GpiQueryModelTransformMatrix

This function returns the current model transform.

Syntax

GpiQueryModelTransformMatrix(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.

A structure in which the elements of the model transform matrix are returned.

Return Value

rc (BOOL) - returns

Success indicator.

TRUE : Successful completion

FALSE : Error occurred.

Remarks

This function is invalid when the drawing mode (see GpiSetDrawingMode) is set to retain.

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_IN_RETAIN_MODE (0x208C)

An attempt was made to issue a function (for example, query) that is invalid when the actual drawing mode is not draw or draw-and-retain.

PMERR_INV_LENGTH_OR_COUNT (0x2092)

An invalid length or count parameter was specified.

PMERR_INV_DC_TYPE (0x2060)

An invalid type parameter was specified with DevOpenDC, or a function was issued that is invalid for a OD_METAFILE_NOQUERY device context.

Example Code

This example uses GpiQueryModelTransformMatrix to query the first element of the current model transform after setting the draw mode to DRAW.

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

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

lCount = 1; /* examine only first element of transform matrix */

if (GpiSetDrawingMode(hps, DM_DRAW) == TRUE)
  fSuccess = GpiQueryModelTransformMatrix(hps, lCount, &pmatlfArray);