ArcTo

The ArcTo function draws an elliptical arc.

BOOL ArcTo(
  HDC hdc,          // handle to device context
  int nLeftRect,    // x-coord of bounding rectangle's upper-left corner
  int nTopRect,     // y-coord of bounding rectangle's upper-left corner
  int nRightRect,   // x-coord of bounding rectangle's lower-right corner
  int nBottomRect,  // y-coord of bounding rectangle's lower-right corner
  int nXRadial1,    // x-coord of the first radial ending point
  int nYRadial1,    // y-coord of the first radial ending point
  int nXRadial2,    // x-coord of the second radial ending point
  int nYRadial2     // y-coord of the second radial ending point
);
 

Parameters

hdc

Handle to the device context where drawing takes place.

nLeftRect

Specifies the logical x-coordinate of the upper-left corner of the bounding rectangle.

nTopRect

Specifies the logical y-coordinate of the upper-left corner of the bounding rectangle.

nRightRect

Specifies the logical x-coordinate of the lower-right corner of the bounding rectangle.

nBottomRect

Specifies the logical y-coordinate of the lower-right corner of the bounding rectangle.

nXRadial1

Specifies the logical x-coordinate of the endpoint of the radial defining the starting point of the arc.

nYRadial1

Specifies the logical y-coordinate of the endpoint of the radial defining the starting point of the arc.

nXRadial2

Specifies the logical x-coordinate of the endpoint of the radial defining the ending point of the arc.

nYRadial2

Specifies the logical y-coordinate of the endpoint of the radial defining the ending point of the arc.

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, call GetLastError.

Remarks

ArcTo is similar to the Arc function, except that the current position is updated.

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 counterclockwise from the point where it intersects the radial line from the center of the bounding rectangle to the (nXRadial1, nYRadial1) point. The arc ends where it intersects the radial line from the center of the bounding rectangle to the (nXRadial2, nYRadial2) point. If the starting point and ending point are the same, a complete ellipse is drawn.

A line is drawn from the current position to the starting point of the arc. If no error occurs, the current position is set to the ending point of the arc.

The arc is drawn using the current pen; it is not filled.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in wingdi.h.
  Import Library: Use gdi32.lib.

See Also

Lines and Curves Overview, Line and Curve Functions, AngleArc, Arc, SetArcDirection