+++ /dev/null
-/*
-libimago - a multi-format image file input/output library.
-Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
-
-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 <http://www.gnu.org/licenses/>.
-*/
-
-/* -- PNG module -- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <png.h>
-#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; i<ysz; i++) {
- memcpy(dest, lineptr[i], xsz * img->pixelsz);
- 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; i<ysz; i++) {
- for(j=0; j<xsz * num_elem; j++) {
- unsigned short val = (lineptr[i][j * 2] << 8) | lineptr[i][j * 2 + 1];
- *dest++ = (float)val / 65535.0;
- }
- }
- }
-
-
- png_destroy_read_struct(&png, &info, 0);
- return 0;
-}
-
-
-static int write_file(struct img_pixmap *img, struct img_io *io)
-{
- png_struct *png;
- png_info *info;
- png_text txt;
- struct img_pixmap tmpimg;
- unsigned char **rows;
- unsigned char *pixptr;
- int i, coltype;
-
- img_init(&tmpimg);
-
- if(!(png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
- return -1;
- }
- if(!(info = png_create_info_struct(png))) {
- png_destroy_write_struct(&png, 0);
- return -1;
- }
-
- /* if the input image is floating-point, we need to convert it to integer */
- if(img_is_float(img)) {
- if(img_copy(&tmpimg, img) == -1) {
- return -1;
- }
- if(img_to_integer(&tmpimg) == -1) {
- img_destroy(&tmpimg);
- return -1;
- }
- img = &tmpimg;
- }
-
- txt.compression = PNG_TEXT_COMPRESSION_NONE;
- txt.key = "Software";
- txt.text = "libimago2";
- txt.text_length = 0;
-
- if(setjmp(png_jmpbuf(png))) {
- png_destroy_write_struct(&png, &info);
- img_destroy(&tmpimg);
- return -1;
- }
- png_set_write_fn(png, io, write_func, flush_func);
-
- coltype = fmt_to_png_type(img->fmt);
- 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; i<img->height; 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;
-}
projects / dosdemo / blobdiff