IConstraint Interface
- SetFreedom
- GetFreedom
- GetConstraint
- Enable
- IsEnabled
Every object in DInsight models have a constraint property, which can
restrict movements of the object in different ways. IConstraint interface
enables and disables constraints for movements of the object it is
implemented by. It also gives access to the geometry of the constraint. See
remarks for SetFreedom and GetConstraint
methods for more details.
IConstraint can be queried from the correspondent ISection interface.
See also Modal View Sample,
Interface List.
HRESULT SetFreedom(int nMovementType, int nDims)
Parameters
nMovementType - [in] identifies the
movement type. Valid values are: 1 for translation and 4 for rotation. See also
remarks.
nDims - [in] New value for degree of freedom.
See remarks.
Returns
DISP_E_PARAMNOTOPTIONAL if nMovementType or nDims is
not one of the valid values.
- S_OK in case of
success.
Remarks:
This method will specify for movement nMovementType (
translation or rotation ) degree of the freedom which will be allowed for
movements of the object.
Translation movements:
Every object keeps its integer Degree of Freedom for
Translations and Translation
Constraint Direction. Vector of Translation Constraint Direction can be
accessed with GetConstraint() method of this interface. Meaning of
Translation Constraint Direction depends on the current degree of freedom
set with SetFreedom method.
Valid options for nDims in this case are:
- 0 - no translations are allowed.
- 1 - translations are allowed only along the current Translation Constraint
Direction.
- 2 - translations are allowed only in directions orthogonal to the Translation
Constraint Direction.
- 3 - all translations are allowed.
-
All other values are invalid for nDim in case of translations.
Rotation movements:
In addition to above properties every object keeps its Degree of Freedom
for Rotations and Rotation Constraint Axis.
Valid options for nDims in this case are:
- 0 - no rotations are allowed.
- 1 - rotations are allowed only around the current Rotation Constraint
Axis.
- 2 - all rotations are allowed.
All other values are invalid for nDim in case of rotations.
HRESULT GetFreedom(int nMovementType, int *pnDims)
Parameters
nMovementType - [in] identifies the
movement type. Valid values are: 1 for translation and 4 for rotation. See also
remarks.
pnDims - [out] pointer to the integer variable, which
will receive the requested degree of freedom.
Return Values
-
- S_OK in case of
success.
-
- Remarks:
-
- Returns current degree of freedom for the requested movement type. See
remarks for SetFreedom method.
HRESULT GetConstraint(int nMovementType, IAxis **ppIAxis)
Parameters
nMovementType - [in] identifies the
movement type. Valid values are: 1 for translation and 4 for rotation. See also
remarks.
IAxis **ppIAxis - [out] pointer to variable, which will
receive pointer to IAxis interface implemented by the constraint of the
requested type. See remarks. In case of translation only directional component is
valid.
Return Values
- S_OK in case of
success.
-
- Remarks:
This method gives access to geometry of the constraint. The result depends on
the movement type and the current degree of freedom set for this type of
movement. See also remarks for SetFreedom
method.
Translation movements:
When the current Degree of Freedom for
Translations is 0 or 3 return from GetConstraint() is not valid. When the
current Degree of Freedom for
Translations is 1 or 2, directional component of the returned IAxis
interface (Get/SetDirection methods) give access to Translation Constraint
Direction. Location component of the IAxis is not valid.
Rotation movements:
When the current Degree of Freedom for
Translations is 0 or 2 return from GetConstraint() is not valid. When the
current Degree of Freedom for
Translations is 1, returned IAxis interface is implemented by and hence
gives access to Rotation Constraint Axis of the object.
See also IAxis interface
HRESULT Enable(bool bEnable)
Parameters
bEnable- [in] New value for the
enabled flag.
Return Values
S_OK in case of success.
- Remarks:
-
- When the constraint is disabled it has no effect on the movements
of the object. All constraints are disabled by default, but enabled during the
operation which retrieves it from ISection
HRESULT IsEnabled(bool *pbEnabled)
Parameters
pbEnabled - [out] pointer to the Boolean variable,
which will receive the current status of the enabled flag.
Return Values
S_OK in case of success.
-
Remarks:
-
- Returns the current status of of the enabled flag. When the
constraint is disabled it has no effect on the movements of the object. All constraints are
disabled by default, but enabled during the operation which retrieves it from
ISection
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