kicad/potrace/potracelib.h

/* 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 POTRACELIB_H
#define POTRACELIB_H

/* this file defines the API for the core Potrace library. For a more
 *  detailed description of the API, see doc/potracelib.txt */

/* ---------------------------------------------------------------------- */
/* tracing parameters */

/* turn policies */
#define POTRACE_TURNPOLICY_BLACK    0
#define POTRACE_TURNPOLICY_WHITE    1
#define POTRACE_TURNPOLICY_LEFT     2
#define POTRACE_TURNPOLICY_RIGHT    3
#define POTRACE_TURNPOLICY_MINORITY 4
#define POTRACE_TURNPOLICY_MAJORITY 5
#define POTRACE_TURNPOLICY_RANDOM   6

/* structure to hold progress bar callback data */
struct potrace_progress_s
{
    void   (* callback)( double progress, void* privdata ); /* callback fn */
    void*  data;                                            /* callback function's private data */
    double min, max;                                        /* desired range of progress, e.g. 0.0 to 1.0 */
    double epsilon;                                         /* granularity: can skip smaller increments */
};
typedef struct potrace_progress_s potrace_progress_t;

/* structure to hold tracing parameters */
struct potrace_param_s
{
    int                turdsize;        /* area of largest path to be ignored */
    int                turnpolicy;      /* resolves ambiguous turns in path decomposition */
    double             alphamax;        /* corner threshold */
    int                opticurve;       /* use curve optimization? */
    double             opttolerance;    /* curve optimization tolerance */
    potrace_progress_t progress;        /* progress callback function */
};
typedef struct potrace_param_s potrace_param_t;

/* ---------------------------------------------------------------------- */
/* bitmaps */

/* native word size */
typedef unsigned long potrace_word;

/* Internal bitmap format. The n-th scanline starts at scanline(n) =
 *  (map + n*dy). Raster data is stored as a sequence of potrace_words
 *  (NOT bytes). The leftmost bit of scanline n is the most significant
 *  bit of scanline(n)[0]. */
struct potrace_bitmap_s
{
    int           w, h;     /* width and height, in pixels */
    int           dy;       /* words per scanline (not bytes) */
    potrace_word* map;      /* raw data, dy*h words */
};
typedef struct potrace_bitmap_s potrace_bitmap_t;

/* ---------------------------------------------------------------------- */
/* curves */

/* point */
struct potrace_dpoint_s
{
    double x, y;
};
typedef struct potrace_dpoint_s potrace_dpoint_t;

/* segment tags */
#define POTRACE_CURVETO 1
#define POTRACE_CORNER  2

/* closed curve segment */
struct potrace_curve_s
{
    int  n;                 // number of segments
    int* tag;               // tag[n]: POTRACE_CURVETO or POTRACE_CORNER
    potrace_dpoint_t( * c )[3]; /* c[n][3]: control points.
                                 *  c[n][0] is unused for tag[n]=POTRACE_CORNER
                                 */
};
typedef struct potrace_curve_s potrace_curve_t;

/* Linked list of signed curve segments. Also carries a tree structure. */
struct potrace_path_s
{
    int             area;               /* area of the bitmap path */
    int             sign;               /* '+' or '-', depending on orientation */
    potrace_curve_t curve;              /* this path's vector data */

    struct potrace_path_s* next;        /* linked list structure */

    struct potrace_path_s* childlist;   /* tree structure */
    struct potrace_path_s* sibling;     /* tree structure */

    struct potrace_privpath_s* priv;    /* private state */
};
typedef struct potrace_path_s potrace_path_t;

/* ---------------------------------------------------------------------- */
/* Potrace state */

#define POTRACE_STATUS_OK         0
#define POTRACE_STATUS_INCOMPLETE 1

struct potrace_state_s
{
    int             status;
    potrace_path_t* plist;              /* vector data */

    struct potrace_privstate_s* priv;   /* private state */
};
typedef struct potrace_state_s potrace_state_t;

/* ---------------------------------------------------------------------- */
/* API functions */

/* get default parameters */
potrace_param_t* potrace_param_default( void );

/* free parameter set */
void             potrace_param_free( potrace_param_t* p );

/* trace a bitmap*/
potrace_state_t* potrace_trace( const potrace_param_t*  param,
                                const potrace_bitmap_t* bm );

/* free a Potrace state */
void             potrace_state_free( potrace_state_t* st );

/* return a static plain text version string identifying this version
 *  of potracelib */
const char*      potrace_version( void );

#endif /* POTRACELIB_H */