/*
* Tiny PNG Output (C)
*
* Copyright (c) 2018 Project Nayuki
* https://www.nayuki.io/page/tiny-png-output
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program (see COPYING.txt and COPYING.LESSER.txt).
* If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
// Treat this data structure as private and opaque. Do not read or write any fields directly.
// This structure can be safely discarded at any time, because the functions of this library don't
// allocate memory or resources. The caller is responsible for initializing objects and cleaning up.
struct TinyPngOut {
// Immutable configuration
uint32_t width; // Measured in pixels
uint32_t height; // Measured in pixels
uint32_t lineSize; // Measured in bytes, equal to (width * 3 + 1)
// Running state
FILE *output;
uint32_t positionX; // Next byte index in current line
uint32_t positionY; // Line index of next byte
uint32_t uncompRemain; // Number of uncompressed bytes remaining
uint16_t deflateFilled; // Bytes filled in the current block (0 <= n < DEFLATE_MAX_BLOCK_SIZE)
uint32_t crc; // Primarily for IDAT chunk
uint32_t adler; // For DEFLATE data within IDAT
};
enum TinyPngOut_Status {
TINYPNGOUT_OK,
TINYPNGOUT_INVALID_ARGUMENT,
TINYPNGOUT_IMAGE_TOO_LARGE,
TINYPNGOUT_IO_ERROR,
};
/*
* Creates a PNG writer with the given width and height (both non-zero) and byte output stream.
* TinyPngOut will leave the output stream still open once it finishes writing the PNG file data.
* Returns an error if the dimensions exceed certain limits (e.g. w * h > 700 million).
*/
enum TinyPngOut_Status TinyPngOut_init(struct TinyPngOut this[static 1], uint32_t w, uint32_t h, FILE out[static 1]);
/*
* Writes 'count' pixels from the given array to the output stream. This reads count*3
* bytes from the array. Pixels are presented from top to bottom, left to right, and with
* subpixels in RGB order. This object keeps track of how many pixels were written and
* various position variables. It is an error to write more pixels in total than width*height.
* Once exactly width*height pixels have been written with this TinyPngOut object,
* there are no more valid operations on the object and it should be discarded.
*/
enum TinyPngOut_Status TinyPngOut_write(struct TinyPngOut this[static 1], const uint8_t pixels[], size_t count);
