trans2d.cpp

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// $Id: trans2d.cpp 1282 2006-06-09 09:46:49Z alex $
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// 2D Matrix transformation classes

#include "camtypes.h"
//#include "docrect.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "matrix.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "trans2d.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "errors.h" - in camtypes.h [AUTOMATICALLY REMOVED]

CC_IMPLEMENT_DYNAMIC(Trans2DMatrix, TransInvertable)

// Declare smart memory handling in Debug builds
#define new CAM_DEBUG_NEW



/********************************************************************************************
>   void Trans2DMatrix::InitDecomposedTransforms()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6//95
    Purpose:    ensure all member vars are init'ed
********************************************************************************************/

void Trans2DMatrix::InitDecomposedTransforms()
{
    Scale       = 0;    // 0 indicates cached values invalid
    Aspect      = 1;
    Rotation    = 0;
    Skew        = 0;
    Translation = DocCoord(0,0);
}
    

/********************************************************************************************
>   Trans2DMatrix::Trans2DMatrix( )

    Author:     Peter_Arnold (Xara Group Ltd) <camelotdev@xara.com>
    Created:    1/2/95
    Purpose:    Builds a 2D Tranform object of the identiry matrix (ie it has no effect)
********************************************************************************************/

Trans2DMatrix::Trans2DMatrix( )
{
    SetTransform();
}

void Trans2DMatrix::SetTransform()
{
    // Build the translation matrix
    TransMatrix = Matrix();

    // Set the flags
    TransLines = FALSE;
    TransFills = TRUE;
    InitDecomposedTransforms();
}
    

/********************************************************************************************

>   Trans2DMatrix::Trans2DMatrix( DocCoord CentreOfRot, ANGLE RotateBy )

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    7/3/94
    Inputs:     CentreOfRot - The centre of rotation
                RotateBy - The angle of the rotation that this transform object will perform
    Purpose:    Creates a 2D Matrix transform object that will perform a rotation about the
                given point by the given number of degrees.

********************************************************************************************/

Trans2DMatrix::Trans2DMatrix(DocCoord CentreOfRot, ANGLE RotateBy)
{
    SetTransform(CentreOfRot,RotateBy);
}

void Trans2DMatrix::SetTransform(DocCoord CentreOfRot, ANGLE RotateBy)
{
    // Build the matricies we need
    Matrix RotateIt(RotateBy);
    Matrix TransFromOrigin( CentreOfRot.x, CentreOfRot.y );
    
    // need to translate the centre of rotation to the origin
    TransMatrix = Matrix( -CentreOfRot.x, -CentreOfRot.y );

    // rotate about the origin
    TransMatrix *= RotateIt;

    // translate back to the centre of rotation
    TransMatrix *= TransFromOrigin;

    // Set the flags
    TransLines = FALSE;
    TransFills = TRUE;
    InitDecomposedTransforms();
}

/********************************************************************************************

>   Trans2DMatrix::Trans2DMatrix( INT32 TransX, INT32 TransY)

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    7/3/94
    Inputs:     TransX - The X translation
                TransY - The Y translation
    Purpose:    Builds a 2D Tranform object that will perform a translation by an offset
                Transx, TransY.

********************************************************************************************/

Trans2DMatrix::Trans2DMatrix(INT32 TransX, INT32 TransY)
{
    SetTransform(TransX,TransY);
}

void Trans2DMatrix::SetTransform(INT32 TransX, INT32 TransY)
{
    // Build the translation matrix
    TransMatrix = Matrix(TransX, TransY);

    // Set the flags
    TransLines = FALSE;
    TransFills = TRUE;
    InitDecomposedTransforms();
}



/********************************************************************************************

>   Trans2DMatrix::Trans2DMatrix( Matrix& NewMatrix )

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    10/02/94
    Inputs:     NewMatrix - The transformation matrix that you wish to apply
    Purpose:    constructor

********************************************************************************************/

Trans2DMatrix::Trans2DMatrix( const Matrix &NewMatrix )
{
    SetTransform(NewMatrix);
}

void Trans2DMatrix::SetTransform(const Matrix& NewMatrix)
{
    // Take a copy of the matrix
    TransMatrix = NewMatrix;

    // Set the flags
    TransLines = FALSE;
    TransFills = TRUE;
    InitDecomposedTransforms();
}



/********************************************************************************************

>   Trans2DMatrix::Trans2DMatrix(const Trans2DMatrix& Other)

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    6/9/94
    Inputs:     Other - The other trans2dmatrix to copy
    Purpose:    Copy constructor

********************************************************************************************/

Trans2DMatrix::Trans2DMatrix(const Trans2DMatrix& Other)
{
    SetTransform(Other);
}

void Trans2DMatrix::SetTransform(const Trans2DMatrix& Other)
{
    // Copy all the elements from the other trans2dmatrix to this new one.
    TransMatrix = Other.TransMatrix;
    TransLines = Other.TransLines;
    TransFills = Other.TransFills;
    InitDecomposedTransforms();
}

/********************************************************************************************

>   void Trans2DMatrix::Transform( DocCoord* Coords, INT32 NumCoords )

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    10/02/94
    Inputs:     Coords - Pointer to an array of coodinates to transform
                NumCoords - the number of coodinates in the array
    Outputs:    Coords - The coordinates in the array will have been transformed
    Purpose:    Transform the coordinates in the array using the matrix in the transform
                object

********************************************************************************************/

void Trans2DMatrix::Transform( DocCoord* Coords, INT32 NumCoords )
{
    // Get the matrix to transform all the coords passed in
    TransMatrix.transform( (Coord*)Coords, NumCoords );
    InitDecomposedTransforms();
}


/********************************************************************************************

>   void Trans2DMatrix::Invert()

    Author:     Rik_Heywood (Xara Group Ltd) <camelotdev@xara.com>
    Created:    10/02/94
    Purpose:    Inverts the transformation matrix held by this transform object. future calls
                to the transform() member function will cause it to transform coordinates
                back to their original positions. ie, call Transform(), call Invert() and 
                call Transform() again should give you the same set of coords as you started
                with

********************************************************************************************/
void Trans2DMatrix::Invert()
{
    // Invert the transformation matrix
    TransMatrix = TransMatrix.Inverse();

    InitDecomposedTransforms();
}


/********************************************************************************************
>   BOOL Trans2DMatrix::IsTranslation()

    Author:     Phil_Martin (Xara Group Ltd) <camelotdev@xara.com>
    Created:    09/12/2004
    Purpose:    Determine whether the transformation is a simple translation
********************************************************************************************/

BOOL Trans2DMatrix::IsTranslation()
{
    return TransMatrix.IsTranslation();
}


/********************************************************************************************

>   INT32 GetWorkingQuadrant()

    Author:     Mark_Howitt (Xara Group Ltd) <camelotdev@xara.com>
    Created:    07/07/00
    Purpose:    To find out which quadrant the current matrix is working in.
                OR To help find out if the matrix is flipping an object and in which way.
                
                1   |   2
                ---------
                4   |   3

                Quadrant 1:     A > 0 && D > 0
                Quadrant 2:     A < 0 && D > 0
                Quadrant 4:     A > 0 && D < 0
                Quadrant 3:     A < 0 && D < 0

                The return value is the quadrant in which the matrix is working in.

********************************************************************************************/
INT32 Trans2DMatrix::GetWorkingQuadrant()
{
    FIXED16 ZERO = 0;
    FIXED16 ABCD[4];
    INT32 XY[2];

    TransMatrix.GetComponents(&ABCD[0],&XY[0]);

    if(ABCD[3] >= ZERO)
    {
        // either 1 or 2
        if(ABCD[0] >= ZERO)
            return 1;
        else
            return 2;
    }
    else
    {
        // either 3 or 4
        if(ABCD[0] >= ZERO)
            return 4;
        else
            return 3;
    }
    
    return 1;
}

/********************************************************************************************
                    
>   Trans2DMatrix& Trans2DMatrix::operator*=(const Trans2DMatrix& op) 

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    07/11/94
    Inputs:     Trans2DMatrix to be multiplied
    Outputs:    None.
    Returns:    result of multiplication.
    Purpose:    Overloads the *= operator for Trans2DMatrix.
    Errors:     None.

********************************************************************************************/
/*
Technical notes:

********************************************************************************************/


Trans2DMatrix& Trans2DMatrix::operator*=(const Trans2DMatrix& op)
{
    TransMatrix*=op.TransMatrix; 
    InitDecomposedTransforms();
    return *this; 
} 



/********************************************************************************************
                    
>   Trans2DMatrix& Trans2DMatrix::operator=(const Trans2DMatrix& rhs) 

    Author:     Peter_Arnold (Xara Group Ltd) <camelotdev@xara.com>
    Created:    2/1/95
    Inputs:     Trans2DMatrix to be copied into this object
    Outputs:    None.
    Returns:    result of assignment
    Purpose:    Overloads the = operator for Trans2DMatrix
    Errors:     None.

********************************************************************************************/

Trans2DMatrix& Trans2DMatrix::operator=(const Trans2DMatrix& rhs)
{
    TransMatrix = rhs.TransMatrix; 

    //Graham 12/8/96: Added these because, well, you need them
    //Fixes bug 4938
    TransLines = rhs.TransLines;
    TransFills = rhs.TransFills;

    InitDecomposedTransforms();
    return *this; 
} 


/********************************************************************************************
>   void Trans2DMatrix::EnsureDecomposedTransformsCached()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    ensures the decomposed transforms are cached
********************************************************************************************/

void Trans2DMatrix::EnsureDecomposedTransformsCached()
{
    if (Scale==0)
    {
        GetpMatrix()->Decompose(&Scale, &Aspect, &Rotation, &Skew, &Translation, &ScaleY);
        Rotation = (Rotation*180)/PI;   
        Skew     = (Skew    *180)/PI;   // convert to degrees!?
    }
}


/********************************************************************************************
>   FIXED16 Trans2DMatrix::GetScale()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's scale component
********************************************************************************************/

FIXED16 Trans2DMatrix::GetScale()
{
    EnsureDecomposedTransformsCached();
    return Scale;
}


/********************************************************************************************
>   FIXED16 Trans2DMatrix::GetAspect()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's Aspect component
********************************************************************************************/

FIXED16 Trans2DMatrix::GetAspect()
{
    EnsureDecomposedTransformsCached();
    return Aspect;
}


/********************************************************************************************
>   ANGLE Trans2DMatrix::GetRotation()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's Rotation component
********************************************************************************************/

ANGLE Trans2DMatrix::GetRotation()
{
    EnsureDecomposedTransformsCached();
    return Rotation;
}


/********************************************************************************************
>   ANGLE Trans2DMatrix::GetSkew()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's Skew component
********************************************************************************************/

ANGLE Trans2DMatrix::GetSkew()
{
    EnsureDecomposedTransformsCached();
    return Skew;
}


/********************************************************************************************
>   DocCoord Trans2DMatrix::GetTranslation()

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's Translation component
********************************************************************************************/

DocCoord Trans2DMatrix::GetTranslation()
{
    EnsureDecomposedTransformsCached();
    return Translation;
}



/********************************************************************************************
>   FIXED16 Trans2DMatrix::GetScalar()

    Author:     Phil_Martin (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/6/95
    Purpose:    get the transform's directionless scale component
                (used for scaling line widths, bevel widths, brush widths, etc.)
                For compatibility reasons this is defined to be the Y scale factor of the
                matrix!
********************************************************************************************/

FIXED16 Trans2DMatrix::GetScalar()
{
    EnsureDecomposedTransformsCached();
    return ScaleY;
}


/********************************************************************************************
>   virtual BOOL Trans2DMatrix::IsInvertable()

    Author:     Peter_Arnold (Xara Group Ltd) <camelotdev@xara.com>
    Created:    2/1/96
    Inputs:     -
    Outputs:    -
    Returns:    TRUE if this transform can be inverted; FALSE if not.
    Purpose:    To see if this transform is really invertable
    SeeAlso:    TransformBase::IsInvertable
********************************************************************************************/
BOOL Trans2DMatrix::IsInvertable()
{
    if (TransMatrix.Type == TRANS_IDENTITY)
        return TRUE;
    
    // The inverse has failed if we get an identity matrix
    Matrix Inversed = TransMatrix.Inverse();

    return (Inversed.Type != TRANS_IDENTITY);
}

---