/**
* Performs one line of sight calculation between the reference position and a specified grid
* position.
*
* @param gridPosition the grid position.
* @throws InterruptedException if the operation is interrupted.
*/
protected void performIntersection(Position gridPosition) throws InterruptedException {
// Intersect the line between this grid point and the selected position.
Intersection[] intersections = this.terrain.intersect(this.referencePosition, gridPosition);
if (intersections == null || intersections.length == 0) {
// No intersection, so the line goes from the center to the grid point.
this.sightLines.add(new Position[] {this.referencePosition, gridPosition});
return;
}
// Only the first intersection is shown.
Vec4 iPoint = intersections[0].getIntersectionPoint();
Vec4 gPoint =
terrain.getSurfacePoint(
gridPosition.getLatitude(), gridPosition.getLongitude(), gridPosition.getAltitude());
// Check to see whether the intersection is beyond the grid point.
if (iPoint.distanceTo3(this.referencePoint) >= gPoint.distanceTo3(this.referencePoint)) {
// Intersection is beyond the grid point; the line goes from the center to the grid point.
this.addSightLine(this.referencePosition, gridPosition);
return;
}
// Compute the position corresponding to the intersection.
Position iPosition = this.terrain.getGlobe().computePositionFromPoint(iPoint);
// The sight line goes from the user-selected position to the intersection position.
this.addSightLine(this.referencePosition, new Position(iPosition, 0));
// Keep track of the intersection positions.
this.addIntersectionPosition(iPosition);
this.updateProgress();
}
public AStarNode createStartNode(Object state) {
Position p = (Position) state;
AStarNode n = new AStarNode(p);
n.setDistTravelled(0);
n.setApproxTotalDist(p.distance((Position) getEndingState()));
List<Position> path = new ArrayList<Position>();
path.add(p);
n.setPath(path);
// System.out.print("createStartNode"); n.printNode();
return n;
}
private boolean inPath(Position pos, List<Position> path) {
for (Position n : path) {
if (pos.equals(n)) return true;
}
;
return false;
}
protected void showIntersections(List<Position> intersections) {
this.intersectionsLayer.removeAllRenderables();
// Display the intersections as CYAN points.
PointPlacemarkAttributes intersectionPointAttributes;
intersectionPointAttributes = new PointPlacemarkAttributes();
intersectionPointAttributes.setLineMaterial(Material.CYAN);
intersectionPointAttributes.setScale(6d);
intersectionPointAttributes.setUsePointAsDefaultImage(true);
for (Position p : intersections) {
PointPlacemark pm = new PointPlacemark(p);
pm.setAltitudeMode(WorldWind.CLAMP_TO_GROUND);
pm.setAttributes(intersectionPointAttributes);
pm.setValue(AVKey.DISPLAY_NAME, p.toString());
this.intersectionsLayer.addRenderable(pm);
}
}
protected void performIntersectionTests(final Position curPos) throws InterruptedException {
// Clear the results lists when the user selects a new location.
this.firstIntersectionPositions.clear();
this.sightLines.clear();
// Raise the selected location and the grid points a little above ground just to show we can.
final double height = 5; // meters
// Form the grid.
double gridRadius = GRID_RADIUS.degrees;
Sector sector =
Sector.fromDegrees(
curPos.getLatitude().degrees - gridRadius, curPos.getLatitude().degrees + gridRadius,
curPos.getLongitude().degrees - gridRadius,
curPos.getLongitude().degrees + gridRadius);
this.grid = buildGrid(sector, height, GRID_DIMENSION, GRID_DIMENSION);
this.numGridPoints = grid.size();
// Compute the position of the selected location (incorporate its height).
this.referencePosition = new Position(curPos.getLatitude(), curPos.getLongitude(), height);
this.referencePoint =
terrain.getSurfacePoint(curPos.getLatitude(), curPos.getLongitude(), height);
// // Pre-caching is unnecessary and is useful only when it occurs before the
// intersection
// // calculations. It will incur extra overhead otherwise. The normal intersection
// calculations
// // cause the same caching, making subsequent calculations on the same area
// faster.
// this.preCache(grid, this.referencePosition);
// On the EDT, show the grid.
SwingUtilities.invokeLater(
new Runnable() {
public void run() {
progressBar.setValue(0);
progressBar.setString(null);
clearLayers();
showGrid(grid, referencePosition);
getWwd().redraw();
}
});
// Perform the intersection calculations.
this.startTime = System.currentTimeMillis();
for (Position gridPos : this.grid) // for each grid point.
{
//noinspection ConstantConditions
if (NUM_THREADS > 0) this.threadPool.execute(new Intersector(gridPos));
else performIntersection(gridPos);
}
}
protected void showGrid(List<Position> grid, Position cPos) {
this.gridLayer.removeAllRenderables();
// Display the grid points in yellow.
PointPlacemarkAttributes gridPointAttributes;
gridPointAttributes = new PointPlacemarkAttributes();
gridPointAttributes.setLineMaterial(Material.YELLOW);
gridPointAttributes.setScale(6d);
gridPointAttributes.setUsePointAsDefaultImage(true);
for (Position p : grid) {
PointPlacemark pm = new PointPlacemark(p);
pm.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
pm.setAttributes(gridPointAttributes);
pm.setLineEnabled(true);
pm.setValue(AVKey.DISPLAY_NAME, p.toString());
this.gridLayer.addRenderable(pm);
}
showCenterPoint(cPos);
}
protected void showGridSightLines(List<Position> grid, Position cPos) {
this.sightLinesLayer.removeAllRenderables();
// Display lines from the center to each grid point.
ShapeAttributes lineAttributes;
lineAttributes = new BasicShapeAttributes();
lineAttributes.setDrawOutline(true);
lineAttributes.setDrawInterior(false);
lineAttributes.setOutlineMaterial(Material.GREEN);
lineAttributes.setOutlineOpacity(0.6);
for (Position p : grid) {
List<Position> endPoints = new ArrayList<Position>();
endPoints.add(cPos);
endPoints.add(new Position(p.getLatitude(), p.getLongitude(), 0));
Path path = new Path(endPoints);
path.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
path.setAttributes(lineAttributes);
this.sightLinesLayer.addRenderable(path);
}
}
protected void showCenterPoint(Position cPos) {
// Display the center point in red.
PointPlacemarkAttributes selectedLocationAttributes;
selectedLocationAttributes = new PointPlacemarkAttributes();
selectedLocationAttributes.setLineMaterial(Material.RED);
selectedLocationAttributes.setScale(8d);
selectedLocationAttributes.setUsePointAsDefaultImage(true);
PointPlacemark pm = new PointPlacemark(cPos);
pm.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
pm.setAttributes(selectedLocationAttributes);
pm.setValue(AVKey.DISPLAY_NAME, cPos.toString());
pm.setLineEnabled(true);
this.gridLayer.addRenderable(pm);
}
protected List<Position> buildGrid(Sector sector, double height, int nLatCells, int nLonCells) {
List<Position> grid = new ArrayList<Position>((nLatCells + 1) * (nLonCells + 1));
double dLat = sector.getDeltaLatDegrees() / nLatCells;
double dLon = sector.getDeltaLonDegrees() / nLonCells;
for (int j = 0; j <= nLatCells; j++) {
double lat =
j == nLatCells
? sector.getMaxLatitude().degrees
: sector.getMinLatitude().degrees + j * dLat;
for (int i = 0; i <= nLonCells; i++) {
double lon =
i == nLonCells
? sector.getMaxLongitude().degrees
: sector.getMinLongitude().degrees + i * dLon;
grid.add(Position.fromDegrees(lat, lon, height));
}
}
return grid;
}
public List<Node> expandFunc(Node n) {
AStarNode node = (AStarNode) n;
// loop computes the positions you can get to from node
List<Node> expandedNodes = new ArrayList<Node>();
List<Position> path = node.getPath();
Position pos = node.getPosition();
int x = pos.getX();
int y = pos.getY();
// this next pair of loops will create all the possible moves
// from pos.
for (int i = -1; i <= 1; i += 2) { // Checks nodes to left and right
// create the potential next position
int nextX = x + i;
int nextY = y;
// make sure next point is on the grid
if ((nextX + 1 > grid.length || nextY + 1 > grid[0].length) || (nextX < 0 || nextY < 0))
continue;
Position next = new Position(nextX, nextY);
// System.out.println("considering"+next);
if (inPath(next, path) || !next.open(grid)) continue;
// printCurrentList();
// System.out.println("available"+next);
AStarNode nodeTemp = new AStarNode(next);
// update distance travelled
nodeTemp.setDistTravelled(node.getDistTravelled() + pos.distance(next));
// update approximate total distance to destination
// note that we are computing the straight-line
// heuristic on the fly right here from next to endingState
nodeTemp.setApproxTotalDist(next.distance((Position) endingState));
// update internal path
nodeTemp.updatePath(path);
expandedNodes.add(nodeTemp); // could have just added
// them directly to nodelist
}
for (int j = -1; j <= 1; j += 2) { // Checks nodes above and below
// create the potential next position
int nextX = x;
int nextY = y + j;
// make sure next point is on the grid
if ((nextX + 1 > grid.length || nextY + 1 > grid[0].length) || (nextX < 0 || nextY < 0))
continue;
Position next = new Position(nextX, nextY);
// System.out.println("considering"+next);
if (inPath(next, path) || !next.open(grid)) continue;
// printCurrentList();
// System.out.println("available"+next);
AStarNode nodeTemp = new AStarNode(next);
// update distance travelled
nodeTemp.setDistTravelled(node.getDistTravelled() + pos.distance(next));
// update approximate total distance to destination
// note that we are computing the straight-line
// heuristic on the fly right here from next to endingState
nodeTemp.setApproxTotalDist(next.distance((Position) endingState));
// update internal path
nodeTemp.updatePath(path);
expandedNodes.add(nodeTemp); // could have just added
// them directly to nodelist
}
return expandedNodes;
} // end expandFunc
