protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
_spriteBatch.Begin();
for (int y = 0; y < G.GetSize(); y++)
{
for (int x = 0; x < G.GetSize(); x++)
{
int v = G.GetAtom(x, y);
Color pc = ColorMap[v];
_spriteBatch.Draw(OnePx, new Rectangle(x * CellWidth, y * CellHeight, CellWidth, CellHeight), pc);
}
}
_spriteBatch.End();
{
// Do some simulated annealing.
// Putting this in Update method ruins the animation due to large computation time.
for (int i = 0; i < G.GetSize() * G.GetSize() * 10; i++)
{
SA.AnnealStep();
}
// Slowly reduce temperature but don't allow it to go too low.
if (SA.T > 0.1)
{
SA.T *= 0.99f;
}
}
base.Draw(gameTime);
}
protected override void Initialize()
{
OnePx = new Texture2D(_graphics.GraphicsDevice, 1, 1);
OnePx.SetData <Color>(new Color[1] {
Color.White
});
// NOTE: Too large a grid takes a long time per frame.
G = new AtomGrid(14, 4);
SA = new SimulatedAnnealing(G);
//SA.Anneal();
_graphics.PreferredBackBufferWidth = G.GetSize() * CellWidth;
_graphics.PreferredBackBufferHeight = G.GetSize() * CellHeight;
_graphics.ApplyChanges();
base.Initialize();
}
public void Anneal()
{
Debug.WriteLine("Starting energy: {0}", G.GetSystemEnergy());
int iters = 0;
while (T > 0 && iters++ < 35)
{
// Technically we should loop until we reach a thermal equilibrium at this temperature.
// Just assume many iterations reach this point.
int totalReduction = 0;
for (int i = 0; i < G.GetSize() * G.GetSize() * 10; i++)
{
int dE = AnnealStep();
totalReduction += dE;
}
// If we are still reducing E then continue, else give-in
// Currently we just do a fixed num of steps in here.
T = T * 0.9f; // Reduce temperature
}
Debug.WriteLine("Finished annealing state, final energy = {0}, T={1}", G.GetSystemEnergy(), T);
}
