ModifyWorldTransform

The ModifyWorldTransform function changes the world transformation for a device context using the specified mode.

BOOL ModifyWorldTransform(
  HDC hdc,               // handle of device context
  CONST XFORM *lpXform,  // address of transformation data
  DWORD iMode            // modification mode
);
 

Parameters

hdc

Specifies the device context.

lpXform

Pointer to an XFORM structure used to modify the world transformation for the given device context.

iMode

Specifies how the transformation data modifies the current world transformation. This parameter must be one of the following values:

Value	Description
MWT_IDENTITY	Resets the current world transformation by using the identity matrix. If this mode is specified, the XFORM structure pointed to by lpXform is ignored.
MWT_LEFTMULTIPLY	Multiplies the current transformation by the data in the XFORM structure. (The data in the XFORM structure becomes the left multiplicand, and the data for the current transformation becomes the right multiplicand.)
MWT_RIGHTMULTIPLY	Multiplies the current transformation by the data in the XFORM structure. (The data in the XFORM structure becomes the right multiplicand, and the data for the current transformation becomes the left multiplicand.)

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 ModifyWorldTransform function will fail unless graphics mode for the specified device context has been set to GM_ADVANCED by previously calling the SetGraphicsMode function. Likewise, it will not be possible to reset the graphics mode for the device context to the default GM_COMPATIBLE mode, unless world transform has first been reset to the default identity transform by calling SetWorldTransform or ModifyWorldTransform.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Unsupported.
  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, GetWorldTransform, SetWorldTransform, SetGraphicsMode, XFORM