#ifndef RENDER_MULTI_H
#define RENDER_MULTI_H

#include <event2/util.h>
#include <event2/buffer.h>

#include "render.h"
#include "remote_pool.h"

/*
 * Execute a given render_t operate across multiple remote render nodes, and aggregate the results into a single PNG stream locally
 */

struct render_multi;

// how many nodes can be involved in a render operation at most
#define RENDER_MULTI_NODES_MAX 2

/*
 * Execute the given render operation on multiple nodes from the given remote pool, streaming back the result in PNG format via the given callbacks
 *
 * The behaviour of the callbacks is mostly the same as for render_remote.h
 */
struct render_multi *render_multi (
        struct render *render_ctx,               // what to render
        struct remote_pool *pool_info,    // what render pool to use
        void (*cb_sent)(void *arg),
        void (*cb_data)(struct evbuffer *buf, void *arg),
        void (*cb_done)(void *arg),
        void (*cb_fail)(void *arg),
        void *cb_arg
);

void render_multi_cancel (struct render_multi *ctx);

void render_multi_set_recv (struct render_multi *ctx, size_t recv_threshold, size_t unread_buffer);

int render_multi_flush (struct render_multi *ctx);

void render_multi_free (struct render_multi *ctx);

#endif /* RENDER_MULTI_H */