GraphicsDevice.ScissorRectangle Property
Gets or sets the rectangle used for scissor testing. By default, the size matches the render target size.
Namespace: Microsoft.Xna.Framework.Graphics
Assembly: Microsoft.Xna.Framework.Graphics (in microsoft.xna.framework.graphics.dll)
The scissor rectangle is used as a rectangular clipping region. Use ScissorTestEnable to enable scissor testing.