#include <assert.h>
#include <memory.h>
#include <math.h>
+#include "../mem.h"
#include "../q.h"
#include "poly.h"
#include "active.h"
#include "xrow.h"
-#define DEBUG
+//#define DEBUG
+//#undef assert
+//#define assert(x)
char point_equals(const void*o1, const void*o2)
{
int y;
actlist_t*actlist;
heap_t*queue;
+ edge_t*output;
#ifdef DEBUG
dict_t*seen_crossings; //list of crossing we saw so far
dict_t*intersecting_segs; //list of segments intersecting in this scanline
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) {
}
void gfxpoly_destroy(gfxpoly_t*poly)
{
- segment_t* s = poly;
+ edge_t* s = poly;
while(s) {
- segment_t*right = s->right;
+ edge_t*next = s->next;
free(s);
- s = right;
- if(s==poly)
- break;
+ s = next;
}
}
void gfxpoly_dump(gfxpoly_t*poly)
{
- segment_t* s = (segment_t*)poly;
+ edge_t* s = (edge_t*)poly;
while(s) {
- printf("[%d] (%d,%d) -> (%d,%d) %s\n",
- s->nr, s->a.x, s->a.y, s->b.x, s->b.y,
- s->dir==DIR_UP?"up":"down");
- s = s->right;
- if(s==poly)
- break;
+ fprintf(stderr, "(%d,%d) -> (%d,%d)\n", s->a.x, s->a.y, s->b.x, s->b.y);
+ s = s->next;
}
}
void event_dump(event_t*e)
{
if(e->type == EVENT_START) {
- printf("event: segment [%d] starts at (%d,%d)\n", e->s1->nr, e->p.x, e->p.y);
+ fprintf(stderr, "event: segment [%d] starts at (%d,%d)\n", e->s1->nr, e->p.x, e->p.y);
} else if(e->type == EVENT_END) {
- printf("event: segment [%d] ends at (%d,%d)\n", e->s1->nr, e->p.x, e->p.y);
+ fprintf(stderr, "event: segment [%d] ends at (%d,%d)\n", e->s1->nr, e->p.x, e->p.y);
} else if(e->type == EVENT_CROSS) {
- printf("event: segment [%d] and [%d] intersect at (%d,%d)\n", e->s1->nr, e->s2->nr, e->p.x, e->p.y);
- } else assert(0);
+ fprintf(stderr, "event: segment [%d] and [%d] intersect at (%d,%d)\n", e->s1->nr, e->s2->nr, e->p.x, e->p.y);
+ } else {
+ assert(0);
+ }
}
static inline max32(int32_t v1, int32_t v2) {return v1>v2?v1:v2;}
dict_init2(&s->scheduled_crossings, &ptr_type, 0);
}
-segment_t*segment_new(int x1, int y1, int x2, int y2)
+segment_t* segment_new(int32_t x1, int32_t y1, int32_t x2, int32_t y2)
{
- segment_t*s = malloc(sizeof(segment_t));
+ segment_t*s = (segment_t*)rfx_calloc(sizeof(segment_t));
segment_init(s, x1, y1, x2, y2);
return s;
}
-
-void segment_insert_before(segment_t**list, segment_t*add)
+void segment_destroy(segment_t*s)
{
- if(!*list) {
- *list = add;
- add->left = add->right = add;
- } else {
- add->left = (*list)->left;
- add->right = (*list);
- add->right->left = add;
- add->left->right = add;
- }
+ dict_clear(&s->scheduled_crossings);
+ free(s);
}
-void segments_enqueue(segment_t*list, heap_t*queue)
+void gfxpoly_enqueue(edge_t*list, heap_t*queue)
{
- segment_t*l = list;
+ edge_t*l = list;
while(l) {
- segment_t*right = l->right;
- l->left = l->right = 0;
+ segment_t*s = segment_new(l->a.x, l->a.y, l->b.x, l->b.y);
+#ifdef DEBUG
+ fprintf(stderr, "[%d] (%d,%d) -> (%d,%d) %s\n",
+ s->nr, s->a.x, s->a.y, s->b.x, s->b.y,
+ s->dir==DIR_UP?"up":"down");
+#endif
event_t e = event_new();
e.type = EVENT_START;
- e.p = l->a;e.s1 = l;e.s2 = 0;
+ e.p = s->a;
+ e.s1 = s;
+ e.s2 = 0;
heap_put(queue, &e);
- e.type = EVENT_END;
- e.p = l->b;e.s1 = l;e.s2 = 0;
- heap_put(queue, &e);
- l = right;
- if(l==list) break;
+ l = l->next;
}
}
-void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2, int miny)
+void schedule_endpoint(status_t*status, segment_t*s)
+{
+ // schedule end point of segment
+ assert(s->b.y > status->y);
+ event_t e;
+ e.type = EVENT_END;
+ e.p = s->b;
+ e.s1 = s;
+ e.s2 = 0;
+ heap_put(status->queue, &e);
+}
+
+void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2)
{
/* the code that's required (and the checks you can perform) before
it can be said with 100% certainty that we indeed have a valid crossing
amazes me every time. -mk */
assert(s1!=s2);
- if(dict_contains(&s1->scheduled_crossings, s2)) {
- // we already know about this one
- return;
- }
-
/* we probably could precompute these */
int32_t minx1 = min32(s1->a.x,s1->b.x);
int32_t miny1 = min32(s1->a.y,s1->b.y);
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));
+
+ /* TODO: optimize this. remove y, precompute the two x values */
if(maxx1 <= minx2 || maxx2 <= minx1 ||
maxy1 <= miny2 || maxy2 <= miny1) {
/* bounding boxes don't intersect */
return;
}
+
+ if(dict_contains(&s1->scheduled_crossings, s2)) {
+ // we already know about this one
+ return;
+ }
+
double adx = s1->delta.x;
double ady = s1->delta.y;
double bdx = s2->delta.x;
if(!det) {
if(s1->k == s2->k) {
// lines are exactly on top of each other (ignored)
+#ifdef DEBUG
fprintf(stderr, "Notice: segments [%d] and [%d] are exactly on top of each other\n", s1->nr, s2->nr);
+#endif
return;
} else {
/* lines are parallel */
point_t p;
p.x = (int32_t)ceil((-la*bdx +lb*adx) / det);
p.y = (int32_t)ceil((+lb*ady -la*bdy) / det);
- /* we only schedule crossings if they are *after* the current y. That way, we don't
- schedule the same crossing twice */
- if(p.y >= miny) {
-#ifdef DEBUG
- point_t pair;
- pair.x = s1->nr;
- pair.y = s2->nr;
- assert(!dict_contains(status->seen_crossings, &pair));
- dict_put(status->seen_crossings, &pair, 0);
-#endif
- event_t e = event_new();
- e.type = EVENT_CROSS;
- e.p = p;
- e.s1 = s1;
- e.s2 = s2;
+
+ assert(p.y >= status->y);
#ifdef DEBUG
- printf("schedule crossing between [%d] and [%d] at (%d,%d)\n", s1->nr, s2->nr, e.p.x, e.p.y);
+ point_t pair;
+ pair.x = s1->nr;
+ pair.y = s2->nr;
+ assert(!dict_contains(status->seen_crossings, &pair));
+ dict_put(status->seen_crossings, &pair, 0);
+ fprintf(stderr, "schedule crossing between [%d] and [%d] at (%d,%d)\n", s1->nr, s2->nr, p.x, p.y);
#endif
- /* we insert into each other's intersection history because these segments might switch
- places */
- dict_put(&s1->scheduled_crossings, s2, 0);
- dict_put(&s2->scheduled_crossings, s1, 0);
- heap_put(status->queue, &e);
- }
- return;
-}
+ /* we insert into each other's intersection history because these segments might switch
+ places and we still want to look them up quickly after they did */
+ dict_put(&s1->scheduled_crossings, s2, 0);
+ dict_put(&s2->scheduled_crossings, s1, 0);
-/* routine dealing with the special case of a number of line segments intersecting in exactly one
- point */
-void exchange_many(status_t*status, event_t*e)
-{
- int size = 16;
- int n = 0;
- segment_t**segs = (segment_t**)malloc(sizeof(segment_t*)*size);
- segs[n] = e->s1;e->s1->tmp = n;n++;
- segs[n] = e->s2;e->s2->tmp = n;n++;
-#ifdef DEBUG
- dict_put(status->intersecting_segs, e->s1, 0);
- dict_put(status->intersecting_segs, e->s2, 0);
-#endif
- while(1) {
- event_t*ee = heap_peek(status->queue);
- if(ee->p.x != e->p.x ||
- ee->p.y != e->p.y ||
- ee->type != e->type) {
- break;
- }
- if(n>=size-1) {
- size *= 2;
- segs = realloc(segs, sizeof(segment_t*)*size);
- }
- ee = heap_chopmax(status->queue);
- if(ee->s1->tmp<0) {
- segs[n] = ee->s1;ee->s1->tmp = n;n++;
- }
- if(ee->s2->tmp<0) {
- segs[n] = ee->s2;ee->s2->tmp = n;n++;
- }
-#ifdef DEBUG
- dict_put(status->intersecting_segs, ee->s1, 0);
- dict_put(status->intersecting_segs, ee->s2, 0);
-#endif
- }
- int t;
-#ifdef DEBUG
- printf("event: multi-intersect: ");
- for(t=0;t<n;t++) {
- printf("[%d] ", segs[t]->nr);
- }
- printf("\n");
-#endif
- segment_t*left = 0;
- segment_t*right = 0;
- char warn = 0;
- for(t=0;t<n;t++) {
- if(!segs[t]->left || segs[t]->left->tmp<0) {
- assert(!left);
- left = segs[t];
- }
- if(!segs[t]->right || segs[t]->right->tmp<0) {
- assert(!right);
- right = segs[t];
- }
- if(segs[t]->tmp<0)
- warn = 1;
- }
- if(warn)
- fprintf(stderr, "Warning: multi-cross section contains rogue segments\n");
-
- assert(left);
- assert(right);
- assert(left!=right);
- actlist_invert_fromto(status->actlist, left, right);
- for(t=0;t<n;t++) {
- segs[t]->tmp = -1;
- }
- free(segs);
- if(right->left)
- schedule_crossing(status, right->left, right, status->y);
- if(left->right)
- schedule_crossing(status, left, left->right, status->y);
+ event_t e = event_new();
+ e.type = EVENT_CROSS;
+ e.p = p;
+ e.s1 = s1;
+ e.s2 = s2;
+ heap_put(status->queue, &e);
+ return;
}
void exchange_two(status_t*status, event_t*e)
segment_t*s1 = e->s1;
segment_t*s2 = e->s2;
#ifdef DEBUG
- dict_put(status->intersecting_segs, s1, 0);
- dict_put(status->intersecting_segs, s2, 0);
+ if(!dict_contains(status->intersecting_segs, s1))
+ dict_put(status->intersecting_segs, s1, 0);
+ if(!dict_contains(status->intersecting_segs, s2))
+ dict_put(status->intersecting_segs, s2, 0);
#endif
segment_t*left = actlist_left(status->actlist, s2);
segment_t*right = actlist_right(status->actlist, s1);
left = actlist_left(status->actlist, s2);
right = actlist_right(status->actlist, s1);
if(left)
- schedule_crossing(status, left, s2, status->y);
+ schedule_crossing(status, left, s2);
if(right)
- schedule_crossing(status, s1, right, status->y);
+ schedule_crossing(status, s1, right);
}
-void insert_point_into_segment(segment_t*s, point_t p)
+void insert_point_into_segment(status_t*status, segment_t*s, point_t p)
{
- if(s->pos.x == p.x && s->pos.y == p.y) {
#ifdef DEBUG
- fprintf(stderr, "Notice: tried to add (%d,%d) to segment [%d] twice\n", p.x, p.y, s->nr);
-#endif
- return;
+ if(s->pos.x == p.x && s->pos.y == p.y) {
+ fprintf(stderr, "Error: tried to add (%d,%d) to segment [%d] twice\n", p.x, p.y, s->nr);
}
+#endif
+ assert(s->pos.x != p.x || s->pos.y != p.y);
#ifdef DEBUG
- printf("[%d] gets extra point (%d,%d)\n", s->nr, p.x, p.y);
+ fprintf(stderr, "[%d] gets extra point (%d,%d)\n", s->nr, p.x, p.y);
#endif
+
+ edge_t*e = malloc(sizeof(edge_t));
+ e->a = s->pos;
+ e->b = p;
+ e->next = status->output;
+ status->output = e;
+
s->pos = p;
}
#ifdef DEBUG
dict_put(status->segs_with_point, seg, 0);
#endif
- insert_point_into_segment(seg, box.right2);
+ insert_point_into_segment(status, seg, box.right2);
} else {
break;
}
#ifdef DEBUG
dict_put(status->segs_with_point, seg, 0);
#endif
- insert_point_into_segment(seg, box.right2);
+ insert_point_into_segment(status, seg, box.right2);
} else {
break;
}
switch(e->type) {
case EVENT_END: {
//delete segment from list
- event_dump(e);
segment_t*s = e->s1;
- insert_point_into_segment(s, s->b);
+#ifdef DEBUG
+ event_dump(e);
+ dict_del(status->intersecting_segs, s);
+ dict_del(status->segs_with_point, s);
+ assert(!dict_contains(status->intersecting_segs, s));
+ assert(!dict_contains(status->segs_with_point, s));
+#endif
+ insert_point_into_segment(status, s, s->b);
segment_t*left = actlist_left(status->actlist, s);
segment_t*right = actlist_right(status->actlist, s);
actlist_delete(status->actlist, s);
- dict_clear(&s->scheduled_crossings);
if(left && right)
- schedule_crossing(status, left, right, status->y+1);
+ schedule_crossing(status, left, right);
+ segment_destroy(s);e->s1=0;
break;
}
case EVENT_START: {
//insert segment into list
+#ifdef DEBUG
event_dump(e);
+#endif
segment_t*s = e->s1;
actlist_insert(status->actlist, e->p, s);
segment_t*left = actlist_left(status->actlist, s);
segment_t*right = actlist_right(status->actlist, s);
if(left)
- schedule_crossing(status, left, s, status->y+1);
+ schedule_crossing(status, left, s);
if(right)
- schedule_crossing(status, s, right, status->y+1);
+ schedule_crossing(status, s, right);
+
+ schedule_endpoint(status, e->s1);
break;
}
case EVENT_CROSS: {
// exchange two (or more) segments
- event_t*ee = heap_peek(status->queue);
- if(ee->p.x != e->p.x ||
- ee->p.y != e->p.y ||
- ee->type != e->type) {
- event_dump(e);
+ if(actlist_right(status->actlist, e->s1) == e->s2 &&
+ actlist_left(status->actlist, e->s2) == e->s1) {
exchange_two(status, e);
} else {
- exchange_many(status, e);
+ /* ignore this crossing for now (there are some line segments in between).
+ it'll get rescheduled as soon as the "obstacles" are gone */
+ char del1 = dict_del(&e->s1->scheduled_crossings, e->s2);
+ char del2 = dict_del(&e->s2->scheduled_crossings, e->s1);
+ assert(del1 && del2);
+#ifdef DEBUG
+ point_t pair;
+ pair.x = e->s1->nr;
+ pair.y = e->s2->nr;
+ assert(dict_contains(status->seen_crossings, &pair));
+ dict_del(status->seen_crossings, &pair);
+#endif
}
}
}
void check_status(status_t*status)
{
DICT_ITERATE_KEY(status->intersecting_segs, segment_t*, s) {
- if(!dict_contains(status->segs_with_point, s)) {
+ if((s->pos.x != s->b.x ||
+ 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,
s->delta.x<0?"-":"+",
}
#endif
-void gfxpoly_process(segment_t*poly)
+edge_t* gfxpoly_process(edge_t*poly)
{
heap_t* queue = heap_new(sizeof(event_t), compare_events);
- segments_enqueue(poly, queue);
+ gfxpoly_enqueue(poly, queue);
status_t status;
memset(&status, 0, sizeof(status_t));
status.queue = queue;
status.actlist = actlist_new();
#ifdef DEBUG
status.seen_crossings = dict_new2(&point_type);
+ gfxpoly_dump(poly);
#endif
xrow_t*xrow = xrow_new();
#ifdef DEBUG
status.intersecting_segs = dict_new2(&ptr_type);
status.segs_with_point = dict_new2(&ptr_type);
- printf("----------------------------------- %d\n", status.y);
+ fprintf(stderr, "----------------------------------- %d\n", status.y);
actlist_verify_and_dump(status.actlist, status.y-1);
#endif
xrow_reset(xrow);
#ifdef DEBUG
dict_destroy(status.seen_crossings);
#endif
+ actlist_destroy(status.actlist);
heap_destroy(queue);
- gfxpoly_destroy(poly);
xrow_destroy(xrow);
+
+ return status.output;
}
git.asbjorn.biz / swftools.git / blobdiff