Editing Linear interpolation (section)

==Programming language support==
Many libraries and [[shading language]]s have a "lerp" helper-function (in [[GLSL]] known instead as '''mix'''), returning an interpolation between two inputs <code>(v0, v1)</code> for a parameter <code>t</code> in the closed unit interval [0, 1]. Signatures between lerp functions are variously implemented in both the forms <code>(v0, v1, t)</code> and <code>(t, v0, v1)</code>.
<syntaxhighlight lang="c" line>
// Imprecise method, which does not guarantee v = v1 when t = 1, due to floating-point arithmetic error.
// This method is monotonic. This form may be used when the hardware has a native fused multiply-add instruction.
float lerp(float v0, float v1, float t) {
  return v0 + t * (v1 - v0);
}

// Precise method, which guarantees v = v1 when t = 1. This method is monotonic only when v0 * v1 < 0.
// Lerping between same values might not produce the same value
float lerp(float v0, float v1, float t) {
  return (1 - t) * v0 + t * v1;
}
</syntaxhighlight>
This lerp function is commonly used for [[alpha blending]] (the parameter "{{var|t}}" is the "alpha value"), and the formula may be extended to blend multiple components of a vector (such as spatial ''x'', ''y'', ''z'' axes or ''r'', ''g'', ''b'' colour components) in parallel.