public static void AddConnection(Cell traceCur, Cell traceStart, NavMeshCell navCell)
{
if (traceCur == null || traceStart == null)
{
return;
}
// Determine which side the connected cell is on.
// Generate edge at opposite side.
Vector2 center;
if (traceCur.Mid.X > navCell.CollisionRect.Right) // East
{
center = (traceStart.CollisionRect.CenterLeft() + traceCur.CollisionRect.CenterLeft()) / 2;
}
else if (traceCur.Mid.X < navCell.CollisionRect.Left) // West
{
center = (traceStart.CollisionRect.CenterRight() + traceCur.CollisionRect.CenterRight()) / 2;
}
else if (traceCur.Mid.Y < navCell.CollisionRect.Top) // North
{
center = (traceStart.CollisionRect.CenterBottom() + traceCur.CollisionRect.CenterBottom()) / 2;
}
else // South
{
center = (traceStart.CollisionRect.CenterTop() + traceCur.CollisionRect.CenterTop()) / 2;
}
NavMeshCell other = navCells[(int)traceStart.MeshID - 1];
navCell.Neighbours.Add(other);
navCell.Waypoints.Add(other, center);
}
private static List <Cell> GetNextNorthRow(NavMeshCell curCell)
{
var result = new List <Cell>();
Point topLeft = Grid.IndexAt(new Vector2(curCell.Pos.X, curCell.Pos.Y - 1));
int numCols = curCell.Width / Grid.CellSize;
for (int i = 0; i < numCols; i++)
{
Grid.AddCell(Grid[topLeft.Col() + i, topLeft.Row()], result);
}
return(result);
}
private static List <Cell> GetNextWestCol(NavMeshCell curCell)
{
var result = new List <Cell>();
Point topLeft = Grid.IndexAt(new Vector2(curCell.Pos.X - 1, curCell.Pos.Y));
int numRows = curCell.Height / Grid.CellSize;
for (int i = 0; i < numRows; i++)
{
Grid.AddCell(Grid[topLeft.Col(), topLeft.Row() + i], result);
}
return(result);
}
private static List <Cell> GetNextBorder(NavMeshCell curCell)
{
return(GetNextEastCol(curCell).Concat(GetNextSouthRow(curCell)).Concat(GetNextWestCol(curCell)).Concat(GetNextNorthRow(curCell)).ToList());
}
public static void RenderNavMeshCalculation(Point startCellAtIndex,
NavMeshCell curNavCell,
bool blockedOnCols,
bool blockedOnRows,
List <Cell> toBeConsidered,
List <Cell> frontier,
Cell traceStart,
Cell traceCur)
{
if (!Debug.IsOn(DebugOp.CalcNavMesh))
{
return;
}
SpriteBatch spriteBatch = Game1.Instance.spriteBatch;
Input.UpdateStates();
Game1.Instance.GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin();
Game1.Instance.world.Render(spriteBatch);
// Render already constructed nav cells dark blue.
foreach (NavMeshCell cell in navCells)
{
spriteBatch.DrawRectangle(cell.RenderRect, Color.DarkBlue, 2);
}
// Render currently being constructed nav cell pink
spriteBatch.FillRectangle(curNavCell.RenderRect, Color.Pink);
// Render current location to start new nav cell
spriteBatch.FillRectangle(Grid[startCellAtIndex].RenderRect, Color.Teal);
// Render frontier brown
foreach (Cell c in frontier)
{
spriteBatch.FillRectangle(c.RenderRect, Color.Brown);
}
// Render new cells to be considered in yellow
foreach (Cell c in toBeConsidered)
{
spriteBatch.FillRectangle(c.RenderRect, Color.Yellow);
}
// Render neighbours white
foreach (NavMeshCell navCell in navCells)
{
foreach (Vector2 pos in navCell.Waypoints.Values)
{
spriteBatch.DrawLine(navCell.RenderMid, pos, Color.White, 1);
}
spriteBatch.DrawPoint(navCell.RenderMid, Color.Orange, 6);
}
// Render trace.
if (traceStart != null)
{
spriteBatch.FillRectangle(traceStart.RenderRect, Color.DarkViolet);
}
if (traceCur != null)
{
spriteBatch.FillRectangle(traceCur.RenderRect, Color.DarkViolet);
}
if (traceStart != null && traceCur != null)
{
spriteBatch.DrawLine(traceStart.RenderMid, traceCur.RenderMid, Color.Red, 3);
}
foreach (NavMeshCell cell in navCells)
{
Game1.Instance.spriteBatch.DrawString(Game1.Instance.smallFont, cell.NavMeshID.ToString(), cell.RenderMid, Color.Black);
}
Game1.Instance.spriteBatch.End();
Game1.Instance.GraphicsDevice.Present();
//System.Threading.Thread.Sleep(400);
}
private static void AddNavCell(NavMeshCell cell)
{
navCells.Add(cell);
navCells = navCells.OrderBy(c => c.NavMeshID).ToList();
}
public static List <NavMeshCell> CalculateNavMeshCells(Grid grid)
{
NavMeshCell.ResetMeshIDs();
Grid = grid;
for (int col = 0; col < Grid.Cols; col++)
{
for (int row = 0; row < Grid.Rows; row++)
{
Grid[col, row].MeshID = Cell.NOT_PART_OF_MESH;
}
}
startAt = new Point(Grid.Cols / 2, Grid.Rows / 2);
Grid[startAt].Passable = true;
//startAt = new Point(0, 0);
finishedCalculating = false;
blockedEast = false;
blockedSouth = false;
blockedWest = false;
blockedNorth = false;
navCells = new List <NavMeshCell>();
curCell = new NavMeshCell(Grid[startAt].Pos, Grid.CellSize, Grid.CellSize);
frontier = new List <Cell>();
while (!finishedCalculating)
{
// If cell is becoming long and skinny, restrict expansion on that axis.
// Restrict East / West expansion
if (curCell.Width >= curCell.Height * 3)
{
blockedEast = true;
blockedWest = true;
}
// Restrict North / South expansion
if (curCell.Height >= curCell.Width * 3)
{
blockedNorth = true;
blockedSouth = true;
}
// Try to expand east.
if (!blockedEast)
{
blockedEast = DoNewCellsBlock(GetNextEastCol(curCell));
// Expansion is valid.
if (!blockedEast)
{
// Increase size of current cell.
curCell.Width += Grid.CellSize;
}
}
// Try to expand south.
if (!blockedSouth)
{
blockedSouth = DoNewCellsBlock(GetNextSouthRow(curCell));
// Expansion is valid
if (!blockedSouth)
{
// Increase size of current cell.
curCell.Height += Grid.CellSize;
}
}
// Try to expand west.
if (!blockedWest)
{
blockedWest = DoNewCellsBlock(GetNextWestCol(curCell));
// Expansion is valid
if (!blockedWest)
{
// Increase size of current cell.
curCell.Width += Grid.CellSize;
curCell.Pos.X -= Grid.CellSize;
}
}
// Try to expand north.
if (!blockedNorth)
{
blockedNorth = DoNewCellsBlock(GetNextNorthRow(curCell));
// Expansion is valid.
if (!blockedNorth)
{
// Increase size of current cell.
curCell.Height += Grid.CellSize;
curCell.Pos.Y -= Grid.CellSize;
}
}
// Blocked on both dimensinos, finalise this nav mesh cell.
if (BlockedOnAllSides)
{
// Finish making this cell and start making a new one.
// Probably calculate neighbours here too.
uint nextMeshID = NavMeshCell.NextMeshID;
curCell.NavMeshID = nextMeshID;
AddNavCell(curCell);
// Assign each cell in the area as part of the new Nav Mesh Cell.
foreach (Cell c in Grid.CellsInRect(curCell.CollisionRect.GetInflated(-1, -1)))
{
c.MeshID = nextMeshID;
}
// Update frontier to remove any cells now part of the mesh
for (int i = frontier.Count - 1; i >= 0; i--)
{
if (frontier[i].MeshID != Cell.NOT_PART_OF_MESH)
{
frontier.RemoveAt(i);
}
}
// Get surrounding cells.
var newCells = GetNextBorder(curCell);
foreach (Cell c in newCells)
{
// Add to frontier if valid
if (c.Passable && c.MeshID == Cell.NOT_PART_OF_MESH)
{
frontier.Add(c);
}
}
if (frontier.Count == 0)
{
finishedCalculating = true;
}
if (!finishedCalculating)
{
startAt = Grid.IndexAt(frontier[0].Mid);
curCell = new NavMeshCell(Grid[startAt].Pos, Grid.CellSize, Grid.CellSize);
blockedEast = false;
blockedSouth = false;
blockedNorth = false;
blockedWest = false;
}
}
}
CalculateNeighbours();
return(navCells);
}
