aves_panorama/lib/panorama.dart
2020-06-14 20:15:09 +08:00

286 lines
9.6 KiB
Dart

library panorama;
import 'dart:async';
import 'dart:ui' as ui;
import 'dart:math' as math;
import 'package:flutter/material.dart';
import 'package:flutter_cube/flutter_cube.dart';
import 'package:motion_sensors/motion_sensors.dart';
enum SensorControl {
None,
Orientation,
}
class Panorama extends StatefulWidget {
Panorama({
Key key,
this.latitude = 0,
this.longitude = 0,
this.zoom = 1.0,
this.minLatitude = -90.0,
this.maxLatitude = 90.0,
this.minLongitude = -180.0,
this.maxLongitude = 180.0,
this.minZoom = 1.0,
this.maxZoom = 5.0,
this.sensitivity = 1.0,
this.animSpeed = 1.0,
this.animReverse = true,
this.latSegments = 32,
this.lonSegments = 64,
this.interactive = true,
this.sensorControl = SensorControl.None,
this.child,
}) : super(key: key);
/// The initial latitude, in degrees, between -90 and 90. default to 0
final double latitude;
/// The initial longitude, in degrees, between -180 and 180. default to 0
final double longitude;
/// The initial zoom, default to 1.0.
final double zoom;
/// The minimal latitude to show. default to -90.0
final double minLatitude;
/// The maximal latitude to show. default to 90.0
final double maxLatitude;
/// The minimal longitude to show. default to -180.0
final double minLongitude;
/// The maximal longitude to show. default to 180.0
final double maxLongitude;
/// The minimal zomm. default to 1.0
final double minZoom;
/// The maximal zomm. default to 5.0
final double maxZoom;
/// The sensitivity of the gesture. default to 1.0
final double sensitivity;
/// The Speed of rotation by animation. default to 1.0
final double animSpeed;
/// Reverse rotation when the current longitude reaches the minimal or maximum. default to true
final bool animReverse;
/// The number of vertical divisions of the sphere.
final int latSegments;
/// The number of horizontal divisions of the sphere.
final int lonSegments;
/// Interact with the panorama. default to true
final bool interactive;
/// Control the panorama with motion sensors.
final SensorControl sensorControl;
/// Specify an Image(equirectangular image) widget to the panorama.
final Image child;
@override
_PanoramaState createState() => _PanoramaState();
}
class _PanoramaState extends State<Panorama> with SingleTickerProviderStateMixin {
Scene scene;
double latitude;
double longitude;
double latitudeDelta = 0;
double longitudeDelta = 0;
double zoomDelta = 0;
Offset _lastFocalPoint;
double _lastZoom;
double _radius = 500;
double _dampingFactor = 0.05;
double _animateDirection = 1.0;
AnimationController _controller;
void _handleScaleStart(ScaleStartDetails details) {
_lastFocalPoint = details.localFocalPoint;
_lastZoom = null;
}
void _handleScaleUpdate(ScaleUpdateDetails details) {
final offset = details.localFocalPoint - _lastFocalPoint;
_lastFocalPoint = details.localFocalPoint;
latitudeDelta += widget.sensitivity * 0.5 * math.pi * offset.dy / scene.camera.viewportHeight;
longitudeDelta -= widget.sensitivity * _animateDirection * 0.5 * math.pi * offset.dx / scene.camera.viewportHeight;
if (_lastZoom == null) {
_lastZoom = scene.camera.zoom;
}
zoomDelta += _lastZoom * details.scale - (scene.camera.zoom + zoomDelta);
if (!_controller.isAnimating) {
_controller.reset();
if (widget.animSpeed != 0) {
_controller.repeat();
} else
_controller.forward();
}
}
void _onSceneCreated(Scene scene) {
this.scene = scene;
scene.camera.near = 1.0;
scene.camera.far = _radius + 1.0;
scene.camera.fov = 75;
scene.camera.zoom = widget.zoom;
scene.camera.position.setFrom(Vector3(0, 0, 0.1));
setCameraTarget(latitude, longitude);
if (widget.child != null) {
loadImageFromProvider(widget.child.image).then((ui.Image image) {
final Mesh mesh = generateSphereMesh(radius: _radius, latSegments: widget.latSegments, lonSegments: widget.lonSegments, texture: image);
scene.world.add(Object(name: 'surface', mesh: mesh, backfaceCulling: false));
scene.updateTexture();
});
}
}
void setCameraTarget(double latitude, double longitude) {
longitude += math.pi;
scene.camera.target.x = math.cos(longitude) * math.cos(latitude) * _radius;
scene.camera.target.y = math.sin(latitude) * _radius;
scene.camera.target.z = math.sin(longitude) * math.cos(latitude) * _radius;
scene.update();
}
@override
void initState() {
super.initState();
latitude = widget.latitude;
longitude = widget.longitude;
if (widget.sensorControl == SensorControl.Orientation) {
motionSensors.orientation.listen((OrientationEvent event) {
Quaternion q = Quaternion.euler(-event.roll, event.pitch, event.yaw);
q *= Quaternion.axisAngle(Vector3(1, 0, 0), math.pi * 0.5);
q.rotate(scene.camera.target..setFrom(Vector3(0, 0, -_radius)));
q.rotate(scene.camera.up..setFrom(Vector3(0, 1, 0)));
scene.update();
});
}
_controller = AnimationController(duration: Duration(milliseconds: 60000), vsync: this)
..addListener(() {
if (scene == null) return;
longitudeDelta += 0.001 * widget.animSpeed;
if (latitudeDelta.abs() < 0.001 && longitudeDelta.abs() < 0.001 && zoomDelta.abs() < 0.001) {
if (widget.animSpeed == 0 && _controller.isAnimating) _controller.stop();
return;
}
// animate vertical rotating
latitude += latitudeDelta * _dampingFactor * widget.sensitivity;
latitudeDelta *= 1 - _dampingFactor * widget.sensitivity;
latitude = latitude.clamp(radians(math.max(-89, widget.minLatitude)), radians(math.min(89, widget.maxLatitude)));
// animate horizontal rotating
longitude += _animateDirection * longitudeDelta * _dampingFactor * widget.sensitivity;
longitudeDelta *= 1 - _dampingFactor * widget.sensitivity;
if (widget.maxLongitude - widget.minLongitude < 360) {
final double lon = longitude.clamp(radians(widget.minLongitude), radians(widget.maxLongitude));
if (longitude != lon) {
longitude = lon;
if (widget.animSpeed != 0) {
if (widget.animReverse) {
_animateDirection *= -1.0;
} else
_controller.stop();
}
}
}
// animate zomming
final double zoom = scene.camera.zoom + zoomDelta * _dampingFactor;
zoomDelta *= 1 - _dampingFactor;
scene.camera.zoom = zoom.clamp(widget.minZoom, widget.maxZoom);
setCameraTarget(latitude, longitude);
});
if (widget.animSpeed != 0) _controller.repeat();
}
@override
void dispose() {
_controller.dispose();
super.dispose();
}
@override
void didUpdateWidget(Panorama oldWidget) {
super.didUpdateWidget(oldWidget);
final Object surface = scene.world.find(RegExp('surface'));
if (surface == null) return;
if (widget.latSegments != oldWidget.latSegments || widget.lonSegments != oldWidget.lonSegments) {
surface.mesh = generateSphereMesh(radius: _radius, latSegments: widget.latSegments, lonSegments: widget.lonSegments, texture: surface.mesh.texture);
}
if (widget.child?.image != oldWidget.child?.image) {
loadImageFromProvider(widget.child.image).then((ui.Image image) {
surface.mesh.texture = image;
surface.mesh.textureRect = Rect.fromLTWH(0, 0, image.width.toDouble(), image.height.toDouble());
scene.updateTexture();
});
}
}
@override
Widget build(BuildContext context) {
return widget.interactive
? GestureDetector(
onScaleStart: _handleScaleStart,
onScaleUpdate: _handleScaleUpdate,
child: Cube(interactive: false, onSceneCreated: _onSceneCreated),
)
: Cube(interactive: false, onSceneCreated: _onSceneCreated);
}
}
Mesh generateSphereMesh({num radius = 1.0, int latSegments = 16, int lonSegments = 16, ui.Image texture}) {
int count = (latSegments + 1) * (lonSegments + 1);
List<Vector3> vertices = List<Vector3>(count);
List<Offset> texcoords = List<Offset>(count);
List<Polygon> indices = List<Polygon>(latSegments * lonSegments * 2);
int i = 0;
for (int y = 0; y <= latSegments; ++y) {
final double v = y / latSegments;
final double sv = math.sin(v * math.pi);
final double cv = math.cos(v * math.pi);
for (int x = 0; x <= lonSegments; ++x) {
final double u = x / lonSegments;
vertices[i] = Vector3(radius * math.cos(u * math.pi * 2.0) * sv, radius * cv, radius * math.sin(u * math.pi * 2.0) * sv);
texcoords[i] = Offset(u, 1.0 - v);
i++;
}
}
i = 0;
for (int y = 0; y < latSegments; ++y) {
final int base1 = (lonSegments + 1) * y;
final int base2 = (lonSegments + 1) * (y + 1);
for (int x = 0; x < lonSegments; ++x) {
indices[i++] = Polygon(base1 + x, base1 + x + 1, base2 + x);
indices[i++] = Polygon(base1 + x + 1, base2 + x + 1, base2 + x);
}
}
final Mesh mesh = Mesh(vertices: vertices, texcoords: texcoords, indices: indices, texture: texture);
return mesh;
}
/// Get ui.Image from ImageProvider
Future<ui.Image> loadImageFromProvider(ImageProvider provider) async {
final Completer<ui.Image> completer = Completer<ui.Image>();
final ImageStream imageStream = provider.resolve(ImageConfiguration());
ImageStreamListener listener;
listener = ImageStreamListener((ImageInfo imageInfo, bool synchronousCall) {
completer.complete(imageInfo.image);
imageStream.removeListener(listener);
});
imageStream.addListener(listener);
return completer.future;
}