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); }
/** * 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); }