private void Erode(int width, int height, float seaLevel, Overworld.MapData[,] heightMap, int numRains, int rainLength, int numRainSamples, float[,] buffer)
{
float remaining = 1.0f - Progress.Value - 0.2f;
float orig = Progress.Value;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
buffer[x, y] = heightMap[x, y].Height;
}
}
for (int i = 0; i < numRains; i++)
{
LoadingMessage = "Erosion " + i + "/" + numRains;
Progress.Value = orig + remaining * ((float)i / (float)numRains);
Vector2 currentPos = new Vector2(0, 0);
Vector2 bestPos = currentPos;
float bestHeight = 0.0f;
for (int k = 0; k < numRainSamples; k++)
{
int randX = PlayState.Random.Next(1, width - 1);
int randY = PlayState.Random.Next(1, height - 1);
currentPos = new Vector2(randX, randY);
float h = Overworld.GetHeight(buffer, currentPos);
if (h > bestHeight)
{
bestHeight = h;
bestPos = currentPos;
}
}
currentPos = bestPos;
const float erosionRate = 0.99f;
Vector2 velocity = Vector2.Zero;
for (int j = 0; j < rainLength; j++)
{
Vector2 g = Overworld.GetMinNeighbor(buffer, currentPos);
float h = Overworld.GetHeight(buffer, currentPos);
if (h < seaLevel || g.LengthSquared() < 1e-12)
{
break;
}
Overworld.MinBlend(Overworld.Map, currentPos, erosionRate * Overworld.GetValue(Overworld.Map, currentPos, Overworld.ScalarFieldType.Erosion), Overworld.ScalarFieldType.Erosion);
velocity = 0.1f * g + 0.7f * velocity + 0.2f * MathFunctions.RandVector2Circle();
currentPos += velocity;
}
}
}
