int GetCost(PathFindingAgent agent, Node fromNode, Node toNode, TransitionType transitionType)
{
int dy;
switch (transitionType)
{
case TransitionType.Walk:
return(1);
case TransitionType.Jump:
dy = toNode.Y - fromNode.Y;
int dx = toNode.X - fromNode.X;
return(agent.JumpStrength + Mathf.Abs(dx) /*+ agent.JumpStrength - dy*/);
case TransitionType.Fall:
dy = fromNode.Y - toNode.Y;
return(dy);
case TransitionType.None:
Debug.LogError("Transition type is None.");
return(-1);
default:
throw new ArgumentOutOfRangeException(nameof(transitionType), transitionType, null);
}
}
public List <Node> FindPath(PathFindingAgent agent, Transform goalObject)
{
Node start = WorldPositionToNode(agent.transform.position);
Node goal = WorldPositionToNode(goalObject.position);
return(_search.Search(start, goal, _pathFindingRules, agent));
}
static bool CheckTrajectory(PathFindingGrid grid, PathFindingAgent agent, Node jumpStart, Node jumpLanding,
int xDelta, int precision = 12)
{
float cellSize = grid.CellSize;
Vector2 a = jumpStart.WorldPosition + new Vector2(-.5f, agent.Height - .5f) * cellSize;
Vector2 b = a + Vector2.up * (agent.JumpStrength * cellSize);
Vector2 c = b + Vector2.right * (xDelta * cellSize);
Vector2 d = jumpLanding.WorldPosition + new Vector2(-.5f, agent.Height - .5f) * cellSize;
var bezierCurve = new BezierCurve(a, b, c, d);
bool isRight = xDelta > 0;
Node lastNode = null;
float offset = 1f / precision;
float t = 0;
for (int i = 0; i < precision - 1; i++)
{
t += offset;
var curveValue = bezierCurve.GetValue(t);
var node = grid.WorldPositionToNode(curveValue);
if (node == lastNode)
{
continue;
}
if (!AllNodes(grid, node.Y, node.X, 1, agent.Width + 1, IsAir))
{
return(false);
}
if (isRight)
{
if (!AllNodes(grid, node.Y - (agent.Height - 1), node.X + agent.Width,
agent.Height + 1, 1, IsAir))
{
return(false);
}
}
else
{
if (!AllNodes(grid, node.Y - (agent.Height - 1), node.X - 1,
agent.Height + 1, 1, IsAir))
{
return(false);
}
}
lastNode = node;
}
return(true);
}
public int GetCost(Node fromNode, Node toNode, PathFindingAgent agent)
{
int deltaY = toNode.Y - fromNode.Y,
deltaX = toNode.X - fromNode.X;
if (Node.IsWalkTransition(fromNode, toNode) != TransitionType.Jump)
{
return(1);
}
return(agent.JumpStrength + Mathf.Abs(deltaX) + agent.JumpStrength - deltaY);
}
public List <Node> Search(Node start, Node goal, IPathFindingRules rules, PathFindingAgent agent)
{
_openSet.Clear();
_closedSet.Clear();
_openSet.Add(start);
var foundGoal = false;
while (_openSet.Count > 0)
{
Node node = _openSet.RemoveFirst();
_closedSet.Add(node);
if (node == goal)
{
foundGoal = true;
break;
}
var transitions = rules.GetTransitions(_pathFindingGrid, agent, node);
foreach (var transition in transitions)
{
Node neighbour = transition.Node;
if (/*!neighbour.IsWalkable ||*/ _closedSet.Contains(neighbour))
{
continue;
}
int newCost = node.GCost + transition.Cost;
if (newCost < neighbour.GCost || !_openSet.Contains(neighbour))
{
neighbour.GCost = newCost;
neighbour.HCost = rules.GetHeuristic(neighbour, goal, agent);
neighbour.Parent = node;
neighbour.Transition = transition.Transition;
if (_openSet.Contains(neighbour))
{
_openSet.UpdateItem(neighbour);
}
else
{
_openSet.Add(neighbour);
}
}
}
}
return(foundGoal ? RetracePath(start, goal) : null);
}
public List <TransitionData> GetTransitions(PathFindingGrid grid, PathFindingAgent agent, Node node)
{
var neighbours = new List <TransitionData>();
bool isGrounded = AnyNode(grid, node.X, node.Y - 1, agent.Width, 1, IsGround);
if (isGrounded)
{
if (AllInColumn(grid, node.X - 1, node.Y, agent.Height, IsAir))
{
var neighbourNode = grid.GetNode(node.X - 1, node.Y);
var neighbour = new TransitionData(neighbourNode, TransitionType.Walk, 1);
neighbours.Add(neighbour);
}
if (AllInColumn(grid, node.X + agent.Width, node.Y, agent.Height, IsAir))
{
var neighbourNode = grid.GetNode(node.X + 1, node.Y);
var neighbour = new TransitionData(neighbourNode, TransitionType.Walk, 1);
neighbours.Add(neighbour);
}
for (var dx = 2; dx <= agent.JumpStrength; dx++)
{
CheckJump(grid, agent, neighbours, node, dx);
}
for (var dx = -2; dx >= -agent.JumpStrength; --dx)
{
CheckJump(grid, agent, neighbours, node, dx);
}
}
else
{
Node landing = GetFallOnGroundNode(grid, agent, node.X, node.Y);
if (landing != null)
{
int fallHeight = node.Y - landing.Y;
if (fallHeight <= agent.FallLimit)
{
const TransitionType fall = TransitionType.Fall;
var neighbour = new TransitionData(landing, fall, GetCost(agent, node, landing, fall));
neighbours.Add(neighbour);
}
}
}
return(neighbours);
}
static Node GetFallOnGroundNode(PathFindingGrid grid, PathFindingAgent agent, int x, int y)
{
if (!AllInRow(grid, x, y, agent.Width, node => node != null))
{
return(null);
}
while (AllInRow(grid, x, y - 1, agent.Width, IsAir))
{
--y;
}
return(grid.GetNode(x, y));
}
static bool CheckTrajectory(PathFindingGrid grid, PathFindingAgent agent, Node jumpStart, Node jumpEnd)
{
int dx = jumpEnd.X - jumpStart.X,
dy = jumpEnd.Y - jumpStart.Y;
var offsets = agent.GetCheckNodes(dx, dy);
foreach (var offset in offsets)
{
Node toCheck = grid.GetNode(jumpStart.X + offset.x, jumpStart.Y + offset.y);
if (!IsAir(toCheck))
{
return(false);
}
}
return(true);
}
void CheckJump(PathFindingGrid grid, PathFindingAgent agent, List <TransitionData> neighbours,
Node node, int dx)
{
Node landing = GetFallOnGroundNode(grid, agent, node.X + dx, node.Y + agent.JumpStrength);
if (landing == null)
{
return;
}
int fallHeight = node.Y + agent.JumpStrength - landing.Y;
if (fallHeight > agent.FallLimit)
{
return;
}
if (CheckTrajectory(grid, agent, node, landing))
{
const TransitionType jump = TransitionType.Jump;
var neighbour = new TransitionData(landing, jump, GetCost(agent, node, landing, jump));
neighbours.Add(neighbour);
}
}
public int GetHeuristic(Node node, Node goal, PathFindingAgent agent)
{
return(Mathf.Abs(node.X - goal.X) + Mathf.Abs(node.Y - goal.Y));
}
public PlatformerRules(PathFindingAgent agent)
{
int neighboursMaxSize = 2 + 2 * (agent.JumpStrength - 1);
_neighbours = new Node[neighboursMaxSize];
}
public Node[] GetNeighbours(PathFindingGrid grid, Node node, PathFindingAgent agent, out int count)
{
count = 0;
bool isGrounded = AnyNode(grid, node.Y - 1, node.X, 1, agent.Width, IsGround);
if (isGrounded)
{
Node neighbour;
if (AllNodes(grid, node.Y, node.X - 1, agent.Height, 1, IsAir))
{
neighbour = grid.GetNode(node.Y, node.X - 1);
_neighbours[count++] = neighbour;
}
if (AllNodes(grid, node.Y, node.X + agent.Width, agent.Height, 1, IsAir))
{
neighbour = grid.GetNode(node.Y, node.X + 1);
_neighbours[count++] = neighbour;
}
// Jump to the Right
for (var x = 2; x <= agent.JumpStrength; ++x)
{
neighbour = GetFallOnGroundNode(grid, node.Y + agent.JumpStrength, node.X + x, agent.Width);
if (neighbour == null)
{
continue;
}
if (CheckTrajectory(grid, agent, node, neighbour, x))
{
_neighbours[count++] = neighbour;
}
}
// Jump to the Left
for (var x = -2; x >= -agent.JumpStrength; --x)
{
neighbour = GetFallOnGroundNode(grid, node.Y + agent.JumpStrength, node.X + x, agent.Width);
if (neighbour == null)
{
continue;
}
if (CheckTrajectory(grid, agent, node, neighbour, x))
{
_neighbours[count++] = neighbour;
}
}
}
// Falling Down. This should only happen if spawned above the ground.
else
{
_neighbours[count++] = grid.GetNode(node.Y - 1, node.X);
}
return(_neighbours);
}
