ScaleViewportExtEx info  Overview  Group

The ScaleViewportExtEx function modifies the viewport for a device context (DC) by using the ratios formed by the specified multiplicands and divisors.

BOOL ScaleViewportExtEx(

HDC hdc,	// handle of device context
int Xnum,	// horizontal multiplicand
int Xdenom,	// horizontal divisor
int Ynum,	// vertical multiplicand
int Ydenom,	// vertical divisor
LPSIZE lpSize	// address of previous viewport extents
);

Parameters

hdc

Identifies the device context.

Xnum

Specifies the amount by which to multiply the current horizontal extent.

Xdenom

Specifies the amount by which to divide the current horizontal extent.

Ynum

Specifies the amount by which to multiply the current vertical extent.

Ydenom

Specifies the amount by which to divide the current vertical extent.

lpSize

Points to a SIZE structure. The previous viewport extents (in device units) are placed in this structure. If lpSize is NULL, nothing is returned.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The viewport extents are modified as follows:

    xNewVE = (xOldVE * Xnum) / Xdenom 

    yNewVE = (yOldVE * Ynum) / Ydenom 

 

See Also

GetViewportExtEx, SIZE