#include <stdlib.h>
-#include <assert.h>
#include <memory.h>
#include <math.h>
#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;t<stroke->num_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));
n->y = p->y;
return n;
}
-void point_free(void*o)
+static void point_free(void*o)
{
point_t*p = o;
p->x = 0;
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) {
+ for(s=0;s<stroke->num_points;s++) {
+ point_t p = stroke->points[s];
+ int num = (s>=1 && s<stroke->num_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 (%f,%f) occurs %d times\n", p->x*poly->gridsize, p->y*poly->gridsize, count);
+ dict_destroy(d);
+ return 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 %08x (gridsize: %f)\n", (int)poly, poly->gridsize);
+ gfxpolystroke_t*stroke = poly->strokes;
+ for(;stroke;stroke=stroke->next) {
+ fprintf(stderr, "%08x", (int)stroke);
+ for(s=0;s<stroke->num_points-1;s++) {
+ point_t a = stroke->points[s];
+ point_t b = stroke->points[s+1];
+ fprintf(stderr, "%s (%f,%f) -> (%f,%f)%s\n", s?" ":"", a.x*g, a.y*g, b.x*g, b.y*g,
+ s==stroke->num_points-2?"]":"");
+ }
}
}
-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;s<stroke->num_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);
}
}
-static inline max32(int32_t v1, int32_t v2) {return v1>v2?v1:v2;}
-static inline min32(int32_t v1, int32_t v2) {return v1<v2?v1:v2;}
+static inline int32_t max32(int32_t v1, int32_t v2) {return v1>v2?v1:v2;}
+static inline int32_t min32(int32_t v1, int32_t v2) {return v1<v2?v1:v2;}
-void segment_init(segment_t*s, int x1, int y1, int x2, int y2)
+static void segment_dump(segment_t*s)
{
- if(y1<y2) {
- s->dir = 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) ", 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\n", s->delta.x, s->delta.y, s->k,
+ (double)s->delta.x / s->delta.y);
+}
+
+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(y1<y2);
} else {
- s->dir = 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;
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
|\ /|
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);
+ 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 %08x, %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->dir==DIR_HORIZONTAL?EVENT_HORIZONTAL:EVENT_START;
- e.p = s->a;
- e.s1 = s;
- e.s2 = 0;
- heap_put(queue, &e);
+ 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;
}
}
-void schedule_endpoint(status_t*status, segment_t*s)
+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;s<stroke->num_points-1;s++) {
+ assert(stroke->points[s].y <= stroke->points[s+1].y);
+ }
+#endif
+ advance_stroke(queue, hqueue, stroke, polygon_nr, 0);
+ }
+}
+
+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)
#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
#endif
return;
}
+ double bsign2 = LINE_EQ(s1->b, s2);
if(bsign2==0) {
// segment1 touches segment2 in a single point (ignored)
#ifdef DEBUG
#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
#endif
return;
}
+ double bsign1 = LINE_EQ(s2->b, s1);
if(asign2==0) {
// segment2 touches segment1 in a single point (ignored)
#ifdef DEBUG
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)
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;
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);
+ /* XXX we probably will never output circular/anticircular polygons, but if
+ we do, we would need to set the segment direction here */
+ fillstyle_t*fs = s->fs_out;
+
+ // 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;
+ while(stroke) {
+ point_t p = stroke->points[stroke->num_points-1];
+ if(p.x == a.x && p.y == a.y && stroke->fs == fs)
+ break;
+ stroke = stroke->next;
+ }
+ if(!stroke) {
+ stroke = rfx_calloc(sizeof(gfxpolystroke_t));
+ stroke->dir = DIR_DOWN;
+ 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) {
+ 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 || x<range->xmin) {
+ 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;t<status->xrow->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:
| + /| + / /
| 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: check 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 fillstyle 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);
+ fillstyle_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: {
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: {
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",
+ s->nr,
s->delta.x<0?"-":"+",
status->y);
assert(0);
}
#endif
-edge_t* gfxpoly_process(edge_t*poly)
+static void add_horizontals(gfxpoly_t*poly, windrule_t*windrule, windcontext_t*context)
+{
+ /*
+ |..| |...........| | |
+ |..| |...........| | |
+ |..+ + +..| +--+ +--+
+ |...........| |..| | |
+ |...........| |..| | |
+ */
+
+#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;
+ char fill = 0;
+#ifdef DEBUG
+ fprintf(stderr, "HORIZONTALS ----------------------------------- %d\n", y);
+ actlist_dump(actlist, y-1);
+#endif
+#ifdef CHECKS
+ actlist_verify(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
+ assert(x<e->p.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; // FIXME
+ stroke->fs = 0;
+ 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 hacking through 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*left = 0;
+ segment_t*s = e->s1;
+
+ 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);
+ 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);
+ 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\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
+ char 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)
{
- heap_t* queue = heap_new(sizeof(event_t), compare_events);
- gfxpoly_enqueue(poly, queue);
+ 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) {
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;
+
+ add_horizontals(p, &windrule_evenodd, context); // output is always even/odd
+ 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);
}