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, |
// address of
application-defined callback function |
|
LPARAM lpData |
// address of
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
Specifies the
address of an application-defined callback function. For more information, see
the LineDDAProc
callback function.
lpData
Points 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.
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.
See Also