Class: Magick::GradientFill

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

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

Extern: GradientFill#initialize(start_color, stop_color) Purpose: store the vector points and the start and stop colors



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# File 'ext/RMagick/rmfill.c', line 82

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;
}

Class Method Details

.new(x1, y1, x2, y2, start_color, stop_color) ⇒ Object 



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# File 'ext/RMagick/rmfill.c', line 38

VALUE
GradientFill_new(
    VALUE class,
    VALUE x1,
    VALUE y1,
    VALUE x2,
    VALUE y2,
    VALUE start_color,
    VALUE stop_color)
{
    rm_GradientFill *fill;
    volatile VALUE new_fill;
    VALUE argv[6];

    argv[0] = x1;
    argv[1] = y1;
    argv[2] = x2;
    argv[3] = y2;
    argv[4] = start_color;
    argv[5] = stop_color;

    new_fill = Data_Make_Struct(class
                              , rm_GradientFill
                              , NULL
                              , free_Fill
                              , fill);

    rb_obj_call_init((VALUE)new_fill, 6, argv);
    return new_fill;
}

Instance Method Details

#fill(image_obj) ⇒ Object

Extern: GradientFill_fill(image_obj) Purpose: the GradientFill#fill method - call GradientFill with the

start and stop colors specified when this fill object
was created.



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# File 'ext/RMagick/rmfill.c', line 460

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);
    Data_Get_Struct(image_obj, Image, image);

    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. (Yes, really do pass x1
        // as both the 2nd and 4th arguments!)
        else
        {
            vertical_fill(image, x1, &start_color, &stop_color);
        }
    }

    // A horizontal line is a special case.
    else if (fabs(y2-y1) < 0.5)
    {
        // Pass y1 as both the 3rd and 5th arguments!
        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;
}