graphene:vec4-init-from-vec2 (v src z w)

v -- a graphene:vec4-t instance
source -- a graphene:vec2-t instance
z -- a number coerced to a float with the value of the third component of v
w -- a number coerced to a float with the value of the fourth component of v

The initialized graphene:vec4-t instance.

Initializes a graphene:vec4-t instance using another graphene:vec2-t instance and the values of z and w. This function can be called multiple times.