From cbb6286cb92020dd7ae88798ed831ed76fd2130e Mon Sep 17 00:00:00 2001 From: Anas Nashif Date: Fri, 7 Dec 2012 02:53:31 -0800 Subject: Imported Upstream version 2.6 --- png.c | 259 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 259 insertions(+) create mode 100644 png.c (limited to 'png.c') diff --git a/png.c b/png.c new file mode 100644 index 0000000..7ed1563 --- /dev/null +++ b/png.c @@ -0,0 +1,259 @@ +/* png.c + * PNG decoding + * (c) 2002 Karel 'Clock' Kulhavy + * This is a part of the Links program, released under GPL. + */ +#include "cfg.h" + +#ifdef G +#include "links.h" + +#ifdef HAVE_ENDIAN_H +#include +#endif /* #ifdef HAVE_ENDIAN_H */ + +#ifdef REPACK_16 +#undef REPACK_16 +#endif /* #ifdef REPACK_16 */ + +#if SIZEOF_UNSIGNED_SHORT != 2 +#define REPACK_16 +#endif /* #if SIZEOF_UNSIGNED_SHORT != 2 */ + +#ifndef REPACK_16 +#ifndef C_LITTLE_ENDIAN +#ifndef C_BIG_ENDIAN +#define REPACK_16 +#endif /* #ifndef C_BIG_ENDIAN */ +#endif /* #ifndef C_LITTLE_ENDIAN */ +#endif /* #ifndef REPACK_16 */ + +/* Decoder structs */ + +/* Warning for from-web PNG images */ +static void img_my_png_warning(png_structp a, png_const_charp b) +{ +} + +/* Error for from-web PNG images. */ +static void img_my_png_error(png_structp png_ptr, png_const_charp error_string) +{ +#if (PNG_LIBPNG_VER < 10500) + longjmp(png_ptr->jmpbuf,1); +#else + png_longjmp(png_ptr,1); +#endif +} + +static void png_info_callback(png_structp png_ptr, png_infop info_ptr) +{ + int bit_depth, color_type, intent; + double gamma; + int bytes_per_pixel=3; + struct cached_image *cimg; + + cimg=global_cimg; + + bit_depth=png_get_bit_depth(png_ptr, info_ptr); + color_type=png_get_color_type(png_ptr, info_ptr); + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_expand(png_ptr); + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand(png_ptr); + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)){ + png_set_expand(png_ptr); /* Legacy version of + png_set_tRNS_to_alpha(png_ptr); */ + bytes_per_pixel++; + } + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + if (bit_depth==16){ +#ifndef REPACK_16 +#ifdef C_LITTLE_ENDIAN + /* We use native endianity only if unsigned short is 2-byte + * because otherwise we have to reassemble the buffer so we + * will leave in the libpng-native big endian. + */ + png_set_swap(png_ptr); +#endif /* #ifdef C_LITTLE_ENDIAN */ +#endif /* #ifndef REPACK_16 */ + bytes_per_pixel*=sizeof(unsigned short); + } + png_set_interlace_handling(png_ptr); + if (color_type==PNG_COLOR_TYPE_RGB_ALPHA + ||color_type==PNG_COLOR_TYPE_GRAY_ALPHA){ + if (bytes_per_pixel==3 + ||bytes_per_pixel==3*sizeof(unsigned short)) + bytes_per_pixel=4*bytes_per_pixel/3; + } + cimg->width=png_get_image_width(png_ptr,info_ptr); + cimg->height=png_get_image_height(png_ptr,info_ptr); + cimg->buffer_bytes_per_pixel=bytes_per_pixel; + if (png_get_sRGB(png_ptr, info_ptr, &intent)){ + gamma=sRGB_gamma; + } + else + { + if (!png_get_gAMA(png_ptr, info_ptr, &gamma)){ + gamma=sRGB_gamma; + } + } + cimg->red_gamma=gamma; + cimg->green_gamma=gamma; + cimg->blue_gamma=gamma; + png_read_update_info(png_ptr,info_ptr); + cimg->strip_optimized=0; + if (header_dimensions_known(cimg)) + img_my_png_error(png_ptr, "bad image size"); +} + +#ifdef REPACK_16 +/* Converts unsigned shorts to doublechars (in big endian) */ +static void a2char_from_unsigned_short(unsigned char *chr, unsigned short *shrt, int len) +{ + unsigned short s; + + for (;len;len--,shrt++,chr+=2){ + s=*shrt; + *chr=s>>8; + chr[1]=s; + } +} + +/* Converts doublechars (in big endian) to unsigned shorts */ +static void unsigned_short_from_2char(unsigned short *shrt, unsigned char *chr, int len) +{ + unsigned short s; + + for (;len;len--,shrt++,chr+=2){ + s=((*chr)<<8)|chr[1]; + *shrt=s; + } +} +#endif + +static void png_row_callback(png_structp png_ptr, png_bytep new_row, png_uint_32 + row_num, int pass) +{ + struct cached_image *cimg; +#ifdef REPACK_16 + unsigned char *tmp; + int channels; +#endif /* #ifdef REPACK_16 */ + + cimg=global_cimg; +#ifdef REPACK_16 + if (cimg->buffer_bytes_per_pixel>4) + { + channels=cimg->buffer_bytes_per_pixel/sizeof(unsigned + short); + if (PNG_INTERLACE_NONE==png_get_interlace_type(png_ptr, + ((struct png_decoder *)cimg->decoder)->info_ptr)) + { + unsigned_short_from_2char((unsigned short *)(cimg->buffer+cimg + ->buffer_bytes_per_pixel *cimg->width + *row_num), new_row, cimg->width + *channels); + }else{ + if ((unsigned)cimg->width > MAXINT / 2 / channels) overalloc(); + tmp=mem_alloc(cimg->width*2*channels); + a2char_from_unsigned_short(tmp, (unsigned short *)(cimg->buffer + +cimg->buffer_bytes_per_pixel + *cimg->width*row_num), cimg->width*channels); + png_progressive_combine_row(png_ptr, tmp, new_row); + unsigned_short_from_2char((unsigned short *)(cimg->buffer + +cimg->buffer_bytes_per_pixel + *cimg->width*row_num), tmp, cimg->width*channels); + mem_free(tmp); + } + }else +#endif /* #ifdef REPACK_16 */ + { + png_progressive_combine_row(png_ptr, + cimg->buffer+cimg->buffer_bytes_per_pixel + *cimg->width*row_num, new_row); + } + cimg->rows_added=1; +} + +static void png_end_callback(png_structp png_ptr, png_infop info) +{ + end_callback_hit=1; +} + +/* Decoder structs */ + +void png_start(struct cached_image *cimg) +{ + png_structp png_ptr; + png_infop info_ptr; + struct png_decoder *decoder; + + retry1: + png_ptr=png_create_read_struct(PNG_LIBPNG_VER_STRING, + NULL, img_my_png_error, img_my_png_warning); + if (!png_ptr) { + if (out_of_memory(NULL, 0)) goto retry1; + error("png_create_read_struct failed"); + fatal_tty_exit(); + exit(RET_FATAL); + } + retry2: + info_ptr=png_create_info_struct(png_ptr); + if (!info_ptr) { + if (out_of_memory(NULL, 0)) goto retry2; + error("png_create_info_struct failed"); + fatal_tty_exit(); + exit(RET_FATAL); + } + if (setjmp(png_jmpbuf(png_ptr))){ +error: + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + img_end(cimg); + return; + } + png_set_progressive_read_fn(png_ptr, NULL, + png_info_callback, &png_row_callback, + png_end_callback); + if (setjmp(png_jmpbuf(png_ptr))) goto error; + decoder=mem_alloc(sizeof(*decoder)); + decoder->png_ptr=png_ptr; + decoder->info_ptr=info_ptr; + cimg->decoder=decoder; +} + +void png_restart(struct cached_image *cimg, unsigned char *data, int length) +{ + png_structp png_ptr; + png_infop info_ptr; + +#ifdef DEBUG + if (!cimg->decoder) + internal("decoder NULL in png_restart\n"); +#endif /* #ifdef DEBUG */ + png_ptr=((struct png_decoder *)(cimg->decoder))->png_ptr; + info_ptr=((struct png_decoder *)(cimg->decoder))->info_ptr; + end_callback_hit=0; + if (setjmp(png_jmpbuf(png_ptr))){ + img_end(cimg); + return; + } + png_process_data(png_ptr, info_ptr, data, length); + if (end_callback_hit) img_end(cimg); +} + +void add_png_version(unsigned char **s, int *l) +{ + add_to_str(s, l, "PNG ("); +#ifdef HAVE_PNG_GET_LIBPNG_VER + add_to_str(s, l, (unsigned char *)png_get_libpng_ver(NULL)); +#else + add_to_str(s, l, PNG_LIBPNG_VER_STRING); +#endif + add_to_str(s, l, ")"); +} + +#endif /* #ifdef G */ -- cgit v1.2.3