1 /* Libart_LGPL - library of basic graphic primitives
2 * Copyright (C) 1998 Raph Levien
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
20 /* Basic constructors and operations for sorted vector paths */
27 /* Add a new segment. The arguments can be zero and NULL if the caller
28 would rather fill them in later.
30 We also realloc one auxiliary array of ints of size n_segs if
34 * art_svp_add_segment: Add a segment to an #ArtSVP structure.
35 * @p_vp: Pointer to where the #ArtSVP structure is stored.
36 * @pn_segs_max: Pointer to the allocated size of *@p_vp.
37 * @pn_points_max: Pointer to where auxiliary array is stored.
38 * @n_points: Number of points for new segment.
39 * @dir: Direction for new segment; 0 is up, 1 is down.
40 * @points: Points for new segment.
41 * @bbox: Bounding box for new segment.
43 * Adds a new segment to an ArtSVP structure. This routine reallocates
44 * the structure if necessary, updating *@p_vp and *@pn_segs_max as
47 * The new segment is simply added after all other segments. Thus,
48 * this routine should be called in order consistent with the #ArtSVP
51 * If the @bbox argument is given, it is simply stored in the new
52 * segment. Otherwise (if it is NULL), the bounding box is computed
53 * from the @points given.
56 art_svp_add_segment (ArtSVP
**p_vp
, int *pn_segs_max
,
58 int n_points
, int dir
, ArtPoint
*points
,
66 seg_num
= svp
->n_segs
++;
67 if (*pn_segs_max
== seg_num
)
70 svp
= (ArtSVP
*)art_realloc (svp
, sizeof(ArtSVP
) +
71 (*pn_segs_max
- 1) * sizeof(ArtSVPSeg
));
73 if (pn_points_max
!= NULL
)
74 *pn_points_max
= art_renew (*pn_points_max
, int, *pn_segs_max
);
76 seg
= &svp
->segs
[seg_num
];
77 seg
->n_points
= n_points
;
87 x_min
= x_max
= points
[0].x
;
88 for (i
= 1; i
< n_points
; i
++)
90 if (x_min
> points
[i
].x
)
92 if (x_max
< points
[i
].x
)
96 seg
->bbox
.y0
= points
[0].y
;
99 seg
->bbox
.y1
= points
[n_points
- 1].y
;
106 * art_svp_free: Free an #ArtSVP structure.
107 * @svp: #ArtSVP to free.
109 * Frees an #ArtSVP structure and all the segments in it.
112 art_svp_free (ArtSVP
*svp
)
114 int n_segs
= svp
->n_segs
;
117 for (i
= 0; i
< n_segs
; i
++)
118 art_free (svp
->segs
[i
].points
);
122 #ifdef ART_USE_NEW_INTERSECTOR
129 * art_svp_seg_compare: Compare two segments of an svp.
130 * @seg1: First segment to compare.
131 * @seg2: Second segment to compare.
133 * Compares two segments of an svp. Return 1 if @seg2 is below or to the
134 * right of @seg1, -1 otherwise.
137 art_svp_seg_compare (const void *s1
, const void *s2
)
139 const ArtSVPSeg
*seg1
= (ArtSVPSeg
*)s1
;
140 const ArtSVPSeg
*seg2
= (ArtSVPSeg
*)s2
;
142 if (seg1
->points
[0].y
- EPSILON
> seg2
->points
[0].y
) return 1;
143 else if (seg1
->points
[0].y
+ EPSILON
< seg2
->points
[0].y
) return -1;
144 else if (seg1
->points
[0].x
- EPSILON
> seg2
->points
[0].x
) return 1;
145 else if (seg1
->points
[0].x
+ EPSILON
< seg2
->points
[0].x
) return -1;
146 else if ((seg1
->points
[1].x
- seg1
->points
[0].x
) *
147 (seg2
->points
[1].y
- seg2
->points
[0].y
) -
148 (seg1
->points
[1].y
- seg1
->points
[0].y
) *
149 (seg2
->points
[1].x
- seg2
->points
[0].x
) > 0) return 1;