You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
5.3 KiB
110 lines
5.3 KiB
2 years ago
|
/*
|
||
|
|
Copyright (C) 2017 Milo Yip. All rights reserved.
|
||
|
|
|
||
|
|
Redistribution and use in source and binary forms, with or without
|
||
|
|
modification, are permitted provided that the following conditions are met:
|
||
|
|
|
||
|
|
* Redistributions of source code must retain the above copyright notice, this
|
||
|
|
list of conditions and the following disclaimer.
|
||
|
|
|
||
|
|
* Redistributions in binary form must reproduce the above copyright notice,
|
||
|
|
this list of conditions and the following disclaimer in the documentation
|
||
|
|
and/or other materials provided with the distribution.
|
||
|
|
|
||
|
|
* Neither the name of pngout nor the names of its
|
||
|
|
contributors may be used to endorse or promote products derived from
|
||
|
|
this software without specific prior written permission.
|
||
|
|
|
||
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||
|
|
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
||
|
|
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
|
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||
|
|
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||
|
|
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||
|
|
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*! \file
|
||
|
|
\brief svpng() is a minimalistic C function for saving RGB/RGBA image into uncompressed PNG.
|
||
|
|
\author Milo Yip
|
||
|
|
\version 0.1.1
|
||
|
|
\copyright MIT license
|
||
|
|
\sa http://github.com/miloyip/svpng
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SVPNG_INC_
|
||
|
|
#define SVPNG_INC_
|
||
|
|
|
||
|
|
/*! \def SVPNG_LINKAGE
|
||
|
|
\brief User customizable linkage for svpng() function.
|
||
|
|
By default this macro is empty.
|
||
|
|
User may define this macro as static for static linkage,
|
||
|
|
and/or inline in C99/C++, etc.
|
||
|
|
*/
|
||
|
|
#ifndef SVPNG_LINKAGE
|
||
|
|
#define SVPNG_LINKAGE
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*! \def SVPNG_OUTPUT
|
||
|
|
\brief User customizable output stream.
|
||
|
|
By default, it uses C file descriptor and fputc() to output bytes.
|
||
|
|
In C++, for example, user may use std::ostream or std::vector instead.
|
||
|
|
*/
|
||
|
|
#ifndef SVPNG_OUTPUT
|
||
|
|
#include <stdio.h>
|
||
|
|
#define SVPNG_OUTPUT FILE* fp
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*! \def SVPNG_PUT
|
||
|
|
\brief Write a byte
|
||
|
|
*/
|
||
|
|
#ifndef SVPNG_PUT
|
||
|
|
#define SVPNG_PUT(u) fputc(u, fp)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
/*!
|
||
|
|
\brief Save a RGB/RGBA image in PNG format.
|
||
|
|
\param SVPNG_OUTPUT Output stream (by default using file descriptor).
|
||
|
|
\param w Width of the image. (<16383)
|
||
|
|
\param h Height of the image.
|
||
|
|
\param img Image pixel data in 24-bit RGB or 32-bit RGBA format.
|
||
|
|
\param alpha Whether the image contains alpha channel.
|
||
|
|
*/
|
||
|
|
SVPNG_LINKAGE void svpng(SVPNG_OUTPUT, unsigned w, unsigned h, const unsigned char* img, int alpha) {
|
||
|
|
static const unsigned t[] = { 0, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
|
||
|
|
/* CRC32 Table */ 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c };
|
||
|
|
unsigned a = 1, b = 0, c, p = w * (alpha ? 4 : 3) + 1, x, y, i; /* ADLER-a, ADLER-b, CRC, pitch */
|
||
|
|
#define SVPNG_U8A(ua, l) for (i = 0; i < l; i++) SVPNG_PUT((ua)[i]);
|
||
|
|
#define SVPNG_U32(u) do { SVPNG_PUT((u) >> 24); SVPNG_PUT(((u) >> 16) & 255); SVPNG_PUT(((u) >> 8) & 255); SVPNG_PUT((u) & 255); } while(0)
|
||
|
|
#define SVPNG_U8C(u) do { SVPNG_PUT(u); c ^= (u); c = (c >> 4) ^ t[c & 15]; c = (c >> 4) ^ t[c & 15]; } while(0)
|
||
|
|
#define SVPNG_U8AC(ua, l) for (i = 0; i < l; i++) SVPNG_U8C((ua)[i])
|
||
|
|
#define SVPNG_U16LC(u) do { SVPNG_U8C((u) & 255); SVPNG_U8C(((u) >> 8) & 255); } while(0)
|
||
|
|
#define SVPNG_U32C(u) do { SVPNG_U8C((u) >> 24); SVPNG_U8C(((u) >> 16) & 255); SVPNG_U8C(((u) >> 8) & 255); SVPNG_U8C((u) & 255); } while(0)
|
||
|
|
#define SVPNG_U8ADLER(u) do { SVPNG_U8C(u); a = (a + (u)) % 65521; b = (b + a) % 65521; } while(0)
|
||
|
|
#define SVPNG_BEGIN(s, l) do { SVPNG_U32(l); c = ~0U; SVPNG_U8AC(s, 4); } while(0)
|
||
|
|
#define SVPNG_END() SVPNG_U32(~c)
|
||
|
|
SVPNG_U8A("\x89PNG\r\n\32\n", 8); /* Magic */
|
||
|
|
SVPNG_BEGIN("IHDR", 13); /* IHDR chunk { */
|
||
|
|
SVPNG_U32C(w); SVPNG_U32C(h); /* Width & Height (8 bytes) */
|
||
|
|
SVPNG_U8C(8); SVPNG_U8C(alpha ? 6 : 2); /* Depth=8, Color=True color with/without alpha (2 bytes) */
|
||
|
|
SVPNG_U8AC("\0\0\0", 3); /* Compression=Deflate, Filter=No, Interlace=No (3 bytes) */
|
||
|
|
SVPNG_END(); /* } */
|
||
|
|
SVPNG_BEGIN("IDAT", 2 + h * (5 + p) + 4); /* IDAT chunk { */
|
||
|
|
SVPNG_U8AC("\x78\1", 2); /* Deflate block begin (2 bytes) */
|
||
|
|
for (y = 0; y < h; y++) { /* Each horizontal line makes a block for simplicity */
|
||
|
|
SVPNG_U8C(y == h - 1); /* 1 for the last block, 0 for others (1 byte) */
|
||
|
|
SVPNG_U16LC(p); SVPNG_U16LC(~p); /* Size of block in little endian and its 1's complement (4 bytes) */
|
||
|
|
SVPNG_U8ADLER(0); /* No filter prefix (1 byte) */
|
||
|
|
for (x = 0; x < p - 1; x++, img++)
|
||
|
|
SVPNG_U8ADLER(*img); /* Image pixel data */
|
||
|
|
}
|
||
|
|
SVPNG_U32C((b << 16) | a); /* Deflate block end with adler (4 bytes) */
|
||
|
|
SVPNG_END(); /* } */
|
||
|
|
SVPNG_BEGIN("IEND", 0); SVPNG_END(); /* IEND chunk {} */
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* SVPNG_INC_ */
|