GpiQueryDefaultViewMatrix

This function returns the current default viewing transform; see GpiSetDefaultViewMatrix.

Syntax

GpiQueryDefaultViewMatrix(hps, lCount, pmatlfArray)

Parameters

hps (HPS) - input

Presentation-space handle.

lCount (LONG) - input

Number of elements.

The number of elements to be returned in pmatlfArray; must be in the range 0 through 9. If 0 is specified, no matrix elements are returned.

pmatlfArray (PMATRIXLF) - output

Transform matrix.

An array into which the elements of the default viewing transform matrix are returned.

Return Value

rc (BOOL) - returns

Success indicator.

TRUE : Successful completion

FALSE : Error occurred.

Errors

Possible returns from WinGetLastError:

PMERR_INV_HPS (0x207F)

An invalid presentation-space handle was specified.

PMERR_PS_BUSY (0x20F4)

An attempt was made to access the presentation space from more than one thread simultaneously.

PMERR_INV_LENGTH_OR_COUNT (0x2092)

An invalid length or count parameter was specified.

Example Code

This example uses GpiQueryDefaultViewMatrix to return the default viewing transform and, if successful, defines - via GpiSetDefaultViewMatrix - the returned value as the new default transform.

#define INCL_GPITRANSFORMS /* Transform functions */
#include <os2.h>

BOOL fSuccess; /* success indicator */
HPS hps; /* Presentation-space handle */
LONG lCount; /* number of elements */
MATRIXLF pmatlfArray; /* transform matrix */
LONG lOptions; /* set default options */

lCount = 1; /* examine only first element of transform matrix */
fSuccess = GpiQueryDefaultViewMatrix(hps, lCount, &pmatlfArray);

/* set default to returned transform */
if (fSuccess == TRUE)
{
  lOptions = TRANSFORM_REPLACE;
  fSuccess = GpiSetDefaultViewMatrix(hps, lCount, &pmatlfArray, lOptions);
}