X-Git-Url: http://git.asbjorn.biz/?p=swftools.git;a=blobdiff_plain;f=lib%2Fgfxpoly%2Fpoly.c;h=7eb6509c62c745f1a9a09db2b8aeeda2342d91d7;hp=8b7226999ca350fe579d8bc11691370225bd5622;hb=83aa304f14f03d1a214817fa3af43dda74436415;hpb=163bdd5cab1758e4517e8365b3e40b5461d63640 diff --git a/lib/gfxpoly/poly.c b/lib/gfxpoly/poly.c index 8b72269..7eb6509 100644 --- a/lib/gfxpoly/poly.c +++ b/lib/gfxpoly/poly.c @@ -1,29 +1,59 @@ #include -#include #include #include #include "../mem.h" -#include "../q.h" +#include "../types.h" +#include "../MD5.h" #include "poly.h" #include "active.h" #include "xrow.h" +#include "wind.h" +#include "convert.h" +#include "heap.h" -//#define DEBUG -//#undef assert -//#define assert(x) +static gfxpoly_t*current_polygon = 0; +void gfxpoly_fail(char*expr, char*file, int line, const char*function) +{ + if(!current_polygon) { + fprintf(stderr, "assert(%s) failed in %s in line %d: %s\n", expr, file, line, function); + exit(1); + } + + void*md5 = initialize_md5(); + + int s,t; + gfxpolystroke_t*stroke = current_polygon->strokes; + for(;stroke;stroke=stroke->next) { + for(t=0;tnum_points;t++) { + update_md5(md5, (unsigned char*)&stroke->points[t].x, sizeof(stroke->points[t].x)); + update_md5(md5, (unsigned char*)&stroke->points[t].y, sizeof(stroke->points[t].y)); + } + } + unsigned char h[16]; + char filename[32+4+1]; + finish_md5(md5, h); + sprintf(filename, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x.ps", + h[0],h[1],h[2],h[3],h[4],h[5],h[6],h[7],h[8],h[9],h[10],h[11],h[12],h[13],h[14],h[15]); + + fprintf(stderr, "assert(%s) failed in %s in line %d: %s\n", expr, file, line, function); + fprintf(stderr, "I'm saving a debug file \"%s\" to the current directory.\n", filename); -char point_equals(const void*o1, const void*o2) + gfxpoly_save(current_polygon, filename); + exit(1); +} + +static 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) +static unsigned int point_hash(const void*o) { const point_t*p = o; return p->x^p->y; } -void* point_dup(const void*o) +static void* point_dup(const void*o) { const point_t*p = o; point_t*n = malloc(sizeof(point_t)); @@ -31,7 +61,7 @@ void* point_dup(const void*o) n->y = p->y; return n; } -void point_free(void*o) +static void point_free(void*o) { point_t*p = o; p->x = 0; @@ -45,103 +75,232 @@ type_t point_type = { free: point_free, }; +typedef struct _event { + eventtype_t type; + point_t p; + segment_t*s1; + segment_t*s2; +} event_t; + +/* compare_events_simple differs from compare_events in that it schedules + events from left to right regardless of type. It's only used in horizontal + processing, in order to get an x-wise sorting of the current scanline */ +static inline int compare_events_simple(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; + d = b->p.x - a->p.x; + if(d) return d; + return 0; +} + +static inline 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 need to schedule end after intersect (so that a segment about + to end has a chance to tear up a few other segs first) and start + events after end (in order not to confuse the intersection check, which + assumes there's an actual y overlap between active segments, and + because ending segments in the active list make it difficult to insert + starting segments at the right position)). + Horizontal lines come last, because the only purpose + they have is to create snapping coordinates for the segments (still) + existing in this scanline. + */ + d = b->type - a->type; + if(d) return d; + return 0; + + /* I don't see any reason why we would need to order by x- at least as long + as we do horizontal lines in a seperate pass */ + //d = b->p.x - a->p.x; + //return d; +} + +#define COMPARE_EVENTS(x,y) (compare_events(x,y)>0) +#define COMPARE_EVENTS_SIMPLE(x,y) (compare_events_simple(x,y)>0) +HEAP_DEFINE(queue,event_t,COMPARE_EVENTS); +HEAP_DEFINE(hqueue,event_t,COMPARE_EVENTS_SIMPLE); + typedef struct _status { - int y; + int32_t y; actlist_t*actlist; - heap_t*queue; - edge_t*output; + queue_t queue; xrow_t*xrow; -#ifdef DEBUG + windrule_t*windrule; + windcontext_t*context; + segment_t*ending_segments; + + gfxpolystroke_t*strokes; +#ifdef CHECKS dict_t*seen_crossings; //list of crossing we saw so far dict_t*intersecting_segs; //list of segments intersecting in this scanline dict_t*segs_with_point; //lists of segments that received a point in this scanline #endif } status_t; -int compare_events(const void*_a,const void*_b) + +int gfxpoly_num_segments(gfxpoly_t*poly) { - event_t* a = (event_t*)_a; - 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 -1; - } else - return 0; -} - -gfxpoly_t* gfxpoly_new() + gfxpolystroke_t*stroke = poly->strokes; + int count = 0; + for(;stroke;stroke=stroke->next) { + count++; + } + return count; +} +int gfxpoly_size(gfxpoly_t*poly) { - return 0; + int s,t; + int edges = 0; + gfxpolystroke_t*stroke = poly->strokes; + for(;stroke;stroke=stroke->next) { + edges += stroke->num_points-1; + } + return edges; } -void gfxpoly_destroy(gfxpoly_t*poly) + +char gfxpoly_check(gfxpoly_t*poly) { - edge_t* s = poly; - while(s) { - edge_t*next = s->next; - free(s); - s = next; + current_polygon = poly; + dict_t*d = dict_new2(&point_type); + int s,t; + gfxpolystroke_t*stroke = poly->strokes; + for(;stroke;stroke=stroke->next) { + /* In order to not confuse the fill/wind logic, existing segments must have + a non-zero edge style */ + assert(stroke->fs); + + /* put all the segments into dictionaries so that we can check + that the endpoint multiplicity is two */ + for(s=0;snum_points;s++) { + point_t p = stroke->points[s]; + int num = (s>=1 && snum_points-1)?2:1; // mid points are two points (start+end) + if(!dict_contains(d, &p)) { + dict_put(d, &p, (void*)(ptroff_t)num); + } else { + int count = (ptroff_t)dict_lookup(d, &p); + dict_del(d, &p); + count+=num; + dict_put(d, &p, (void*)(ptroff_t)count); + } + } + } + DICT_ITERATE_ITEMS(d, point_t*, p, void*, c) { + int count = (ptroff_t)c; + if(count&1) { + fprintf(stderr, "Point (%d,%d) occurs %d times\n", p->x, p->y, count); + dict_destroy(d); + assert(count%2 == 0); + } } + dict_destroy(d); + return 1; } void gfxpoly_dump(gfxpoly_t*poly) { - edge_t* s = (edge_t*)poly; - while(s) { - fprintf(stderr, "(%d,%d) -> (%d,%d)\n", s->a.x, s->a.y, s->b.x, s->b.y); - s = s->next; + int s,t; + double g = poly->gridsize; + fprintf(stderr, "polyon %p (gridsize: %f)\n", poly, poly->gridsize); + gfxpolystroke_t*stroke = poly->strokes; + for(;stroke;stroke=stroke->next) { + fprintf(stderr, "%11p", stroke); + if(stroke->dir==DIR_UP) { + for(s=stroke->num_points-1;s>=1;s--) { + point_t a = stroke->points[s]; + point_t b = stroke->points[s-1]; + fprintf(stderr, "%s (%f,%f) -> (%f,%f)%s%s\n", s!=stroke->num_points-1?" ":"", a.x*g, a.y*g, b.x*g, b.y*g, + s==1?"]":"", a.y==b.y?"H":""); + } + } else { + for(s=0;snum_points-1;s++) { + point_t a = stroke->points[s]; + point_t b = stroke->points[s+1]; + fprintf(stderr, "%s (%f,%f) -> (%f,%f)%s%s\n", s?" ":"", a.x*g, a.y*g, b.x*g, b.y*g, + s==stroke->num_points-2?"]":"", a.y==b.y?"H":""); + } + } } } -inline static event_t event_new() +void gfxpoly_save(gfxpoly_t*poly, const char*filename) { - event_t e; - memset(&e, 0, sizeof(e)); + FILE*fi = fopen(filename, "wb"); + fprintf(fi, "%% gridsize %f\n", poly->gridsize); + fprintf(fi, "%% begin\n"); + int s,t; + gfxpolystroke_t*stroke = poly->strokes; + for(;stroke;stroke=stroke->next) { + fprintf(fi, "%g setgray\n", stroke->dir==DIR_UP ? 0.7 : 0); + point_t p = stroke->points[0]; + fprintf(fi, "%d %d moveto\n", p.x, p.y); + for(s=1;snum_points;s++) { + p = stroke->points[s]; + fprintf(fi, "%d %d lineto\n", p.x, p.y); + } + fprintf(fi, "stroke\n"); + } + fprintf(fi, "showpage\n"); + fclose(fi); +} + +inline static event_t* event_new() +{ + event_t*e = rfx_calloc(sizeof(event_t)); return e; } +inline static void event_free(event_t*e) +{ + free(e); +} -void event_dump(event_t*e) +static void event_dump(event_t*e) { if(e->type == EVENT_HORIZONTAL) { - fprintf(stderr, "Horizontal [%d] (%d,%d) -> (%d,%d)\n", e->s1->nr, e->s1->a.x, e->s1->a.y, e->s1->b.x, e->s1->b.y); + fprintf(stderr, "Horizontal [%d] (%d,%d) -> (%d,%d)\n", (int)e->s1->nr, e->s1->a.x, e->s1->a.y, e->s1->b.x, e->s1->b.y); } else if(e->type == EVENT_START) { - fprintf(stderr, "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", (int)e->s1->nr, e->p.x, e->p.y); } else if(e->type == EVENT_END) { - fprintf(stderr, "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", (int)e->s1->nr, e->p.x, e->p.y); } else if(e->type == EVENT_CROSS) { - fprintf(stderr, "event: segment [%d] and [%d] intersect at (%d,%d)\n", e->s1->nr, e->s2->nr, e->p.x, e->p.y); + fprintf(stderr, "event: segment [%d] and [%d] intersect at (%d,%d)\n", (int)e->s1->nr, (int)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;} -static inline min32(int32_t v1, int32_t v2) {return v1v2?v1:v2;} +static inline int32_t min32(int32_t v1, int32_t v2) {return v1dir = DIR_DOWN; - } else if(y1>y2) { - int x = x1;x1=x2;x2=x; - int y = y1;y1=y2;y2=y; - s->dir = DIR_UP; + fprintf(stderr, "[%d] (%d,%d)->(%d,%d) ", (int)s->nr, s->a.x, s->a.y, s->b.x, s->b.y); + fprintf(stderr, " dx:%d dy:%d k:%f dx/dy=%f fs=%p\n", s->delta.x, s->delta.y, s->k, + (double)s->delta.x / s->delta.y, s->fs); +} + +static void segment_init(segment_t*s, int32_t x1, int32_t y1, int32_t x2, int32_t y2, int polygon_nr, segment_dir_t dir) +{ + s->dir = dir; + if(y1!=y2) { + assert(y1dir = DIR_HORIZONTAL; + /* We need to make sure horizontal segments always go from left to right. + "up/down" for horizontal segments is handled by "rotating" + them 90° anticlockwise in screen coordinates (tilt your head to + the right). + */ + s->dir = DIR_UP; if(x1>x2) { - int x = x1;x1=x2;x2=x; - int y = y1;y1=y2;y2=y; + s->dir = DIR_DOWN; + int32_t x = x1;x1=x2;x2=x; + int32_t y = y1;y1=y2;y2=y; } } s->a.x = x1; @@ -152,18 +311,23 @@ void segment_init(segment_t*s, int x1, int y1, int x2, int y2) s->left = s->right = 0; s->delta.x = x2-x1; s->delta.y = y2-y1; + s->minx = min32(x1,x2); + s->maxx = max32(x1,x2); + s->pos = s->a; - s->tmp = -1; - s->new_point.y = y1-1; -#define XDEBUG -#ifdef XDEBUG + s->polygon_nr = polygon_nr; static int segment_count=0; s->nr = segment_count++; -#endif +#ifdef CHECKS + /* notice: on some systems (with some compilers), for the line + (1073741823,-1073741824)->(1073741823,1073741823) + we get LINE_EQ(s->a, s) == 1. + That's why we now clamp to 26 bit. + */ assert(LINE_EQ(s->a, s) == 0); assert(LINE_EQ(s->b, s) == 0); - + /* check that all signs are in order: a a |\ /| @@ -176,98 +340,151 @@ void segment_init(segment_t*s, int x1, int y1, int x2, int y2) assert(LINE_EQ(p, s) <= 0); p.x = max32(s->a.x, s->b.x); assert(LINE_EQ(p, s) >= 0); +#endif +#ifndef DONT_REMEMBER_CROSSINGS dict_init2(&s->scheduled_crossings, &ptr_type, 0); +#endif } -segment_t* segment_new(int32_t x1, int32_t y1, int32_t x2, int32_t y2) +static segment_t* segment_new(point_t a, point_t b, int polygon_nr, segment_dir_t dir) { segment_t*s = (segment_t*)rfx_calloc(sizeof(segment_t)); - segment_init(s, x1, y1, x2, y2); + segment_init(s, a.x, a.y, b.x, b.y, polygon_nr, dir); return s; } -void segment_destroy(segment_t*s) + +static void segment_clear(segment_t*s) { +#ifndef DONT_REMEMBER_CROSSINGS dict_clear(&s->scheduled_crossings); +#endif +} +static void segment_destroy(segment_t*s) +{ + segment_clear(s); free(s); } -void gfxpoly_enqueue(edge_t*list, heap_t*queue) +static void advance_stroke(queue_t*queue, hqueue_t*hqueue, gfxpolystroke_t*stroke, int polygon_nr, int pos) { - edge_t*l; - for(l=list;l;l=l->next) { - if(l->a.x == l->b.x && - l->a.y == l->b.y) { - fprintf(stderr, "Warning: intersector input contains zero-length segments\n"); - continue; - } - segment_t*s = segment_new(l->a.x, l->a.y, l->b.x, l->b.y); + if(!stroke) + return; + segment_t*s = 0; + /* we need to queue multiple segments at once because we need to process start events + before horizontal events */ + while(pos < stroke->num_points-1) { + assert(stroke->points[pos].y <= stroke->points[pos+1].y); + s = segment_new(stroke->points[pos], stroke->points[pos+1], polygon_nr, stroke->dir); + s->fs = stroke->fs; + pos++; + s->stroke = 0; + s->stroke_pos = 0; #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"); + /*if(l->tmp) + s->nr = l->tmp;*/ + fprintf(stderr, "[%d] (%d,%d) -> (%d,%d) %s (stroke %p, %d more to come)\n", + s->nr, s->a.x, s->a.y, s->b.x, s->b.y, + s->dir==DIR_UP?"up":"down", stroke, stroke->num_points - 1 - pos); +#endif + event_t* e = event_new(); + e->type = s->delta.y ? EVENT_START : EVENT_HORIZONTAL; + e->p = s->a; + e->s1 = s; + e->s2 = 0; + + if(queue) queue_put(queue, e); + else hqueue_put(hqueue, e); + + if(e->type != EVENT_HORIZONTAL) { + break; + } + } + if(s) { + s->stroke = stroke; + s->stroke_pos = pos; + } +} + +static void gfxpoly_enqueue(gfxpoly_t*p, queue_t*queue, hqueue_t*hqueue, int polygon_nr) +{ + int t; + gfxpolystroke_t*stroke = p->strokes; + for(;stroke;stroke=stroke->next) { + assert(stroke->num_points > 1); + +#ifdef CHECKS + int s; + for(s=0;snum_points-1;s++) { + assert(stroke->points[s].y <= stroke->points[s+1].y); + } #endif - event_t e = event_new(); - e.type = s->dir==DIR_HORIZONTAL?EVENT_HORIZONTAL:EVENT_START; - e.p = s->a; - e.s1 = s; - e.s2 = 0; - heap_put(queue, &e); + advance_stroke(queue, hqueue, stroke, polygon_nr, 0); } } -void schedule_endpoint(status_t*status, segment_t*s) +static 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); + event_t*e = event_new(); + e->type = EVENT_END; + e->p = s->b; + e->s1 = s; + e->s2 = 0; + queue_put(&status->queue, e); } -void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) +static 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 */ +#ifdef CHECKS assert(s1!=s2); - - /* we probably could precompute these */ - int32_t minx1 = min32(s1->a.x,s1->b.x); + assert(s1->right == s2); + assert(s2->left == s1); int32_t miny1 = min32(s1->a.y,s1->b.y); - int32_t maxx1 = max32(s1->a.x,s1->b.x); int32_t maxy1 = max32(s1->a.y,s1->b.y); - int32_t minx2 = min32(s2->a.x,s2->b.x); 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); - + int32_t minx1 = min32(s1->a.x,s1->b.x); + int32_t minx2 = min32(s2->a.x,s2->b.x); + int32_t maxx1 = max32(s1->a.x,s1->b.x); + int32_t maxx2 = max32(s2->a.x,s2->b.x); + /* check that precomputation is sane */ + assert(minx1 == s1->minx && minx2 == s2->minx); + assert(maxx1 == s1->maxx && maxx2 == s2->maxx); /* both segments are active, so this can't happen */ assert(!(maxy1 <= miny2 || maxy2 <= miny1)); + /* we know that right now, s2 is to the right of s1, so there's + no way the complete bounding box of s1 is to the right of s1 */ + assert(!(s1->minx > s2->maxx)); + assert(s1->minx != s2->maxx || (!s1->delta.x && !s2->delta.x)); +#endif - /* TODO: optimize this. remove y, precompute the two x values */ - if(maxx1 <= minx2 || maxx2 <= minx1 || - maxy1 <= miny2 || maxy2 <= miny1) { + if(s1->maxx <= s2->minx) { +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: bounding boxes don't intersect\n", s1->nr, s2->nr); +#endif /* 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); - // we already know about this one - return; +#ifndef DONT_REMEMBER_CROSSINGS + if(dict_contains(&s1->scheduled_crossings, (void*)(ptroff_t)s2->nr)) { + /* FIXME: this whole segment hashing thing is really slow */ +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: we already scheduled this intersection\n", s1->nr, s2->nr); +// DICT_ITERATE_KEY(&s1->scheduled_crossings, void*, x) { +// fprintf(stderr, "[%d]<->[%d]\n", s1->nr, (int)(ptroff_t)x); +// } +#endif + return; // we already know about this one } +#endif - double adx = s1->delta.x; - double ady = s1->delta.y; - double bdx = s2->delta.x; - double bdy = s2->delta.y; - double det = adx*bdy - ady*bdx; + double det = (double)s1->delta.x*s2->delta.y - (double)s1->delta.y*s2->delta.x; if(!det) { if(s1->k == s2->k) { // lines are exactly on top of each other (ignored) @@ -276,20 +493,15 @@ void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) #endif return; } else { +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: they are parallel to each other\n", s1->nr, s2->nr); +#endif /* lines are parallel */ return; } } + double asign2 = LINE_EQ(s1->a, s2); - double bsign2 = LINE_EQ(s1->b, s2); - if(asign2<0 && bsign2<0) { - // segment1 is completely to the left of segment2 - return; - } - if(asign2>0 && bsign2>0) { - // segment2 is completely to the left of segment1 - return; - } if(asign2==0) { // segment1 touches segment2 in a single point (ignored) #ifdef DEBUG @@ -297,6 +509,7 @@ void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) #endif return; } + double bsign2 = LINE_EQ(s1->b, s2); if(bsign2==0) { // segment1 touches segment2 in a single point (ignored) #ifdef DEBUG @@ -304,16 +517,26 @@ void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) #endif return; } - double asign1 = LINE_EQ(s2->a, s1); - double bsign1 = LINE_EQ(s2->b, s1); - if(asign1<0 && bsign1<0) { + + if(asign2<0 && bsign2<0) { // segment1 is completely to the left of segment2 +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: [%d] is completely to the left of [%d]\n", s1->nr, s2->nr, s1->nr, s2->nr); +#endif return; } - if(asign1>0 && bsign1>0) { - // segment2 is completely to the left of segment1 + if(asign2>0 && bsign2>0) { + // segment1 is completely to the right of segment2 +#ifndef DONT_REMEMBER_CROSSINGS + assert(0); +#endif +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: [%d] is completely to the left of [%d]\n", s1->nr, s2->nr, s2->nr, s1->nr); +#endif return; } + + double asign1 = LINE_EQ(s2->a, s1); if(asign1==0) { // segment2 touches segment1 in a single point (ignored) #ifdef DEBUG @@ -321,6 +544,7 @@ void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) #endif return; } + double bsign1 = LINE_EQ(s2->b, s1); if(asign2==0) { // segment2 touches segment1 in a single point (ignored) #ifdef DEBUG @@ -329,57 +553,93 @@ void schedule_crossing(status_t*status, segment_t*s1, segment_t*s2) return; } + if(asign1<0 && bsign1<0) { + // segment2 is completely to the left of segment1 +#ifndef DONT_REMEMBER_CROSSINGS + assert(0); +#endif +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: [%d] is completely to the left of [%d]\n", s1->nr, s2->nr, s1->nr, s2->nr); +#endif + return; + } + if(asign1>0 && bsign1>0) { + // segment2 is completely to the right of segment1 +#ifdef DEBUG + fprintf(stderr, "[%d] doesn't intersect with [%d] because: [%d] is completely to the left of [%d]\n", s1->nr, s2->nr, s2->nr, s1->nr); +#endif + return; + } + +#ifdef DONT_REMEMBER_CROSSINGS + /* s2 crosses s1 from *left* to *right*. This is a crossing we already processed- + there's not way s2 would be to the left of s1 otherwise */ + if(asign1<0 && bsign1>0) return; + if(asign2>0 && bsign2<0) return; +#endif + + assert(!(asign1<0 && bsign1>0)); + assert(!(asign2>0 && bsign2<0)); + + /* TODO: should we precompute these? */ double la = (double)s1->a.x*(double)s1->b.y - (double)s1->a.y*(double)s1->b.x; double lb = (double)s2->a.x*(double)s2->b.y - (double)s2->a.y*(double)s2->b.x; point_t p; - p.x = (int32_t)ceil((-la*bdx +lb*adx) / det); - p.y = (int32_t)ceil((+lb*ady -la*bdy) / det); + p.x = (int32_t)ceil((-la*s2->delta.x + lb*s1->delta.x) / det); + p.y = (int32_t)ceil((+lb*s1->delta.y - la*s2->delta.y) / det); assert(p.y >= status->y); -#ifdef DEBUG +#ifdef CHECKS + assert(p.x >= s1->minx && p.x <= s1->maxx); + assert(p.x >= s2->minx && p.x <= s2->maxx); + point_t pair; pair.x = s1->nr; pair.y = s2->nr; +#ifndef DONT_REMEMBER_CROSSINGS assert(!dict_contains(status->seen_crossings, &pair)); dict_put(status->seen_crossings, &pair, 0); +#endif +#endif +#ifdef DEBUG fprintf(stderr, "schedule crossing between [%d] and [%d] at (%d,%d)\n", s1->nr, s2->nr, p.x, p.y); #endif +#ifndef DONT_REMEMBER_CROSSINGS /* 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); - - event_t e = event_new(); - e.type = EVENT_CROSS; - e.p = p; - e.s1 = s1; - e.s2 = s2; - heap_put(status->queue, &e); + dict_put(&s1->scheduled_crossings, (void*)(ptroff_t)(s2->nr), 0); + dict_put(&s2->scheduled_crossings, (void*)(ptroff_t)(s1->nr), 0); +#endif + + event_t* e = event_new(); + e->type = EVENT_CROSS; + e->p = p; + e->s1 = s1; + e->s2 = s2; + queue_put(&status->queue, e); return; } -void exchange_two(status_t*status, event_t*e) +static void exchange_two(status_t*status, event_t*e) { //exchange two segments in list segment_t*s1 = e->s1; segment_t*s2 = e->s2; -#ifdef DEBUG +#ifdef CHECKS 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); - assert(left == s1); - assert(right == s2); + assert(s2->left == s1); + assert(s1->right == s2); actlist_swap(status->actlist, s1, s2); - assert(actlist_right(status->actlist, s2) == s1); - assert(actlist_left(status->actlist, s1) == s2); - left = actlist_left(status->actlist, s2); - right = actlist_right(status->actlist, s1); + assert(s2->right == s1); + assert(s1->left == s2); + segment_t*left = s2->left; + segment_t*right = s1->right; if(left) schedule_crossing(status, left, s2); if(right) @@ -389,7 +649,7 @@ void exchange_two(status_t*status, event_t*e) typedef struct _box { point_t left1, left2, right1, right2; } box_t; -static inline box_t box_new(int x, int y) +static inline box_t box_new(int32_t x, int32_t y) { box_t box; box.right1.x = box.right2.x = x; @@ -399,74 +659,155 @@ static inline box_t box_new(int x, int y) return box; } -void insert_point_into_segment(status_t*status, segment_t*s, point_t p) +static void insert_point_into_segment(status_t*status, segment_t*s, point_t p) { - edge_t*e = malloc(sizeof(edge_t)); - e->a = s->pos; - e->b = p; - assert(e->a.y != e->b.y); - e->next = status->output; - status->output = e; -} + assert(s->pos.x != p.x || s->pos.y != p.y); -void mark_point_in_segment(status_t*status, segment_t*s, point_t p) -{ +#ifdef CHECKS + if(!dict_contains(status->segs_with_point, s)) + dict_put(status->segs_with_point, s, 0); + assert(s->fs_out_ok); +#endif + + if(s->fs_out) { #ifdef DEBUG - 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); - } + fprintf(stderr, "[%d] receives next point (%d,%d)->(%d,%d) (drawing)\n", s->nr, + s->pos.x, s->pos.y, p.x, p.y); #endif - assert(s->pos.x != p.x || s->pos.y != p.y); + edgestyle_t*fs = s->fs_out; + segment_dir_t dir = s->wind.is_filled?DIR_DOWN:DIR_UP; + + // omit horizontal lines + if(s->pos.y != p.y) { + point_t a = s->pos; + point_t b = p; + assert(a.y != b.y); + + gfxpolystroke_t*stroke = status->strokes; + /* find a stoke to attach this segment to. It has to have an endpoint + matching our start point, and a matching edgestyle */ + while(stroke) { + point_t p = stroke->points[stroke->num_points-1]; + if(p.x == a.x && p.y == a.y && stroke->fs == fs && stroke->dir == dir) + break; + stroke = stroke->next; + } + if(!stroke) { + stroke = rfx_calloc(sizeof(gfxpolystroke_t)); + stroke->dir = dir; + stroke->fs = fs; + stroke->next = status->strokes; + status->strokes = stroke; + stroke->points_size = 2; + stroke->points = rfx_calloc(sizeof(point_t)*stroke->points_size); + stroke->points[0] = a; + stroke->num_points = 1; + } else if(stroke->num_points == stroke->points_size) { + assert(stroke->fs); + stroke->points_size *= 2; + stroke->points = rfx_realloc(stroke->points, sizeof(point_t)*stroke->points_size); + } + stroke->points[stroke->num_points++] = b; + } + } else { #ifdef DEBUG - fprintf(stderr, "[%d] gets extra point (%d,%d)\n", s->nr, p.x, p.y); - if(!dict_contains(status->segs_with_point, s)) - dict_put(status->segs_with_point, s, 0); + fprintf(stderr, "[%d] receives next point (%d,%d) (omitting)\n", s->nr, p.x, p.y); #endif - if(s->new_point.y != p.y) { - s->new_point = p; } - s->new_pos = p; + s->pos = p; +} + +typedef struct _segrange { + double xmin; + segment_t*segmin; + double xmax; + segment_t*segmax; +} segrange_t; + +static void segrange_adjust_endpoints(segrange_t*range, int32_t y) +{ +#define XPOS_EQ(s1,s2,ypos) (XPOS((s1),(ypos))==XPOS((s2),(ypos))) + segment_t*min = range->segmin; + segment_t*max = range->segmax; + + /* we need this because if two segments intersect exactly on + the scanline, segrange_test_segment_{min,max} can't tell which + one is smaller/larger */ + if(min) while(min->left && XPOS_EQ(min, min->left, y)) { + min = min->left; + } + if(max) while(max->right && XPOS_EQ(max, max->right, y)) { + max = max->right; + } + range->segmin = min; + range->segmax = max; +} +static void segrange_test_segment_min(segrange_t*range, segment_t*seg, int32_t y) +{ + if(!seg) return; + /* we need to calculate the xpos anew (and can't use start coordinate or + intersection coordinate), because we need the xpos exactly at the end of + this scanline. + */ + double x = XPOS(seg, y); + if(!range->segmin || xxmin) { + range->segmin = seg; + range->xmin = x; + } +} +static void segrange_test_segment_max(segrange_t*range, segment_t*seg, int32_t y) +{ + if(!seg) return; + double x = XPOS(seg, y); + if(!range->segmax || x>range->xmax) { + range->segmax = seg; + range->xmax = x; + } } -/* possible optimizations: - 1.) keep two different active lists around, one for negative and one for - positive slopes - 2.) delay starting events until after this function (tricky, because we *do* - need the start coordinates) -*/ /* SLOPE_POSITIVE: - \+ \ + ------- I \I - -I\---- I + \+ \ + +------ I \I + -I\---- I I \ --I\--- I \ I \ ------- + \ + \ */ -static void mark_points_in_positively_sloped_segments(status_t*status, int32_t y) +static void add_points_to_positively_sloped_segments(status_t*status, int32_t y, segrange_t*range) { + segment_t*first=0, *last = 0; int t; for(t=0;txrow->num;t++) { box_t box = box_new(status->xrow->x[t], y); segment_t*seg = actlist_find(status->actlist, box.left2, box.left2); + seg = actlist_right(status->actlist, seg); while(seg) { if(seg->a.y == y) { - // this segment just started, ignore it - } else if(seg->delta.x < 0) { + // this segment started in this scanline, ignore it + seg->changed = 1;last = seg;if(!first) {first=seg;} + } else if(seg->delta.x <= 0) { // ignore segment w/ negative slope } else { + last = seg;if(!first) {first=seg;} double d1 = LINE_EQ(box.right1, seg); double d2 = LINE_EQ(box.right2, seg); - if(d1>=0 || d2>=0) { - mark_point_in_segment(status, seg, box.right2); + if(d1>0 || d2>=0) { + seg->changed = 1; + insert_point_into_segment(status, seg, box.right2); } else { - break; + /* we unfortunately can't break here- the active list is sorted according + to the *bottom* of the scanline. hence pretty much everything that's still + coming might reach into our box */ + //break; } } - seg = actlist_right(status->actlist, seg); + seg = seg->right; } } + segrange_test_segment_min(range, first, y); + segrange_test_segment_max(range, last, y); } /* SLOPE_NEGATIVE: | + /| + / / @@ -476,88 +817,218 @@ static void mark_points_in_positively_sloped_segments(status_t*status, int32_t y | I | /I / | /+ |/ + / */ -static void mark_points_in_negatively_sloped_segments(status_t*status, int32_t y) +static void add_points_to_negatively_sloped_segments(status_t*status, int32_t y, segrange_t*range) { + segment_t*first=0, *last = 0; int t; for(t=status->xrow->num-1;t>=0;t--) { box_t box = box_new(status->xrow->x[t], y); segment_t*seg = actlist_find(status->actlist, box.right2, box.right2); + while(seg) { if(seg->a.y == y) { - // this segment just started, ignore it - } else if(seg->delta.x >= 0) { + // this segment started in this scanline, ignore it + seg->changed = 1;last = seg;if(!first) {first=seg;} + } else if(seg->delta.x > 0) { // ignore segment w/ positive slope } else { + last = seg;if(!first) {first=seg;} double d1 = LINE_EQ(box.left1, seg); double d2 = LINE_EQ(box.left2, seg); if(d1<0 || d2<0) { - mark_point_in_segment(status, seg, box.right2); + seg->changed = 1; + insert_point_into_segment(status, seg, box.right2); } else { + //break; + } + } + seg = seg->left; + } + } + segrange_test_segment_min(range, last, y); + segrange_test_segment_max(range, first, y); +} + +/* segments ending in the current scanline need xrow treatment like everything else. + (consider an intersection taking place just above a nearly horizontal segment + ending on the current scanline- the intersection would snap down *below* the + ending segment if we don't add the intersection point to the latter right away) + we need to treat ending segments seperately, however. we have to delete them from + the active list right away to make room for intersect operations (which might + still be in the current scanline- consider two 45° polygons and a vertical polygon + intersecting on an integer coordinate). but once they're no longer in the active list, + we can't use the add_points_to_*_sloped_segments() functions anymore, and re-adding + them to the active list just for point snapping would be overkill. + (One other option to consider, however, would be to create a new active list only + for ending segments) +*/ +static void add_points_to_ending_segments(status_t*status, int32_t y) +{ + segment_t*seg = status->ending_segments; + while(seg) { + segment_t*next = seg->right;seg->right=0; + + assert(seg->b.y == status->y); + + if(status->xrow->num == 1) { + // shortcut + assert(seg->b.x == status->xrow->x[0]); + point_t p = {status->xrow->x[0], y}; + insert_point_into_segment(status, seg, p); + } else { + int t; + int start=0,end=status->xrow->num,dir=1; + if(seg->delta.x < 0) { + start = status->xrow->num-1; + end = dir = -1; + } + for(t=start;t!=end;t+=dir) { + box_t box = box_new(status->xrow->x[t], y); + double d0 = LINE_EQ(box.left1, seg); + double d1 = LINE_EQ(box.left2, seg); + double d2 = LINE_EQ(box.right1, seg); + double d3 = LINE_EQ(box.right2, seg); + if(!(d0>=0 && d1>=0 && d2>=0 && d3>0 || + d0<=0 && d1<=0 && d2<=0 && d3<0)) { + insert_point_into_segment(status, seg, box.right2); break; } } - seg = actlist_left(status->actlist, seg); + +#ifdef CHECKS + /* we *need* to find a point to insert. the segment's own end point + is in that list, for Pete's sake. */ + assert(t!=end); +#endif } + // now that this is done, too, we can also finally free this segment + segment_destroy(seg); + seg = next; } + status->ending_segments = 0; } -static void add_points(status_t*status) +static void recalculate_windings(status_t*status, segrange_t*range) { - /* TODO: we could use some clever second linked list structure so that we - only need to process points which we know we marked */ - int t; - segment_t*s = actlist_leftmost(status->actlist); +#ifdef DEBUG + fprintf(stderr, "range: [%d]..[%d]\n", SEGNR(range->segmin), SEGNR(range->segmax)); +#endif + segrange_adjust_endpoints(range, status->y); + + segment_t*s = range->segmin; + segment_t*end = range->segmax; + segment_t*last = 0; + +#ifdef DEBUG + s = actlist_leftmost(status->actlist); while(s) { - if(s->new_point.y == status->y) { - insert_point_into_segment(status, s, s->new_point); - s->pos = s->new_pos; + fprintf(stderr, "[%d]%d%s ", s->nr, s->changed, + s == range->segmin?"S":( + s == range->segmax?"E":"")); + s = s->right; + } + fprintf(stderr, "\n"); + s = range->segmin; +#endif +#ifdef CHECKS + /* test sanity: verify that we don't have changed segments + outside of the given range */ + s = actlist_leftmost(status->actlist); + while(s && s!=range->segmin) { + assert(!s->changed); + s = s->right; + } + s = actlist_rightmost(status->actlist); + while(s && s!=range->segmax) { + assert(!s->changed); + s = s->left; + } + /* in check mode, go through the whole interval so we can test + that all polygons where the edgestyle changed also have seg->changed=1 */ + s = actlist_leftmost(status->actlist); + end = 0; +#endif + + if(end) + end = end->right; + while(s!=end) { +#ifndef CHECKS + if(s->changed) +#endif + { + segment_t* left = actlist_left(status->actlist, s); + windstate_t wind = left?left->wind:status->windrule->start(status->context); + s->wind = status->windrule->add(status->context, wind, s->fs, s->dir, s->polygon_nr); + edgestyle_t*fs_old = s->fs_out; + s->fs_out = status->windrule->diff(&wind, &s->wind); + +#ifdef DEBUG + fprintf(stderr, "[%d] dir=%s wind=%d wind.filled=%s fs_old/new=%s/%s %s\n", s->nr, s->dir==DIR_UP?"up":"down", s->wind.wind_nr, s->wind.is_filled?"fill":"nofill", + fs_old?"draw":"omit", s->fs_out?"draw":"omit", + fs_old!=s->fs_out?"CHANGED":""); +#endif + assert(!(!s->changed && fs_old!=s->fs_out)); + s->changed = 0; + +#ifdef CHECKS + s->fs_out_ok = 1; +#endif } - s = actlist_right(status->actlist, s); + s = s->right; } } -void intersect_with_horizontal(status_t*status, segment_t*h) +/* we need to handle horizontal lines in order to add points to segments + we otherwise would miss during the windrule re-evaluation */ +static 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; + + if(!right) { + assert(!left); + return; + } + + left = actlist_right(status->actlist, left); //first seg to the right of h->a + right = right->right; //first seg to the right of h->b + segment_t* s = left; - while(s!=left) { + while(s!=right) { assert(s); - /* - 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); + int32_t x = XPOS_INT(s, status->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 + x, status->y ); #endif - assert(p.x >= h->a.x); - assert(p.x <= h->b.x); - assert(s->delta.x > 0 && p.x >= s->a.x || s->delta.x <= 0 && p.x <= s->a.x); - 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); + assert(x >= h->a.x); + assert(x <= h->b.x); + assert(s->delta.x > 0 && x >= s->a.x || s->delta.x <= 0 && x <= s->a.x); + assert(s->delta.x > 0 && x <= s->b.x || s->delta.x <= 0 && x >= s->b.x); + xrow_add(status->xrow, x); - s = actlist_left(status->actlist, s); + s = s->right; } - xrow_add(status->xrow, h->a.x); } -void event_apply(status_t*status, event_t*e) +static void event_apply(status_t*status, event_t*e) { switch(e->type) { case EVENT_HORIZONTAL: { + segment_t*s = e->s1; #ifdef DEBUG event_dump(e); #endif - intersect_with_horizontal(status, e->s1); + intersect_with_horizontal(status, s); + advance_stroke(&status->queue, 0, s->stroke, s->polygon_nr, s->stroke_pos); + segment_destroy(s);e->s1=0; break; } case EVENT_END: { @@ -565,18 +1036,23 @@ void event_apply(status_t*status, event_t*e) segment_t*s = e->s1; #ifdef DEBUG event_dump(e); +#endif +#ifdef CHECKS 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); + segment_t*left = s->left; + segment_t*right = s->right; actlist_delete(status->actlist, s); if(left && right) schedule_crossing(status, left, right); - segment_destroy(s);e->s1=0; + + /* schedule segment for xrow handling */ + s->left = 0; s->right = status->ending_segments; + status->ending_segments = s; + advance_stroke(&status->queue, 0, s->stroke, s->polygon_nr, s->stroke_pos); break; } case EVENT_START: { @@ -585,49 +1061,60 @@ void event_apply(status_t*status, event_t*e) 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); + assert(e->p.x == s->a.x && e->p.y == s->a.y); + actlist_insert(status->actlist, s->a, s->b, s); + segment_t*left = s->left; + segment_t*right = s->right; if(left) schedule_crossing(status, left, s); if(right) schedule_crossing(status, s, right); - - schedule_endpoint(status, e->s1); + schedule_endpoint(status, s); break; } case EVENT_CROSS: { - // exchange two (or more) segments - if(actlist_right(status->actlist, e->s1) == e->s2 && - actlist_left(status->actlist, e->s2) == e->s1) { + // exchange two segments +#ifdef DEBUG + event_dump(e); +#endif + if(e->s1->right == e->s2) { + assert(e->s2->left == e->s1); exchange_two(status, e); } else { + assert(e->s2->left != e->s1); +#ifdef DEBUG + fprintf(stderr, "Ignore this crossing ([%d] not next to [%d])\n", e->s1->nr, e->s2->nr); +#endif +#ifndef DONT_REMEMBER_CROSSINGS /* 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); + char del1 = dict_del(&e->s1->scheduled_crossings, (void*)(ptroff_t)e->s2->nr); + char del2 = dict_del(&e->s2->scheduled_crossings, (void*)(ptroff_t)e->s1->nr); assert(del1 && del2); -#ifdef DEBUG +#endif +#ifdef CHECKS point_t pair; pair.x = e->s1->nr; pair.y = e->s2->nr; +#ifndef DONT_REMEMBER_CROSSINGS assert(dict_contains(status->seen_crossings, &pair)); dict_del(status->seen_crossings, &pair); #endif +#endif } } } } -#ifdef DEBUG -void check_status(status_t*status) +#ifdef CHECKS +static void check_status(status_t*status) { 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", + SEGNR(s), s->delta.x<0?"-":"+", status->y); assert(0); @@ -636,56 +1123,261 @@ void check_status(status_t*status) } #endif -edge_t* gfxpoly_process(edge_t*poly) +static void add_horizontals(gfxpoly_t*poly, windrule_t*windrule, windcontext_t*context) { - heap_t* queue = heap_new(sizeof(event_t), compare_events); - gfxpoly_enqueue(poly, queue); + /* + |..| |...........| | | + |..| |...........| | | + |..+ + +..| +--+ +--+ + |...........| |..| | | + |...........| |..| | | + */ + +#ifdef DEBUG + fprintf(stderr, "========================================================================\n"); +#endif + hqueue_t hqueue; + hqueue_init(&hqueue); + gfxpoly_enqueue(poly, 0, &hqueue, 0); + + actlist_t* actlist = actlist_new(); + + event_t*e = hqueue_get(&hqueue); + while(e) { + int32_t y = e->p.y; + int32_t x = 0; +#ifdef DEBUG + fprintf(stderr, "HORIZONTALS ----------------------------------- %d\n", y); + actlist_dump(actlist, y-1); +#endif +#ifdef CHECKS + actlist_verify(actlist, y-1); +#endif + edgestyle_t*fill = 0; + char dir_up = 0; + char dir_down = 0; + + do { + assert(e->s1->fs); + if(fill && x != e->p.x) { + assert(!dir_up || !dir_down); + assert(dir_up || dir_down); +#ifdef DEBUG + fprintf(stderr, "%d) draw horizontal line from %d to %d\n", y, x, e->p.x); +#endif + assert(xp.x); + + gfxpolystroke_t*stroke = rfx_calloc(sizeof(gfxpolystroke_t)); + stroke->next = poly->strokes; + poly->strokes = stroke; + + stroke->num_points = 2; + stroke->points = malloc(sizeof(point_t)*2); + stroke->dir = dir_up?DIR_UP:DIR_DOWN; + stroke->fs = fill; + point_t a,b; + a.y = b.y = y; + /* we draw from low x to high x so that left/right fillstyles add up + (because the horizontal line's fill style controls the area *below* the line) + */ + a.x = e->p.x; + b.x = x; + stroke->points[0] = a; + stroke->points[1] = b; +#ifdef CHECKS + /* the output should always be intersection free polygons, so check this horizontal + line isn't puncturing any segments in the active list */ + segment_t* start = actlist_find(actlist, b, b); + segment_t* s = actlist_find(actlist, a, a); + while(s!=start) { + assert(s->a.y == y || s->b.y == y); + s = s->left; + } +#endif + } + + segment_t*s = e->s1; + + segment_t*left = 0; + switch(e->type) { + case EVENT_START: { + assert(e->p.x == s->a.x && e->p.y == s->a.y); + actlist_insert(actlist, s->a, s->b, s); + event_t* e = event_new(); + e->type = EVENT_END; + e->p = s->b; + e->s1 = s; + e->s2 = 0; + hqueue_put(&hqueue, e); + left = actlist_left(actlist, s); + if(e->s1->dir==DIR_UP) + dir_up^=1; + else + dir_down^=1; + break; + } + case EVENT_END: { + left = actlist_left(actlist, s); + actlist_delete(actlist, s); + advance_stroke(0, &hqueue, s->stroke, s->polygon_nr, s->stroke_pos); + if(e->s1->dir==DIR_DOWN) + dir_up^=1; + else + dir_down^=1; + break; + } + default: assert(0); + } + + x = e->p.x; + + fill = fill?0:&edgestyle_default; +#if 0 + if(windrule==&windrule_evenodd) { + if(!!fill != !!fill2) { + segment_dump(s); + event_dump(e); + printf("at y=%d x=%d (hline:%p)\n", e->p.y, x, old_fill); + if(e->type==EVENT_END) { + printf(" %9p\n", s->fs); + printf(" |\n"); + } + printf(" %3d %c%2d \n", before1.is_filled, e->type==EVENT_END?'|':' ', after1.is_filled); + printf("%12p -----+----- %p\n", old_fill, fill2); + printf(" %3d %c%2d \n", before2.is_filled, e->type==EVENT_START?'|':' ', after2.is_filled); + if(e->type==EVENT_START) { + printf(" |\n"); + printf(" %9p\n", s->fs); + } + } + assert(!!fill == !!fill2); + } +#endif + +#ifdef DEBUG + fprintf(stderr, "%d) event=%s[%d] left:[%d] x:%d\n", + y, e->type==EVENT_START?"start":"end", + s->nr, + left?left->nr:-1, + x); +#endif + + if(e->type == EVENT_END) + segment_destroy(s); + + event_free(e); + e = hqueue_get(&hqueue); + } while(e && y == e->p.y); + +#ifdef CHECKS + edgestyle_t*bleeding = fill; + assert(!bleeding); +#endif + } + + actlist_destroy(actlist); + hqueue_destroy(&hqueue); +} + +gfxpoly_t* gfxpoly_process(gfxpoly_t*poly1, gfxpoly_t*poly2, windrule_t*windrule, windcontext_t*context) +{ + current_polygon = poly1; + status_t status; memset(&status, 0, sizeof(status_t)); - status.queue = queue; + queue_init(&status.queue); + gfxpoly_enqueue(poly1, &status.queue, 0, /*polygon nr*/0); + if(poly2) { + assert(poly1->gridsize == poly2->gridsize); + gfxpoly_enqueue(poly2, &status.queue, 0, /*polygon nr*/1); + } + + status.windrule = windrule; + status.context = context; status.actlist = actlist_new(); -#ifdef DEBUG + +#ifdef CHECKS status.seen_crossings = dict_new2(&point_type); - gfxpoly_dump(poly); + int32_t lasty=-0x80000000; #endif - + status.xrow = xrow_new(); - event_t*e = heap_chopmax(queue); + event_t*e = queue_get(&status.queue); while(e) { + assert(e->s1->fs); status.y = e->p.y; -#ifdef DEBUG +#ifdef CHECKS + assert(status.y>=lasty); + lasty = status.y; status.intersecting_segs = dict_new2(&ptr_type); status.segs_with_point = dict_new2(&ptr_type); +#endif + +#ifdef DEBUG fprintf(stderr, "----------------------------------- %d\n", status.y); - actlist_verify_and_dump(status.actlist, status.y-1); + actlist_dump(status.actlist, status.y-1); +#endif +#ifdef CHECKS + actlist_verify(status.actlist, status.y-1); #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); + event_free(e); + e = queue_get(&status.queue); } while(e && status.y == e->p.y); xrow_sort(status.xrow); - mark_points_in_positively_sloped_segments(&status, status.y); - mark_points_in_negatively_sloped_segments(&status, status.y); - add_points(&status); + segrange_t range; + memset(&range, 0, sizeof(range)); #ifdef DEBUG + actlist_dump(status.actlist, status.y); +#endif + add_points_to_positively_sloped_segments(&status, status.y, &range); + add_points_to_negatively_sloped_segments(&status, status.y, &range); + add_points_to_ending_segments(&status, status.y); + + recalculate_windings(&status, &range); +#ifdef CHECKS check_status(&status); dict_destroy(status.intersecting_segs); dict_destroy(status.segs_with_point); #endif } -#ifdef DEBUG +#ifdef CHECKS dict_destroy(status.seen_crossings); #endif actlist_destroy(status.actlist); - heap_destroy(queue); + queue_destroy(&status.queue); xrow_destroy(status.xrow); - return status.output; + gfxpoly_t*p = (gfxpoly_t*)malloc(sizeof(gfxpoly_t)); + p->gridsize = poly1->gridsize; + p->strokes = status.strokes; + +#ifdef CHECKS + /* we only add segments with non-empty edgestyles to strokes in + recalculate_windings, but better safe than sorry */ + gfxpolystroke_t*stroke = p->strokes; + while(stroke) { + assert(stroke->fs); + stroke = stroke->next; + } +#endif + + add_horizontals(p, &windrule_evenodd, context); // output is always even/odd + //add_horizontals(p, windrule, context); + return p; +} + +static windcontext_t twopolygons = {2}; +gfxpoly_t* gfxpoly_intersect(gfxpoly_t*p1, gfxpoly_t*p2) +{ + return gfxpoly_process(p1, p2, &windrule_intersect, &twopolygons); +} +gfxpoly_t* gfxpoly_union(gfxpoly_t*p1, gfxpoly_t*p2) +{ + return gfxpoly_process(p1, p2, &windrule_union, &twopolygons); }