public Point2D getClosestIntersectionToStart(Shape withThisShape) {
// first, get the sides of the shape
List<LineSegment> shapeSides = Utilities.getSides(withThisShape);
// go through all the sides, and see if there are any intersections
// there may be more than 1
List<Point2D> shapeIntersectionPoints = new ArrayList<Point2D>();
for (Line2D curSide : shapeSides) {
if (curSide.intersectsLine(this)) {
Point2D intersectionPoint = Utilities.getIntersectionPoint(this, curSide);
shapeIntersectionPoints.add(intersectionPoint);
}
}
if (shapeIntersectionPoints.size() <= 0) {
return null;
} else if (shapeIntersectionPoints.size() == 1) {
return shapeIntersectionPoints.get(0);
} else {
// get the point closest to P1
Point2D closestIntersectionPoint = null;
double closestIntersectionPointDistSq = java.lang.Double.MAX_VALUE;
for (Point2D curPoint : shapeIntersectionPoints) {
double curDistSq = curPoint.distanceSq(this.getP1());
if (curDistSq < closestIntersectionPointDistSq) {
closestIntersectionPointDistSq = curDistSq;
closestIntersectionPoint = curPoint;
}
}
return closestIntersectionPoint;
}
}
public LinkedList<LineWorldObject> getLineWorldObjectsOnLine(Line2D line, double radius) {
LinkedList<LineWorldObject> objectsInSelection = new LinkedList<LineWorldObject>();
for (LineWorldObject o : lineObjects) {
if (o.getXInCM() == o.getX2InCM()) {
if (line.intersectsLine(
o.getXInCM(), o.getYInCM() - radius, o.getX2InCM(), o.getY2InCM() + radius)) {
objectsInSelection.add(o);
}
} else {
if (line.intersectsLine(
o.getXInCM() - radius, o.getYInCM(), o.getX2InCM() + radius, o.getY2InCM())) {
objectsInSelection.add(o);
}
}
}
return objectsInSelection;
}
public void test(TestHarness harness) {
Line2D line1 = new Line2D.Double(0.0, 0.0, 1.0, 0.0);
harness.check(line1.intersectsLine(0.0, 0.0, 1.0, 0.0));
harness.check(line1.intersectsLine(0.0, 0.0, 1.0, 1.0));
harness.check(line1.intersectsLine(1.0, 1.0, 1.0, 0.0));
harness.check(line1.intersectsLine(0.5, 0.5, 0.5, -0.5));
harness.check(!line1.intersectsLine(0.0, 1.0, 1.0, 1.0));
harness.check(line1.intersectsLine(new Line2D.Double(0.0, 0.0, 1.0, 0.0)));
harness.check(line1.intersectsLine(new Line2D.Double(0.0, 0.0, 1.0, 1.0)));
harness.check(line1.intersectsLine(new Line2D.Double(1.0, 1.0, 1.0, 0.0)));
harness.check(line1.intersectsLine(new Line2D.Double(0.5, 0.5, 0.5, -0.5)));
harness.check(!line1.intersectsLine(new Line2D.Double(0.0, 1.0, 1.0, 1.0)));
boolean pass = false;
try {
line1.intersectsLine(null);
} catch (NullPointerException e) {
pass = true;
}
harness.check(pass);
}
/**
* Compares all edges of two regions to see if any of them intersect.
*
* @param region the region to check
* @return whether any edges of a region intersect
*/
protected boolean intersectsEdges(ProtectedRegion region) {
List<BlockVector2D> pts1 = getPoints();
List<BlockVector2D> pts2 = region.getPoints();
BlockVector2D lastPt1 = pts1.get(pts1.size() - 1);
BlockVector2D lastPt2 = pts2.get(pts2.size() - 1);
for (BlockVector2D aPts1 : pts1) {
for (BlockVector2D aPts2 : pts2) {
Line2D line1 =
new Line2D.Double(
lastPt1.getBlockX(), lastPt1.getBlockZ(), aPts1.getBlockX(), aPts1.getBlockZ());
if (line1.intersectsLine(
lastPt2.getBlockX(), lastPt2.getBlockZ(), aPts2.getBlockX(), aPts2.getBlockZ())) {
return true;
}
lastPt2 = aPts2;
}
lastPt1 = aPts1;
}
return false;
}
public boolean intersects(Line b) {
Line2D line1 = new Line2D.Float(x1, y1, x2, y2);
Line2D line2 = new Line2D.Float(b.x1(), b.y1(), b.x2(), b.y2());
return line2.intersectsLine(line1);
}
public static boolean intersectsLine(Vector2f a, Vector2f b, Vector2f c, Vector2f d) {
Line2D l1 = new Line2D.Float(a.x, a.y, b.x, b.y);
Line2D l2 = new Line2D.Float(c.x, c.y, d.x, d.y);
return l1.intersectsLine(l2);
}