The following example creates a
GraphicsPath object and calls the
GdiAddPathClosedCurve method to add a closed cardinal spline to the path. The code calls the
GdipWidenPath function to widen the path and then draws the path. Next, the code calls the
GdipWindingModeOutline function The code calls the
GdipTranslateWorldTransform function so that the outlined path drawn by the subsequent call to
GdipDrawPath sits to the right of the first path.
C++
VOID OutlineExample(HDC hdc)
{
Graphics graphics(hdc);
Pen bluePen(Color(255, 0, 0, 255));
Pen greenPen(Color(255, 0, 255, 0), 10);
PointF points[] = {
PointF(20.0f, 20.0f),
PointF(160.0f, 100.0f),
PointF(140.0f, 60.0f),
PointF(60.0f, 100.0f)};
GraphicsPath path;
path.AddClosedCurve(points, 4);
path.Widen(&greenPen);
graphics.DrawPath(&bluePen, &path);
path.Outline();
graphics.TranslateTransform(180.0f, 0.0f);
graphics.DrawPath(&bluePen, &path);
}
SUB GDIP_WindingModeOutline (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pPath AS DWORD
LOCAL pBluePen AS DWORD
LOCAL pGreenPen AS DWORD
DIM pts(3) AS POINTF
LOCAL result AS LONG
LOCAL i AS LONG
hStatus = GdipCreateFromHDC(hdc, pGraphics)
hStatus = GdipCreatePen1(GDIP_ARGB(255, 0, 0, 255), 1, %UnitWorld, pBluePen)
hStatus = GdipCreatePen1(GDIP_ARGB(255, 255, 255, 0), 10, %UnitWorld, pGreenPen)
hStatus = GdipCreatePath(%FillModeAlternate, pPath)
pts(0).x = 20 : pts(0).y = 20
pts(1).x = 160 : pts(1).y = 100
pts(2).x = 140 : pts(2).y = 60
pts(3).x = 60 : pts(3).y = 100
hStatus = GdipAddPathClosedCurve(pPath, pts(0), 4)
hStatus = GdipWidenPath(pPath, pGreenPen, %NULL, FlatnessDefault)
hStatus = GdipDrawPath(pGraphics, pBluePen, pPath)
hStatus = GdipWindingModeOutline(pPath, %NULL, FlatnessDefault)
hStatus = GdipTranslateWorldTransform(pGraphics, 180, 0, %MatrixOrderPrepend)
hStatus = GdipDrawPath(pGraphics, pBluePen, pPath)
' // Cleanup
IF pBluePen THEN GdipDeletePen(pBluePen)
IF pGreenPen THEN GdipDeletePen(pGreenPen)
IF pPath THEN GdipDeletePath(pPath)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
(http://www.jose.it-berater.org/captures/GdipWindingModeOutline.png)