine``、刻度数字与轴标签用 ``String``。
reportlab 原点在左下(y-up),与 SVG 的 y-down 相反,故对几何里的像素 y 统一翻转;
轴标签(ylabel)用 ``Group.rotate`` 旋转为竖向文本。中文字体复用内置 STSong-Light
guarded 注册避免与 pdf.py 重复注册。
"""
from __future__ import annotations
from reportlab.graphics.shapes import Drawing, Group, Line, PolyLine, String
from reportlab.lib.colors import HexColor
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.cidfonts import UnicodeCIDFont
from app.plot.model import FunctionPlot
from app.plot.render import PlotGeometry, _fmt_num, _sx, _sy, compute_geometry
_FONT = "STSong-Light"
if _FONT not in pdfmetrics.getRegisteredFontNames():
pdfmetrics.registerFont(UnicodeCIDFont(_FONT))
_GRID_COLOR = HexColor("#eaeef2")
_AXIS_COLOR = HexColor("#57606a")
_LABEL_COLOR = HexColor("#1f2328")
_TICK_FONT_SIZE = 10
_LABEL_FONT_SIZE = 12
def _build_drawing(geo: PlotGeometry) -> Drawing:
"""由共享几何构建矢量 Drawing(坐标翻转后仍沿用 SVG 的像素布局)。"""
drawing = Drawing(geo.width, geo.height)
# SVG y-down → reportlab y-up:翻转像素 y
def sx(x: float) -> float:
return _sx(x, geo.xmin, geo.xmax)
def sy(y: float) -> float:
return geo.height - _sy(y, geo.ymin, geo.ymax)
# 网格
if geo.grid:
for x in geo.xticks:
drawing.add(
Line(sx(x), sy(geo.ymin), sx(x), sy(geo.ymax), strokeColor=_GRID_COLOR, strokeWidth=0.5)
)
for y in geo.yticks:
drawing.add(
Line(sx(geo.xmin), sy(y), sx(geo.xmax), sy(y), strokeColor=_GRID_COLOR, strokeWidth=0.5)
)
# 坐标轴(过原点画在原点,否则贴边,与 SVG 一致)
drawing.add(
Line(sx(geo.xmin), sy(geo.x_axis_y), sx(geo.xmax), sy(geo.x_axis_y), strokeColor=_AXIS_COLOR, strokeWidth=0.7)
)
drawing.add(
Line(sx(geo.y_axis_x), sy(geo.ymin), sx(geo.y_axis_x), sy(geo.ymax), strokeColor=_AXIS_COLOR, strokeWidth=0.7)
)
# 刻度数字(x 轴下方、y 轴左侧)
for x in geo.xticks:
drawing.add(
String(
sx(x), sy(geo.x_axis_y) - 14, _fmt_num(x),
fontName=_FONT, fontSize=_TICK_FONT_SIZE, fillColor=_AXIS_COLOR, textAnchor="middle",
)
)
for y in geo.yticks:
drawing.add(
String(
sx(geo.y_axis_x) - 6, sy(y) - 3, _fmt_num(y),
fontName=_FONT, fontSize=_TICK_FONT_SIZE, fillColor=_AXIS_COLOR, textAnchor="end",
)
)
# 曲线(非有限点处已由几何断成多段)
for segments, color in zip(geo.polylines, geo.colors):
for seg in segments:
flipped = [(px, geo.height - py) for px, py in seg]
drawing.add(PolyLine(flipped, strokeColor=HexColor(color), strokeWidth=1.4))
# 轴标签
if geo.xlabel:
drawing.add(
String(
geo.width / 2, 10, geo.xlabel,
fontName=_FONT, fontSize=_LABEL_FONT_SIZE, fillColor=_LABEL_COLOR, textAnchor="middle",
)
)
if geo.ylabel:
# 竖向标签:rotate(90) 在 y-up 坐标下等价于 SVG 的 rotate(-90)
label = Group()
label.add(
String(
16, geo.height / 2, geo.ylabel,
fontName=_FONT, fontSize=_LABEL_FONT_SIZE, fillColor=_LABEL_COLOR, textAnchor="middle",
)
)
label.rotate(90, 16, geo.height / 2)
drawing.add(label)
return drawing
def render_drawing(plot: FunctionPlot, width: float | None = None) -> Drawing:
"""把已解析的 FunctionPlot 渲染为 reportlab Drawing(可直接追加到 platypus story)。
``width`` 为目标输出宽度(点),用于把 640px 的几何缩放到页面内容宽;省略则按
原始尺寸输出。缩放只影响 PDF 渲染,不改动共享几何。
"""
geo = compute_geometry(plot)
drawing = _build_drawing(geo)
if width is not None and width > 0:
drawing.renderScale = min(1.0, width / geo.width)
return drawing