ScaleViewportExtEx

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

Handle to 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

Pointer 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.

Windows NT: To get extended error information, call GetLastError.

Remarks

The viewport extents are modified as follows:

xNewVE = (xOldVE * Xnum) / Xdenom 
    yNewVE = (yOldVE * Ynum) / Ydenom 
 

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in wingdi.h.
  Import Library: Use gdi32.lib.

See Also

Coordinate Spaces and Transformations Overview, Coordinate Space and Transformation Functions, GetViewportExtEx, SIZE