gistfile1.c

int kr_compositor_control_easers_to_offset(int member_type) {
  switch (member_type) {
    case KR_X:
      return offsetof(struct kr_compositor_control_easers,x);
    case KR_Y:
      return offsetof(struct kr_compositor_control_easers,y);
    case KR_Z:
      return offsetof(struct kr_compositor_control_easers,z);
    case KR_WIDTH:
      return offsetof(struct kr_compositor_control_easers,w);
    case KR_HEIGHT:
      return offsetof(struct kr_compositor_control_easers,h);
    case KR_ROTATION:
      return offsetof(struct kr_compositor_control_easers,rotation);
    case KR_OPACITY:
      return offsetof(struct kr_compositor_control_easers,opacity);
    default : 
      return -1;
  }
}

int kr_struct_to_offset(int struct_type, int member_type) {
  switch (struct_type) {
    ...
    ...
    ...
    case KR_COMPOSITOR_CONTROL_EASERS:
      return kr_compositor_control_easers_to_offset(member_type);
  }

}