blob: 655b53a82cb70d6f216556bfbb2d4efe007d322c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
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 */
|
