public FluidSimulation(World world, SpriteBatch spriteBatch, SpriteFont font)
{
_world = world;
_spriteBatch = spriteBatch;
_font = font;
_activeParticles = new List<int>(MAX_PARTICLES);
_liquid = new Particle[MAX_PARTICLES];
for (int i = 0; i < MAX_PARTICLES; i++)
{
_liquid[i] = new Particle(Vector2.Zero, Vector2.Zero, false);
_liquid[i].index = i;
}
_delta = new Vector2[MAX_PARTICLES];
_scaledPositions = new Vector2[MAX_PARTICLES];
_scaledVelocities = new Vector2[MAX_PARTICLES];
_grid = new Dictionary<int, Dictionary<int, List<int>>>();
_pixel = new Texture2D(_spriteBatch.GraphicsDevice, 1, 1);
_pixel.SetData<Color>(new[] { Color.White });
_random = new Random();
_halfScreen = new Vector2(
_spriteBatch.GraphicsDevice.Viewport.Width,
_spriteBatch.GraphicsDevice.Viewport.Height) / 2f;
_simulationAABB.LowerBound.X = -(_halfScreen.X + 100f);
_simulationAABB.LowerBound.Y = -(_halfScreen.Y + 100f);
_simulationAABB.UpperBound.X = _halfScreen.X + 100f;
_simulationAABB.UpperBound.Y = _halfScreen.Y + 100f;
}
private void findNeighbors(Particle particle)
{
particle.neighborCount = 0;
Dictionary<int, List<int>> gridX;
List<int> gridY;
for (int nx = -1; nx < 2; nx++)
{
for (int ny = -1; ny < 2; ny++)
{
int x = particle.ci + nx;
int y = particle.cj + ny;
if (_grid.TryGetValue(x, out gridX) && gridX.TryGetValue(y, out gridY))
{
for (int a = 0; a < gridY.Count; a++)
{
if (gridY[a] != particle.index)
{
particle.neighbors[particle.neighborCount] = gridY[a];
particle.neighborCount++;
if (particle.neighborCount >= MAX_NEIGHBORS)
return;
}
}
}
}
}
}
