code: func Vec3Copy(dst, src Vec3) {
  	dst[0] = src[0]
  	dst[1] = src[1]
  	dst[2] = src[2]
  }
docs: // Vec3 functions
  // Vec3Copy performs a vector copy. dst = src
  //
  //     dst   [out] The destination vector.
  //     src    [in]  The source vector.