/**
* Cache the {@link Line2D} objects making up the maze.
*
* @param x Initial x coordinate.
* @param y Initial y coordinate.
* @param width Width of a cell.
* @param height Height of a cell.
*/
private void buildWalls(double x, double y, double width, double height) {
Point p = maze.getSize();
wallList = new ArrayList(p.getX() * p.getY());
for (int i = 0; i < p.getY(); i++) {
for (int j = 0; j < p.getX(); j++) {
Cell cell = maze.getCell(new Point(j, i));
if (cell.isWall(Direction.North)) {
wallList.add(
new Line2D.Double(
x + j * width, y + (i + 1) * height, x + (j + 1) * width, y + (i + 1) * height));
}
if (cell.isWall(Direction.East)) {
wallList.add(
new Line2D.Double(
x + (j + 1) * width, y + i * height, x + (j + 1) * width, y + (i + 1) * height));
}
}
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g); // paint background
Graphics2D g2 = (Graphics2D) g;
// Turn on antialiasing
Map m = new HashMap();
m.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.addRenderingHints(m);
// Figure out how large the maze is
Point p = maze.getSize();
double llx = 0.0, lly = 0.0, width = 0.0, height = 0.0, cellwidth = 0.0, cellheight = 0.0;
// Do we need to update our cache?
if ((panelSize == null) || (panelSize != getSize())) {
panelSize = getSize();
llx = (double) panelSize.width * 0.025;
lly = (double) panelSize.height * 0.025;
width = (double) panelSize.width - (double) panelSize.width * 0.05;
height = (double) panelSize.height - (double) panelSize.height * 0.05;
cellwidth = width / (double) p.getX();
cellheight = height / (double) p.getY();
buildWalls(llx, lly, cellwidth, cellheight);
double diameter = java.lang.Math.min(cellwidth, cellheight) * 0.75;
player =
new Arc2D.Double(
new Rectangle2D.Double(-diameter / 2.0, -diameter / 2.0, diameter, diameter),
30.0,
300.0,
Arc2D.PIE);
diameter = java.lang.Math.min(cellwidth, cellheight) * 0.30;
projectile =
new Arc2D.Double(
new Rectangle2D.Double(-diameter / 2.0, -diameter / 2.0, diameter, diameter),
0.0,
360.0,
Arc2D.PIE);
}
// Flip coordinate system
g2.translate(0.0, (double) panelSize.height);
g2.scale(1.0, -1.0);
// Draw the maze walls
g2.setStroke(new BasicStroke(2.0f));
g2.setColor(Color.black);
g2.draw(new Rectangle2D.Double(llx, lly, width, height));
Iterator it = wallList.iterator();
while (it.hasNext()) {
Object o = it.next();
if (o instanceof Shape) {
g2.draw((Shape) o);
} else {
throw new Error();
}
}
Font font = new Font("Arial", Font.PLAIN, 9);
FontRenderContext frc = g2.getFontRenderContext();
// Obtain the location of the distinguished client
Point cp = maze.getClientPoint(client);
for (int i = 0; i < p.getY(); i++) {
for (int j = 0; j < p.getX(); j++) {
boolean cellVisible = true;
Line2D visLine =
new Line2D.Double(
llx + (cp.getX() + 0.5) * cellwidth,
lly + (cp.getY() + 0.5) * cellheight,
llx + (j + 0.5) * cellwidth,
lly + (i + 0.5) * cellheight);
/* Visibility testing */
/* Iterator visIt = wallList.iterator();
while(visIt.hasNext()) {
Object o = visIt.next();
if(o instanceof Line2D) {
Line2D l = (Line2D)o;
if(l.intersectsLine(visLine)) {
cellVisible = false;
}
} else {
throw new Error();
}
} */
if (cellVisible) {
Cell cell = maze.getCell(new Point(j, i));
Object o = cell.getContents();
if (o != null) {
if (o instanceof Client) {
Client c = (Client) o;
if (c instanceof GUIClient) {
g2.setColor(Color.green);
} else if (c instanceof RobotClient) {
g2.setColor(Color.red);
} else if (c instanceof RemoteClient) {
g2.setColor(Color.magenta);
}
double xoffset = llx + j * cellwidth + (cellwidth / 2.0);
double yoffset = lly + i * cellheight + (cellheight / 2.0);
Direction orient = c.getOrientation();
g2.translate(xoffset, yoffset);
double rotation = 0.0;
if (orient.equals(Direction.South)) {
rotation = -java.lang.Math.PI / 2.0;
} else if (orient.equals(Direction.North)) {
rotation = java.lang.Math.PI / 2.0;
} else if (orient.equals(Direction.West)) {
rotation = java.lang.Math.PI;
}
g2.rotate(rotation);
g2.fill(player);
g2.rotate(-rotation);
GlyphVector name = font.createGlyphVector(frc, c.getName());
g2.scale(1.0, -1.0);
g2.setColor(Color.black);
g2.drawGlyphVector(name, 0.0f, 0.0f);
g2.scale(1.0, -1.0);
g2.translate(-xoffset, -yoffset);
} else {
if (o instanceof Projectile) {
g2.setColor(Color.yellow);
double xoffset = llx + j * cellwidth + (cellwidth / 2.0);
double yoffset = lly + i * cellheight + (cellheight / 2.0);
g2.translate(xoffset, yoffset);
g2.fill(projectile);
g2.translate(-xoffset, -yoffset);
}
}
}
}
}
}
}
/**
* Implements a Depth First Search on a Maze Object
*
* @param myMaze
* @return
*/
public static char[] depthFirstSearch(Maze myMaze) {
// For breadth-first search
Stack<MazeCell> frontier = new Stack<MazeCell>();
// Add the Starting State
frontier.add(myMaze.getCell(myMaze.getStartX(), myMaze.getStartY()));
while (!frontier.isEmpty()) {
// Get the Top Node
MazeCell currentNode = frontier.pop();
if (currentNode.getVisited() == true) {
continue;
}
// Mark the current node as visited
currentNode.setVisited();
nodesExpanded += 1;
int currentX = currentNode.getX();
int currentY = currentNode.getY();
// Reached the Goal State
if ((currentX == myMaze.getGoalX()) && (currentY == myMaze.getGoalY())) {
return myMaze.getCell(currentX, currentY).getPath().toCharArray();
}
// Go Rightwards (0)
if ((!myMaze.getCell(currentX, currentY + 1).isWall())
&& (!myMaze.getCell(currentX, currentY + 1).getVisited())) {
// Add to the Frontier
frontier.add(myMaze.getCell(currentX, currentY + 1));
// Adjust it's Path
myMaze
.getCell(currentX, currentY + 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "0");
}
// Go Downwards (1)
if ((!myMaze.getCell(currentX + 1, currentY).isWall())
&& (!myMaze.getCell(currentX + 1, currentY).getVisited())) {
// Add to the Frontier
frontier.add(myMaze.getCell(currentX + 1, currentY));
// Adjust it's Path
myMaze
.getCell(currentX + 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "1");
}
// Go Leftwards (2)
if ((!myMaze.getCell(currentX, currentY - 1).isWall())
&& (!myMaze.getCell(currentX, currentY - 1).getVisited())) {
// Add to the Frontier
frontier.add(myMaze.getCell(currentX, currentY - 1));
// Adjust it's Path
myMaze
.getCell(currentX, currentY - 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "2");
}
// Go Upwards (3)
if ((!myMaze.getCell(currentX - 1, currentY).isWall())
&& (!myMaze.getCell(currentX - 1, currentY).getVisited())) {
// Add to the Frontier
frontier.add(myMaze.getCell(currentX - 1, currentY));
// Adjust it's Path
myMaze
.getCell(currentX - 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "3");
}
}
return null;
}
/**
* Implements an A-Star Search on a Maze Object
*
* @param myMaze
* @return
*/
public static char[] aStarSearch(Maze myMaze) {
// For Greedy Best First Search
List<MazeCell> frontier = new LinkedList<MazeCell>();
// Add the Starting State
frontier.add(myMaze.getCell(myMaze.getStartX(), myMaze.getStartY()));
// Store the current Coordinates
int currentX = 0, currentY = 0;
while (!frontier.isEmpty()) {
// Remove the best node based on heuristic path cost and current path cost
int currentNodeIndex = getIndexWithSmallestCurrentPath(frontier);
MazeCell currentNode = frontier.remove(currentNodeIndex);
// Check if this node has been visited
if (currentNode.getVisited() == true) {
continue;
}
// Move the Ghost
// myMaze.scaryGhost.move();
// Mark the current node as visited
currentNode.setVisited();
// Obtain the current coordinates
currentX = currentNode.getX();
currentY = currentNode.getY();
// myMaze.getCell(myMaze.scaryGhost.getGhostX(), myMaze.scaryGhost.getGhostY()).setWall(true);
// The ghost is in the same place
if ((currentX == myMaze.scaryGhost.getGhostX())
&& (currentY == myMaze.scaryGhost.getGhostY())) {
continue;
}
// Reached the Goal State
if ((currentX == myMaze.getGoalX()) && (currentY == myMaze.getGoalY())) {
return myMaze.getCell(myMaze.getGoalX(), myMaze.getGoalY()).getPath().toCharArray();
}
// Increase the number of Expanded Nodes
nodesExpanded += 1;
// Initial values of heuristics
int heuristicRight = Integer.MAX_VALUE,
heuristicLeft = Integer.MAX_VALUE,
heuristicUp = Integer.MAX_VALUE,
heuristicDown = Integer.MAX_VALUE;
// Go Rightwards (0)
if ((!myMaze.getCell(currentX, currentY + 1).isWall())
&& (!myMaze.getCell(currentX, currentY + 1).getVisited())) {
// Obtain the heuristic
// heuristicRight = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX, currentY+1);
heuristicRight =
estimatedManhattan(
myMaze.getCell(currentX, currentY + 1), myMaze.getGoalX(), myMaze.getGoalY());
// Adjust the Path
myMaze
.getCell(currentX, currentY + 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "0");
// Set the Heuristic
myMaze.getCell(currentX, currentY + 1).setHeuristicDistance(heuristicRight);
// Find the current path cost
int currentDistanceCost =
pathCost(myMaze.getCell(currentX, currentY + 1).getPath().toCharArray());
// Set the Current Path Distance
myMaze.getCell(currentX, currentY + 1).setCurrentDistanceCost(currentDistanceCost);
}
// Go Downwards (1)
if ((!myMaze.getCell(currentX + 1, currentY).isWall())
&& (!myMaze.getCell(currentX + 1, currentY).getVisited())) {
// Obtain the Heuristic
// heuristicDown = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX+1, currentY);
heuristicDown =
estimatedManhattan(
myMaze.getCell(currentX + 1, currentY), myMaze.getGoalX(), myMaze.getGoalY());
// Adjust the Path
myMaze
.getCell(currentX + 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "1");
// Set the Heuristic
myMaze.getCell(currentX + 1, currentY).setHeuristicDistance(heuristicDown);
// Find the current path cost
int currentDistanceCost =
pathCost(myMaze.getCell(currentX + 1, currentY).getPath().toCharArray());
// Set the Current Path Distance
myMaze.getCell(currentX + 1, currentY).setCurrentDistanceCost(currentDistanceCost);
}
// Go Leftwards (2)
if ((!myMaze.getCell(currentX, currentY - 1).isWall())
&& (!myMaze.getCell(currentX, currentY - 1).getVisited())) {
// Obtain the Heuristic
// heuristicLeft = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX, currentY-1);
heuristicLeft =
estimatedManhattan(
myMaze.getCell(currentX, currentY - 1), myMaze.getGoalX(), myMaze.getGoalY());
// Adjust the Path
myMaze
.getCell(currentX, currentY - 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "2");
// Set the Heuristic
myMaze.getCell(currentX, currentY - 1).setHeuristicDistance(heuristicLeft);
// Find the current path cost
int currentDistanceCost =
pathCost(myMaze.getCell(currentX, currentY - 1).getPath().toCharArray());
// Set the Current Path Distance
myMaze.getCell(currentX, currentY - 1).setCurrentDistanceCost(currentDistanceCost);
}
// Go Upwards (3)
if ((!myMaze.getCell(currentX - 1, currentY).isWall())
&& (!myMaze.getCell(currentX - 1, currentY).getVisited())) {
// Obtain the Heuristic
// heuristicUp = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX-1, currentY);
heuristicUp =
estimatedManhattan(
myMaze.getCell(currentX - 1, currentY), myMaze.getGoalX(), myMaze.getGoalY());
// Adjust the Path
myMaze
.getCell(currentX - 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "3");
// Set the Heuristic
myMaze.getCell(currentX - 1, currentY).setHeuristicDistance(heuristicUp);
// Find the current path cost
int currentDistanceCost =
pathCost(myMaze.getCell(currentX - 1, currentY).getPath().toCharArray());
// Set the Current Path Distance
myMaze.getCell(currentX - 1, currentY).setCurrentDistanceCost(currentDistanceCost);
}
// Add the Neighbors to the frontier
if (heuristicRight != Integer.MAX_VALUE) {
frontier.add(myMaze.getCell(currentX, currentY + 1));
}
if (heuristicDown != Integer.MAX_VALUE) {
frontier.add(myMaze.getCell(currentX + 1, currentY));
}
if (heuristicLeft != Integer.MAX_VALUE) {
frontier.add(myMaze.getCell(currentX, currentY - 1));
}
if (heuristicUp != Integer.MAX_VALUE) {
frontier.add(myMaze.getCell(currentX - 1, currentY));
}
// myMaze.getCell(myMaze.scaryGhost.getGhostX(),
// myMaze.scaryGhost.getGhostY()).setWall(false);
}
return myMaze.getCell(myMaze.getGoalX(), myMaze.getGoalY()).getPath().toCharArray();
}
/**
* Implements a Greedy Best First Search on a Maze Object
*
* @param myMaze
* @return
*/
public static char[] greedyBestFirstSearch(Maze myMaze) {
// For Greedy Best First Search
Stack<MazeCell> frontier = new Stack<MazeCell>();
// Add the Starting State
frontier.add(myMaze.getCell(myMaze.getStartX(), myMaze.getStartY()));
// Store the current Co-ordinates
int currentX = 0, currentY = 0;
while (!frontier.isEmpty()) {
// Get the Top Node
MazeCell currentNode = frontier.pop();
// Check if this node has been visited
if (currentNode.getVisited() == true) {
continue;
}
// Mark the current node as visited
currentNode.setVisited();
// Obtain the current cordinates
currentX = currentNode.getX();
currentY = currentNode.getY();
// Reached the Goal State
if ((currentX == myMaze.getGoalX()) && (currentY == myMaze.getGoalY())) {
return myMaze.getCell(myMaze.getGoalX(), myMaze.getGoalY()).getPath().toCharArray();
}
// Increase the number of Expanded Nodes
nodesExpanded += 1;
// Check that you're not out of Bounds
if (currentX <= 0
|| currentY <= 0
|| currentX >= myMaze.getHeight() - 1
|| currentY >= myMaze.getWidth() - 1) {
continue;
}
// Initial values of heuristics
int heuristicRight = Integer.MAX_VALUE,
heuristicLeft = Integer.MAX_VALUE,
heuristicUp = Integer.MAX_VALUE,
heuristicDown = Integer.MAX_VALUE;
// Go Rightwards (0)
if ((!myMaze.getCell(currentX, currentY + 1).isWall())
&& (!myMaze.getCell(currentX, currentY + 1).getVisited())) {
// Obtain the heuristic
heuristicRight = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX, currentY + 1);
// Adjust the Path
myMaze
.getCell(currentX, currentY + 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "0");
// Set the Heuristic
myMaze.getCell(currentX, currentY + 1).setHeuristicDistance(heuristicRight);
}
// Go Downwards (1)
if ((!myMaze.getCell(currentX + 1, currentY).isWall())
&& (!myMaze.getCell(currentX + 1, currentY).getVisited())) {
heuristicDown = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX + 1, currentY);
myMaze
.getCell(currentX + 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "1");
myMaze.getCell(currentX + 1, currentY).setHeuristicDistance(heuristicDown);
}
// Go Leftwards (2)
if ((!myMaze.getCell(currentX, currentY - 1).isWall())
&& (!myMaze.getCell(currentX, currentY - 1).getVisited())) {
heuristicLeft = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX, currentY - 1);
myMaze
.getCell(currentX, currentY - 1)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "2");
myMaze.getCell(currentX, currentY - 1).setHeuristicDistance(heuristicLeft);
}
// Go Upwards (3)
if ((!myMaze.getCell(currentX - 1, currentY).isWall())
&& (!myMaze.getCell(currentX - 1, currentY).getVisited())) {
heuristicUp = manhattan(myMaze.getGoalX(), myMaze.getGoalY(), currentX - 1, currentY);
myMaze
.getCell(currentX - 1, currentY)
.appendPath(myMaze.getCell(currentX, currentY).getPath() + "3");
myMaze.getCell(currentX - 1, currentY).setHeuristicDistance(heuristicUp);
}
// Used to Sort the Values
ArrayList<MazeCell> myNeighbors = new ArrayList<MazeCell>();
if (heuristicRight != Integer.MAX_VALUE) {
myNeighbors.add(myMaze.getCell(currentX, currentY + 1));
}
if (heuristicDown != Integer.MAX_VALUE) {
myNeighbors.add(myMaze.getCell(currentX + 1, currentY));
}
if (heuristicLeft != Integer.MAX_VALUE) {
myNeighbors.add(myMaze.getCell(currentX, currentY - 1));
}
if (heuristicUp != Integer.MAX_VALUE) {
myNeighbors.add(myMaze.getCell(currentX - 1, currentY));
}
// Sort the Cells based on Heuristic Values
myNeighbors = sortNeighbors(myNeighbors);
// Add the Cells to the Frontier in the Sorted Order
for (MazeCell temp : myNeighbors) {
if (temp.getHeuristicDistance() != Integer.MAX_VALUE) {
frontier.add(temp);
}
}
}
return myMaze.getCell(myMaze.getGoalX(), myMaze.getGoalY()).getPath().toCharArray();
}