libQGLViewer Version 2.7.2

Signals | Public Member Functions | List of all members
Frame Class Reference

The Frame class represents a coordinate system, defined by a position and an orientation. More...

## Signals
void | modified ()
void | interpolated ()

## Public Member Functions
| Frame ()
virtual | ~Frame ()
| Frame (const Frame &frame)
Frame & | operator= (const Frame &frame)

## World coordinates position and orientation
| Frame (const Vec &position, const Quaternion &orientation)
void | setPosition (const Vec &position)
void | setPosition (qreal x, qreal y, qreal z)
void | setPositionWithConstraint (Vec &position)
void | setOrientation (const Quaternion &orientation)
void | setOrientation (qreal q0, qreal q1, qreal q2, qreal q3)
void | setOrientationWithConstraint (Quaternion &orientation)
void | setPositionAndOrientation (const Vec &position, const Quaternion &orientation)
void | setPositionAndOrientationWithConstraint (Vec &position, Quaternion &orientation)
Vec | position () const
Quaternion | orientation () const
void | getPosition (qreal &x, qreal &y, qreal &z) const
void | getOrientation (qreal &q0, qreal &q1, qreal &q2, qreal &q3) const

## Local translation and rotation w/r reference Frame
void | setTranslation (const Vec &translation)
void | setTranslation (qreal x, qreal y, qreal z)
void | setTranslationWithConstraint (Vec &translation)
void | setRotation (const Quaternion &rotation)
void | setRotation (qreal q0, qreal q1, qreal q2, qreal q3)
void | setRotationWithConstraint (Quaternion &rotation)
void | setTranslationAndRotation (const Vec &translation, const Quaternion &rotation)
void | setTranslationAndRotationWithConstraint (Vec &translation, Quaternion &rotation)
Vec | translation () const
Quaternion | rotation () const
void | getTranslation (qreal &x, qreal &y, qreal &z) const
void | getRotation (qreal &q0, qreal &q1, qreal &q2, qreal &q3) const

## Frame hierarchy
const Frame * | referenceFrame () const
void | setReferenceFrame (const Frame *const refFrame)
bool | settingAsReferenceFrameWillCreateALoop (const Frame *const frame)

## Frame modification
void | translate (Vec &t)
void | translate (const Vec &t)
void | translate (qreal x, qreal y, qreal z)
void | translate (qreal &x, qreal &y, qreal &z)
void | rotate (Quaternion &q)
void | rotate (const Quaternion &q)
void | rotate (qreal q0, qreal q1, qreal q2, qreal q3)
void | rotate (qreal &q0, qreal &q1, qreal &q2, qreal &q3)
void | rotateAroundPoint (Quaternion &rotation, const Vec &point)
void | rotateAroundPoint (const Quaternion &rotation, const Vec &point)
void | alignWithFrame (const Frame *const frame, bool move=false, qreal threshold=0.0)
void | projectOnLine (const Vec &origin, const Vec &direction)

## Coordinate system transformation of 3D coordinates
Vec | coordinatesOf (const Vec &src) const
Vec | inverseCoordinatesOf (const Vec &src) const
Vec | localCoordinatesOf (const Vec &src) const
Vec | localInverseCoordinatesOf (const Vec &src) const
Vec | coordinatesOfIn (const Vec &src, const Frame *const in) const
Vec | coordinatesOfFrom (const Vec &src, const Frame *const from) const
void | getCoordinatesOf (const qreal src[3], qreal res[3]) const
void | getInverseCoordinatesOf (const qreal src[3], qreal res[3]) const
void | getLocalCoordinatesOf (const qreal src[3], qreal res[3]) const
void | getLocalInverseCoordinatesOf (const qreal src[3], qreal res[3]) const
void | getCoordinatesOfIn (const qreal src[3], qreal res[3], const Frame *const in) const
void | getCoordinatesOfFrom (const qreal src[3], qreal res[3], const Frame *const from) const

## Coordinate system transformation of vectors
Vec | transformOf (const Vec &src) const
Vec | inverseTransformOf (const Vec &src) const
Vec | localTransformOf (const Vec &src) const
Vec | localInverseTransformOf (const Vec &src) const
Vec | transformOfIn (const Vec &src, const Frame *const in) const
Vec | transformOfFrom (const Vec &src, const Frame *const from) const
void | getTransformOf (const qreal src[3], qreal res[3]) const
void | getInverseTransformOf (const qreal src[3], qreal res[3]) const
void | getLocalTransformOf (const qreal src[3], qreal res[3]) const
void | getLocalInverseTransformOf (const qreal src[3], qreal res[3]) const
void | getTransformOfIn (const qreal src[3], qreal res[3], const Frame *const in) const
void | getTransformOfFrom (const qreal src[3], qreal res[3], const Frame *const from) const

## Constraint on the displacement
Constraint * | constraint () const
void | setConstraint (Constraint *const constraint)

## Associated matrices
const GLdouble * | matrix () const
void | getMatrix (GLdouble m[4][4]) const
void | getMatrix (GLdouble m[16]) const
const GLdouble * | worldMatrix () const
void | getWorldMatrix (GLdouble m[4][4]) const
void | getWorldMatrix (GLdouble m[16]) const
void | setFromMatrix (const GLdouble m[4][4])
void | setFromMatrix (const GLdouble m[16])

## Inversion of the transformation
Frame | inverse () const
Frame | worldInverse () const

## XML representation
virtual QDomElement | domElement (const QString &name, QDomDocument &document) const
virtual void | initFromDOMElement (const QDomElement &element)

## Detailed Description

The Frame class represents a coordinate system, defined by a position and an orientation.

A Frame is a 3D coordinate system, represented by a position() and an orientation(). The order of these transformations is important: the Frame is first translated and then rotated around the new translated origin.

A Frame is useful to define the position and orientation of a 3D rigid object, using its matrix() method, as shown below:

// Builds a Frame at position (0.5,0,0) and oriented such that its Y axis is
along the (1,1,1)
// direction. One could also have used setPosition() and setOrientation().
Frame fr(Vec(0.5,0,0), Quaternion(Vec(0,1,0), Vec(1,1,1)));
glPushMatrix();
glMultMatrixd(fr.matrix());
// Draw your object here, in the local fr coordinate system.
glPopMatrix();

Many functions are provided to transform a 3D point from one coordinate system (Frame) to an other: see coordinatesOf(), inverseCoordinatesOf(), coordinatesOfIn(), coordinatesOfFrom()...

You may also want to transform a 3D vector (such as a normal), which corresponds to applying only the rotational part of the frame transformation: see transformOf() and inverseTransformOf(). See the frameTransform example for an illustration.

The translation() and the rotation() that are encapsulated in a Frame can also be used to represent a rigid transformation of space. Such a transformation can also be interpreted as a change of coordinate system, and the coordinate system conversion functions actually allow you to use a Frame as a rigid transformation. Use inverseCoordinatesOf() (resp. coordinatesOf()) to apply the transformation (resp. its inverse). Note the inversion.

### Hierarchy of Frames

The position and the orientation of a Frame are actually defined with respect to a referenceFrame(). The default referenceFrame() is the world coordinate system (represented by a `nullptr` referenceFrame()). If you setReferenceFrame() to a different Frame, you must then differentiate:

- the local translation() and rotation(), defined with respect to the referenceFrame(),

- the global position() and orientation(), always defined with respect to the world coordinate system.

A Frame is actually defined by its translation() with respect to its referenceFrame(), and then by a rotation() of the coordinate system around the new translated origin.

This terminology for local (translation() and rotation()) and global (position() and orientation()) definitions is used in all the methods' names and should be sufficient to prevent ambiguities. These notions are obviously identical when the referenceFrame() is `nullptr`, i.e. when the Frame is defined in the world coordinate system (the one you are in at the beginning of the QGLViewer::draw() method, see the introduction page).

Frames can hence easily be organized in a tree hierarchy, which root is the world coordinate system. A loop in the hierarchy would result in an inconsistent (multiple) Frame definition. settingAsReferenceFrameWillCreateALoop() checks this and prevents setReferenceFrame() from creating such a loop.

This frame hierarchy is used in methods like coordinatesOfIn(), coordinatesOfFrom()... which allow coordinates (or vector) conversions from a Frame to any other one (including the world coordinate system).

However, one must note that this hierarchical representation is internal to the Frame classes. When the Frames represent OpenGL coordinates system, one should map this hierarchical representation to the OpenGL GL_MODELVIEW matrix stack. See the matrix() documentation for details.

### Constraints

An interesting feature of Frames is that their displacements can be constrained. When a Constraint is attached to a Frame, it filters the input of translate() and rotate(), and only the resulting filtered motion is applied to the Frame. The default constraint() is `nullptr` resulting in no filtering. Use setConstraint() to attach a Constraint to a frame.

Constraints are especially usefull for the ManipulatedFrame instances, in order to forbid some mouse motions. See the constrainedFrame, constrainedCamera and luxo examples for an illustration.

Classical constraints are provided for convenience (see LocalConstraint, WorldConstraint and CameraConstraint) and new constraints can very easily be implemented.

### Derived classes

The ManipulatedFrame class inherits Frame and implements a mouse motion convertion, so that a Frame (and hence an object) can be manipulated in the scene with the mouse.

## Constructor & Destructor Documentation

## ◆ Frame() [1/3]

Frame | ( |  | ) |

Creates a default Frame.

Its position() is (0,0,0) and it has an identity orientation() Quaternion. The referenceFrame() and the constraint() are `nullptr`.

## ◆ ~Frame()

virtual ~Frame | ( |  | ) |
| virtual

Virtual destructor. Empty.

## ◆ Frame() [2/3]

Frame | ( | const Frame & | frame | ) |

Copy constructor.

The translation() and rotation() as well as constraint() and referenceFrame() pointers are copied.

## ◆ Frame() [3/3]

Frame | ( | const Vec & | position,
|  | const Quaternion & | orientation
| ) |  |

Creates a Frame with a position() and an orientation().

See the Vec and Quaternion documentations for convenient constructors and methods.

The Frame is defined in the world coordinate system (its referenceFrame() is `nullptr`). It has a `nullptr` associated constraint().

## Member Function Documentation

## ◆ alignWithFrame()

void alignWithFrame | ( | const Frame *const | frame,
|  | bool | move = `false`,
|  | qreal | threshold = `0.0`
| ) |  |

Aligns the Frame with `frame`, so that two of their axis are parallel.

If one of the X, Y and Z axis of the Frame is almost parallel to any of the X, Y, or Z axis of `frame`, the Frame is rotated so that these two axis actually become parallel.

If, after this first rotation, two other axis are also almost parallel, a second alignment is performed. The two frames then have identical orientations, up to 90 degrees rotations.

`threshold` measures how close two axis must be to be considered parallel. It is compared with the absolute values of the dot product of the normalized axis. As a result, useful range is sqrt(2)/2 (systematic alignment) to 1 (no alignment).

When `move` is set to `true`, the Frame position() is also affected by the alignment. The new Frame's position() is such that the `frame` position (computed with coordinatesOf(), in the Frame coordinates system) does not change.

`frame` may be `nullptr` and then represents the world coordinate system (same convention than for the referenceFrame()).

The rotation (and translation when `move` is `true`) applied to the Frame are filtered by the possible constraint().

## ◆ constraint()

Constraint* constraint | ( |  | ) | const

Returns the current constraint applied to the Frame.

A `nullptr` value (default) means that no Constraint is used to filter Frame translation and rotation. See the Constraint class documentation for details.

You may have to use a `dynamic_cast` to convert the result to a Constraint derived class.

## ◆ coordinatesOf()

Vec coordinatesOf | ( | const Vec & | src | ) | const

Returns the Frame coordinates of a point `src` defined in the world coordinate system (converts from world to Frame).

inverseCoordinatesOf() performs the inverse convertion. transformOf() converts 3D vectors instead of 3D coordinates.

See the frameTransform example for an illustration.

## ◆ coordinatesOfFrom()

Vec coordinatesOfFrom | ( | const Vec & | src,
|  | const Frame *const | from
| ) |  | const

Returns the Frame coordinates of the point whose position in the `from` coordinate system is `src` (converts from `from` to Frame).

coordinatesOfIn() performs the inverse transformation.

## ◆ coordinatesOfIn()

Vec coordinatesOfIn | ( | const Vec & | src,
|  | const Frame *const | in
| ) |  | const

Returns the `in` coordinates of the point whose position in the Frame coordinate system is `src` (converts from Frame to `in`).

coordinatesOfFrom() performs the inverse transformation.

## ◆ domElement()

QDomElement domElement | ( | const QString & | name,
|  | QDomDocument & | document
| ) |  | const
| virtual

Returns an XML `QDomElement` that represents the Frame.

`name` is the name of the QDomElement tag. `doc` is the `QDomDocument` factory used to create QDomElement.

The resulting QDomElement looks like:

<name>
<position x=".." y=".." z=".." />
<orientation q0=".." q1=".." q2=".." q3=".." />
</name>

Use initFromDOMElement() to restore the Frame state from the resulting `QDomElement`.

See Vec::domElement() for a complete example. See also Quaternion::domElement(), Camera::domElement()...

Attention
  The constraint() and referenceFrame() are not saved in the QDomElement.

Reimplemented in ManipulatedFrame, and ManipulatedCameraFrame.

## ◆ getCoordinatesOf()

void getCoordinatesOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as coordinatesOf(), but with `qreal` parameters.

## ◆ getCoordinatesOfFrom()

void getCoordinatesOfFrom | ( | const qreal | src[3],
|  | qreal | res[3],
|  | const Frame *const | from
| ) |  | const

Same as coordinatesOfFrom(), but with `qreal` parameters.

## ◆ getCoordinatesOfIn()

void getCoordinatesOfIn | ( | const qreal | src[3],
|  | qreal | res[3],
|  | const Frame *const | in
| ) |  | const

Same as coordinatesOfIn(), but with `qreal` parameters.

## ◆ getInverseCoordinatesOf()

void getInverseCoordinatesOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as inverseCoordinatesOf(), but with `qreal` parameters.

## ◆ getInverseTransformOf()

void getInverseTransformOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as inverseTransformOf(), but with `qreal` parameters.

## ◆ getLocalCoordinatesOf()

void getLocalCoordinatesOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as localCoordinatesOf(), but with `qreal` parameters.

## ◆ getLocalInverseCoordinatesOf()

void getLocalInverseCoordinatesOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as localInverseCoordinatesOf(), but with `qreal` parameters.

## ◆ getLocalInverseTransformOf()

void getLocalInverseTransformOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as localInverseTransformOf(), but with `qreal` parameters.

## ◆ getLocalTransformOf()

void getLocalTransformOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as localTransformOf(), but with `qreal` parameters.

## ◆ getMatrix() [1/2]

void getMatrix | ( | GLdouble | m[16] | ) | const

`GLdouble`[16] version of matrix(). See also getWorldMatrix() and matrix().

## ◆ getMatrix() [2/2]

void getMatrix | ( | GLdouble | m[4][4] | ) | const

`GLdouble`[4][4] version of matrix(). See also getWorldMatrix() and matrix().

## ◆ getOrientation()

void getOrientation | ( | qreal & | q0,
|  | qreal & | q1,
|  | qreal & | q2,
|  | qreal & | q3
| ) |  | const

Get the current orientation of the frame (same as orientation()). Parameters are the orientation Quaternion values. See also setOrientation().

The `q` are set to the orientation() of the Frame.

See Quaternion::Quaternion(qreal, qreal, qreal, qreal) for details on `q`.

## ◆ getPosition()

void getPosition | ( | qreal & | x,
|  | qreal & | y,
|  | qreal & | z
| ) |  | const

`x`, `y` and `z` are set to the position() of the Frame.

## ◆ getRotation()

void getRotation | ( | qreal & | q0,
|  | qreal & | q1,
|  | qreal & | q2,
|  | qreal & | q3
| ) |  | const

The `q` are set to the rotation() of the Frame.

See Quaternion::Quaternion(qreal, qreal, qreal, qreal) for details on `q`.

## ◆ getTransformOf()

void getTransformOf | ( | const qreal | src[3],
|  | qreal | res[3]
| ) |  | const

Same as transformOf(), but with `qreal` parameters.

## ◆ getTransformOfFrom()

void getTransformOfFrom | ( | const qreal | src[3],
|  | qreal | res[3],
|  | const Frame *const | from
| ) |  | const

Same as transformOfFrom(), but with `qreal` parameters.

## ◆ getTransformOfIn()

void getTransformOfIn | ( | const qreal | src[3],
|  | qreal | res[3],
|  | const Frame *const | in
| ) |  | const

Same as transformOfIn(), but with `qreal` parameters.

## ◆ getTranslation()

void getTranslation | ( | qreal & | x,
|  | qreal & | y,
|  | qreal & | z
| ) |  | const

Fill `x`, `y` and `z` with the translation() of the Frame.

## ◆ getWorldMatrix() [1/2]

void getWorldMatrix | ( | GLdouble | m[16] | ) | const

qreal[16] parameter version of worldMatrix(). See also getMatrix() and matrix().

## ◆ getWorldMatrix() [2/2]

void getWorldMatrix | ( | GLdouble | m[4][4] | ) | const

qreal[4][4] parameter version of worldMatrix(). See also getMatrix() and matrix().

## ◆ initFromDOMElement

void initFromDOMElement | ( | const QDomElement & | element | ) |
| virtual slot

Restores the Frame state from a `QDomElement` created by domElement().

See domElement() for the `QDomElement` syntax. See the Vec::initFromDOMElement() and Quaternion::initFromDOMElement() documentations for details on default values if an argument is missing.

Attention
  The constraint() and referenceFrame() are not restored by this method and are left unchanged.

## ◆ interpolated

void interpolated | ( |  | ) |
| signal

This signal is emitted when the Frame is interpolated by a KeyFrameInterpolator.

See the KeyFrameInterpolator documentation for details.

If a KeyFrameInterpolator is used to successively interpolate several Frames in your scene, connect the KeyFrameInterpolator::interpolated() signal instead (identical, but independent of the interpolated Frame).

## ◆ inverse()

Frame inverse | ( |  | ) | const

Returns a Frame representing the inverse of the Frame space transformation.

The rotation() of the new Frame is the Quaternion::inverse() of the original rotation. Its translation() is the negated inverse rotated image of the original translation.

If a Frame is considered as a space rigid transformation (translation and rotation), the inverse() Frame performs the inverse transformation.

Only the local Frame transformation (i.e. defined with respect to the referenceFrame()) is inverted. Use worldInverse() for a global inverse.

The resulting Frame has the same referenceFrame() as the Frame and a `nullptr` constraint().

Note
  The scaling factor of the 4x4 matrix is 1.0.

## ◆ inverseCoordinatesOf()

Vec inverseCoordinatesOf | ( | const Vec & | src | ) | const

Returns the world coordinates of the point whose position in the Frame coordinate system is `src` (converts from Frame to world).

coordinatesOf() performs the inverse convertion. Use inverseTransformOf() to transform 3D vectors instead of 3D coordinates.

## ◆ inverseTransformOf()

Vec inverseTransformOf | ( | const Vec & | src | ) | const

Returns the world transform of the vector whose coordinates in the Frame coordinate system is `src` (converts vectors from Frame to world).

transformOf() performs the inverse transformation. Use inverseCoordinatesOf() to transform 3D coordinates instead of 3D vectors.

## ◆ localCoordinatesOf()

Vec localCoordinatesOf | ( | const Vec & | src | ) | const

Returns the Frame coordinates of a point `src` defined in the referenceFrame() coordinate system (converts from referenceFrame() to Frame).

localInverseCoordinatesOf() performs the inverse convertion. See also localTransformOf().

## ◆ localInverseCoordinatesOf()

Vec localInverseCoordinatesOf | ( | const Vec & | src | ) | const

Returns the referenceFrame() coordinates of a point `src` defined in the Frame coordinate system (converts from Frame to referenceFrame()).

localCoordinatesOf() performs the inverse convertion. See also localInverseTransformOf().

## ◆ localInverseTransformOf()

Vec localInverseTransformOf | ( | const Vec & | src | ) | const

Returns the referenceFrame() transform of a vector `src` defined in the Frame coordinate system (converts vectors from Frame to referenceFrame()).

localTransformOf() performs the inverse transformation. See also localInverseCoordinatesOf().

## ◆ localTransformOf()

Vec localTransformOf | ( | const Vec & | src | ) | const

Returns the Frame transform of a vector `src` defined in the referenceFrame() coordinate system (converts vectors from referenceFrame() to Frame).

localInverseTransformOf() performs the inverse transformation. See also localCoordinatesOf().

## ◆ matrix()

const GLdouble * matrix | ( |  | ) | const

Returns the 4x4 OpenGL transformation matrix represented by the Frame.

This method should be used in conjunction with `glMultMatrixd()` to modify the OpenGL modelview matrix from a Frame hierarchy. With this Frame hierarchy:

Frame* body = new Frame();
Frame* leftArm = new Frame();
Frame* rightArm = new Frame();
leftArm->setReferenceFrame(body);
rightArm->setReferenceFrame(body);

The associated OpenGL drawing code should look like:

void Viewer::draw()
{
glPushMatrix();
glMultMatrixd(body->matrix());
drawBody();
glPushMatrix();
glMultMatrixd(leftArm->matrix());
drawArm();
glPopMatrix();
glPushMatrix();
glMultMatrixd(rightArm->matrix());
drawArm();
glPopMatrix();
glPopMatrix();
}

Note the use of nested `glPushMatrix()` and `glPopMatrix()` blocks to represent the frame hierarchy: `leftArm` and `rightArm` are both correctly drawn with respect to the `body` coordinate system.

This matrix only represents the local Frame transformation (i.e. with respect to the referenceFrame()). Use worldMatrix() to get the full Frame transformation matrix (i.e. from the world to the Frame coordinate system). These two match when the referenceFrame() is `nullptr`.

The result is only valid until the next call to matrix(), getMatrix(), worldMatrix() or getWorldMatrix(). Use it immediately (as above) or use getMatrix() instead.

Attention
  The OpenGL format of the result is the transpose of the actual mathematical European representation (translation is on the last line instead of the last column).

Note
  The scaling factor of the 4x4 matrix is 1.0.

## ◆ modified

void modified | ( |  | ) |
| signal

This signal is emitted whenever the position() or the orientation() of the Frame is modified.

Connect this signal to any object that must be notified:

QObject::connect(myFrame, SIGNAL(modified()), myObject, SLOT(update()));

Use the QGLViewer::QGLViewerPool() to connect the signal to all the viewers.

Note
  If your Frame is part of a Frame hierarchy (see referenceFrame()), a modification of one of the parents of this Frame will not emit this signal. Use code like this to change this behavior (you can do this recursively for all the referenceFrame() until the `nullptr` world root frame is encountered):
  // Emits the Frame modified() signal when its referenceFrame() is modified().
  connect(myFrame->referenceFrame(), SIGNAL(modified()), myFrame,
  SIGNAL(modified()));

Attention
  Connecting this signal to a QOpenGLWidget::update() slot (or a method that calls it) will prevent you from modifying the Frame inside your QGLViewer::draw() method as it would result in an infinite loop. However, QGLViewer::draw() should not modify the scene.

Note
  Note that this signal might be emitted even if the Frame is not actually modified, for instance after a translate(Vec(0,0,0)) or a setPosition(position()).

## ◆ operator=()

Frame & operator= | ( | const Frame & | frame | ) |

Equal operator.

The referenceFrame() and constraint() pointers are copied.

Attention
  Signal and slot connections are not copied.

## ◆ orientation()

Quaternion orientation | ( |  | ) | const

Returns the orientation of the Frame, defined in the world coordinate system. See also position(), setOrientation() and rotation().

## ◆ position()

Vec position | ( |  | ) | const

Returns the position of the Frame, defined in the world coordinate system. See also orientation(), setPosition() and translation().

## ◆ projectOnLine()

void projectOnLine | ( | const Vec & | origin,
|  | const Vec & | direction
| ) |  |

Translates the Frame so that its position() lies on the line defined by `origin` and `direction` (defined in the world coordinate system).

Simply uses an orthogonal projection. `direction` does not need to be normalized.

## ◆ referenceFrame()

const Frame* referenceFrame | ( |  | ) | const

Returns the reference Frame, in which coordinates system the Frame is defined.

The translation() and rotation() of the Frame are defined with respect to the referenceFrame() coordinate system. A `nullptr` referenceFrame() (default value) means that the Frame is defined in the world coordinate system.

Use position() and orientation() to recursively convert values along the referenceFrame() chain and to get values expressed in the world coordinate system. The values match when the referenceFrame() is `nullptr`.

Use setReferenceFrame() to set this value and create a Frame hierarchy. Convenient functions allow you to convert 3D coordinates from one Frame to an other: see coordinatesOf(), localCoordinatesOf(), coordinatesOfIn() and their inverse functions.

Vectors can also be converted using transformOf(), transformOfIn, localTransformOf() and their inverse functions.

## ◆ rotate() [1/4]

void rotate | ( | const Quaternion & | q | ) |

Rotates the Frame by `q` (defined in the Frame coordinate system): R = R*q.

The rotation actually applied to the Frame may differ from `q` since it can be filtered by the constraint(). Use rotate(Quaternion&) or setRotationWithConstraint() to retrieve the filtered rotation value. Use setRotation() to directly rotate the Frame without taking the constraint() into account.

See also translate(const Vec&). Emits the modified() signal.

## ◆ rotate() [2/4]

void rotate | ( | qreal & | q0,
|  | qreal & | q1,
|  | qreal & | q2,
|  | qreal & | q3
| ) |  |

Same as rotate(Quaternion&) but with `qreal` Quaternion parameters.

## ◆ rotate() [3/4]

void rotate | ( | qreal | q0,
|  | qreal | q1,
|  | qreal | q2,
|  | qreal | q3
| ) |  |

Same as rotate(const Quaternion&) but with `qreal` Quaternion parameters.

## ◆ rotate() [4/4]

void rotate | ( | Quaternion & | q | ) |

Same as rotate(const Quaternion&) but `q` may be modified to satisfy the rotation constraint(). Its new value corresponds to the rotation that has actually been applied to the Frame.

## ◆ rotateAroundPoint() [1/2]

void rotateAroundPoint | ( | const Quaternion & | rotation,
|  | const Vec & | point
| ) |  |

Same as rotateAroundPoint(), but with a `const` `rotation` Quaternion. Note that the actual rotation may differ since it can be filtered by the constraint().

## ◆ rotateAroundPoint() [2/2]

void rotateAroundPoint | ( | Quaternion & | rotation,
|  | const Vec & | point
| ) |  |

Makes the Frame rotate() by `rotation` around `point`.

`point` is defined in the world coordinate system, while the `rotation` axis is defined in the Frame coordinate system.

If the Frame has a constraint(), `rotation` is first constrained using Constraint::constrainRotation(). The translation which results from the filtered rotation around `point` is then computed and filtered using Constraint::constrainTranslation(). The new `rotation` value corresponds to the rotation that has actually been applied to the Frame.

Emits the modified() signal.

## ◆ rotation()

Quaternion rotation | ( |  | ) | const

Returns the Frame rotation, defined with respect to the referenceFrame().

Use orientation() to get the result in the world coordinates. These two values are identical when the referenceFrame() is `nullptr` (default).

See also setRotation() and setRotationWithConstraint().

Returns the current Quaternion orientation. See setRotation().

## ◆ setConstraint()

void setConstraint | ( | Constraint *const | constraint | ) |

Sets the constraint() attached to the Frame.

A `nullptr` value means no constraint. The previous constraint() should be deleted by the calling method if needed.

## ◆ setFromMatrix() [1/2]

void setFromMatrix | ( | const GLdouble | m[16] | ) |

Sets the Frame from an OpenGL matrix representation (rotation in the upper left 3x3 matrix and translation on the last line).

Hence, if a code fragment looks like:

GLdouble m[16]={...};
glMultMatrixd(m);

It is equivalent to write:

Frame fr;
fr.setFromMatrix(m);
glMultMatrixd(fr.matrix());

Using this conversion, you can benefit from the powerful Frame transformation methods to translate points and vectors to and from the Frame coordinate system to any other Frame coordinate system (including the world coordinate system). See coordinatesOf() and transformOf().

Emits the modified() signal. See also matrix(), getMatrix() and Quaternion::setFromRotationMatrix().

Attention
  A Frame does not contain a scale factor. The possible scaling in `m` will not be converted into the Frame by this method.

## ◆ setFromMatrix() [2/2]

void setFromMatrix | ( | const GLdouble | m[4][4] | ) |

This is an overloaded method provided for convenience. Same as setFromMatrix().

## ◆ setOrientation() [1/2]

void setOrientation | ( | const Quaternion & | orientation | ) |

Sets the orientation() of the Frame, defined in the world coordinate system. Emits the modified() signal.

Use setRotation() to define the local frame rotation (with respect to the referenceFrame()). The potential constraint() of the Frame is not taken into account, use setOrientationWithConstraint() instead.

## ◆ setOrientation() [2/2]

void setOrientation | ( | qreal | q0,
|  | qreal | q1,
|  | qreal | q2,
|  | qreal | q3
| ) |  |

Same as setOrientation(), but with `qreal` parameters.

## ◆ setOrientationWithConstraint()

void setOrientationWithConstraint | ( | Quaternion & | orientation | ) |

Same as setOrientation(), but `orientation` is modified so that the potential constraint() of the Frame is satisfied. See also setPositionWithConstraint() and setRotationWithConstraint().

## ◆ setPosition() [1/2]

void setPosition | ( | const Vec & | position | ) |

Sets the position() of the Frame, defined in the world coordinate system. Emits the modified() signal.

Use setTranslation() to define the local frame translation (with respect to the referenceFrame()). The potential constraint() of the Frame is not taken into account, use setPositionWithConstraint() instead.

## ◆ setPosition() [2/2]

void setPosition | ( | qreal | x,
|  | qreal | y,
|  | qreal | z
| ) |  |

Same as setPosition(), but with `qreal` parameters.

## ◆ setPositionAndOrientation()

void setPositionAndOrientation | ( | const Vec & | position,
|  | const Quaternion & | orientation
| ) |  |

Same as successive calls to setPosition() and then setOrientation().

Only one modified() signal is emitted, which is convenient if this signal is connected to a QGLViewer::update() slot. See also setTranslationAndRotation() and setPositionAndOrientationWithConstraint().

## ◆ setPositionAndOrientationWithConstraint()

void setPositionAndOrientationWithConstraint | ( | Vec & | position,
|  | Quaternion & | orientation
| ) |  |

Same as setPositionAndOrientation() but `position` and `orientation` are modified to satisfy the constraint. Emits the modified() signal.

## ◆ setPositionWithConstraint()

void setPositionWithConstraint | ( | Vec & | position | ) |

Same as setPosition(), but `position` is modified so that the potential constraint() of the Frame is satisfied. See also setOrientationWithConstraint() and setTranslationWithConstraint().

## ◆ setReferenceFrame()

void setReferenceFrame | ( | const Frame *const | refFrame | ) |

Sets the referenceFrame() of the Frame.

The Frame translation() and rotation() are then defined in the referenceFrame() coordinate system. Use position() and orientation() to express these in the world coordinate system.

Emits the modified() signal if `refFrame` differs from the current referenceFrame().

Using this method, you can create a hierarchy of Frames. This hierarchy needs to be a tree, which root is the world coordinate system (i.e. a `nullptr` referenceFrame()). A warning is printed and no action is performed if setting `refFrame` as the referenceFrame() would create a loop in the Frame hierarchy (see settingAsReferenceFrameWillCreateALoop()).

## ◆ setRotation() [1/2]

void setRotation | ( | const Quaternion & | rotation | ) |

Set the current rotation Quaternion. See rotation() and the different Quaternion constructors. Emits the modified() signal. See also setTranslation() and setRotationWithConstraint().

Sets the rotation() of the Frame, locally defined with respect to the referenceFrame(). Emits the modified() signal.

Use setOrientation() to define the world coordinates orientation(). The potential constraint() of the Frame is not taken into account, use setRotationWithConstraint() instead.

## ◆ setRotation() [2/2]

void setRotation | ( | qreal | q0,
|  | qreal | q1,
|  | qreal | q2,
|  | qreal | q3
| ) |  |

Same as setRotation() but with `qreal` Quaternion parameters.

## ◆ setRotationWithConstraint()

void setRotationWithConstraint | ( | Quaternion & | rotation | ) |

Same as setRotation(), but `rotation` is modified so that the potential constraint() of the Frame is satisfied.

Emits the modified() signal. See also setTranslationWithConstraint() and setOrientationWithConstraint().

## ◆ settingAsReferenceFrameWillCreateALoop()

bool settingAsReferenceFrameWillCreateALoop | ( | const Frame *const | frame | ) |

Returns `true` if setting `frame` as the Frame's referenceFrame() would create a loop in the Frame hierarchy.

## ◆ setTranslation() [1/2]

void setTranslation | ( | const Vec & | translation | ) |

Sets the translation() of the frame, locally defined with respect to the referenceFrame(). Emits the modified() signal.

Use setPosition() to define the world coordinates position(). Use setTranslationWithConstraint() to take into account the potential constraint() of the Frame.

## ◆ setTranslation() [2/2]

void setTranslation | ( | qreal | x,
|  | qreal | y,
|  | qreal | z
| ) |  |

Same as setTranslation(), but with `qreal` parameters.

## ◆ setTranslationAndRotation()

void setTranslationAndRotation | ( | const Vec & | translation,
|  | const Quaternion & | rotation
| ) |  |

Same as successive calls to setTranslation() and then setRotation().

Only one modified() signal is emitted, which is convenient if this signal is connected to a QGLViewer::update() slot. See also setPositionAndOrientation() and setTranslationAndRotationWithConstraint().

## ◆ setTranslationAndRotationWithConstraint()

void setTranslationAndRotationWithConstraint | ( | Vec & | translation,
|  | Quaternion & | rotation
| ) |  |

Same as setTranslationAndRotation(), but `translation` and `orientation` are modified to satisfy the constraint(). Emits the modified() signal.

## ◆ setTranslationWithConstraint()

void setTranslationWithConstraint | ( | Vec & | translation | ) |

Same as setTranslation(), but `translation` is modified so that the potential constraint() of the Frame is satisfied.

Emits the modified() signal. See also setRotationWithConstraint() and setPositionWithConstraint().

## ◆ transformOf()

Vec transformOf | ( | const Vec & | src | ) | const

Returns the Frame transform of a vector `src` defined in the world coordinate system (converts vectors from world to Frame).

inverseTransformOf() performs the inverse transformation. coordinatesOf() converts 3D coordinates instead of 3D vectors (here only the rotational part of the transformation is taken into account).

See the frameTransform example for an illustration.

## ◆ transformOfFrom()

Vec transformOfFrom | ( | const Vec & | src,
|  | const Frame *const | from
| ) |  | const

Returns the Frame transform of the vector whose coordinates in the `from` coordinate system is `src` (converts vectors from `from` to Frame).

transformOfIn() performs the inverse transformation.

## ◆ transformOfIn()

Vec transformOfIn | ( | const Vec & | src,
|  | const Frame *const | in
| ) |  | const

Returns the `in` transform of the vector whose coordinates in the Frame coordinate system is `src` (converts vectors from Frame to `in`).

transformOfFrom() performs the inverse transformation.

## ◆ translate() [1/4]

void translate | ( | const Vec & | t | ) |

Translates the Frame of `t` (defined in the Frame coordinate system).

The translation actually applied to the Frame may differ from `t` since it can be filtered by the constraint(). Use translate(Vec&) or setTranslationWithConstraint() to retrieve the filtered translation value. Use setTranslation() to directly translate the Frame without taking the constraint() into account.

See also rotate(const Quaternion&). Emits the modified() signal.

## ◆ translate() [2/4]

void translate | ( | qreal & | x,
|  | qreal & | y,
|  | qreal & | z
| ) |  |

Same as translate(Vec&) but with `qreal` parameters.

## ◆ translate() [3/4]

void translate | ( | qreal | x,
|  | qreal | y,
|  | qreal | z
| ) |  |

Same as translate(const Vec&) but with `qreal` parameters.

## ◆ translate() [4/4]

void translate | ( | Vec & | t | ) |

Same as translate(const Vec&) but `t` may be modified to satisfy the translation constraint(). Its new value corresponds to the translation that has actually been applied to the Frame.

## ◆ translation()

Vec translation | ( |  | ) | const

Returns the Frame translation, defined with respect to the referenceFrame().

Use position() to get the result in the world coordinates. These two values are identical when the referenceFrame() is `nullptr` (default).

See also setTranslation() and setTranslationWithConstraint().

## ◆ worldInverse()

Frame worldInverse | ( |  | ) | const

Returns the inverse() of the Frame world transformation.

The orientation() of the new Frame is the Quaternion::inverse() of the original orientation. Its position() is the negated and inverse rotated image of the original position.

The result Frame has a `nullptr` referenceFrame() and a `nullptr` constraint().

Use inverse() for a local (i.e. with respect to referenceFrame()) transformation inverse.

## ◆ worldMatrix()

const GLdouble * worldMatrix | ( |  | ) | const

Returns the 4x4 OpenGL transformation matrix represented by the Frame.

This method should be used in conjunction with `glMultMatrixd()` to modify the OpenGL modelview matrix from a Frame:

// The modelview here corresponds to the world coordinate system.
Frame fr(pos, Quaternion(from, to));
glPushMatrix();
glMultMatrixd(fr.worldMatrix());
// draw object in the fr coordinate system.
glPopMatrix();

This matrix represents the global Frame transformation: the entire referenceFrame() hierarchy is taken into account to define the Frame transformation from the world coordinate system. Use matrix() to get the local Frame transformation matrix (i.e. defined with respect to the referenceFrame()). These two match when the referenceFrame() is `nullptr`.

The OpenGL format of the result is the transpose of the actual mathematical European representation (translation is on the last line instead of the last column).

Attention
  The result is only valid until the next call to matrix(), getMatrix(), worldMatrix() or getWorldMatrix(). Use it immediately (as above) or use getWorldMatrix() instead.

Note
  The scaling factor of the 4x4 matrix is 1.0.

qglviewer::Frame::Frame
Frame()
Definition: frame.cpp:33
qglviewer::Frame::modified
void modified()
qglviewer::Frame::orientation
Quaternion orientation() const
Definition: frame.cpp:527
qglviewer::Frame::position
Vec position() const
Definition: frame.cpp:518
qglviewer::Frame::matrix
const GLdouble * matrix() const
Definition: frame.cpp:118