X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=demo_prior;a=blobdiff_plain;f=libs%2Fimago2%2Fsrc%2Ffile_png.c;fp=libs%2Fimago2%2Fsrc%2Ffile_png.c;h=c764de4d1426df7b1d94274025bdd2fb3e793fbf;hp=0000000000000000000000000000000000000000;hb=3a9f6854df479d81442273c9d0b133c49c5c8f66;hpb=0b24071f728b7c8550daa1b7aa7c4012cb70ef4c diff --git a/libs/imago2/src/file_png.c b/libs/imago2/src/file_png.c new file mode 100644 index 0000000..c764de4 --- /dev/null +++ b/libs/imago2/src/file_png.c @@ -0,0 +1,273 @@ +/* +libimago - a multi-format image file input/output library. +Copyright (C) 2010 John Tsiombikas + +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. If not, see . +*/ + +/* -- PNG module -- */ +#ifndef NO_PNG + +#include +#include +#include +#include "imago2.h" +#include "ftype_module.h" + +static int check_file(struct img_io *io); +static int read_file(struct img_pixmap *img, struct img_io *io); +static int write_file(struct img_pixmap *img, struct img_io *io); + +static void read_func(png_struct *png, unsigned char *data, size_t len); +static void write_func(png_struct *png, unsigned char *data, size_t len); +static void flush_func(png_struct *png); + +static int png_type_to_fmt(int color_type, int channel_bits); +static int fmt_to_png_type(enum img_fmt fmt); + + +int img_register_png(void) +{ + static struct ftype_module mod = {".png", check_file, read_file, write_file}; + return img_register_module(&mod); +} + +static int check_file(struct img_io *io) +{ + unsigned char sig[8]; + int res; + long pos = io->seek(0, SEEK_CUR, io->uptr); + + if(io->read(sig, 8, io->uptr) < 8) { + io->seek(pos, SEEK_SET, io->uptr); + return -1; + } + + res = png_sig_cmp(sig, 0, 8) == 0 ? 0 : -1; + io->seek(pos, SEEK_SET, io->uptr); + return res; +} + +static int read_file(struct img_pixmap *img, struct img_io *io) +{ + png_struct *png; + png_info *info; + int channel_bits, color_type, ilace_type, compression, filtering, fmt; + png_uint_32 xsz, ysz; + + if(!(png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) { + return -1; + } + + if(!(info = png_create_info_struct(png))) { + png_destroy_read_struct(&png, 0, 0); + return -1; + } + + if(setjmp(png_jmpbuf(png))) { + png_destroy_read_struct(&png, &info, 0); + return -1; + } + + png_set_read_fn(png, io, read_func); + png_set_sig_bytes(png, 0); + png_read_png(png, info, 0, 0); + + png_get_IHDR(png, info, &xsz, &ysz, &channel_bits, &color_type, &ilace_type, + &compression, &filtering); + if((fmt = png_type_to_fmt(color_type, channel_bits)) == -1) { + png_destroy_read_struct(&png, &info, 0); + return -1; + } + + if(img_set_pixels(img, xsz, ysz, fmt, 0) == -1) { + png_destroy_read_struct(&png, &info, 0); + return -1; + } + + + if(channel_bits == 8) { + unsigned int i; + unsigned char **lineptr = (unsigned char**)png_get_rows(png, info); + unsigned char *dest = img->pixels; + + for(i=0; ipixelsz); + dest += xsz * img->pixelsz; + } + } else { + unsigned int i, j, num_elem; + unsigned char **lineptr = (unsigned char**)png_get_rows(png, info); + float *dest = img->pixels; + + num_elem = img->pixelsz / sizeof(float); + for(i=0; ifmt); + png_set_IHDR(png, info, img->width, img->height, 8, coltype, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); + png_set_text(png, info, &txt, 1); + + if(!(rows = malloc(img->height * sizeof *rows))) { + png_destroy_write_struct(&png, &info); + img_destroy(&tmpimg); + return -1; + } + + pixptr = img->pixels; + for(i=0; iheight; i++) { + rows[i] = pixptr; + pixptr += img->width * img->pixelsz; + } + png_set_rows(png, info, rows); + + png_write_png(png, info, 0, 0); + png_write_end(png, info); + png_destroy_write_struct(&png, &info); + + free(rows); + + img_destroy(&tmpimg); + return 0; +} + +static void read_func(png_struct *png, unsigned char *data, size_t len) +{ + struct img_io *io = (struct img_io*)png_get_io_ptr(png); + + if(io->read(data, len, io->uptr) == -1) { + longjmp(png_jmpbuf(png), 1); + } +} + +static void write_func(png_struct *png, unsigned char *data, size_t len) +{ + struct img_io *io = (struct img_io*)png_get_io_ptr(png); + + if(io->write(data, len, io->uptr) == -1) { + longjmp(png_jmpbuf(png), 1); + } +} + +static void flush_func(png_struct *png) +{ + /* XXX does it matter that we can't flush? */ +} + +static int png_type_to_fmt(int color_type, int channel_bits) +{ + /* only 8 and 16 bits per channel ar supported at the moment */ + if(channel_bits != 8 && channel_bits != 16) { + return -1; + } + + switch(color_type) { + case PNG_COLOR_TYPE_RGB: + return channel_bits == 16 ? IMG_FMT_RGBF : IMG_FMT_RGB24; + + case PNG_COLOR_TYPE_RGB_ALPHA: + return channel_bits == 16 ? IMG_FMT_RGBAF : IMG_FMT_RGBA32; + + case PNG_COLOR_TYPE_GRAY: + return channel_bits == 16 ? IMG_FMT_GREYF : IMG_FMT_GREY8; + + default: + break; + } + return -1; +} + +static int fmt_to_png_type(enum img_fmt fmt) +{ + switch(fmt) { + case IMG_FMT_GREY8: + return PNG_COLOR_TYPE_GRAY; + + case IMG_FMT_RGB24: + return PNG_COLOR_TYPE_RGB; + + case IMG_FMT_RGBA32: + return PNG_COLOR_TYPE_RGBA; + + default: + break; + } + return -1; +} + +#else +/* building with PNG support disabled */ + +int img_register_png(void) +{ + return -1; +} + +#endif