Merge pull request #6 from saurabhb17/master

minor additions

1 files changed, 58 insertions, 0 deletions

diff --git a/potrace/greymap.h b/potrace/greymap.h
new file mode 100644
index 0000000..dcb926a
--- /dev/null
+++ b/potrace/greymap.h
@@ -0,0 +1,58 @@
+/* Copyright (C) 2001-2007 Peter Selinger.
+   This file is part of Potrace. It is free software and it is covered
+   by the GNU General Public License. See the file COPYING for details. */
+
+/* $Id: greymap.h 147 2007-04-09 00:44:09Z selinger $ */
+
+#ifndef PGM_H
+#define PGM_H
+
+#include <stdio.h>
+
+/* internal format for greymaps. Note: in this format, rows are
+   ordered from bottom to top. The pixels in each row are given from
+   left to right. */
+
+struct greymap_s {
+  int w;                 /* width, in pixels */
+  int h;                 /* height, in pixels */
+  signed short int *map;    /* raw data, w*h values */
+};
+typedef struct greymap_s greymap_t;
+
+/* macros for accessing pixel at index (x,y). Note that the origin is
+   in the *lower* left corner. U* macros omit the bounds check. */
+
+#define gm_index(gm, x, y) (&(gm)->map[(x)+(y)*(gm)->w])
+#define gm_safe(gm, x, y) ((int)(x)>=0 && (int)(x)<(gm)->w && (int)(y)>=0 && (int)(y)<(gm)->h)
+#define gm_bound(x, m) ((x)<0 ? 0 : (x)>=(m) ? (m)-1 : (x))
+#define GM_UGET(gm, x, y) (*gm_index(gm, x, y))
+#define GM_UINC(gm, x, y, b) (*gm_index(gm, x, y) += (short int)(b))
+#define GM_UINV(gm, x, y) (*gm_index(gm, x, y) = 255 - *gm_index(gm, x, y))
+#define GM_UPUT(gm, x, y, b) (*gm_index(gm, x, y) = (short int)(b))
+#define GM_GET(gm, x, y) (gm_safe(gm, x, y) ? GM_UGET(gm, x, y) : 0)
+#define GM_INC(gm, x, y, b) (gm_safe(gm, x, y) ? GM_UINC(gm, x, y, b) : 0)
+#define GM_INV(gm, x, y) (gm_safe(gm, x, y) ? GM_UINV(gm, x, y) : 0)
+#define GM_PUT(gm, x, y, b) (gm_safe(gm, x, y) ? GM_UPUT(gm, x, y, b) : 0)
+#define GM_BGET(gm, x, y) GM_UGET(gm, gm_bound(x, gm->w), gm_bound(y, gm->h))
+
+/* modes for cutting off out-of-range values. The following names
+   refer to winding numbers. I.e., make a pixel black if winding
+   number is nonzero, odd, or positive, respectively. We assume that 0
+   winding number corresponds to white (255). */
+#define GM_MODE_NONZERO 1
+#define GM_MODE_ODD 2
+#define GM_MODE_POSITIVE 3
+#define GM_MODE_NEGATIVE 4
+
+extern const char *gm_read_error;
+
+greymap_t *gm_new(int w, int h);
+greymap_t *gm_dup(greymap_t *gm);
+void gm_free(greymap_t *gm);
+void gm_clear(greymap_t *gm, int b);
+int gm_read(FILE *f, greymap_t **gmp);
+int gm_writepgm(FILE *f, greymap_t *gm, char *comment, int raw, int mode, double gamma);
+int gm_print(FILE *f, greymap_t *gm);
+
+#endif /* PGM_H */