Method: Magick::Image#<=>

Defined in:
ext/RMagick/rmimage.c

#<=>(other) ⇒ Object

Compare two images.

Ruby usage:

- @verbatim Image#<=> @endverbatim

Parameters:

  • self —

    this image

  • other —

    other image

Returns:

  • -1, 0, 1

[View source]

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# File 'ext/RMagick/rmimage.c', line 12207

VALUE
Image_spaceship(VALUE self, VALUE other)
{
    Image *imageA, *imageB;
    const char *sigA, *sigB;
    int res;

    imageA = rm_check_destroyed(self);

    // If the other object isn't a Image object, then they can't be equal.
    if (!rb_obj_is_kind_of(other, Class_Image))
    {
        return Qnil;
    }

    imageB = rm_check_destroyed(other);

    (void) SignatureImage(imageA);
    (void) SignatureImage(imageB);
    sigA = rm_get_property(imageA, "signature");
    sigB = rm_get_property(imageB, "signature");
    if (!sigA || !sigB)
    {
        rb_raise(Class_ImageMagickError, "can't get image signature");
    }

    res = memcmp(sigA, sigB, 64);
    res = res > 0 ? 1 : (res < 0 ? -1 :  0);    // reduce to 1, -1, 0

    return INT2FIX(res);
}