#ifndef RENDER_PNG_H
#define RENDER_PNG_H

#include "render.h"

/*
 * For rendering PNG images
 */
struct render_png;

/*
 * Build and return a render_png that can be used to render a PNG of the given struct render.
 *
 * The dimensions of the PNG image will be read from render. If render's I/O 
 * was set using render_io_stream, then the PNG data will be written to that
 * stream. If it was set using render_io_custom, then the write_fn will be
 * called with chunks of PNG data, and flush_fn from time to time as a hint to
 * flush the data, but this may be omitted.
 *
 * returns NULL on failure.
 */
struct render_png *render_png_alloc (struct render *render);

/*
 * Feed a full row of raw pixel data into the PNG image.
 *
 * buf must be render.img_w bytes wide.
 */
int render_png_row (struct render_png *ctx, unsigned char *rowbuf);

/*
 * Mark the render as complete and free the render_png, flushing out any remaining data.
 */
int render_png_done (struct render_png *ctx);

/*
 * Abort the render, free the render_png, and discard any remaining data.
 */
int render_png_abort (struct render_png *ctx);

#endif /* RENDER_PNG_H */