/**
* Insert point at the end of the list.
*
* @param point the point
*/
public void insertEnd(Point point) {
PointElement newElement = new PointElement(point, null, null);
if (start == null) {
startNotInitialized(newElement);
} else {
newElement.setPrev(end);
end.setNext(newElement);
start.setPrev(newElement);
newElement.setNext(start);
end = newElement;
}
size++;
}
/**
* Check if a list contains an element.
*
* @param point the point
* @return true, if successful
*/
public boolean contains(PointElement point) {
if (size == 0) {
System.out.println("The list is empty");
return false;
}
PointElement pointer = start;
while (pointer.getNext() != start) {
if (pointer.equals(point)) {
return true;
}
pointer = pointer.getNext();
}
return false;
}
private static boolean boundingBox(
PointElement a, PointElement b, PointElement c, PointElement d) {
return (a.getX() == c.getX()
&& a.getY() == c.getY()
&& b.getX() == d.getX()
&& b.getY() == d.getY());
}
/**
* Gets the element at a specific index.
*
* @param index the index
* @return the element
*/
public PointElement getElement(int index) {
if (index == 0) {
return start;
}
if (index == (size - 1)) {
return end;
}
PointElement pointer = start;
for (int i = 1; i < size; i++) {
if (i == index) {
return pointer.getNext();
}
pointer = pointer.getNext();
}
return null;
}
/**
* Insert a point at a given index.
*
* @param point the point
* @param index the index
*/
public void insertIndex(Point point, int index) {
PointElement newElement = new PointElement(point, null, null);
if (index == 0) {
insertStart(point);
return;
}
PointElement pointer = start;
for (int i = 1; i <= size; i++) {
if (i == index) {
PointElement nextElement = pointer.getNext();
pointer.setNext(newElement);
newElement.setPrev(pointer);
newElement.setNext(nextElement);
nextElement.setPrev(newElement);
}
pointer = pointer.getNext();
}
size++;
}
private static int turn(PointElement a, PointElement b, PointElement c) {
double res =
(b.getX() - a.getX()) * (c.getY() - a.getY())
- (b.getY() - a.getY()) * (c.getX() - a.getX());
double check = 0.1;
if (res > check) {
return 1;
}
if (res < -check) {
return -1;
}
return 0;
}
/**
* This method is a help method and is invoked when the list is still empty.
*
* @param newElement the new element
*/
private void startNotInitialized(PointElement newElement) {
newElement.setNext(newElement);
newElement.setPrev(newElement);
start = newElement;
end = start;
}
/**
* Deletes a point from a given index.
*
* @param index the index
* @return true, if successful
*/
public boolean deleteIndex(int index) {
if (index == 0) {
if (size == 1) {
clearList();
return true;
}
start = start.getNext();
start.setPrev(end);
end.setNext(start);
size--;
return true;
}
if (index == (size - 1)) {
end = end.getPrev();
end.setNext(start);
start.setPrev(end);
size--;
return true;
}
PointElement pointer = start.getNext();
for (int i = 1; i < size; i++) {
if (i == index) {
PointElement previousElement = pointer.getPrev();
PointElement nextElement = pointer.getNext();
previousElement.setNext(nextElement);
nextElement.setPrev(previousElement);
size--;
return true;
}
pointer = pointer.getNext();
}
return false;
}
public static float length(PointElement a, PointElement b) {
float sqrX = (a.getX() - b.getX()) * (a.getX() - b.getX());
float sqrY = (a.getY() - b.getY()) * (a.getY() - b.getY());
return (float) Math.sqrt(sqrX + sqrY);
}
