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 $x\text{'}\; equiv\; x\; pmod\{w\}$.

Implementation

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

:$x\text{'}\; =\; x\; -\; lfloor\; (x\; -\; x\_\{min\})\; /\; (x\_\{max\}\; -\; x\_\{min\})\; floor\; *\; (x\_\{max\}\; -\; x\_\{min\})$

where $x\_\{max\}$ is the highest value in the range, and $x\_\{min\}$ 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;

ee also

*Clamping