Clamping (graphics)

In computer graphics, clamping is the process of limiting a position to an area. Unlike wrapping, clamping merely moves the point to the nearest available value.

To put clamping into perspective, pseudocode (in Python) for clamping is as follows:

 def clamp(x, minimum, maximum):
     if x < minimum:
         x = minimum
     elif x > maximum:
         x = maximum
     return x

Uses

In general, clamping is used to restrict a value to a given range. For example, in OpenGL the glClearColor function takes four GLfloat values which are then 'clamped' to the range $[0,1]$.

Y = clamp(X, 1, 5)
X	Y
X < 1	1
1	1
1.5	1.5
2	2
3	3
4	4
5	5
X > 5	5

One of the many uses of clamping in computer graphics is the placing of a detail inside a polygon—for example, a bullet hole on a wall. It can also be used with wrapping to create a variety of effects.