//#define DEBUG
//#undef assert
-//#define assert(x)
+//#define assert(x)
-char point_equals(const void*o1, const void*o2)
+char point_equals(const void*o1, const void*o2)
{
const point_t*p1 = o1;
const point_t*p2 = o2;
return p1->x == p2->x && p1->y == p2->y;
}
-unsigned int point_hash(const void*o)
+unsigned int point_hash(const void*o)
{
const point_t*p = o;
return p->x^p->y;
}
-void* point_dup(const void*o)
+void* point_dup(const void*o)
{
const point_t*p = o;
point_t*n = malloc(sizeof(point_t));
n->y = p->y;
return n;
}
-void point_free(void*o)
+void point_free(void*o)
{
point_t*p = o;
p->x = 0;
#endif
} status_t;
-int compare_events(const void*_a,const void*_b)
+int compare_events_simple(const void*_a,const void*_b)
{
event_t* a = (event_t*)_a;
- event_t* b = (event_t*)_b;
+ event_t* b = (event_t*)_b;
if(a->p.y < b->p.y) {
return 1;
} else if(a->p.y > b->p.y) {
return -1;
- /* we should schedule start events after end/intersect.
- The order of end/intersect doesn't actually matter, however,
- so this might be doing too much */
- } else if(a->type < b->type) {
- return 1;
- } else if(a->type > b->type) {
- return -1;
} else if(a->p.x < b->p.x) {
return 1;
} else if(a->p.x > b->p.x) {
return 0;
}
+int compare_events(const void*_a,const void*_b)
+{
+ event_t* a = (event_t*)_a;
+ event_t* b = (event_t*)_b;
+ int d = b->p.y - a->p.y;
+ if(d) return d;
+ /* we should schedule start events after end/intersect.
+ The order of end/intersect doesn't actually matter, however,
+ so this might be doing too much */
+ d = b->type - a->type;
+ if(d) return d;
+ d = b->p.x - a->p.x;
+ return d;
+}
+
gfxpoly_t* gfxpoly_new(double gridsize)
{
gfxpoly_t*p = (gfxpoly_t*)rfx_calloc(sizeof(gfxpoly_t));
s->dir = DIR_UP;
} else {
/* up/down for horizontal segments is handled by "rotating"
- them 90° anticlockwise in screen coordinates (tilt your head to
+ them 90° anticlockwise in screen coordinates (tilt your head to
the right) */
s->dir = DIR_UP;
if(x1>x2) {
assert(LINE_EQ(s->a, s) == 0);
assert(LINE_EQ(s->b, s) == 0);
-
+
/* check that all signs are in order:
a a
|\ /|
{
edge_t*l;
for(l=list;l;l=l->next) {
- if(l->a.x == l->b.x &&
+ if(l->a.x == l->b.x &&
l->a.y == l->b.y) {
fprintf(stderr, "Warning: intersector input contains zero-length segments\n");
continue;
int32_t miny2 = min32(s2->a.y,s2->b.y);
int32_t maxx2 = max32(s2->a.x,s2->b.x);
int32_t maxy2 = max32(s2->a.y,s2->b.y);
-
+
/* both segments are active, so this can't happen */
assert(!(maxy1 <= miny2 || maxy2 <= miny1));
/* bounding boxes don't intersect */
return;
}
-
+
if(dict_contains(&s1->scheduled_crossings, s2)) {
/* FIXME: this whole segment hashing thing is really slow */
//fprintf(stderr, "Encountered crossing between [%d] and [%d] twice\n", s1->nr, s2->nr);
*/
/*
SLOPE_POSITIVE:
- \+ \ +
------- I \I
- -I\---- I
+ \+ \ +
+------ I \I
+ -I\---- I
I \ --I\---
I \ I \ -------
+ \ + \
{
/* TODO: we could use some clever second linked list structure so that we
only need to process points we know we marked */
-
+
segment_t*s = actlist_leftmost(status->actlist);
segment_t*last = 0;
while(s) {
}
+/* we need to handle horizontal lines in order to add points to segments
+ we otherwise would miss during the windrule re-evaluation */
void intersect_with_horizontal(status_t*status, segment_t*h)
{
segment_t* left = actlist_find(status->actlist, h->a, h->a);
segment_t* right = actlist_find(status->actlist, h->b, h->b);
- segment_t* s = right;
+ /* not strictly necessary, also done by the event */
+ xrow_add(status->xrow, h->a.x);
+ point_t o = h->a;
+
+ left = actlist_right(status->actlist, left);
+ right = actlist_right(status->actlist, right);
+ segment_t* s = left;
- while(s!=left) {
+ while(s!=right) {
assert(s);
/*
- x1 + ((x2-x1)*(y-y1)) / dy =
+ x1 + ((x2-x1)*(y-y1)) / dy =
(x1*(y2-y) + x2*(y-y1)) / dy
*/
point_t p;
p.y = status->y;
p.x = XPOS(s, p.y);
#ifdef DEBUG
- fprintf(stderr, "...into [%d] (%d,%d) -> (%d,%d) at (%d,%d)\n", s->nr,
+ fprintf(stderr, "...into [%d] (%d,%d) -> (%d,%d) at (%d,%d)\n", s->nr,
s->a.x, s->a.y,
s->b.x, s->b.y,
p.x, p.y
assert(s->delta.x > 0 && p.x <= s->b.x || s->delta.x <= 0 && p.x >= s->b.x);
xrow_add(status->xrow, p.x);
- s = actlist_left(status->actlist, s);
+ s = actlist_right(status->actlist, s);
}
- xrow_add(status->xrow, h->a.x);
}
void event_apply(status_t*status, event_t*e)
{
DICT_ITERATE_KEY(status->intersecting_segs, segment_t*, s) {
if((s->pos.x != s->b.x ||
- s->pos.y != s->b.y) &&
+ s->pos.y != s->b.y) &&
!dict_contains(status->segs_with_point, s)) {
- fprintf(stderr, "Error: segment [%d] (%sslope) intersects in scanline %d, but it didn't receive a point\n",
- s->nr,
+ fprintf(stderr, "Error: segment [%d] (%sslope) intersects in scanline %d, but it didn't receive a point\n",
+ s->nr,
s->delta.x<0?"-":"+",
status->y);
assert(0);
}
#endif
+static void add_horizontals(gfxpoly_t*poly, windrule_t*windrule)
+{
+ /*
+ |..| |...........| | |
+ |..| |...........| | |
+ |..+ + +..| +--+ +--+
+ |...........| |..| | |
+ |...........| |..| | |
+ */
+
+#ifdef DEBUG
+ fprintf(stderr, "========================================================================\n");
+#endif
+ heap_t* queue = heap_new(sizeof(event_t), compare_events_simple);
+ gfxpoly_enqueue(poly->edges, queue, windrule->start(1), 0);
+
+ actlist_t* actlist = actlist_new();
+
+ event_t*e = heap_chopmax(queue);
+ while(e) {
+ int y = e->p.y;
+ int x = 0;
+ char fill = 0;
+#ifdef DEBUG
+ actlist_verify_and_dump(actlist, y-1);
+#endif
+ do {
+ if(fill && x != e->p.x) {
+#ifdef DEBUG
+ fprintf(stderr, "%d) draw horizontal line from %d to %d\n", y, x, e->p.x);
+#endif
+ edge_t*l= malloc(sizeof(edge_t));
+ l->a.y = l->b.y = y;
+ l->a.x = x;
+ l->b.x = e->p.x;
+ l->next = poly->edges;
+ poly->edges = l;
+ }
+ segment_t*left = 0;
+ segment_t*s = e->s1;
+
+ windstate_t before,after;
+ switch(e->type) {
+ case EVENT_START: {
+ actlist_insert(actlist, e->p, s);
+ event_t e;
+ e.type = EVENT_END;
+ e.p = s->b;
+ e.s1 = s;
+ e.s2 = 0;
+ heap_put(queue, &e);
+ left = actlist_left(actlist, s);
+
+ before = left?left->wind:windrule->start(1);
+ after = s->wind = windrule->add(before, s->fs, s->dir, s->polygon_nr);
+ break;
+ }
+ case EVENT_END: {
+ left = actlist_left(actlist, s);
+ actlist_delete(actlist, s);
+
+ before = s->wind;
+ after = left?left->wind:windrule->start(1);
+ break;
+ }
+ default: assert(0);
+ }
+
+ x = e->p.x;
+ fill ^= 1;//(before.is_filled != after.is_filled);
+#ifdef DEBUG
+ fprintf(stderr, "%d) event=%s[%d] left:[%d] x:%d before:%d after:%d\n",
+ y, e->type==EVENT_START?"start":"end",
+ s->nr,
+ left?left->nr:-1,
+ x,
+ before.is_filled, after.is_filled);
+#endif
+
+ if(e->type == EVENT_END)
+ segment_destroy(s);
+
+ e = heap_chopmax(queue);
+ } while(e && y == e->p.y);
+
+ if(fill) {
+ fprintf(stderr, "Error: polygon is bleeding\n");
+ exit(0);
+ }
+ }
+}
+
gfxpoly_t* gfxpoly_process(gfxpoly_t*poly, windrule_t*windrule)
{
heap_t* queue = heap_new(sizeof(event_t), compare_events);
-
+
gfxpoly_enqueue(poly->edges, queue, windrule->start(1), /*polygon nr*/0);
status_t status;
#ifdef DEBUG
status.seen_crossings = dict_new2(&point_type);
#endif
-
+
status.xrow = xrow_new();
event_t*e = heap_chopmax(queue);
#endif
xrow_reset(status.xrow);
do {
- if(e->type != EVENT_HORIZONTAL) {
- xrow_add(status.xrow, e->p.x);
- }
+ xrow_add(status.xrow, e->p.x);
event_apply(&status, e);
free(e);
e = heap_chopmax(queue);
gfxpoly_t*p = gfxpoly_new(poly->gridsize);
p->edges = status.output;
+
+ add_horizontals(p, &windrule_evenodd); // output is always even/odd
return p;
}
git.asbjorn.biz / swftools.git / commitdiff