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Diffstat (limited to 'potrace/curve.h')
| -rw-r--r-- | potrace/curve.h | 80 |
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 */ |