typedef struct zimg_image_buffer_const {
        unsigned version;
        const void *data[3];
        ptrdiff_t stride[3];
        unsigned mask[3];
} zimg_image_buffer_const;

typedef union zimg_image_buffer {
        struct {
                unsigned version;
                void *data[3];
                ptrdiff_t stride[3];
                unsigned mask[3];
        } m;

        zimg_image_buffer_const c;
} zimg_image_buffer;

typedef struct zimg_graph zimg_graph;


// Minimum buffering mask required for input.
unsigned zimg_graph_input_mask(const zimg_graph *graph);

// Minimum buffering mask required for output.
unsigned zimg_graph_output_mask(const zimg_graph *graph);

// Other temporary data.
size_t zimg_graph_tmp_size(const zimg_graph *graph);


// Make line i available to the input buffer.
typedef int (*zimg_unpack_func)(void *user, unsigned i);

// Notify that line i is available in the output buffer.
typedef int (*zimg_pack_func)(void *user, unsigned i);

typedef struct zimg_unpack_yuy2_context {
        unsigned version;
        zimg_image_buffer *buf; // same as argument to graph_traverse
        const void *packed_plane;
        ptrdiff_t packed_stride;
} zimg_unpack_yuy2_context;

typedef struct zimg_pack_yuy2_context {
        unsigned version;
        zimg_image_buffer_const *buf; // same as argument to graph_traverse
        void *packed_plane;
        ptrdiff_t packed_stride;
} zimg_pack_yuy2_context;


typedef struct zimg_unpack_rgb32_context {
        unsigned version;
        zimg_image_buffer *buf; // same as argument to graph_traverse
        const void *packed_plane;
        ptrdiff_t packed_stride;

        void *alpha_plane; // dumps alpha here
        ptrdiff_t alpha_stride;
} zimg_unpack_rgb_context;

typedef struct zimg_pack_rgb32_context {
        unsigned version;
        zimg_image_buffer_const *buf; // same as argument to graph_traverse
        void *packed_plane;
        ptrdiff_t packed_stride;

        const void *alpha_plane; // reinterleaves alpha from here (must be planar)
        ptrdiff_t alpha_stride;
} zimg_pack_rgb_context;


// use zimg_unpack/pack_yuy2_context
int zimg_unpack_yuy2(void *user, unsigned i);
int zimg_pack_yuy2(void *user, unsigned i);

// use zimg_unpack/pack_rgb_context
int zimg_unpack_rgb32(void *user, unsigned i);
int zimg_pack_rgb32(void *user, unsigned i);
int zimg_unpack_rgb24(void *user, unsigned i);
int zimg_pack_rgb24(void *user, unsigned i);

// To run on a fully allocated planar image:
//   zimg_graph_traverse(g, src_buf, dst, tmp, 0, 0, 0, 0);
// To convert YUY2 to RGB32:
//   zimg_unpack_yuy2_context unpack_yuy2 = { ZIMG_API_VERSION, src_mutable, yuy2_ptr, yuy2_stride };
//   zimg_pack_rgb_context pack_rgb = { ZIMG_API_VERSION, dst, rgb32_ptr, rgb32_stride, 0, 0 };
//   zimg_graph_traverse(g, &src_mutable->c, dst, tmp, &zimg_unpack_yuy2, &unpack_yuy2, &zimg_pack_rgb32, &pack_rgb);

void zimg_graph_traverse(const zimg_graph *graph, const zimg_image_buffer_const *src, const zimg_image_buffer *dst,
                         void *tmp, zimg_unpack_func unpack_cb, void *unpack_priv, zimg_pack_func pack_cb, void *pack_priv);