An automap: the source

since 0.4.1 or earlier Simulation, audio and XR
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: grid (line 36), reveal (line 60), live (line 81), check (line 128).
1/// The level as the player has seen it, from above: floor where they walked,
2/// walls where the floor stopped, nothing where they have not been.
3///
4/// Quoted by `automap.md` and shown whole in the Source tab.
5library;

7import 'package:flutter/widgets.dart';
8import 'package:flutter3d/flutter3d.dart';
9import 'package:flutter3d_showcase/src/demo/demo.dart';
10import 'package:flutter3d_sim/flutter3d_sim.dart';
11import 'package:vector_math/vector_math.dart';

13final class AutomapDemo extends ShowcaseDemo {
late final NavGrid _grid;
late Automap _map;

double speed = 3.0;
bool _forgetAsked = false;
final Vector3 _walker = Vector3(2.0, 0.0, 2.0);
int _leg = 0;

/// The walk: room, doorway, corridor, second room, and round again.
static final List<Vector3> _route = <Vector3>[
  Vector3(2.0, 0.0, 2.0),
  Vector3(8.0, 0.0, 8.0),
  Vector3(5.0, 0.0, 5.0),
  Vector3(13.0, 0.0, 5.0),
  Vector3(20.0, 0.0, 3.0),
  Vector3(23.0, 0.0, 8.0),
  Vector3(20.0, 0.0, 5.0),
  Vector3(13.0, 0.0, 5.0),
];

@override
Scene build(DemoContext context) {
  // Two rooms and a corridor between them.
  _grid = NavGrid.bake(<Brush>[
    Brush(centre: Vector3(5, 0, 5), size: Vector3(10, 1, 10)),
    Brush(centre: Vector3(13, 0, 5), size: Vector3(6, 1, 2)),
    Brush(centre: Vector3(21, 0, 5), size: Vector3(10, 1, 10)),
  ], cellSize: 0.5);
  _map = Automap(_grid, revealRadius: 3.0);

  final material = Material(
    name: 'walker',
    baseColor: Vector4(0.6, 0.9, 0.7, 1.0),
  );
  final node = MeshNode(
    DeviceMesh.upload(context.device, SphereShape(segments: 16).build()),
    material,
  );
  return Scene()
    ..add(node)
    ..add(
      LightNode(name: 'sun', intensity: 3.0)
        ..setLocalForward(Vector3(-0.4, -1.0, -0.3)),
    );
}

void _walk() {
  _map.reveal(Vector3(1.0, 0.0, 1.0));
  _map.reveal(Vector3(3.0, 0.0, 1.0));
}

@override
void update(DemoContext context, double dt) {
  if (_forgetAsked) {
    _forgetAsked = false;
    _map = Automap(_grid, revealRadius: 3.0);
  }
  // Walk the route at `speed`, a leg at a time.
  final Vector3 to = _route[(_leg + 1) % _route.length];
  final Vector3 way = to - _walker;
  final double step = speed * dt;
  if (way.length <= step) {
    _walker.setFrom(to);
    _leg = (_leg + 1) % _route.length;
  } else {
    _walker.add(way.normalized() * step);
  }
  // Every frame the player stands somewhere, and the map learns of it.
  _map.reveal(_walker);
}

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Walking speed',
    min: 1.0,
    max: 10.0,
    value: () => speed,
    onChanged: (double v) => speed = v,
    format: (double v) => '${v.toStringAsFixed(1)} m/s',
  ),
  ToggleControl(
    'Forget the map',
    value: () => false,
    onChanged: (bool v) {
      if (v) _forgetAsked = true;
    },
  ),
];

@override
Widget? customBody(BuildContext buildContext, DemoContext context) =>
    ColoredBox(
      color: const Color(0xFF14161A),
      child: Padding(
        padding: const EdgeInsets.all(24),
        child: Center(
          child: AspectRatio(
            aspectRatio: _grid.columns / _grid.rows,
            child: CustomPaint(
              painter: _MapPainter(_grid, _map, _walker),
              child: const SizedBox.expand(),
            ),
          ),
        ),
      ),
    );

@override
void verify(Scene scene, FrameResult frame) {
  if (frame.drawCalls < 1) {
    throw StateError('the walker marker was not drawn');
  }
  _walk();
  final nearWhereWalked = _map.isFloor(_grid.cellAtPoint(2.0, 1.0));
  final farAcrossTheFloor = _map.isRevealed(_grid.cellAtPoint(9.0, 9.0));
  if (!nearWhereWalked) {
    throw StateError(
      'a cell the walk passed near should be revealed as floor',
    );
  }
  if (farAcrossTheFloor) {
    throw StateError(
      'the automap should not reveal floor nobody walked near',
    );
  }
}
141}

143/// Draws revealed floor light, revealed walls dark, and everything else
144/// blank.
145final class _MapPainter extends CustomPainter {
const _MapPainter(this.grid, this.map, this.walker);

final NavGrid grid;
final Automap map;
final Vector3 walker;

@override
void paint(Canvas canvas, Size size) {
  final cellW = size.width / grid.columns;
  final cellH = size.height / grid.rows;
  final paint = Paint();
  for (var index = 0; index < grid.cellCount; index++) {
    if (!map.isRevealed(index)) continue;
    final cx = grid.cellX(index);
    final cz = grid.cellZ(index);
    paint.color = map.isFloor(index)
        ? const Color(0xFFB6E3B0)
        : const Color(0xFF3A2A2A);
    canvas.drawRect(
      Rect.fromLTWH(cx * cellW, cz * cellH, cellW, cellH),
      paint,
    );
  }
  // Where the player is, in the same cells.
  canvas.drawCircle(
    Offset(
      walker.x / grid.cellSize * cellW,
      walker.z / grid.cellSize * cellH,
    ),
    cellW * 1.4,
    Paint()..color = const Color(0xFFE8A33D),
  );
}

@override
bool shouldRepaint(covariant _MapPainter oldDelegate) => true;
182}