Imported Upstream version 2.6upstream/2.6upstream

1 files changed, 259 insertions, 0 deletions

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 <endian.h>
+#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 */