((function modf
   (signature float
     (parameters
       (declare (in)  float x)
       (declare (out) float i))
     ((declare () float t)
      (assign (x) (var_ref t) (expression float trunc (var_ref x)))
      (assign (x) (var_ref i) (var_ref t))
      (return (expression float - (var_ref x) (var_ref t)))))

   (signature vec2
     (parameters
       (declare (in)  vec2 x)
       (declare (out) vec2 i))
     ((declare () vec2 t)
      (assign (xy) (var_ref t) (expression vec2 trunc (var_ref x)))
      (assign (xy) (var_ref i) (var_ref t))
      (return (expression vec2 - (var_ref x) (var_ref t)))))

   (signature vec3
     (parameters
       (declare (in)  vec3 x)
       (declare (out) vec3 i))
     ((declare () vec3 t)
      (assign (xyz) (var_ref t) (expression vec3 trunc (var_ref x)))
      (assign (xyz) (var_ref i) (var_ref t))
      (return (expression vec3 - (var_ref x) (var_ref t)))))

   (signature vec4
     (parameters
       (declare (in)  vec4 x)
       (declare (out) vec4 i))
     ((declare () vec4 t)
      (assign (xyzw) (var_ref t) (expression vec4 trunc (var_ref x)))
      (assign (xyzw) (var_ref i) (var_ref t))
      (return (expression vec4 - (var_ref x) (var_ref t)))))
))
