7 typedef enum {DIR_UP, DIR_DOWN} segment_dir_t;
8 typedef enum {EVENT_CROSS, EVENT_END, EVENT_CORNER, EVENT_START, EVENT_HORIZONTAL} eventtype_t;
9 typedef enum {SLOPE_POSITIVE, SLOPE_NEGATIVE} slope_t;
11 typedef struct _point {
16 typedef struct _fillstyle {
20 typedef struct _edge {
28 typedef struct _windstate
35 typedef struct _windrule
37 windstate_t (*start)(int num_polygons);
38 windstate_t (*add)(windstate_t left, fillstyle_t*edge, segment_dir_t dir, int polygon_nr);
39 fillstyle_t* (*diff)(windstate_t*left, windstate_t*right);
42 typedef struct _segment {
46 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)
59 struct _segment*right;
64 dict_t scheduled_crossings;
67 #define LINE_EQ(p,s) ((double)(s)->delta.y*(p).x - (double)(s)->delta.x*(p).y - (s)->k)
69 /* x1 + ((x2-x1)*(y-y1)) / dy =
70 (x1*(y2-y1) + (x2-x1)*(y-y1)) / dy =
71 (x1*(y2-y) + x2 *(y-y1)) / dy =
72 (x1*y2 - x2*y1 + x2*y - y*x1) / dy =
73 (k + x2*y - x1*y) / dy
76 //#define XPOS(s,ypos) ((s)->a.x + ((s)->delta.x * (double)((ypos) - (s)->a.y)) / (s)->delta.y)
77 #define XPOS(s,ypos) (((s)->k + (double)(s)->delta.x*ypos) / (s)->delta.y)
79 #define XPOS_INT(s,ypos) ((int)ceil(XPOS((s),ypos)))
80 #define XDIFF(s1,s2,ypos) (((s1)->k + (double)(s1)->delta.x*ypos)*(s2)->delta.y - \
81 ((s2)->k + (double)(s1)->delta.x*ypos)*(s1)->delta.y)
83 // rewrite as XDIFF==0?
84 #define XPOS_EQ(s1,s2,ypos) (XPOS((s1),(ypos))==XPOS((s2),(ypos)))
86 typedef struct _gfxpoly {
91 gfxpoly_t* gfxpoly_new(double gridsize);
92 char gfxpoly_check(gfxpoly_t*poly);
93 int gfxpoly_size(gfxpoly_t*poly);
94 void gfxpoly_dump(gfxpoly_t*poly);
95 gfxpoly_t* gfxpoly_process(gfxpoly_t*poly, windrule_t*windrule);
97 typedef struct _event {