ModifyWorldTransform function (wingdi.h)

Article
02/22/2024

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

Syntax

BOOL ModifyWorldTransform(
  [in] HDC         hdc,
  [in] const XFORM *lpxf,
  [in] DWORD       mode
);

Parameters

[in] hdc

A handle to the device context.

[in] lpxf

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

[in] mode

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

Value	Meaning
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 value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

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.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	wingdi.h (include Windows.h)
Library	Gdi32.lib
DLL	Gdi32.dll