/// <summary>
/// Method that adds new Join to snake's tail
/// </summary>
/// <param name="j">Join that should be added</param>
public void addJoinToTail(Join j)
{
if (j != null)
{
tail.setNext(j);
j.setPrev(tail);
tail = j;
length++;
}
}
/// <summary>
/// Method that moves snake's head by adding new Join to it. Snake is following received direction
/// </summary>
/// <param name="direction">direction in whitch snake is moving</param>
/// <returns></returns>
public Coordinates moveHead(int direction)
{
//creates next bone and connects it before snake's head. That imitates that head was moved
Bone newBone = new Bone(direction, head.getBone().getCoord().getX(), head.getBone().getCoord().getY());
Join j = new Join(newBone, null, head);
head.setPrev(j);
//direction of ex-head should be changed. 8-up, 2-down, 4-left, 6-right. 1,7,3,9 - corners.
//use numeric keypad to visualise direction better
int z = head.getBone().getDirection();
if (direction != z)
{//if direction of nex head and ex-head are different, then change diretion of ex-head to hold corner
if (direction == 8)
{
head.getBone().setDirection(z == 4 ? 1 : 3);
j.getBone().getCoord().setY(newBone.getCoord().getY() - 1);
}
else if (direction == 6)
{
head.getBone().setDirection(z == 8 ? 7 : 1);
j.getBone().getCoord().setX(newBone.getCoord().getX() + 1);
}
else if (direction == 2)
{
head.getBone().setDirection(z == 4 ? 7 : 9);
j.getBone().getCoord().setY(newBone.getCoord().getY() + 1);
}
else if (direction == 4)
{
head.getBone().setDirection(z == 8 ? 9 : 3);
j.getBone().getCoord().setX(newBone.getCoord().getX() - 1);
}
}
else
{
switch (direction)
{// correction of coordinates of a new head
case 2: j.getBone().getCoord().setY(newBone.getCoord().getY() + 1); break;
case 4: j.getBone().getCoord().setX(newBone.getCoord().getX() - 1); break;
case 6: j.getBone().getCoord().setX(newBone.getCoord().getX() + 1); break;
case 8: j.getBone().getCoord().setY(newBone.getCoord().getY() - 1); break;
}
}
setHead(j);
length++;
return(head.getBone().getCoord());
}
