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git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@1 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 136 insertions, 0 deletions

diff --git a/lib/pgm.h b/lib/pgm.h
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+/* pgm.h - header file for libpgm portable graymap library
+*/
+
+#ifndef _PGM_H_
+#define _PGM_H_
+
+#include "pbm.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+#if 0
+} /* to fake out automatic code indenters */
+#endif
+
+/* The following definition has nothing to do with the format of a PGM file */
+typedef unsigned int gray;
+
+/* Since April 2000, we are capable of reading and generating raw
+   (binary) PGM files with maxvals up to 65535.  However, before that
+   the maximum (as usually implemented) was 255, and people still want
+   to generate files with a maxval of no more than 255 in most cases
+   (because then old Netpbm programs can process them, and they're
+   only half as big).
+
+   So we keep PGM_MAXMAXVAL = 255, even though it's kind of a misnomer.  
+
+   Note that one could always write a file with maxval > PGM_MAXMAXVAL and
+   it would just go into plain (text) format instead of raw (binary) format.
+   Along with the expansion to 16 bit raw files, we took away that ability.
+   Unless you specify 'forceplain' on the pgm_writepgminit() call, it will
+   fail if you specify a maxval > PGM_OVERALLMAXVAL.  I made this design
+   decision because I don't think anyone really wants to get a plain format
+   file with samples larger than 65535 in it.  However, it should be possible
+   just to increase PGM_OVERALLMAXVAL and get that old function back for
+   maxvals that won't fit in 16 bits.  I think the only thing really
+   constraining PGM_OVERALLMAXVAL is the size of the 'gray' data structure,
+   which is generally 32 bits.
+*/
+
+#define PGM_OVERALLMAXVAL 65535
+#define PGM_MAXMAXVAL 255
+
+
+/* Magic constants. */
+
+#define PGM_MAGIC1 'P'
+#define PGM_MAGIC2 '2'
+#define RPGM_MAGIC2 '5'
+#define PGM_FORMAT (PGM_MAGIC1 * 256 + PGM_MAGIC2)
+#define RPGM_FORMAT (PGM_MAGIC1 * 256 + RPGM_MAGIC2)
+#define PGM_TYPE PGM_FORMAT
+
+/* For the alpha-mask variant of PGM: */
+#define PGM_TRANSPARENT 0
+
+/* Macro for turning a format number into a type number. */
+
+#define PGM_FORMAT_TYPE(f) ((f) == PGM_FORMAT || (f) == RPGM_FORMAT ? PGM_TYPE : PBM_FORMAT_TYPE(f))
+
+
+/* Declarations of routines. */
+
+void 
+pgm_init(int *   const argcP,
+         char ** const argv);
+
+gray *
+pgm_allocrow(unsigned int const cols);
+
+#define pgm_freerow(grayrow) free(grayrow)
+
+#define pgm_allocarray( cols, rows ) \
+  ((gray**) pm_allocarray( cols, rows, sizeof(gray) ))
+#define pgm_freearray( grays, rows ) pm_freearray( (char**) grays, rows )
+
+gray **
+pgm_readpgm(FILE * const file,
+            int *  const colsP,
+            int *  const rowsP, 
+            gray * const maxvalP);
+
+void
+pgm_readpgminit(FILE * const file,
+                int *  const colsP, 
+                int *  const rowsP,
+                gray * const maxvalP,
+                int *  const formatP);
+
+void
+pgm_readpgmrow(FILE * const file,
+               gray * const grayrow, 
+               int    const cols,
+               gray   const maxval,
+               int    const format);
+
+void
+pgm_writepgminit(FILE * const fileP, 
+                 int    const cols, 
+                 int    const rows, 
+                 gray   const maxval, 
+                 int    const forceplain);
+
+void
+pgm_writepgmrow(FILE *       const fileP, 
+                const gray * const grayrow, 
+                int          const cols, 
+                gray         const maxval, 
+                int          const forceplain);
+
+void
+pgm_writepgm(FILE *  const fileP,
+             gray ** const grays,
+             int     const cols,
+             int     const rows,
+             gray    const maxval,
+             int     const forceplain);
+
+void
+pgm_nextimage(FILE * const file, int * const eofP);
+
+void
+pgm_check(FILE *               const file, 
+          enum pm_check_type   const check_type, 
+          int                  const format, 
+          int                  const cols, 
+          int                  const rows, 
+          gray                 const maxval,
+          enum pm_check_code * const retval_p);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /*_PGM_H_*/