The following example creates a region from a path and fills it. The code then transforms the region and fills the transformed region to show the transformation.
C++
VOID Example_Transform(HDC hdc)
{
Graphics graphics(hdc);
Point points[] = {
Point(110, 20),
Point(120, 30),
Point(100, 60),
Point(120, 70),
Point(150, 60),
Point(140, 10)};
GraphicsPath path;
SolidBrush solidBrush(Color(255, 255, 0, 0));
path.AddClosedCurve(points, 6);
// Create a region from a path.
Region pathRegion(&path);
graphics.FillRegion(&solidBrush, &pathRegion);
// Transform the region.
Matrix matrix(1, 0, 0, 3, 100, 0); // vertical stretch, shift right
pathRegion.Transform(&matrix);
graphics.FillRegion(&solidBrush, &pathRegion);
}
SUB GDIP_TransformRegion (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pPath AS DWORD
LOCAL pSolidBrush AS DWORD
LOCAL pPathRegion AS DWORD
LOCAL pMatrix AS DWORD
DIM pts(5) AS POINTL
hStatus = GdipCreateFromHDC(hdc, pGraphics)
pts(0).x = 110 : pts(0).y = 20
pts(1).x = 120 : pts(1).y = 30
pts(2).x = 100 : pts(2).y = 60
pts(3).x = 120 : pts(3).y = 70
pts(4).x = 150 : pts(4).y = 60
pts(5).x = 140 : pts(5).y = 10
hStatus = GdipCreatePath(%FillModeAlternate, pPath)
hStatus = GdipCreateSolidFill(GDIP_ARGB(255, 255, 0, 0), pSolidBrush)
hStatus = GdipAddPathClosedCurveI(pPath, pts(0), 6)
' // Create a region from a path.
hStatus = GdipCreateRegionPath(pPath, pPathRegion)
hStatus = GdipFillRegion(pGraphics, pSolidBrush, pPathRegion)
' // Transform the region.
hStatus = GdipCreateMatrix2(1, 0, 0, 3, 100, 0, pMatrix) ' // vertical stretch, shift right
hStatus = GdipTransformRegion(pPathRegion, pMatrix)
hStatus = GdipFillRegion(pGraphics, pSolidBrush, pPathRegion)
' // Cleanup
IF pMatrix THEN GdipDeleteMatrix(pMatrix)
IF pPathRegion THEN GdipDeleteRegion(pPathRegion)
IF pSolidBrush THEN GdipDeleteBrush(pSolidBrush)
IF pPath THEN GdipDeletePath(pPath)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
The following illustration shows the output of the preceding code.
(http://www.jose.it-berater.org/captures/GdipTransformRegion.png)