public FluidSimulation(World world, SpriteBatch spriteBatch, SpriteFont font)
{
_world = world;
_spriteBatch = spriteBatch;
_font = font;
_activeParticles = new List<int>(MAX_PARTICLES);
_liquid = new FluidParticle[MAX_PARTICLES];
_liquidDelete = new FluidParticle[MAX_PARTICLES];
for (int i = 0; i < MAX_PARTICLES; i++)
{
_liquid[i] = new FluidParticle(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(FluidParticle 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;
}
}
}
}
}
}
public void update()
{
MouseState mouseState = Mouse.GetState();
_halfScreen = new Vector2(
_spriteBatch.GraphicsDevice.Viewport.Width,
_spriteBatch.GraphicsDevice.Viewport.Height) / 2f;
//_mouse = (new Vector2(mouseState.X, mouseState.Y) - _halfScreen) / Game1.scale;
//_mouse = new Vector2(Game1.mouseTruePos.X*Game1.scale, Game1.mouseTruePos.Y*Game1.scale);
_mouse = new Vector2(Game1.mouseTruePos.X, Game1.mouseTruePos.Y);
if (mouseState.LeftButton == ButtonState.Pressed && !Game1.strafeMode)
createParticle();
// Prepare simulation
Parallel.For(0, _numActiveParticles, i => { prepareSimulation(_activeParticles[i]); });
// Prepare collisions
prepareCollisions();
// Calculate pressures
Parallel.For(0, _numActiveParticles, i => { calculatePressure(_activeParticles[i]); });
// Calculate forces
Parallel.For(
0,
_numActiveParticles,
() => new Vector2[MAX_PARTICLES],
(i, state, accumulatedDelta) => calculateForce(_activeParticles[i], accumulatedDelta),
(accumulatedDelta) =>
{
lock (_calculateForcesLock)
{
for (int i = _numActiveParticles - 1; i >= 0; i--)
{
int index = _activeParticles[i];
_delta[index] += accumulatedDelta[index] / MULTIPLIER;
}
}
}
);
// Resolve collisions
Parallel.For(0, _numActiveParticles, i => resolveCollision(_activeParticles[i]));
/*for (int i = 0; i < _numActiveParticles; i++)
{
FluidParticle particle = _liquid[_activeParticles[i]];
//_spriteBatch.Draw(_pixel, new Vector2(2400,1800), new Rectangle(0, 0, 20, 20), Color.Black, 0f, new Vector2(1, 1), 1f, SpriteEffects.None, 0f);
//Game1.checkGridLiquid(new Vector2(((float)particle.position.X + (particle.position.X-particle.oldPosition.X)/10)*Game1.scale, ((float)particle.position.Y + (particle.position.Y - particle.oldPosition.Y)/10))*Game1.scale);
Game1.checkGridLiquid(new Vector2(((float)particle.position.X + (particle.position.X - particle.oldPosition.X)), ((float)particle.position.Y + (particle.position.Y - particle.oldPosition.Y))));
//Game1.checkGridLiquid(new Vector2((float)particle.position.X, (float)particle.position.Y));
//_spriteBatch.Draw(_pixel, (particle.position) * Game1.scale, new Rectangle(0, 0, 2, 2), Color.DarkBlue, 0f, new Vector2(1, 1), 1f, SpriteEffects.None, 0f);
}*/
foreach (KeyValuePair<int, Dictionary<int, List<int>>> row1 in _grid)
{
foreach (KeyValuePair<int, List<int>> row2 in row1.Value)
{
Game1.checkGridLiquid(new Vector2((float)row1.Key * CELL_SIZE, (float)row2.Key * CELL_SIZE));
}
}
bool delete;
for (int i = 0; i < _numActiveParticles; i++)
{
FluidParticle particle = _liquid[_activeParticles[i]];
delete = Game1.checkParticle(new Vector2(((float)particle.position.X + (particle.position.X - particle.oldPosition.X)), ((float)particle.position.Y + (particle.position.Y - particle.oldPosition.Y))));
if (delete)
{
particle.velocity = new Vector2(0, 0);
//particle.position = particle.oldPosition;
}
//if(particle.position.X
}
// Update particle cells
for (int i = 0; i < _numActiveParticles; i++)
moveParticle(_activeParticles[i]);
if (clearParticles)
{
//_activeParticles.Clear();
_activeParticles = new List<int>(MAX_PARTICLES);
_liquid = new FluidParticle[MAX_PARTICLES];
for (int i = 0; i < MAX_PARTICLES; i++)
{
_liquid[i] = new FluidParticle(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>>>();
_numActiveParticles = 0;
clearParticles = false;
}
}