/// <summary>
/// Creates a new vertex
/// </summary>
/// <param name="name">The name of this vertex</param>
/// <param name="position">The position of this vertex</param>
public Vertex(String name, Vector2 position)
{
// Save the data
this.name = name;
this.position = position;
// Defaults
visited = false;
permanent = false;
adjacent = null;
weight = 0;
}
/// <summary>
/// Helper method for drawing a single edge
/// </summary>
/// <param name="v1">The first vertex</param>
/// <param name="v2">The second vertex</param>
/// <param name="color">The color of the edge & weight</param>
/// <param name="sb">The spritebatch to use when drawing</param>
private void DrawOneEdge(Vertex v1, Vertex v2, Color color, SpriteBatch sb)
{
// Calculate the scale of the edge in pixels
Vector2 scale = new Vector2(Vector2.Distance(v2.Position, v1.Position), EDGE_WIDTH);
// Calculate the rotation
float rotation = (float)Math.Atan2(v2.Position.Y - v1.Position.Y, v2.Position.X - v1.Position.X);
// Draw
sb.Draw(
pixel,
v1.Position,
null,
color,
rotation,
Vector2.Zero,
scale,
SpriteEffects.None,
0.0f
);
// Get the edge's weight
int weight = adjMatrix[vertNameToIndex[v1.Name], vertNameToIndex[v2.Name]];
// Draw above the center
Vector2 pos = v1.Position;
pos.X += (v2.Position.X - v1.Position.X) / 2.0f;
pos.Y += (v2.Position.Y - v1.Position.Y) / 2.0f;
// Draw the text
sb.DrawString(font, weight.ToString(), pos, Color.White);
}
//Create a method that will search through the vertices list and find out which non-permanent node
//contains the smallest label and has been visited
public Vertex SmallestLabel()
{
//Create a local variable for smallest vertex
Vertex smallest = new Vertex("foo", new Vector2(0, 0));
smallest.Weight = int.MaxValue;
for (int i = 0; i < vertices.Count; i++)
{
if (vertices[i].Weight < smallest.Weight && vertices[i].Permanent == false && vertices[i].Visited)
{
smallest = vertices[i];
}
}
//Make smallest node permanent
smallest.Permanent = true;
//Highlight the shortest path
edgeColor[vertNameToIndex[smallest.Name], vertNameToIndex[smallest.Adjacent.Name]] = HIGHLIGHT_EDGE_COLOR;
//Add to the visitedlist
visitedVerticesList.Add(smallest);
return smallest;
}
//Create a method that will examine each non-permanent node adjacent to the working node
public void Label(Vertex current)
{
//Loop through the vertices in vertexList
foreach (Vertex vert in vertices)
{
//If a vertex in the list matches the given room
if (vert == current)
{
//Go through the 2d array
for (int i = 0; i < vertices.Count; i++)
{
//If there is a connection and permanent is false
if (adjMatrix[vertNameToIndex[vert.Name], i] != 0 && vertices[i].Permanent == false && vertices[i].Adjacent == null)
{
//Label with total distance from the source and the name of the working node
//Total distance from source
vertices[i].Weight = adjMatrix[vertNameToIndex[vert.Name], i] + vert.Weight;
//Set adjacent vertex's adjacent vertex to working node
vertices[i].Adjacent = vert;
vertices[i].Visited = true;
}
//If there is a connection and if it has already been labeled
if (adjMatrix[vertNameToIndex[vert.Name], i] != 0 && vertices[i].Adjacent != null)
{
//Check to see if the cost computed using the working node is better
//than the current cost in the label
int newCost = adjMatrix[vertNameToIndex[vert.Name], i] + vert.Weight;
if (newCost < vertices[i].Weight)
{
//If so, change the label
//Change the total distance and current working node
vertices[i].Weight = newCost;
vertices[i].Visited = true;
vertices[i].Adjacent = vert;
}
}
}
}
}
}
public void HighlightShortestPaths(Vertex v)
{
//Call Reset method to set all of the vertices weight to the largest int max value
if (visitedVerticesList.Count == 0)
{
Reset();
}
//Keep doing the algorithm until it is finished
while (Finished() != true)
{
//Check to see if the room is in the vertex list
if (vertices.Contains(v))
{
if (visitedVerticesList.Count == 0)
{
//Set the source vertex to the source node
source = v;
//Make source node permanent
source.Permanent = true;
source.Weight = 0;
//Call the label method
Label(source);
}
else
{
Label(current);
}
}
if (visitedVerticesList.Count == 0)
{
visitedVerticesList.Add(source);
}
current = SmallestLabel();
}
//Call the clear list to clear the vertices in vistedVerticesList
//so that the algorithm can be runned again
visitedVerticesList.Clear();
}
/// <summary>
/// Adds a vertex to the graph
/// </summary>
/// <param name="vert">The vert to add</param>
public void AddVertex(Vertex vert)
{
// Add the vertex if we're below the maximum
if (vertices.Count < MAX_VERTICES)
{
vertNameToIndex.Add(vert.Name, vertices.Count);
vertices.Add(vert);
}
}