// Adds this boundary to a graph as a series of nodes and edges
public void AddToGraph(BoundaryGraph graph)
{
List <Vector2> corners = Get2DBounds();
List <BoundaryGraphNode> nodes = new List <BoundaryGraphNode>();
int i = 0;
// Convert each point into a node
for (i = 0; i < corners.Count; i++)
{
BoundaryGraphNode node = new BoundaryGraphNode(corners[i]);
nodes.Add(node);
}
// Link each node to the next one (note linking is reciprical so I don't have to link the reverse)
for (i = 0; i < nodes.Count; i++)
{
int nextInd = (i + 1) % nodes.Count;
nodes[i].AddNeighbor(nodes[nextInd]);
}
// Add the nodes to the graph
foreach (BoundaryGraphNode node in nodes)
{
node.AddParentBoundary(this);
graph.AddNode(node);
}
}
// Compiles the level recovering interior geometry
// Output is saved as a scriptable object instance in assets
public void CompileLevel()
{
// Build a list of boundaries and a shape graph
List <Boundary> boundaries = new List <Boundary>();
BoundaryGraph graph = new BoundaryGraph();
foreach (Transform trans in transform)
{
Boundary temp = trans.gameObject.GetComponent <Boundary>();
if (temp != null)
{
boundaries.Add(temp);
temp.AddToGraph(graph);
}
}
// Unify the graph and make sure any intersections have a vertex
graph.Unify();
// Remove any verticies interior to another boundary
// This does not account for exterior - exterior edges that cross the shape
List <BoundaryGraphNode> deleteList = new List <BoundaryGraphNode>();
foreach (BoundaryGraphNode node in graph)
{
foreach (Boundary bound in boundaries)
{
// Ignore its parent boundaries
//if (node.IsParent(bound))
//continue;
// If position is interior, remove this node
if (bound.Interior(node.position))
{
deleteList.Add(node);
break;
}
}
}
// Cleanup deleted nodes
foreach (BoundaryGraphNode node in deleteList)
{
graph.DeleteNode(node);
}
// Now we will delete any edges who's midpoint is interior to another boundary
// These edges can remain when there's an exterior-exterior edge crossing polygons
// Consider a T shape made of 2 boundaries. Right at the cross section
foreach (UnorderedPair <BoundaryGraphNode, BoundaryGraphNode> edge in graph.getEdgesAsUniquePairs())
{
// Find the midpoint
Vector3 midpoint = new Vector3((edge.item1.position.x + edge.item2.position.x) / 2, (edge.item1.position.y + edge.item2.position.y) / 2, 0);
foreach (Boundary bound in boundaries)
{
// Ignore its parent boundaries
//if (edge.item1.IsParent(bound) || edge.item2.IsParent(bound))
//continue;
// If position is interior, remove this node
if (bound.Interior(midpoint))
{
edge.item1.RemoveNeighbor(edge.item2); // Edge removal is reciprical
break;
}
}
}
// NOTE: work still needed. Needs to handle multiple islands and error cases.
// right now it only works for the trivial case
// While the graph has nodes remaining
while (!graph.IsEmpty())
{
// Pick an extrema node. This will belong to the exterior most cycle in the graph
BoundaryGraphNode extrema = graph.GetExtrema();
// Clean up any exterior - exterior edges that could connect two seperate layers
// These are left over after deleting the interior nodes
// To do this, we track whether we are currently in an exterior
// Remove that node and all nodes connected. This will give you the loop.
List <BoundaryGraphNode> loop = graph.RemoveConnectedComponent(extrema);
// Convert loop into a list of vector2
List <Vector2> vertexList = new List <Vector2>();
foreach (BoundaryGraphNode node in loop)
{
vertexList.Add(node.position);
}
vertexList.RemoveAt(vertexList.Count - 1); // There is a bug causing duplicate nodes and instead of fixing it I did this... f**k me :(
Polygon poly = Undo.AddComponent <Polygon>(gameObject);
poly.SetVerticies(vertexList);
}
return;
}
// Remove a neighbor from the node. Also removes the reciprical relation
public void RemoveNeighbor(BoundaryGraphNode node)
{
neighbors.Remove(node);
node.neighbors.Remove(this);
}
// Checks if this node has other node as a neighbor
public bool HasNeighbor(BoundaryGraphNode other)
{
return(neighbors.Contains(other));
}
// Add a neighbor to the node. Also adds the reciprical relation
public void AddNeighbor(BoundaryGraphNode node)
{
neighbors.Add(node);
node.neighbors.Add(this);
}