/**
* Check the two triangles of a given grid space for intersection.
*
* @param gridX grid row
* @param gridY grid column
* @param pick our pick ray
* @param intersection the store variable
* @param block the terrain block we are currently testing against.
* @return true if a pick was found on these triangles.
*/
protected boolean checkTriangles(
float gridX, float gridY, Ray pick, Vector3f intersection, TerrainBlock block) {
if (!getTriangles(gridX, gridY, block)) return false;
if (!pick.intersectWhere(_gridTriA, intersection)) {
return pick.intersectWhere(_gridTriB, intersection);
} else {
return true;
}
}
/** {@inheritDoc} */
public Vector3f getIntersection(Ray ray, Spatial parent, Vector3f store, boolean local) {
if (store == null) {
store = new Vector3f();
}
TrianglePickResults results = new TrianglePickResults();
results.setCheckDistance(true);
Vector3f[] vertices = new Vector3f[3];
parent.findPick(ray, results);
boolean hit = false;
if (results.getNumber() > 0) {
PickData data = results.getPickData(0);
ArrayList<Integer> triangles = data.getTargetTris();
if (!triangles.isEmpty()) {
TriMesh mesh = (TriMesh) data.getTargetMesh();
mesh.getTriangle(triangles.get(0).intValue(), vertices);
for (int j = 0; j < vertices.length; j++) {
mesh.localToWorld(vertices[j], vertices[j]);
}
hit = ray.intersectWhere(vertices[0], vertices[1], vertices[2], store);
if (hit && local) {
parent.worldToLocal(store, store);
return store;
} else if (hit && !local) {
return store;
}
}
}
return null;
}
/**
* Ask for the point of intersection between the given ray and the terrain.
*
* @param worldPick our pick ray, in world space.
* @param store if not null, the results will be stored in this vector and the vector returned. If
* store is null, a new vector will be created.
* @return null if no pick is found. Otherwise it returns a Vector3f (the store param, if that was
* not null) populated with the pick coordinates.
*/
public Vector3f getTerrainIntersection(final Ray worldPick, final Vector3f store) {
if (_root == null || _root.getWorldBound() == null) return null;
if (!_root.getWorldBound().intersects(worldPick)) return null;
// Set up our working ray
_workRay.set(worldPick);
// Grab all terrain blocks and do a grid walk on each starting from
// closest.
_pr.clear();
_root.findPick(_workRay, _pr);
for (int i = 0, max = _pr.getNumber(); i < max; i++) {
PickData pd = _pr.getPickData(i);
if (pd == null) continue;
Geometry g = pd.getTargetMesh();
if (g instanceof TerrainBlock) {
TerrainBlock block = (TerrainBlock) g;
_tracer.getGridSpacing().set(block.getWorldScale()).multLocal(block.getStepScale());
_tracer.setGridOrigin(block.getWorldTranslation());
_workRay
.getOrigin()
.set(worldPick.getDirection())
.multLocal(pd.getDistance() - .1f)
.addLocal(worldPick.getOrigin());
_tracer.startWalk(_workRay);
if (_tracer.isRayPerpendicularToGrid()) {
// no intersection
return null;
}
final Vector3f intersection = store != null ? store : new Vector3f();
final Vector2f loc = _tracer.getGridLocation();
while (loc.x >= -1 && loc.x <= block.getSize() && loc.y >= -1 && loc.y <= block.getSize()) {
// check the triangles of main square for intersection.
if (checkTriangles(loc.x, loc.y, _workRay, intersection, block)) {
// we found an intersection, so return that!
return intersection;
}
// because of how we get our height coords, we will
// sometimes be off be a grid spot, so we check the next
// grid space up.
int dx = 0, dz = 0;
Direction d = _tracer.getLastStepDirection();
switch (d) {
case PositiveX:
case NegativeX:
dx = 0;
dz = 1;
break;
case PositiveZ:
case NegativeZ:
dx = 1;
dz = 0;
break;
}
if (checkTriangles(loc.x + dx, loc.y + dz, _workRay, intersection, block)) {
// we found an intersection, so return that!
return intersection;
}
_tracer.next();
}
}
}
return null;
}
