/// <summary>
/// Gets the surviving units of the army that won the combat
/// </summary>
/// <param name="combat_result"></param>
/// <param name="combat_winner"></param>
/// <returns></returns>
public static int GetSurvivingUnits(LanchesterCombatResult combat_result, CombatWinner combat_winner)
{
double surviving_units = 0;
try
{
switch (combat_winner)
{
case CombatWinner.Owned_Army:
surviving_units = Math.Sqrt(Math.Abs(Math.Pow(combat_result.OwnedArmy_Count, 2) - ((combat_result.OwnedArmy_CombatEffectiveness / combat_result.EnemyArmy_CombatEffectiveness) * Math.Pow(combat_result.EnemyArmy_Count, 2))));
break;
case CombatWinner.Draw:
surviving_units = 0;
break;
case CombatWinner.Enemy_Army:
surviving_units = Math.Sqrt(Math.Abs(Math.Pow(combat_result.EnemyArmy_Count, 2) - ((combat_result.EnemyArmy_CombatEffectiveness / combat_result.OwnedArmy_CombatEffectiveness) * Math.Pow(combat_result.OwnedArmy_Count, 2))));
break;
}
}
catch (Exception ex)
{
Console.WriteLine($@"GetSurvivingUnits() -> {ex.Message}");
surviving_units = 0;
}
return(Convert.ToInt32(surviving_units));
}
/// <summary>
/// Checks the <see cref="LanchesterCombatResult.OwnedArmy_RelativeCombatEffectiveness"/>
/// and returns which army won in the combat
/// </summary>
/// <param name="combat_result"></param>
/// <returns></returns>
public static CombatWinner GetCombatWinner(LanchesterCombatResult combat_result)
{
CombatWinner combat_winner = CombatWinner.Draw;
try
{
var relative_cardinality = (combat_result.OwnedArmy_Count / combat_result.EnemyArmy_Count);
//Owned Army Loss
if (relative_cardinality < combat_result.OwnedArmy_RelativeCombatEffectiveness)
{
combat_winner = CombatWinner.Enemy_Army;
}
//Owned Army Won
else if (relative_cardinality > combat_result.OwnedArmy_RelativeCombatEffectiveness)
{
combat_winner = CombatWinner.Owned_Army;
}
//Draw
else
{
combat_winner = CombatWinner.Draw;
}
}
catch (Exception ex)
{
Console.WriteLine($@"GetCombatWinner() -> {ex.Message}");
combat_winner = CombatWinner.Draw;
}
return(combat_winner);
}
/// <summary>
/// <para>
/// Lanchester-based Prediction Algorithm is the highest form of abstraction. It uses the
/// Lanchester formula to compute the combat winner, including the survivor in the winning army.
/// As a highest-abstraction prediction algorithm, it exchanges fine detail for faster computing. It
/// does not consider the case that Health and Energy decreases over time, and that some skills
/// have cooldown and duration. However, it considers that some units cannot target some
/// other units such as air units. It also consider skills that deals damage/boost damage but not on the finest
/// detail. Lastly, it also consider that the damage is reduced by the armor.
/// </para>
/// <para>
/// This method returns a string of survived units from the winning army, but the cost worth
/// of doing battle is always relative to the player. As such, if the opposing army won, the cost worth
/// returned is negative since it represents as a loss.
/// </para>
/// </summary>
/// <remarks>
/// <para>
/// While it is said to be the fastest out of the three algorithm, it is still dependent on the target policy.
/// The probably running time is O(4n^2 + 2n).
/// </para>
/// <para>
/// In summary, the Lanchester-based prediction considers and does not consider the following:
/// Considers:
/// <list type="bullet">
/// <item>True Current Damage (Current Damage applied with opposing Armor)</item>
/// <item>Restrictions in targeting unit (Some unit cannot target air unit, and vice versa)</item>
/// <item>Current Health</item>
/// <item>Skills that deals damage and gives boost to the Current damage</item>
/// </list>
/// Does not Consider:
/// <list type="bullet">
/// <item>Decreasing Health</item>
/// <item>Decreasing Energy</item>
/// <item>Skills with Cooldown and Duration</item>
/// <item>Skills that affects Health/Energy</item>
/// <item>AoE Damage / Chaining Damage</item>
/// <item>Transforming Units</item>
/// <item>Time and its related properties to battle</item>
/// <item>Damage with bonus to target type</item>
/// </list>
/// </para>
/// </remarks>
/// <param name="target_policy"></param>
/// <returns></returns>
public Tuple <string, CostWorth> LanchesterBasedPrediction(TargetPolicy target_policy)
{
Tuple <string, CostWorth> battle_result = null;
try
{
//Create a copy of the units
var owned_units = _owned_units.GetDeepCopy();
var enemy_units = _enemy_units.GetDeepCopy();
//Set the targets for each army
//This will get the true damage of unit, since Damage with Armor is applied
switch (target_policy)
{
case TargetPolicy.Random:
RandomBasedTargetPolicy(ref owned_units, enemy_units);
RandomBasedTargetPolicy(ref enemy_units, owned_units);
break;
case TargetPolicy.Priority:
PriorityBasedTargetPolicy(ref owned_units, enemy_units);
PriorityBasedTargetPolicy(ref enemy_units, owned_units);
break;
case TargetPolicy.Resource:
ResourceBasedTargetPolicy(ref owned_units, enemy_units);
ResourceBasedTargetPolicy(ref enemy_units, owned_units);
break;
}
//Compute the battle output
var combat_result = new LanchesterCombatResult(owned_units, enemy_units);
var combat_winner = LanchesterCombatResult.GetCombatWinner(combat_result);
var combat_survivor = LanchesterCombatResult.GetSurvivingUnits(combat_result, combat_winner);
//Get the surviving units of the winner
Army survived_units = default(Army);
switch (combat_winner)
{
case LanchesterCombatResult.CombatWinner.Owned_Army:
//Based on policy, pick which units will survive
switch (target_policy)
{
case TargetPolicy.Random:
survived_units = owned_units.RandomlyTake(combat_survivor);
break;
case TargetPolicy.Priority:
survived_units = owned_units.PriorityTake(combat_survivor);
break;
case TargetPolicy.Resource:
survived_units = owned_units.ResourceTake(combat_survivor);
break;
}
battle_result = new Tuple <string, CostWorth>(survived_units.ToString(), survived_units.GetValueOfArmy());
break;
case LanchesterCombatResult.CombatWinner.Draw:
battle_result = new Tuple <string, CostWorth>(@"""""", default(CostWorth));
break;
case LanchesterCombatResult.CombatWinner.Enemy_Army:
//Based on policy, pick which units will survive
switch (target_policy)
{
case TargetPolicy.Random:
survived_units = enemy_units.RandomlyTake(combat_survivor);
break;
case TargetPolicy.Priority:
survived_units = enemy_units.PriorityTake(combat_survivor);
break;
case TargetPolicy.Resource:
survived_units = enemy_units.ResourceTake(combat_survivor);
break;
}
battle_result = new Tuple <string, CostWorth>(survived_units.ToString(), !survived_units.GetValueOfArmy());
break;
}
}
catch (ArgumentNullException ex)
{
Console.WriteLine($@"LanchesterBasedPrediction() [{target_policy.ToString()}] -> {ex.Message}");
throw new Exception("");
}
catch (Exception ex)
{
Console.WriteLine($@"LanchesterBasedPrediction() -> {ex.Message}");
battle_result = null;
}
return(battle_result);
}
