Re: [boost] GIL Review - Integration with other graphics libraries, such as Cairo.

From: Lubomir Bourdev (lbourdev_at_[hidden])
Date: 2006-10-12 17:29:06

> Is there a comparison with Anti-Grain?  IIRC it also was
representation
> independent.
> 
> Bruno
> 

Question for Bruno (or anyone familiar with Anti-Grain):

1. How does Anti-Grain deal with planar images? 

Let's take the simplest possible example: Fill an image with the color
red.
Here is a possible code in GIL to do that:

template <typename View, typename Pixel>
void fill_pixels(const View& view, const Pixel& color) {
    typename View::pixel_t value;
    color_convert(color, value);
    for (typename View::iterator it=view.begin(); it!=view.end(); ++it)
        *it = value;
};

Here is how to call it:

rgb8_pixel_t red(255,0,0);

// Channel ordering: RGBRGBRGBRGB...
rgb8_image_t interleaved_image(100,100);
fill_pixels(view(interleaved_image), red);

// Channel ordering: RRR... GGG... BBB...
rgb8_planar_image_t planar_image(100,100);
fill_pixels(view(planar_image), red);

How would this example look with Anti-Grain?

__________________

Second question, how does AGG deal with images whose type is
instantiated at run-time? (For example, suppose you read the image from
a file and want to keep it in native form). Here is the extra GIL code
to do this:

template <typename Pixel>
struct fill_pixels_op {
    typedef void result_type;

    Pixel _color;
    fill_pixels_op(const Pixel& color) : _color(color) {}

    template <typename View>
    void operator()(const View& view) const { fill_pixels(view, _color);
}
};

template <typename ViewTypes, typename Pixel>
void fill_pixels(const any_image_view<ViewTypes>& view, const Pixel&
color) {
    apply_operation(view, fill_pixels_op<Pixel>(color));
}

Here is how to call it:

typedef mpl::vector<rgb8_view_t, rgb8_planar_view_t> my_views_t;
any_image_view<my_views_t> runtime_view;

runtime_view = view(interleaved_image);
fill_pixels(runtime_view, red);

runtime_view = view(planar_image);
fill_pixels(runtime_view, red);

Again, my question is, how would this look in Anti-Grain?

For the Vigra fans out there... How would the above two examples look in
Vigra?
For the Cairo fans... same question.

Thanks,
Lubomir