QMedia Matrix commands

QM_RotateMatrix

QM_RotateMatrix(matrixRec; numDegrees; anchorH; anchorV):error
matrixRec Array real Matrix record
numDegrees Real Number of degrees
anchorH Real Horizontal coordinate of the anchor point
anchorV Real Vertical coordinate of the anchor point
error Longint Error result

Adds a rotation transformation to a matrix record.

Parameter matrixRec specifies the matrix. It must be declared as a 3 x 3 array of reals. QMedia updates and returns the contents matrixRec with the specified rotation operation.

Parameter numDegrees specifies the number of degrees of the rotation operation.

Parameters anchorH and anchorV specify the horizontal and vertical coordinates of the anchor point.

Example

  `Rotate track ID $trackID of movie $movie by 30 degrees around its center
 
ARRAY REAL($matrix;3;3)
$err:=QM_SetIdentityMatrix ($matrix)
 
C_REAL($trachWidth;$trackHeight)
$err:=QM_GetTrackDimensions ($movie;$trackID;$trachWidth;$trackHeight)
 
C_REAL($degrees;$hAnchor;$vAnchor)
$degrees:=30 `Rotate 30 degrees
$hAnchor:=$trachWidth/2 `Anchor at center of track
$vAnchor:=$trackHeight/2
$err:=QM_RotateMatrix ($matrix;$degrees;$hAnchor;$vAnchor)
 
$err:=QM_SetTrackMatrix ($movie;$trackID;$matrix)
 

Related commands

QM_SetIdentityMatrix Sets the contents of a matrix record to the identity matrix.
QM_TranslateMatrix Adds a translation transformation to a matrix record.
QM_ScaleMatrix Adds a scaling transformation to a matrix record.
QM_SkewMatrix Adds a skew transformation to a matrix record.
QM_ConcatMatrix Concatenates two matrices.
QM_SetTrackMatrix Changes the track's transormation matrix.
QM_GetTrackMatrix Returns the track's transormation matrix.

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