public void MakeEroded(LiquidSettings liquidSettings, int dropCount)
{
for (int i = 0; i < dropCount; i++)
{
int xInd = Random.Range(0, map.resolution);
int yInd = Random.Range(0, map.resolution);
Droplet drop = new Droplet(liquidSettings, xInd, yInd, 1, 0);
ErodeDroplet(drop);
}
}
public bool CanDropletRun(Droplet droplet)
{
if (droplet.lifetime >= droplet.settings.maxLifetime)
{
return(false);
}
if (droplet.volume <= 0)
{
return(false);
}
return(true);
}
// Return true if x2/y2 is lower than x1/y1
// Return false if higher, same height, or out of bounds
// https://stackoverflow.com/questions/49640250/calculate-normals-from-heightmap
public Vector3 GetFlowDir(Droplet drop)
{
int xInd = (int)drop.xPos;
int yInd = (int)drop.yPos;
// Get the heights of the 4 bordering cells
// If out of bounds, use height of map[y,x]
float negX = GetHeightNegX(xInd, yInd);
float negY = GetHeightNegY(xInd, yInd);
float posX = GetHeightPosX(xInd, yInd);
float posY = GetHeightPosY(xInd, yInd);
Vector3 normal = new Vector3(negX - posX, negY - posY, -4);
return(normal.normalized);
}
private void ErodeDirt(float[,] brush, int xInd, int yInd, Droplet drop, float erodeAmount)
{
//float[,] brush = GetErosionBrush(drop.settings, erodeAmount);
float lowestNeighborHeight = GetHeightOfLowestNeighbor(xInd, yInd);
int xLen_map = map.resolution;
int yLen_map = map.resolution;
int xLen_brush = brush.GetLength(1);
int yLen_brush = brush.GetLength(0);
int xOffset = -(xLen_brush / 2);
int yOffset = -(yLen_brush / 2);
for (int y = 0; y < yLen_brush; y++)
{
for (int x = 0; x < xLen_brush; x++)
{
int xInd_map = xInd + xOffset + x;
int yInd_map = yInd + yOffset + y;
// Out of bounds
if (!IsInBounds(xLen_map, yLen_map, xInd_map, yInd_map))
{
continue;
}
// Too low to erode
float heightDif = map[yInd_map, xInd_map].GroundHeight - lowestNeighborHeight;
if (heightDif <= 0)
{
continue;
}
// Only erode down to lowest neighbor at most
float actualErodeAmount = Mathf.Min(brush[y, x] * erodeAmount, heightDif);
drop.dirt += actualErodeAmount;
//map[yInd_map, xInd_map][TerrainValTypes.Rock] -= actualErodeAmount;
map[yInd_map, xInd_map].RemoveGround(actualErodeAmount);
}
}
}
public void ErodeDroplet(Droplet drop)
{
int xLen = map.resolution;
int yLen = map.resolution;
float[,] brush = drop.settings.GetErosionBrush();
while (CanDropletRun(drop))
{
drop.lifetime++;
int xInd = (int)drop.xPos;
int yInd = (int)drop.yPos;
// If in a pit, fast track evaporation
// Deposit dirt up to height of lowest neighbor, reduce liquid volume proportionally
if (!IsMovementPossible(xInd, yInd))
{
float neighborHeight = GetHeightOfLowestNeighbor(xInd, yInd);
float depositAmount = Mathf.Min(drop.dirt, neighborHeight - map[yInd, xInd].GroundHeight);
// Lower liquid volume proportionally and deposit dirt
drop.volume *= 1 - (drop.dirt / depositAmount);
//map[yInd, xInd] += depositAmount;
continue;
//break;
}
Vector3 downDir = GetFlowDir(drop).Zof(0).normalized;
drop.xPos = drop.xPos + downDir.x;
drop.yPos = drop.yPos + downDir.y;
int xIndNew = (int)drop.xPos;
int yIndNew = (int)drop.yPos;
// Verify new location is in bounds
if (!IsInBounds(xLen, yLen, xIndNew, yIndNew))
{
break;
}
// Hasn't moved enough to do a calculation this iteration
if (!HasIndChanged(xInd, yInd, xIndNew, yIndNew))
{
continue;
}
float dHeight = GetHeightDif(xInd, yInd, xIndNew, yIndNew);
//TODO: What exactly is this doing?
float totalCapacity = Mathf.Max(
drop.settings.minDirt,
drop.settings.dirtCapacity * -dHeight /* * drop.volume*/);
// Deposit dirt
if (drop.dirt > totalCapacity)
{
float dirtAmount = (drop.dirt - totalCapacity) * drop.settings.depositSpeed;
DepositDirt(xInd, yInd, drop, dirtAmount);
}
// Erode dirt
else
{
float dirtAmount = Mathf.Min((totalCapacity - drop.dirt) * drop.settings.erodeSpeed, -dHeight);
ErodeDirt(brush, xInd, yInd, drop, dirtAmount);
}
// Slowly reduce amount of water
drop.volume *= (1 - drop.settings.evapSpeed);
}
}
private void DepositDirt(int xInd, int yInd, Droplet drop, float depositAmount)
{
drop.dirt -= depositAmount;
//map[yInd, xInd][TerrainValTypes.Rock] += depositAmount;
map[yInd, xInd].AddGround(depositAmount);
}