/// <summary>
/// creates a biome for a given type of terrain
/// </summary>
private void createBiome(Terrain.TerrainTypes terrain)
{
// calculate biome half length proportional to the map size
int biomeLenghtValue = (int)(Mathf.Max(WIDTH, HEIGHT) / 7);
int biomeHalfLength = random.Next(biomeLenghtValue - 2, biomeLenghtValue + 2);
// random anchor spot for biome
// index 0 for x and 1 and y coordinate
int[] anchor = new int[2];
anchor[0] = random.Next(0, WIDTH);
anchor[1] = random.Next(0, HEIGHT);
int counter = 0;
while (biomeAnchorTooClose(anchor, biomeLenghtValue) && counter < 100)
{
anchor[0] = random.Next(0, WIDTH);
anchor[1] = random.Next(0, HEIGHT);
counter++;
}
// adding anchor to screen
MapTile anchorTile = ScriptableObject.CreateInstance <MapTile>();
Vector3Int anchorVector = new Vector3Int(-anchor[0] + WIDTH / 2, -anchor[1] + HEIGHT / 2, 0);
Vector3 anchorMappedVector = map.CellToWorld(anchorVector);
anchorTile.Canvas = parent;
anchorTile.ScreenPosition = anchorMappedVector;
biomeAnchors[anchor] = terrain;
// occupiedBiomSpots[anchor] = terrain;
anchorTile.Terrain = new Terrain(terrain);
growBoime(anchor, biomeHalfLength, terrain);
// create beach biom if the biome type is Ocean
if (terrain.Equals(Terrain.TerrainTypes.Ocean))
{
addBeachBiome(anchor, biomeHalfLength);
}
else if (terrain.Equals(Terrain.TerrainTypes.DesertHill))
{
addDessertBiome(anchor, biomeHalfLength);
}
else if (terrain.Equals(Terrain.TerrainTypes.Grass))
{
addMountainBiome(anchor, biomeHalfLength);
}
}
/// <summary>
/// grows a biome
/// </summary>
private void growBoime(int[] anchor, int biomHalfLength, Terrain.TerrainTypes terrain)
{
// constants that will be used further down the line
float k = Mathf.Sqrt(Mathf.Pow(biomHalfLength, 2) * 2);
float a = (float)2.0f / Mathf.Log10(Mathf.Pow(k, 2) - 2.0f);
// growing biom
for (int i = 0; i < biomHalfLength * 3; i++)
{
for (int j = 0; j < biomHalfLength * 3; j++)
{
// current position array where index 0 is X and index 1 is Y coordinate
int[] curPos = new int[2];
curPos[0] = anchor[0] - biomHalfLength + i;
curPos[1] = anchor[1] - biomHalfLength + j;
// check if X and Y values are within the map
if (curPos[0] < WIDTH && curPos[0] >= 0 && curPos[1] < HEIGHT && curPos[1] >= 0)
{
MapTile tile = ScriptableObject.CreateInstance <MapTile>();
// A vector used for hex position
Vector3Int vector = new Vector3Int(-curPos[0] + WIDTH / 2, -curPos[1] + HEIGHT / 2, 0);
// Find the real position (the position on the screen)
Vector3 mappedVector = map.CellToWorld(vector);
tile.Canvas = parent;
tile.ScreenPosition = mappedVector;
// check if terrain is vacant
if (getTileTerrain(curPos).Equals(Terrain.TerrainTypes.NotSet))
{
// Debug.Log("Cur: X: " + curX + ", Y: " + curY);
// weighted random terrain allocation depending on distance from anchor
int value = random.Next(0, 100);
// weighting is done in such a that:
// P = (k^2 - d^2)^a,
// where:
// P = probability of the biome tile being set
// k = a constant (calculated earlier before the nested for loops)
// d = absolute distance between the anchor and any potential biome tile
// a = a constant (calculated earlier before the nested for loops)
//
// the formula satisfies the two equations below:
// 100 = (k^2 - 2)^a, this ensures that the biome is atleast 3x3
// 0 = (k^2 - d^2)^a, where d is a distance for an arbitrary square just outside the biome half length
//
// so if biome half length is 7 then k = 11.3 and a = 0.484
float dist = Mathf.Sqrt(Mathf.Pow(anchor[0] - curPos[0], 2) + Mathf.Pow(anchor[1] - curPos[1], 2));
double prob = Mathf.Pow(Mathf.Pow(k, 2) - Mathf.Pow(dist, 2), a);
if (value < prob)
{
occupiedBiomSpots[curPos] = terrain;
tile.Terrain = new Terrain(terrain);
SetTileTo(vector, tile);
// add mountains if the biome is just grass
if (terrain.Equals(Terrain.TerrainTypes.Grass))
{
StructureFactory mountainFactory = new MountainFactory();
if (mountainFactory.CanBuildOnto(tile, out _))
{
mountainFactory.BuildOnto(tile);
}
}
// Refresh the tile whenever its sprite changes.
tile.SpriteChange += () => map.RefreshTile(vector);
}
}
}
}
}
}
