Function rsqrt

external/astc-encoder/Source/astcenc_mathlib.h:388–391

* @brief Fast approximation of 1.0 / sqrt(val). * * @param v The input value. * * @return The approximated result. */

 * @return The approximated result.
 */
static inline float rsqrt(float v)
{
	return 1.0f / std::sqrt(v);
}

/**
 * @brief Fast approximation of sqrt(val).