LineDDA The LineDDA function determines which pixels should be highlighted for a line defined by the specified starting and ending points. BOOL LineDDA( int nXStart, // x-coordinate of line's starting point int nYStart, // y-coordinate of line's starting point int nXEnd, // x-coordinate of line's ending point int nYEnd, // y-coordinate of line's ending point LINEDDAPROC lpLineFunc, // pointer to callback function LPARAM lpData // pointer to application-defined data );
Parameters nXStart Specifies the x-coordinate of the line's starting point. nYStart Specifies the y-coordinate of the line's starting point. nXEnd Specifies the x-coordinate of the line's ending point. nYEnd Specifies the y-coordinate of the line's ending point. lpLineFunc Pointer to an application-defined callback function. For more information, see the LineDDAProc callback function. lpData Pointer to the application-defined data. 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, callGetLastError.Res 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. 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 Lines and Curves Overview, Line and Curve Functions, LineDDAProc
可以 用
InvalidateRect(小车)
The LineDDA function determines which pixels should be highlighted for a line defined by the specified starting and ending points. BOOL LineDDA(
int nXStart, // x-coordinate of line's starting point
int nYStart, // y-coordinate of line's starting point
int nXEnd, // x-coordinate of line's ending point
int nYEnd, // y-coordinate of line's ending point
LINEDDAPROC lpLineFunc, // pointer to callback function
LPARAM lpData // pointer to application-defined data
);
Parameters
nXStart
Specifies the x-coordinate of the line's starting point.
nYStart
Specifies the y-coordinate of the line's starting point.
nXEnd
Specifies the x-coordinate of the line's ending point.
nYEnd
Specifies the y-coordinate of the line's ending point.
lpLineFunc
Pointer to an application-defined callback function. For more information, see the LineDDAProc callback function.
lpData
Pointer to the application-defined data.
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, callGetLastError.Res
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. 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
Lines and Curves Overview, Line and Curve Functions, LineDDAProc