protected List<Position> computePathPositions(
Position startPosition, Position endPosition, Angle delta) {
Angle dist = LatLon.greatCircleDistance(startPosition, endPosition);
dist = dist.multiply(0.6);
Angle azimuth = LatLon.greatCircleAzimuth(startPosition, endPosition);
LatLon locA = LatLon.greatCircleEndPosition(startPosition, azimuth.add(delta), dist);
dist = dist.multiply(0.9);
LatLon locB = LatLon.greatCircleEndPosition(startPosition, azimuth.subtract(delta), dist);
return Arrays.asList(startPosition, new Position(locA, 0), new Position(locB, 0), endPosition);
}
/**
* Setup the view to a first person mode (zoom = 0)
*
* @param view the orbit view to set into a first person view.
*/
protected void setupFirstPersonView(OrbitView view) {
if (view.getZoom() == 0) // already in first person mode
return;
Vec4 eyePoint = view.getEyePoint();
// Center pos at eye pos
Position centerPosition = wwd.getModel().getGlobe().computePositionFromPoint(eyePoint);
// Compute pitch and heading relative to center position
Vec4 normal =
wwd.getModel()
.getGlobe()
.computeSurfaceNormalAtLocation(
centerPosition.getLatitude(), centerPosition.getLongitude());
Vec4 north =
wwd.getModel()
.getGlobe()
.computeNorthPointingTangentAtLocation(
centerPosition.getLatitude(), centerPosition.getLongitude());
// Pitch
view.setPitch(Angle.POS180.subtract(view.getForwardVector().angleBetween3(normal)));
// Heading
Vec4 perpendicular = view.getForwardVector().perpendicularTo3(normal);
Angle heading = perpendicular.angleBetween3(north);
double direction = Math.signum(-normal.cross3(north).dot3(perpendicular));
view.setHeading(heading.multiply(direction));
// Zoom
view.setZoom(0);
// Center pos
view.setCenterPosition(centerPosition);
}
/**
* Find out where on the terrain surface the eye would be looking at with the given heading and
* pitch angles.
*
* @param view the orbit view
* @param heading heading direction clockwise from north.
* @param pitch view pitch angle from the surface normal at the center point.
* @return the terrain surface point the view would be looking at in the viewport center.
*/
protected Vec4 computeSurfacePoint(OrbitView view, Angle heading, Angle pitch) {
Globe globe = wwd.getModel().getGlobe();
// Compute transform to be applied to north pointing Y so that it would point in the view
// direction
// Move coordinate system to view center point
Matrix transform = globe.computeSurfaceOrientationAtPosition(view.getCenterPosition());
// Rotate so that the north pointing axes Y will point in the look at direction
transform = transform.multiply(Matrix.fromRotationZ(heading.multiply(-1)));
transform = transform.multiply(Matrix.fromRotationX(Angle.NEG90.add(pitch)));
// Compute forward vector
Vec4 forward = Vec4.UNIT_Y.transformBy4(transform);
// Return intersection with terrain
Intersection[] intersections =
wwd.getSceneController().getTerrain().intersect(new Line(view.getEyePoint(), forward));
return (intersections != null && intersections.length != 0)
? intersections[0].getIntersectionPoint()
: null;
}
/**
* Reset the view to an orbit view state if in first person mode (zoom = 0)
*
* @param view the orbit view to reset
*/
protected void resetOrbitView(OrbitView view) {
if (view.getZoom() > 0) // already in orbit view mode
return;
// Find out where on the terrain the eye is looking at in the viewport center
// TODO: if no terrain is found in the viewport center, iterate toward viewport bottom until it
// is found
Vec4 centerPoint = computeSurfacePoint(view, view.getHeading(), view.getPitch());
// Reset the orbit view center point heading, pitch and zoom
if (centerPoint != null) {
Vec4 eyePoint = view.getEyePoint();
// Center pos on terrain surface
Position centerPosition = wwd.getModel().getGlobe().computePositionFromPoint(centerPoint);
// Compute pitch and heading relative to center position
Vec4 normal =
wwd.getModel()
.getGlobe()
.computeSurfaceNormalAtLocation(
centerPosition.getLatitude(), centerPosition.getLongitude());
Vec4 north =
wwd.getModel()
.getGlobe()
.computeNorthPointingTangentAtLocation(
centerPosition.getLatitude(), centerPosition.getLongitude());
// Pitch
view.setPitch(Angle.POS180.subtract(view.getForwardVector().angleBetween3(normal)));
// Heading
Vec4 perpendicular = view.getForwardVector().perpendicularTo3(normal);
Angle heading = perpendicular.angleBetween3(north);
double direction = Math.signum(-normal.cross3(north).dot3(perpendicular));
view.setHeading(heading.multiply(direction));
// Zoom
view.setZoom(eyePoint.distanceTo3(centerPoint));
// Center pos
view.setCenterPosition(centerPosition);
}
}
/**
* Create the list of positions that describe the arrow.
*
* @param dc Current draw context.
*/
protected void createShapes(DrawContext dc) {
this.paths = new Path[2];
int i = 0;
Angle azimuth1 = LatLon.greatCircleAzimuth(this.position1, this.position2);
Angle azimuth2 = LatLon.greatCircleAzimuth(this.position1, this.position3);
Angle delta = azimuth2.subtract(azimuth1);
int sign = delta.degrees > 0 ? 1 : -1;
delta = Angle.fromDegrees(sign * 5.0);
// Create a path for the line part of the arrow
List<Position> positions = this.computePathPositions(this.position1, this.position2, delta);
this.paths[i++] = this.createPath(positions);
// Create a polygon to draw the arrow head.
double arrowLength = this.getArrowLength();
Angle arrowAngle = this.getArrowAngle();
positions =
this.computeArrowheadPositions(
dc, positions.get(2), positions.get(3), arrowLength, arrowAngle);
this.arrowHead1 = this.createPolygon(positions);
this.arrowHead1.setLocations(positions);
delta = delta.multiply(-1.0);
positions = this.computePathPositions(this.position1, this.position3, delta);
this.paths[i] = this.createPath(positions);
positions =
this.computeArrowheadPositions(
dc, positions.get(2), positions.get(3), arrowLength, arrowAngle);
this.arrowHead2 = this.createPolygon(positions);
this.arrowHead2.setLocations(positions);
}
