1 #ifndef __poly_h__
2 #define __poly_h__
3 
4 #include <stdint.h>
5 #include "../q.h"
6 #include "../types.h"
7 #include "wind.h"
8 
9 /* features */
10 #define SPLAY
11 #define DONT_REMEMBER_CROSSINGS
12 
13 typedef enum {EVENT_CROSS, EVENT_END, EVENT_START, EVENT_HORIZONTAL} eventtype_t;
14 typedef enum {SLOPE_POSITIVE, SLOPE_NEGATIVE} slope_t;
15 
16 #define INVALID_COORD (0x7fffffff)
17 typedef struct _point {
18     int32_t x;
19     int32_t y;
20 } point_t;
21 type_t point_type;
22 
23 #define SEGNR(s) ((int)((s)?(s)->nr:-1))
24 
25 typedef struct _gfxpolystroke {
26     segment_dir_t dir;
27     edgestyle_t*fs;
28     int points_size;
29     int num_points;
30     point_t*points;
31     struct _gfxpolystroke*next;
32 } gfxpolystroke_t;
33 typedef struct _gfxpoly {
34     double gridsize;
35     gfxpolystroke_t*strokes;
36 } gfxpoly_t;
37 
38 typedef struct _segment {
39     point_t a;
40     point_t b;
41     point_t delta;
42     double k; //k = a.x*b.y-a.y*b.x = delta.y*a.x - delta.x*a.y (=0 for points on the segment)
43     int32_t minx, maxx;
44 
45     segment_dir_t dir;
46     edgestyle_t*fs;
47     edgestyle_t*fs_out;
48 #ifdef CHECKS
49     char fs_out_ok;
50 #endif
51 
52     int polygon_nr;
53     windstate_t wind;
54     ptroff_t nr;
55 
56 #ifdef SPLAY
57     struct _segment*parent;
58     struct _segment*leftchild;
59     struct _segment*rightchild;
60 #endif
61     struct _segment*left;
62     struct _segment*right;
63     char changed;
64 
65     point_t pos;
66 
67     gfxpolystroke_t*stroke;
68     int stroke_pos;
69 
70 #ifndef DONT_REMEMBER_CROSSINGS
71     dict_t scheduled_crossings;
72 #endif
73 } segment_t;
74 
75 typedef struct _moments {
76     double area;
77     double m[3][3];
78 } moments_t;
79 
80 #define LINE_EQ(p,s) ((double)(s)->delta.y*(p).x - (double)(s)->delta.x*(p).y - (s)->k)
81 
82 /* x1 + ((x2-x1)*(y-y1)) / dy =
83    (x1*(y2-y1) + (x2-x1)*(y-y1)) / dy =
84    (x1*(y2-y)  +  x2    *(y-y1)) / dy =
85    (x1*y2 - x2*y1 + x2*y - y*x1) / dy =
86    (k + x2*y - x1*y) / dy
87    (k + dx*y) / dy
88 */
89 //#define XPOS(s,ypos) ((s)->a.x + ((s)->delta.x * (double)((ypos) - (s)->a.y)) / (s)->delta.y)
90 #define XPOS(s,ypos) (((s)->k + (double)(s)->delta.x*ypos) / (s)->delta.y)
91 
92 #define XPOS_INT(s,ypos) ((int)ceil(XPOS((s),ypos)))
93 #define XDIFF(s1,s2,ypos) (((s1)->k + (double)(s1)->delta.x*ypos)*(s2)->delta.y - \
94                            ((s2)->k + (double)(s2)->delta.x*ypos)*(s1)->delta.y)
95 
96 void gfxpoly_fail(char*expr, char*file, int line, const char*function);
97 
98 char gfxpoly_check(gfxpoly_t*poly, char updown);
99 int gfxpoly_num_segments(gfxpoly_t*poly);
100 int gfxpoly_size(gfxpoly_t*poly);
101 void gfxpoly_dump(gfxpoly_t*poly);
102 void gfxpoly_save(gfxpoly_t*poly, const char*filename);
103 void gfxpoly_save_arrows(gfxpoly_t*poly, const char*filename);
104 gfxpoly_t* gfxpoly_process(gfxpoly_t*poly1, gfxpoly_t*poly2, windrule_t*windrule, windcontext_t*context, moments_t*moments);
105 
106 gfxpoly_t* gfxpoly_intersect(gfxpoly_t*p1, gfxpoly_t*p2);
107 gfxpoly_t* gfxpoly_union(gfxpoly_t*p1, gfxpoly_t*p2);
108 double gfxpoly_area(gfxpoly_t*p);
109 double gfxpoly_intersection_area(gfxpoly_t*p1, gfxpoly_t*p2);
110 
111 #ifndef CHECKS
112 #ifdef assert
113 #undef assert
114 #endif
115 #define assert(x)
116 #else
117 #define assert(x) ((x)?0:gfxpoly_fail(__STRING(x), __FILE__, __LINE__, __PRETTY_FUNCTION__))
118 #endif
119 
120 
121 #endif
122