Arc
The Arc
function draws an elliptical arc.
BOOL Arc(
|
HDC hdc, |
// handle to device
context |
|
int nLeftRect, |
// x-coordinate of
bounding rectangle s upper-left corner |
|
int nTopRect, |
// y-coordinate of
bounding rectangle s upper-left corner
|
|
int nRightRect, |
// x-coordinate of
bounding rectangle s lower-right corner
|
|
int nBottomRect, |
// y-coordinate of
bounding rectangle s lower-right corner
|
|
int nXStartArc, |
// first radial
ending point |
|
int nYStartArc, |
// first radial
ending point |
|
int nXEndArc, |
// second radial
ending point |
|
int nYEndArc |
// second radial
ending point |
|
); |
|
Parameters
hdc
Identifies
the device context where drawing takes place.
nLeftRect
Specifies the
logical x-coordinate of the upper-left corner of the bounding rectangle.
Windows
95: The sum of nLeftRect plus
nRightRect must be less than 32768.
nTopRect
Specifies the
logical y-coordinate of the upper-left corner of the bounding rectangle.
Windows
95: The sum of nTopRect plus
nBottomRect must be less than 32768.
nRightRect
Specifies the
logical x-coordinate of the lower-right corner of the bounding rectangle.
Windows
95: The sum of nLeftRect plus
nRightRect must be less than 32768.
nBottomRect
Specifies the
logical y-coordinate of the lower-right corner of the bounding rectangle.
Windows
95: The sum of nTopRect plus
nBottomRect must be less than 32768.
nXStartArc
Specifies the
logical x-coordinate of the ending point of the radial line defining the
starting point of the arc.
nYStartArc
Specifies the
logical y-coordinate of the ending point of the radial line defining the
starting point of the arc.
nXEndArc
Specifies the
logical x-coordinate of the ending point of the radial line defining the ending
point of the arc.
nYEndArc
Specifies the
logical y-coordinate of the ending point of the radial line defining the ending
point of the arc.
Return Values
If the arc is
drawn, the return value is nonzero.
If the arc is
not drawn, the return value is zero.
Remarks
The points (nLeftRect,
nTopRect) and (nRightRect, nBottomRect) specify the bounding
rectangle. An ellipse formed by the specified bounding rectangle defines the
curve of the arc. The arc extends in the current drawing direction from the
point where it intersects the radial from the center of the bounding rectangle
to the (nXStartArc, nYStartArc) point. The arc ends where it intersects
the radial from the center of the bounding rectangle to the (nXEndArc,
nYEndArc) point. If the starting point and ending point are the same, a
complete ellipse is drawn.
The arc is
drawn using the current pen; it is not filled.
The current
position is neither used nor updated by Arc.
Windows
95: The drawing direction is always
counterclockwise.
Windows
NT: Use the GetArcDirection
and SetArcDirection functions to get and set the current drawing
direction for a device context. The default drawing direction is
counterclockwise.
Windows
95: The sum of the coordinates of the
bounding rectangle cannot exceed 32,767. The sum of nLeftRect and nRightRect
or nTopRect and nBottomRect parameters cannot exceed 32,767.
See Also