Method: Magick::Image#shade

Defined in:
ext/RMagick/rmimage.cpp

#shade(shading = false, azimuth = 30.0, elevation = 30.0) ⇒ Magick::Image

Shine a distant light on an image to create a three-dimensional effect. You control the positioning of the light with azimuth and elevation; azimuth is measured in degrees off the x axis and elevation is measured in pixels above the Z axis.

Returns a new image.

Parameters:

  • shading (Boolean) (defaults to: false) —

    If true, shade shades the intensity of each pixel.

  • azimuth (Numeric) (defaults to: 30.0) —

    The light source direction. The azimuth is measured in degrees. 0 is at 9 o’clock. Increasing values move the light source counter-clockwise.

  • elevation (Numeric) (defaults to: 30.0) —

    The light source direction. The azimuth is measured in degrees. 0 is at 9 o’clock. Increasing values move the light source counter-clockwise.

Returns:



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# File 'ext/RMagick/rmimage.cpp', line 12936

VALUE
Image_shade(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double azimuth = 30.0, elevation = 30.0;
    MagickBooleanType shading = MagickFalse;
    ExceptionInfo *exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 3:
            elevation = NUM2DBL(argv[2]);
        case 2:
            azimuth = NUM2DBL(argv[1]);
        case 1:
            shading = (MagickBooleanType)RTEST(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 3)", argc);
            break;
    }

    exception = AcquireExceptionInfo();
    GVL_STRUCT_TYPE(ShadeImage) args = { image, shading, azimuth, elevation, exception };
    new_image = (Image *)CALL_FUNC_WITHOUT_GVL(GVL_FUNC(ShadeImage), &args);
    rm_check_exception(exception, new_image, DestroyOnError);
    DestroyExceptionInfo(exception);

    return rm_image_new(new_image);
}