Clipping

This guide will show you how to clip your draws to a rectangle.

Call SetClipRect to clip everything that gets drawn after it. Pass null to stop clipping. RectangleF comes from MonoGame.Extended:

using MonoGame.Extended;

_sb.Begin();

_sb.SetClipRect(new RectangleF(100, 100, 200, 150));
_sb.FillCircle(new Vector2(120, 120), 75, Color.White);
_sb.SetClipRect(null);

_sb.End();

The circle gets cut off at the edges of the clip rectangle. The outline shows where the clip rectangle is. Clipping is done on the GPU and doesn’t break the batch. It applies to shapes, text, and textures alike.

The clip rectangle is independent from Begin and End. It stays active until you clear it with null.

Rounded corners

The second parameter rounds the corners of the clip rectangle. Fully rounding a square clip gives a circle mask:

_sb.SetClipRect(new RectangleF(100, 100, 200, 200), 100f);

Rotation

The third parameter rotates the clip rectangle around its center. The angle is in radians.

_sb.SetClipRect(new RectangleF(100, 100, 200, 150), 0f, MathF.PI / 4f);

Anti-aliasing

The fourth parameter is the size of the anti-aliasing edge in pixels. The default is 1.5f which matches the shapes. Set it to 0f to get a hard scissor edge.

_sb.SetClipRect(new RectangleF(100, 100, 200, 150), aaSize: 0f);

Both images are zoomed in. The first one uses the default anti-aliasing, the second one has it turned off:

Follow up

Text, a guide that shows how to draw text with the ShapeBatch.