Method: Magick::Image#displace

Defined in:
ext/RMagick/rmimage.cpp

#displace(displacement_map, x_amp, y_amp = x_amp, gravity = Magick::NorthWestGravity, x_offset = 0, y_offset = 0) ⇒ Magick::Image

Uses displacement_map to move color from img to the output image. This method corresponds to the -displace option of ImageMagick’s composite command.

NorthWest corner by default.

Parameters:

  • displacement_map (Magick::Image, Magick::ImageList) —

    The source image for the composite operation. Either an imagelist or an image. If an imagelist, uses the current image.

  • x_amp (Numeric) —

    The maximum displacement on the x-axis.

  • y_amp (Numeric) (defaults to: x_amp) —

    The maximum displacement on the y-axis.

  • gravity (Magick::GravityType) (defaults to: Magick::NorthWestGravity) —

    the gravity for offset. the offsets are measured from the

  • x_offset (Numeric) (defaults to: 0) —

    The offset that measured from the left-hand side of the target image.

  • y_offset (Numeric) (defaults to: 0) —

    The offset that measured from the top of the target image.

Returns:



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# File 'ext/RMagick/rmimage.cpp', line 5605

VALUE
Image_displace(int argc, VALUE *argv, VALUE self)
{
    Image *image, *displacement_map;
    VALUE dmap;
    double x_amplitude = 0.0, y_amplitude = 0.0;
    long x_offset = 0L, y_offset = 0L;

    image = rm_check_destroyed(self);

    if (argc < 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
    }

    dmap = rm_cur_image(argv[0]);
    displacement_map = rm_check_destroyed(dmap);

    if (argc > 3)
    {
        get_composite_offsets(argc-3, &argv[3], image, displacement_map, &x_offset, &y_offset);
        // There must be 3 arguments left
        argc = 3;
    }

    switch (argc)
    {
        case 3:
            y_amplitude = NUM2DBL(argv[2]);
            x_amplitude = NUM2DBL(argv[1]);
            break;
        case 2:
            x_amplitude = NUM2DBL(argv[1]);
            y_amplitude = x_amplitude;
            break;
    }

    RB_GC_GUARD(dmap);

    return special_composite(image, displacement_map, x_amplitude, y_amplitude,
                             x_offset, y_offset, DisplaceCompositeOp);
}