// Clone
public ProjectileSourceBelief Clone()
{
ProjectileSourceBelief source = new ProjectileSourceBelief(Probability, Ammo, WeaponType.None);
HashSet <WeaponType> newPossibleWeapons = new HashSet <WeaponType>(PossibleWeapons);
source.PossibleWeapons = newPossibleWeapons;
return(source);
}
// Adds a belief to a dictionary modifying in place, also adding prob. to counter c
void addBelief(Dictionary <IJCoords, ProjectileSourceBelief> dict, int i, int j,
ProjectileSourceBelief belief, ref float c)
{
IJCoords key = new IJCoords(i, j);
if (dict.ContainsKey(key))
{
ProjectileSourceBelief oldBelief = dict[key];
oldBelief.Probability += belief.Probability;
oldBelief.PossibleWeapons.UnionWith(belief.PossibleWeapons);
oldBelief.Ammo = belief.Ammo > oldBelief.Ammo ? belief.Ammo : oldBelief.Ammo;
}
else
{
dict[key] = belief;
}
// Add to counter
c += belief.Probability;
}
// Adds a belief to a dictionary given an old belief, derived chance, and block world
void addBeliefUsingWorld(Dictionary <IJCoords, ProjectileSourceBelief> dict, int newI, int newJ,
ProjectileSourceBelief oldBelief, float derivedChance, ref float c)
{
ProjectileSourceBelief derivedBelief = oldBelief.Clone();
derivedBelief.Probability = derivedChance;
// Check for ammo in new position
WeaponType ammoTypeCheckResult = blockWorld.CheckAmmo(newI, newJ);
if (ammoTypeCheckResult != WeaponType.None)
{
if (derivedBelief.Ammo != -1)
{
derivedBelief.Ammo = 3; // Lightning doesn't matter
}
derivedBelief.PossibleWeapons.Add(ammoTypeCheckResult);
}
addBelief(dict, newI, newJ, derivedBelief, ref c);
}
// Runs trajectories of projectile source beliefs
void runTrajectories()
{
// Iterate through each possibility
foreach (KeyValuePair <IJCoords, ProjectileSourceBelief> entry in sourceBeliefs)
{
ProjectileSourceBelief sourceBelief = entry.Value;
int sourceI = entry.Key.I;
int sourceJ = entry.Key.J;
int sourceAmmo = sourceBelief.Ammo;
float sourceProbability = sourceBelief.Probability;
// Iterate through each weapon type for each possibility
foreach (WeaponType weaponType in sourceBelief.PossibleWeapons)
{
if (weaponType == WeaponType.Lightning)
{
// Add danger to all above for lightning - easy
for (int j = -World.FloorLevelJ; j < World.BlocksHeight; j++)
{
if (j < sourceJ)
{
addDanger(sourceI, j, sourceProbability * LightningDangerWeight);
}
}
}
else
{
// Recursively add values to the danger zone 2D array
// Use same blockworld for both directions since paths won't cross
BlockWorld newBlockWorld = blockWorld.Clone();
addDangerToBlockAndNeighbors(sourceI, sourceJ, weaponType, sourceProbability, sourceAmmo, true, newBlockWorld);
addDangerToBlockAndNeighbors(sourceI, sourceJ, weaponType, sourceProbability, sourceAmmo, false, newBlockWorld);
}
}
}
}
// Computes a belief distribution for the projectile sources
void computeSourceBeliefs(int playerNum, World world)
{
// Find player
World.Player player = playerNum == 1 ? world.Player1 : world.Player2;
int playerI = World.XToI(player.X);
int playerJ = World.YToJ(player.Y);
sourceI = playerI;
sourceJ = playerJ;
// The initial source is at the player
ProjectileSourceBelief initial = new ProjectileSourceBelief(1.0f, player.Ammo, player.Weapon);
sourceBeliefs.Add(new IJCoords(playerI, playerJ), initial);
// Compute distribution of projectile sources
for (int iter = 0; iter < DistributionSteps; iter++)
{
Dictionary <IJCoords, ProjectileSourceBelief> newBeliefs = new Dictionary <IJCoords, ProjectileSourceBelief>();
float newBeliefsTotal = 0.0f;
// Advance our belief state, except keep the old one around for efficiency
foreach (KeyValuePair <IJCoords, ProjectileSourceBelief> entry in sourceBeliefs)
{
ProjectileSourceBelief belief = entry.Value;
int i = entry.Key.I;
int j = entry.Key.J;
float prior = belief.Probability;
// Determine possible directions
bool upPossible = false;
bool leftPossible = false;
bool rightPossible = false;
bool downPossible = false;
bool stayPossible = false;
int numPossibleDirections = 0;
bool supported = blockWorld.CheckPositionSupported(i, j);
if (!supported)
{
// Can only move down from unsupported positions
numPossibleDirections++;
downPossible = true;
}
else
{
stayPossible = true;
numPossibleDirections++;
if (!blockWorld.CheckGroundByIndex(i, j + 1))
{
downPossible = true;
numPossibleDirections++;
}
if (!blockWorld.CheckGroundByIndex(i + 1, j))
{
leftPossible = true;
numPossibleDirections++;
}
if (!blockWorld.CheckGroundByIndex(i - 1, j))
{
rightPossible = true;
numPossibleDirections++;
}
if (!blockWorld.CheckGroundByIndex(i, j - 1))
{
upPossible = true;
numPossibleDirections++;
}
}
// Compute chance of each direction - uniform
float chance = 1.0f / numPossibleDirections;
float derivedChance = chance * prior;
// Update beliefs based on possible directions
// Staying in place is always an option
if (stayPossible)
{
addBeliefUsingWorld(newBeliefs, i, j, belief, derivedChance, ref newBeliefsTotal);
}
if (upPossible)
{
addBeliefUsingWorld(newBeliefs, i, j - 1, belief, derivedChance, ref newBeliefsTotal);
}
if (downPossible)
{
addBeliefUsingWorld(newBeliefs, i, j + 1, belief, derivedChance, ref newBeliefsTotal);
}
if (leftPossible)
{
addBeliefUsingWorld(newBeliefs, i + 1, j, belief, derivedChance, ref newBeliefsTotal);
}
if (rightPossible)
{
addBeliefUsingWorld(newBeliefs, i - 1, j, belief, derivedChance, ref newBeliefsTotal);
}
}
// Normalize our new belief state
foreach (KeyValuePair <IJCoords, ProjectileSourceBelief> entry in newBeliefs)
{
entry.Value.Probability /= newBeliefsTotal;
}
// Update
sourceBeliefs = newBeliefs;
}
}
