Merge pull request #6 from saurabhb17/master

minor additions

1 files changed, 80 insertions, 0 deletions

diff --git a/potrace/curve.h b/potrace/curve.h
new file mode 100644
index 0000000..655b53a
--- /dev/null
+++ b/potrace/curve.h
@@ -0,0 +1,80 @@
+/* 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. */
+
+#ifndef CURVE_H
+#define CURVE_H
+
+#include <auxiliary.h>
+
+/* vertex is c[1] for tag=POTRACE_CORNER, and the intersection of
+ *  .c[-1][2]..c[0] and c[1]..c[2] for tag=POTRACE_CURVETO. alpha is only
+ *  defined for tag=POTRACE_CURVETO and is the alpha parameter of the curve:
+ *  .c[-1][2]..c[0] = alpha*(.c[-1][2]..vertex), and
+ *  c[2]..c[1] = alpha*(c[2]..vertex).
+ *  Beta is so that (.beta[i])[.vertex[i],.vertex[i+1]] = .c[i][2].
+ */
+
+struct privcurve_s
+{
+    int  n;         /* number of segments */
+    int* tag;       /* tag[n]: POTRACE_CORNER or POTRACE_CURVETO */
+    dpoint_t( * c )[3]; /* c[n][i]: control points.
+                         * c[n][0] is unused for tag[n]=POTRACE_CORNER */
+
+    /* the remainder of this structure is special to privcurve, and is
+     *  used in EPS debug output and special EPS "short coding". These
+     *  fields are valid only if "alphacurve" is set. */
+    int       alphacurve;   /* have the following fields been initialized? */
+    dpoint_t* vertex;       /* for POTRACE_CORNER, this equals c[1] */
+    double*   alpha;        /* only for POTRACE_CURVETO */
+    double*   alpha0;       /* "uncropped" alpha parameter - for debug output only */
+    double*   beta;
+};
+typedef struct privcurve_s privcurve_t;
+
+struct sums_s
+{
+    double x;
+    double y;
+    double x2;
+    double xy;
+    double y2;
+};
+typedef struct sums_s sums_t;
+
+/* the path structure is filled in with information about a given path
+ *  as it is accumulated and passed through the different stages of the
+ *  Potrace algorithm. Backends only need to read the fcurve and fm
+ *  fields of this data structure, but debugging backends may read
+ *  other fields. */
+struct potrace_privpath_s
+{
+    int      len;
+    point_t* pt;            /* pt[len]: path as extracted from bitmap */
+    int*     lon;           /* lon[len]: (i,lon[i]) = longest straight line from i */
+
+    int     x0, y0;         /* origin for sums */
+    sums_t* sums;           /* sums[len+1]: cache for fast summing */
+
+    int  m;                 /* length of optimal polygon */
+    int* po;                /* po[m]: optimal polygon */
+
+    privcurve_t  curve;     /* curve[m]: array of curve elements */
+    privcurve_t  ocurve;    /* ocurve[om]: array of curve elements */
+    privcurve_t* fcurve; /* final curve: this points to either curve or
+                         *  ocurve. Do not free this separately. */
+};
+typedef struct potrace_privpath_s potrace_privpath_t;
+
+/* shorter names */
+typedef potrace_privpath_t privpath_t;
+typedef potrace_path_t     path_t;
+
+path_t* path_new( void );
+void    path_free( path_t* p );
+void    pathlist_free( path_t* plist );
+int     privcurve_init( privcurve_t* curve, int n );
+void    privcurve_to_curve( privcurve_t* pc, potrace_curve_t* c );
+
+#endif /* CURVE_H */