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#define INCL_GPITRANSFORMS
 
BOOL GpiScale(hps, pmatlf, flType, afxScale, pptl)
HPS hps;             /* presentation-space handle               */
PMATRIXLF pmatlf;    /* pointer to structure for matrix         */
LONG flType;         /* transformation type                     */
PFIXED afxScale;     /* pointer to variable with scaling factor */
PPOINTL pptl;        /* pointer to structure with point data    */
 
The GpiScale function creates a transformation that can be used to scale
(expand or contract) an object relative to a given point. GpiScale either
adds the specified scaling factor to an existing transformation or replaces
the existing transformation. The new transformation can be used in a
subsequent call to any transformation function.
 
Parameter  Description
────────────────────────────────────────────────────────────────────────────
 
hps        Identifies the presentation space.
 
pmatlf     Points to the MATRIXLF structure that contains the transformation
           matrix.
 
flType     Specifies how a specified matrix should be used to modify the
           transformation. It can be one of the following values:
 
           Value              Meaning
           ─────────────────────────────────────────────────────────────────
           TRANSFORM_ADD      Additive. The specified transformation matrix
                              is combined with the existing transformation,
                              with the existing transformation first, the
                              new transformation second. This option is
                              useful for incremental updates to
                              transformations.
 
           TRANSFORM_REPLACE  New/replace. The previous transformation is
                              discarded and replaced by the specified
                              transformation matrix.
 
afxScale   Points to the two-element array that contains the scaling factors
           to use. The first element specifies the scaling factor along the
           x-axis; the second specifies the scaling factor along the
           y-axis.
 
pptl       Points to the POINTL structure that contains the coordinates of
           the point, relative to the origin, that defines the center of the
           scale.
 
Return Value
 
The return value is GPI_OK if the function is successful or GPI_ERROR if an
error occurs.
 
Errors
 
Use the WinGetLastError function to retrieve the error value, which may be
the following:
 
PMERR_INV_TRANSFORM_TYPE
 
See Also
 
GpiRotate, GpiSetDefaultViewMatrix, GpiSetModelTransformMatrix,
GpiSetSegmentTransformMatrix, GpiSetViewingTransformMatrix, GpiTranslate,
WinGetLastError, FIXED, MATRIXLF, POINTL
 
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