LineDDA function (wingdi.h)
The LineDDA function determines which pixels should be highlighted for a line defined by the specified starting and ending points.
Syntax
BOOL LineDDA(
[in] int xStart,
[in] int yStart,
[in] int xEnd,
[in] int yEnd,
[in] LINEDDAPROC lpProc,
[in] LPARAM data
);
Parameters
[in] xStart
Specifies the x-coordinate, in logical units, of the line's starting point.
[in] yStart
Specifies the y-coordinate, in logical units, of the line's starting point.
[in] xEnd
Specifies the x-coordinate, in logical units, of the line's ending point.
[in] yEnd
Specifies the y-coordinate, in logical units, of the line's ending point.
[in] lpProc
Pointer to an application-defined callback function. For more information, see the LineDDAProc callback function.
[in] data
Pointer to the application-defined data.
Return value
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero.
Remarks
The LineDDA function passes the coordinates for each point along the line, except for the line's ending point, to the application-defined callback function. In addition to passing the coordinates of a point, this function passes any existing application-defined data.
The coordinates passed to the callback function match pixels on a video display only if the default transformations and mapping modes are used.
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 |