using System;
using System.Linq;
using Unity.MLAgents.Policies;
using UnityEngine;
namespace Unity.MLAgents.Actuators
{
///
/// Defines the structure of the actions to be used by the Actuator system.
///
[Serializable]
public struct ActionSpec
{
[SerializeField]
int m_NumContinuousActions;
///
/// An array of branch sizes for discrete actions.
///
/// For an IActuator that uses discrete actions, the number of
/// branches is the Length of the Array and each index contains the branch size.
/// The cumulative sum of the total number of discrete actions can be retrieved
/// by the property.
///
/// For an IActuator with a Continuous it will be null.
///
public int[] BranchSizes;
///
/// The number of continuous actions that an Agent can take.
///
public int NumContinuousActions { get { return m_NumContinuousActions; } set { m_NumContinuousActions = value; } }
///
/// The number of branches for discrete actions that an Agent can take.
///
public int NumDiscreteActions { get { return BranchSizes == null ? 0 : BranchSizes.Length; } }
///
/// Get the total number of Discrete Actions that can be taken by calculating the Sum
/// of all of the Discrete Action branch sizes.
///
public int SumOfDiscreteBranchSizes { get { return BranchSizes == null ? 0 : BranchSizes.Sum(); } }
///
/// Creates a Continuous with the number of actions available.
///
/// The number of continuous actions available.
/// An Continuous ActionSpec initialized with the number of actions available.
public static ActionSpec MakeContinuous(int numActions)
{
var actuatorSpace = new ActionSpec(numActions, null);
return actuatorSpace;
}
///
/// Creates a Discrete with the array of branch sizes that
/// represents the action space.
///
/// The array of branch sizes for the discrete actions. Each index
/// contains the number of actions available for that branch.
/// An Discrete ActionSpec initialized with the array of branch sizes.
public static ActionSpec MakeDiscrete(params int[] branchSizes)
{
var actuatorSpace = new ActionSpec(0, branchSizes);
return actuatorSpace;
}
///
/// Create an ActionSpec initialized with the specified action sizes.
///
/// The number of continuous actions available.
/// The array of branch sizes for the discrete actions. Each index
/// contains the number of actions available for that branch.
public ActionSpec(int numContinuousActions = 0, int[] discreteBranchSizes = null)
{
m_NumContinuousActions = numContinuousActions;
BranchSizes = discreteBranchSizes;
}
///
/// Check that the ActionSpec uses either all continuous or all discrete actions.
/// This is only used when connecting to old versions of the trainer that don't support this.
///
///
internal void CheckAllContinuousOrDiscrete()
{
if (NumContinuousActions > 0 && NumDiscreteActions > 0)
{
throw new UnityAgentsException(
"Action spaces with both continuous and discrete actions are not supported by the trainer. " +
"ActionSpecs must be all continuous or all discrete."
);
}
}
}
}