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AccessConstraint Class

A constraint between two objects. Constraints have a function (preferably continuous near f(x)=0) which is their degree of satisfaction. This allows the exact start or end of the interval during which the constraint is satisfied to be computed.
Inheritance Hierarchy

Namespace:  AGI.Foundation.Access
Assembly:  AGI.Foundation.Core (in AGI.Foundation.Core.dll) Version: 19.5.402.0 (19.5.402.0)
Syntax
public abstract class AccessConstraint : AccessQuery

The AccessConstraint type exposes the following members.

Constructors
  NameDescription
Protected methodAccessConstraint
Initializes a new instance.
Protected methodAccessConstraint(AccessConstraint, CopyContext)
Initializes a new instance as a copy of an existing instance.
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Properties
  NameDescription
Public propertyApplicability
Gets or sets the Access situation in which this constraint applies.
Public propertyDebuggingLogger
Gets or sets a logger to which debugging information will be written.
(Inherited from AccessQuery.)
Public propertyEvaluationOrder
Gets or sets a number indicating the evaluation order of this constraint relative to other constraints. All constraints involved in an AccessComputation or that share a common parent (e.g. AccessQueryAnd or AccessQueryOr) in an AccessQuery are sorted by this value before being evaluated in ascending order, so constraints with a lower evaluation order are evaluated earlier than constraints with a higher evaluation order.
Public propertyIsFrozen
Gets a value indicating whether this object is frozen. A frozen object cannot be modified and an ObjectFrozenException will be thrown if an attempt is made to do so.
(Inherited from DefinitionalObject.)
Public propertySampling
Gets an instance describing how this constraint is to be sampled.
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Methods
  NameDescription
Public methodBuildQueryEvaluator
Builds a query evaluator from this constraint.
Protected methodCheckForSameDefinition(AccessConstraint)
Checks to determine if another instance has the same definition as this instance and returns if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
Protected methodCheckForSameDefinition(AccessQuery)
Checks to determine if another instance has the same definition as this instance and returns if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
(Overrides AccessQueryCheckForSameDefinition(AccessQuery).)
Protected methodCheckForSameDefinition(DefinitionalObject)
Checks to determine if another instance has the same definition as this instance and returns if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
(Inherited from AccessQuery.)
Public methodClone
Clones this object using the specified context.
(Inherited from DefinitionalObject.)
Protected methodComputeCurrentDefinitionHashCode
Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the CheckForSameDefinition(DefinitionalObject) method.
(Overrides AccessQueryComputeCurrentDefinitionHashCode.)
Public methodEnumerateDependencies
Enumerates the dependencies of this object by calling EnumerateT(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.
(Overrides DefinitionalObjectEnumerateDependencies(DependencyEnumerator).)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodFreeze
Freezes this object. Further attempts to modify it will result in an ObjectFrozenException.
(Inherited from DefinitionalObject.)
Protected methodFreezeAggregatedObjects
Called by Freeze to also freeze any objects that are considered to be a part of this object. Derived classes which contain additional aggregated objects MUST override this method, call the base implementation, and freeze aggregated objects introduced by the derived class. The objects that need to be frozen in this method are frequently created in this object's constructor and are not settable via properties.
(Overrides DefinitionalObjectFreezeAggregatedObjects.)
Public methodGetDefinitionHashCode
Gets a hash code representing the definition of this object.
(Inherited from DefinitionalObject.)
Public methodGetEvaluationOrder
Returns EvaluationOrder, indicating the suggested evaluation order of this constraint when it is used as part of an AccessQuery. Queries that hold sub-queries (such as an AccessQueryAnd) generally evaluate their sub-queries in ascending order of this value, so constraints with a lower evaluation order are evaluated earlier than constraints with a higher evaluation order.
(Overrides AccessQueryGetEvaluationOrder.)
Public methodGetEvaluator
Gets an evaluator that can be used to evaluate this query for a given time or for intervals of time.
(Inherited from AccessQuery.)
Public methodGetEvaluator(IServiceProvider)
Gets an evaluator that can be used to evaluate this query for a given time or for intervals of time.
(Inherited from AccessQuery.)
Public methodGetEvaluator(IServiceProvider, EvaluatorGroup)
Gets an evaluator that can be used to evaluate this query for a given time or for intervals of time.
(Overrides AccessQueryGetEvaluator(IServiceProvider, EvaluatorGroup).)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodIsSameDefinition
Determines if this object has the same definition as another object.
(Inherited from DefinitionalObject.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodThrowIfFrozen
Throws ObjectFrozenException if this object IsFrozen. This method should be called from any method or property that modifies this object.
(Inherited from DefinitionalObject.)
Public methodToDisjunctiveNormalForm
Transforms this query to disjunctive normal form (DNF).
(Overrides AccessQueryToDisjunctiveNormalForm.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Remarks

There are two types of AccessConstraints, those that implement ILinkConstraint and those that implement ISingleObjectConstraint.

ISingleObjectConstraints like AltitudeConstraint have a ConstrainedObject property that must be set before the AccessEvaluator is created.

ILinkConstraints like ElevationAngleConstraint have two properties that must be set. The first is ConstrainedLink, that must be set to an instance of LinkInstantaneous or LinkSpeedOfLight. The second is ConstrainedLinkEnd which must be set to an enumeration of LinkRole.

Some AccessConstraints that implement ILinkConstraint, such as CentralBodyObstructionConstraint do not use ConstrainedLinkEnd, as the Constraint applies to the Link as a whole instead of being dependent on a single Platform.

AccessConstraints that are attached to AccessComputations do not need to have their ConstrainedLink, ConstrainedLinkEnd, or ConstrainedObject properties set. Instead set the Transmitter, and Receiver properties and add the desired constraints to the ReceiverConstraints or TransmitterConstraints collections. The appropriate links will be created and assigned behind the scenes.

See Also
Inheritance Hierarchy
SystemObject
  AGI.Foundation.InfrastructureDefinitionalObject
    AGI.Foundation.AccessAccessQuery
      AGI.Foundation.AccessAccessConstraint
        AGI.Foundation.AccessAlwaysSatisfiedLinkConstraint
        AGI.Foundation.AccessCircularAccessConstraint
        AGI.Foundation.Access.ConstraintsCartographicZoneConstraint
        AGI.Foundation.Access.ConstraintsCentralBodyEllipticCylindricalAccessConstraint
        AGI.Foundation.Access.ConstraintsCentralBodyLayeredProjectedVolumeAccessConstraint
        AGI.Foundation.Access.ConstraintsCentralBodyObstructionConstraint
        AGI.Foundation.Access.ConstraintsCentralBodySurfaceRegionConstraint
        AGI.Foundation.Access.ConstraintsCentralBodySurfaceRegionSensorVolumeConstraint
        AGI.Foundation.Access.ConstraintsSensorVolumeConstraint
        AGI.Foundation.Access.ConstraintsTerrainLineOfSightConstraint
        AGI.Foundation.AccessMinimumMaximumAccessConstraint