mewin/libpng
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Imported from libpng-1.0.2b.tar

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This commit is contained in:
Glenn Randers-Pehrson
1999-01-06 21:50:16 -06:00
parent 5c6aeb25c1
commit c944229859
33 changed files with 112 additions and 87 deletions
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15
example.c
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@@ -15,8 +15,11 @@
#include "png.h"
/* Check to see if a file is a PNG file using png_sig_cmp(). Returns
* non-zero if the image is a PNG, and 0 if it isn't a PNG.
/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp()
* returns zero if the image is a PNG and nonzero if it isn't a PNG.
*
* The function check_if_png() shown here, but not used, returns nonzero (true)
* if the file can be opened and is a PNG, 0 (false) otherwise.
*
* If this call is successful, and you are going to keep the file open,
* you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
@@ -41,12 +44,14 @@ int check_if_png(char *file_name, FILE **fp)
if ((*fp = fopen(file_name, "rb")) != NULL);
return 0;
/* Read in the signature bytes */
/* Read in some of the signature bytes */
if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
return 0;
/* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. */
return(png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
/* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
Return nonzero (true) if they match */
return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
}
/* Read a PNG file. You may want to return an error code if the read