///<summary>
///creates a graph based on a grid layout. This function requires the
///dimensions of the environment and the number of cells required
///horizontally and vertically
///</summary>
///<param name="graph"></param>
///<param name="cySize"></param>
///<param name="cxSize"></param>
///<param name="numCellsY"></param>
///<param name="numCellsX"></param>
public static void CreateGrid(
SparseGraph graph,
int cySize,
int cxSize,
int numCellsY,
int numCellsX)
{
//need some temporaries to help calculate each node center
float cellWidth = (float) cySize/numCellsX;
float cellHeight = (float) cxSize/numCellsY;
float midX = cellWidth/2;
float midY = cellHeight/2;
//first create all the nodes
for (int row = 0; row < numCellsY; ++row)
{
for (int col = 0; col < numCellsX; ++col)
{
graph.AddNode(
new NavGraphNode(
graph.NextFreeNodeIndex,
new Vector2(
midX + (col*cellWidth),
midY + (row*cellHeight))));
}
}
//now to calculate the edges. (A position in a 2D array [x][y] is
//the same as [y*NumCellsX + x] in a 1d array). Each cell has up to
//eight neigbors.
for (int row = 0; row < numCellsY; ++row)
{
for (int col = 0; col < numCellsX; ++col)
{
AddAllNeighborsToGridNode(
graph,
row,
col,
numCellsX,
numCellsY);
}
}
}
