"手写笔就是一个带压感的手指，没有特殊适配" — correct. The new editor fed
RAW LINEAR stylus pressure into perfect_freehand, and the pressureGamma
config (a slider in pen-settings) was read ONLY by that slider's UI and
NEVER applied to a stroke. Dead wiring, like the rest.
Wire it for real:
- PenCanvas applies PressureCurve(floor, gamma) at capture, so stored
pressure carries the feel and live + PDF export replay identically.
- Natural defaults: gamma 0.7 (light touches register more width, rnote/
OneNote-like) + floor 0.12 (thin strokes keep body, not scratchy).
- pen_editor threads PenConfig.pressureGamma into the canvas — the slider
now actually changes stroke width.
- pen_config: natural default + one-time migration of the legacy inert
gamma 1.0, guarded by a marker so a deliberate 1.0 still sticks.
Tests: pen_config_gamma_migration (4) + pressure_curve (6) pass; pen
widget regressions green. flutter analyze: 0 issues.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The user's repeated "可配置笔" ask, as a pure value type: raw normalized
pressure is pre-shaped into [floor, 1] via a min-width floor (the plan's
marker fixed-pressure floor) and a gamma response (γ<1 = more sensitive at light
touch, γ>1 = firmer). Clamps out-of-range + NaN inputs; endpoints anchored at
floor and 1. Widget-free/storage-free; PenConfig + the canvas wire it later
(live-path, on-device validated).
flutter analyze lib/editor clean; 145/145 tests (+6).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
