/**
* {@inheritDoc}
*
* @param positions Control points. This graphic uses only two control point, which determine the
* midpoints of two opposite sides of the quad. See Fire Support Area (2.X.4.3.2.1.2) on pg.
* 652 of MIL-STD-2525C for an example of how these points are interpreted.
*/
public void setPositions(Iterable<? extends Position> positions) {
if (positions == null) {
String message = Logging.getMessage("nullValue.PositionsListIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
Iterator<? extends Position> iterator = positions.iterator();
try {
Position pos1 = iterator.next();
Position pos2 = iterator.next();
LatLon center = LatLon.interpolateGreatCircle(0.5, pos1, pos2);
this.quad.setCenter(center);
Angle heading = LatLon.greatCircleAzimuth(pos2, pos1);
this.quad.setHeading(heading.subtract(Angle.POS90));
this.positions = positions;
this.shapeInvalid = true; // Need to recompute quad size
} catch (NoSuchElementException e) {
String message = Logging.getMessage("generic.InsufficientPositions");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
}
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);
}
protected void computeQuadSize(DrawContext dc) {
if (this.positions == null) return;
Iterator<? extends Position> iterator = this.positions.iterator();
Position pos1 = iterator.next();
Position pos2 = iterator.next();
Angle angularDistance = LatLon.greatCircleDistance(pos1, pos2);
double length = angularDistance.radians * dc.getGlobe().getRadius();
this.quad.setWidth(length);
}
/**
* 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);
}
