Ocideck/lib/models/annotation.dart
Brenno de Winter 227abf351e Add annotation layer (laser, pen, highlighter) over slides
Draw on slides while presenting, kept as a layer fully separate from the
Marp content so the deck stays pure, portable Marp.

Presenter tools (D pen, T highlighter, E eraser, X laser, C clear, Esc
puts the tool away) with a small floating colour/tool bar shown only when
a tool is active. Strokes use coordinates normalized to the 16:9 slide so
they render identically on the laptop and the beamer; in dual-screen mode
the ink and the laser are mirrored live to the audience window.

Persistence (decoupled from the .md):
- In memory the layer is keyed by Slide.id (stable within a session).
- On disk it lives in a sidecar <name>.ink.json next to the deck and as a
  separate entry inside the .ocideck package; the markdown is untouched.
- Because slide ids are regenerated on load, the sidecar anchors strokes
  by order + a content fingerprint, re-attaching them after reordering and
  dropping them when a slide's content changed.
- Deck.annotations carries the layer in memory but is never serialized to
  markdown; deckProvider.setAnnotations keeps it out of undo/redo.

flutter analyze is clean, all tests pass (incl. new stroke/codec tests),
and the macOS debug build compiles. Drawing and live beamer sync still
need verification on real hardware.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-07 11:14:51 +02:00

72 lines
2.2 KiB
Dart

import 'dart:ui';
/// Annotation tools available while presenting. Drawings live in a layer that
/// is fully separate from the Marp content — they are never written to the
/// markdown.
enum InkTool { laser, pen, highlighter, eraser }
/// A single freehand stroke on the annotation layer.
///
/// Coordinates are normalized (0..1) within the 16:9 slide rectangle and the
/// width is a fraction of the slide width, so a stroke renders identically on
/// the laptop preview and the beamer regardless of resolution or letterboxing.
class InkStroke {
final InkTool tool;
final int color; // ARGB
final double width; // fraction of the slide width
final List<Offset> points; // normalized 0..1
const InkStroke({
required this.tool,
required this.color,
required this.width,
required this.points,
});
InkStroke copyWith({List<Offset>? points}) => InkStroke(
tool: tool,
color: color,
width: width,
points: points ?? this.points,
);
/// Compact JSON: points are flattened to [x0, y0, x1, y1, …].
Map<String, dynamic> toJson() => {
'tool': tool.name,
'color': color,
'width': width,
'points': [
for (final p in points) ...[
_round(p.dx),
_round(p.dy),
],
],
};
static double _round(double v) => (v * 10000).roundToDouble() / 10000;
factory InkStroke.fromJson(Map<String, dynamic> json) {
final raw = (json['points'] as List?)?.cast<num>() ?? const [];
final pts = <Offset>[];
for (var i = 0; i + 1 < raw.length; i += 2) {
pts.add(Offset(raw[i].toDouble(), raw[i + 1].toDouble()));
}
return InkStroke(
tool: InkTool.values.firstWhere(
(t) => t.name == json['tool'],
orElse: () => InkTool.pen,
),
color: (json['color'] as num?)?.toInt() ?? 0xFFEF4444,
width: (json['width'] as num?)?.toDouble() ?? 0.004,
points: pts,
);
}
}
/// Encode/decode a per-slide map of strokes keyed by slide id.
List<Map<String, dynamic>> encodeStrokes(List<InkStroke> strokes) =>
[for (final s in strokes) s.toJson()];
List<InkStroke> decodeStrokes(List<dynamic> raw) => [
for (final e in raw) InkStroke.fromJson(Map<String, dynamic>.from(e as Map)),
];