Class: Magick::GradientFill

Inherits:
Object
  • Object
show all
Defined in:
ext/RMagick/rmmain.c

Instance Method Summary collapse

Constructor Details

#initialize(x1, y1, x2, y2, start_color, stop_color) ⇒ Object

Store the vector points and the start and stop colors.

Ruby usage:

- @verbatim GradientFill#initialize(x1,y1,x2,y2,start_color,stop_color) @endverbatim

Parameters:

  • self

    this object

  • x1

    x position of first point

  • y1

    y position of first point

  • x2

    x position of second point

  • y2

    y position of second point

  • start_color

    the start color

  • stop_color

    the stop color


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# File 'ext/RMagick/rmfill.c', line 76

VALUE
GradientFill_initialize(
                       VALUE self,
                       VALUE x1,
                       VALUE y1,
                       VALUE x2,
                       VALUE y2,
                       VALUE start_color,
                       VALUE stop_color)
{
    rm_GradientFill *fill;

    Data_Get_Struct(self, rm_GradientFill, fill);

    fill->x1 = NUM2DBL(x1);
    fill->y1 = NUM2DBL(y1);
    fill->x2 = NUM2DBL(x2);
    fill->y2 = NUM2DBL(y2);
    Color_to_PixelPacket(&fill->start_color, start_color);
    Color_to_PixelPacket(&fill->stop_color, stop_color);

    return self;
}

Instance Method Details

#fill(image_obj) ⇒ Object

Call GradientFill with the start and stop colors specified when this fill object was created.

Ruby usage:

- @verbatim GradientFill#fill(image) @endverbatim

Parameters:

  • self

    this object

  • image_obj

    the image

Returns:

  • self


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# File 'ext/RMagick/rmfill.c', line 558

VALUE
GradientFill_fill(VALUE self, VALUE image_obj)
{
    rm_GradientFill *fill;
    Image *image;
    PixelPacket start_color, stop_color;
    double x1, y1, x2, y2;          // points on the line

    Data_Get_Struct(self, rm_GradientFill, fill);
    image = rm_check_destroyed(image_obj);

    x1 = fill->x1;
    y1 = fill->y1;
    x2 = fill->x2;
    y2 = fill->y2;
    start_color = fill->start_color;
    stop_color  = fill->stop_color;

    if (fabs(x2-x1) < 0.5)       // vertical?
    {
        // If the x1,y1 and x2,y2 points are essentially the same
        if (fabs(y2-y1) < 0.5)
        {
            point_fill(image, x1, y1, &start_color, &stop_color);
        }

        // A vertical line is a special case.
        else
        {
            vertical_fill(image, x1, &start_color, &stop_color);
        }
    }

    // A horizontal line is a special case.
    else if (fabs(y2-y1) < 0.5)
    {
        horizontal_fill(image, y1, &start_color, &stop_color);
    }

    // This is the general case - a diagonal line. If the line is more horizontal
    // than vertical, use the top and bottom of the image as the ends of the
    // gradient, otherwise use the sides of the image.
    else
    {
        double m = ((double)(y2 - y1))/((double)(x2 - x1));
        double diagonal = ((double)image->rows)/image->columns;
        if (fabs(m) <= diagonal)
        {
            v_diagonal_fill(image, x1, y1, x2, y2, &start_color, &stop_color);
        }
        else
        {
            h_diagonal_fill(image, x1, y1, x2, y2, &start_color, &stop_color);
        }
    }

    return self;
}