Wrapping (graphics)

In computer graphics, wrapping is the process of limiting a position to an area. A good example of wrapping is wallpaper, a single pattern repeated indefinitely over a wall. Wrapping is used in 3D computer graphics to repeat a texture over a polygon, eliminating the need for large textures or multiple polygons.

To wrap a position x to an area of width w, calculate the value $$x' = x \text{ mod } w$$.

Implementation
For computational purposes the wrapped value x' of x can be expressed as


 * $$x' = x - \lfloor (x - x_{\text{min}}) / (x_{\text{max}} - x_{\text{min}}) \rfloor \cdot (x_{\text{max}} - x_{\text{min}})$$

where $$x_{\text{max}}$$ is the highest value in the range, and $$x_{\text{min}}$$ is the lowest value in the range.

Pseudocode for wrapping of a value to a range other than 0–1 is function wrap(X, Min, Max: Real): Real; X := X - Int((X - Min) / (Max - Min)) * (Max - Min); if X < 0 then // This corrects the problem caused by using Int instead of Floor X := X + Max - Min; return X;

Pseudocode for wrapping of a value to a range of 0–1 is function wrap(X: Real): Real; X := X - Int(X); if X < 0 then X := X + 1; return X;

Pseudocode for wrapping of a value to a range of 0–1 without branching is, function wrap(X: Real): Real; return ((X mod 1.0) + 1.0) mod 1.0;

See also text wrapping

 * Clamping