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CRgn::CreateEllipticRgn

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BOOLCreateEllipticRgn(intx1**,inty1,intx2,inty2);**

Return Value

Nonzero if the operation succeeded; otherwise 0.

Parameters

x1

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

y1

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

x2

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

y2

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

Remarks

Creates an elliptical region. The region is defined by the bounding rectangle specified by x1, y1, x2, and y2. The region is stored in the CRgn object.

The size of a region is limited to 32,767 by 32,767 logical units or 64K of memory, whichever is smaller.

When it has finished using a region created with the CreateEllipticRgn function, an application should select the region out of the device context and use the DeleteObject function to remove it.

Example

CRgn   rgnA, rgnB, rgnC;

VERIFY(rgnA.CreateEllipticRgn(200, 100, 350, 250));
VERIFY(rgnB.CreateRectRgn( 0, 0, 50, 50 ));
VERIFY(rgnB.CopyRgn( &rgnA ));
int nOffsetResult = rgnB.OffsetRgn( -75, 75 );
ASSERT( nOffsetResult != ERROR || nOffsetResult != NULLREGION );

VERIFY(rgnC.CreateRectRgn( 0, 0, 1, 1));
int nCombineResult = rgnC.CombineRgn( &rgnA, &rgnB, RGN_AND );
ASSERT( nCombineResult != ERROR || nOffsetResult != NULLREGION );

CBrush brA, brB, brC;
VERIFY(brC.CreateHatchBrush( HS_FDIAGONAL, RGB(0, 0, 255) )); // Blue
VERIFY(pDC->FillRgn( &rgnC, &brC ));
VERIFY(brA.CreateSolidBrush( RGB(255, 0, 0) ));  // rgnA Red
VERIFY(pDC->FrameRgn( &rgnA, &brA, 2, 2 ));
VERIFY(brB.CreateSolidBrush( RGB(0, 255, 0) ));  // rgnB Green
VERIFY(pDC->FrameRgn( &rgnB, &brB, 2, 2 ));

CRgn Overview |  Class Members |  Hierarchy Chart

See Also   CRgn::CreateEllipticRgnIndirect,