Region::IsVisible(constRect&,constGraphics*) method (gdiplusheaders.h)

The Region::IsVisible method determines whether a rectangle intersects this region.

Syntax

BOOL IsVisible(
  [in, ref] const Rect &   rect,
  [in]      const Graphics *g
);

Parameters

[in, ref] rect

Type: const Rect

Reference to a rectangle to test.

[in] g

Type: const Graphics*

Optional. Pointer to a Graphics object that contains the world and page transformations required to calculate the device coordinates of this region and the rectangle. The default value is NULL.

Return value

Type: BOOL

If the rectangle intersects this region, this method returns TRUE; otherwise, it returns FALSE.

Remarks

Examples

The following example creates a region from a path and then tests to determine whether a rectangle intersects the region.

VOID Example_IsVisibleRect(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);

   // Check to see whether a rectangle intersects the region.
   Rect testRect(65, 25, 70, 30);

   if(pathRegion.IsVisible(testRect, &graphics))
   {
      // All or part of the rectangle is in the region.
   }

   // Draw the test rectangle.
   Pen pen(Color(255, 0, 0, 0));
   graphics.DrawRectangle(&pen, testRect);
}

Requirements

See also

Graphics

Point

Region