# Path Smoothing Six-Figure Report Design

## Goal

Replace the current one-file, three-panel path-smoothing report with six focused, independent point-plot figures for every scenario. Preserve both SVG and 600 dpi PNG export, retain one CSV metrics file, and never connect trajectory samples with lines.

## Output contract

Every scenario directory contains exactly these six figures in both `.svg` and `.png` form:

1. `01-coarse-path-overview`: raw Hybrid A* samples, map obstacles, start and coarse-path endpoint.
2. `02-all-paths-comparison`: raw, B-spline, Bézier, and quintic samples together; no obstacles, start, or goal marker.
3. `03-cubic-bspline-overview`: faded raw samples, B-spline samples, relevant obstacles, start and endpoint.
4. `04-local-cubic-bezier-overview`: faded raw samples, Bézier samples, relevant obstacles, start and endpoint.
5. `05-piecewise-quintic-overview`: faded raw samples, quintic samples, relevant obstacles, start and endpoint.
6. `06-curvature-comparison`: raw and every available smoother's vehicle-curvature samples against arc length.

`comparison.csv` remains the single numerical report. The legacy composite `comparison.svg` and `comparison.png` are no longer emitted.

## Point-only rendering

Each `SmoothingFigurePoint` in a displayed series becomes one circular marker. SVG must not emit a trajectory polyline/path for any figure; PNG must not call a line-drawing API for trajectory samples. Marker size is fixed in report points so 0.025 m samples remain individually visible at 600 dpi. Start and endpoint remain distinct point markers only in figures 1, 3, 4, and 5.

Raw samples are dark gray, B-spline samples blue, Bézier samples orange, and quintic samples green. A method with no geometry has no markers but remains represented by an `Infeasible` or `Failed` status in that figure's legend.

## Framing and annotation

Every overhead figure derives its world bounds from the displayed path samples, then adds a fixed 10% padding with a 0.25 m minimum. The X/Y scales are equal. Obstacles are clipped by the panel rather than expanding the camera away from the path. Overhead axes show numeric ticks plus `X (m)` and `Y (m)` labels.

The curvature figure uses `s (m)` horizontally and `κ (m⁻¹)` vertically, with numeric ticks, zero axis, and displayed curvature limits. Every figure owns a compact legend describing its visible series and statuses.

## Export and compatibility

The existing shared, immutable comparison data remains the source of all six figures. SVG continues to use SimSun/Times New Roman family references. PNG continues to require exact SimSun and Times New Roman and returns `FontUnavailable` rather than falling back. The report exporter publishes all image files atomically and cleans any temporary files if one fails.

## Validation

Regression coverage verifies the six stable file stems, absence of trajectory line commands/styles, presence of all expected point markers and units, correct legends/statuses, valid PNG signature/CRC/600 dpi metadata, and no leftover `.tmp` files. Visual inspection covers straight, rectangle-detour, forward-reverse-switch, and an infeasible scenario.
