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CDC::PolyDraw

Draws a set of line segments and Bzier splines.

BOOL PolyDraw( 
   const POINT* lpPoints, 
   const BYTE* lpTypes, 
   int nCount  
);

Parameters

  • lpPoints
    Points to an array of POINT data structures that contains the endpoints for each line segment and the endpoints and control points for each Bzier spline.

  • lpTypes
    Points to an array that specifies how each point in the lpPoints array is used. Values can be one of the following:

    • PT_MOVETO   Specifies that this point starts a disjoint figure. This point becomes the new current position.

    • PT_LINETO   Specifies that a line is to be drawn from the current position to this point, which then becomes the new current position.

    • PT_BEZIERTO   Specifies that this point is a control point or ending point for a Bzier spline.

      PT_BEZIERTO types always occur in sets of three. The current position defines the starting point for the Bzier spline. The first two PT_BEZIERTO points are the control points, and the third PT_BEZIERTO point is the ending point. The ending point becomes the new current position. If there are not three consecutive PT_BEZIERTO points, an error results.

      A PT_LINETO or PT_BEZIERTO type can be combined with the following constant by using the bitwise operator OR to indicate that the corresponding point is the last point in a figure and the figure is closed:

    • PT_CLOSEFIGURE   Specifies that the figure is automatically closed after the PT_LINETO or PT_BEZIERTO type for this point is done. A line is drawn from this point to the most recent PT_MOVETO or MoveTo point.

      This flag is combined with the PT_LINETO type for a line, or with the PT_BEZIERTO type of ending point for a Bzier spline, by using the bitwise OR operator. The current position is set to the ending point of the closing line.

  • nCount
    Specifies the total number of points in the lpPoints array, the same as the number of bytes in the lpTypes array.

Return Value

Nonzero if the function is successful; otherwise 0.

Remarks

This function can be used to draw disjoint figures in place of consecutive calls to CDC::MoveTo, CDC::LineTo, and CDC::PolyBezierTo member functions. The lines and splines are drawn using the current pen, and figures are not filled. If there is an active path started by calling the CDC::BeginPath member function, PolyDraw adds to the path. The points contained in the lpPoints array and in lpTypes indicate whether each point is part of a CDC::MoveTo, a CDC::LineTo, or a CDC::BezierTo operation. It is also possible to close figures. This function updates the current position.

Example

See the example for CDC::BeginPath.

Requirements

Header: afxwin.h

See Also

Reference

CDC Class

Hierarchy Chart

CDC::BeginPath

CDC::EndPath

CDC::LineTo

CDC::MoveTo

CDC::PolyBezierTo

CDC::Polyline

PolyDraw

Other Resources

CDC Members