SetViewportOrgEx function (wingdi.h)
The SetViewportOrgEx function specifies which device point maps to the window origin (0,0).
BOOL SetViewportOrgEx(
[in] HDC hdc,
[in] int x,
[in] int y,
[out] LPPOINT lppt
);
[in] hdc
A handle to the device context.
[in] x
The x-coordinate, in device units, of the new viewport origin.
[in] y
The y-coordinate, in device units, of the new viewport origin.
[out] lppt
A pointer to a POINT structure that receives the previous viewport origin, in device coordinates. If lpPoint is NULL, this parameter is not used.
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero.
This function (along with SetViewportExtEx and SetWindowExtEx) helps define the mapping from the logical coordinate space (also known as a window) to the device coordinate space (the viewport). SetViewportOrgEx specifies which device point maps to the logical point (0,0). It has the effect of shifting the axes so that the logical point (0,0) no longer refers to the upper-left corner.
//map the logical point (0,0) to the device point (xViewOrg, yViewOrg)
SetViewportOrgEx ( hdc, xViewOrg, yViewOrg, NULL)
This is related to the SetWindowOrgEx function. Generally, you will use one function or the other, but not both. Regardless of your use of SetWindowOrgEx and SetViewportOrgEx, the device point (0,0) is always the upper-left corner.
For an example, see Redrawing in the Update Region.
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 |
Coordinate Space and Transformation Functions