#include <stdlib.h>
-#include <assert.h>
#include <memory.h>
#include <math.h>
#include "../mem.h"
+#include "../types.h"
#include "../q.h"
#include "poly.h"
#include "active.h"
#include "xrow.h"
+#include "wind.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)
+{
+ fprintf(stderr, "assert(%s) failed in %s in line %d: %s\n", expr, file, line, function);
+ fprintf(stderr, "I'm saving a debug file \"poly.ps\" to the current directory.\n");
+ gfxpoly_save(current_polygon, "poly.ps");
+ exit(1);
+}
-char point_equals(const void*o1, const void*o2)
+char point_equals(const void*o1, const void*o2)
{
const point_t*p1 = o1;
const point_t*p2 = o2;
return p1->x == p2->x && p1->y == p2->y;
}
-unsigned int point_hash(const void*o)
+unsigned int point_hash(const void*o)
{
const point_t*p = o;
return p->x^p->y;
}
-void* point_dup(const void*o)
+void* point_dup(const void*o)
{
const point_t*p = o;
point_t*n = malloc(sizeof(point_t));
n->y = p->y;
return n;
}
-void point_free(void*o)
+void point_free(void*o)
{
point_t*p = o;
p->x = 0;
typedef struct _status {
int y;
+ int num_polygons;
actlist_t*actlist;
heap_t*queue;
edge_t*output;
-#ifdef DEBUG
+ xrow_t*xrow;
+ windrule_t*windrule;
+ segment_t*ending_segments;
+#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 compare_events_simple(const void*_a,const void*_b)
{
event_t* a = (event_t*)_a;
- event_t* b = (event_t*)_b;
+ event_t* b = (event_t*)_b;
if(a->p.y < b->p.y) {
return 1;
} else if(a->p.y > b->p.y) {
return -1;
- /* we should schedule start events after end/intersect.
- The order of end/intersect doesn't actually matter, however,
- so this might be doing too much */
- } else if(a->type < b->type) {
- return 1;
- } else if(a->type > b->type) {
- return -1;
} else if(a->p.x < b->p.x) {
return 1;
} else if(a->p.x > b->p.x) {
return 0;
}
-gfxpoly_t* gfxpoly_new()
+int compare_events(const void*_a,const void*_b)
{
- return 0;
+ 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 before intersect (so that a segment about
+ to end has a chance to tear up a few other segs first) and start
+ events after intersect (so that start segments don't position themselves
+ between two segments about to intersect (not a problem as such, but makes
+ things slower)). 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;
+ d = b->p.x - a->p.x;
+ return d;
+}
+
+gfxpoly_t* gfxpoly_new(double gridsize)
+{
+ gfxpoly_t*p = (gfxpoly_t*)rfx_calloc(sizeof(gfxpoly_t));
+ p->gridsize = gridsize;
+ return p;
}
void gfxpoly_destroy(gfxpoly_t*poly)
{
- edge_t* s = poly;
+ edge_t* s = poly->edges;
while(s) {
edge_t*next = s->next;
free(s);
s = next;
}
+ free(poly);
+}
+int gfxpoly_size(gfxpoly_t*poly)
+{
+ edge_t* s = poly->edges;
+ int t=0;
+ while(s) {
+ s = s->next;t++;
+ }
+ return t;
+}
+char gfxpoly_check(gfxpoly_t*poly)
+{
+ edge_t* s = poly->edges;
+ dict_t*d = dict_new2(&point_type);
+ while(s) {
+ if(!dict_contains(d, &s->a)) {
+ dict_put(d, &s->a, (void*)(ptroff_t)1);
+ } else {
+ int count = (ptroff_t)dict_lookup(d, &s->a);
+ dict_del(d, &s->a);
+ count++;
+ dict_put(d, &s->a, (void*)(ptroff_t)count);
+ }
+ if(!dict_contains(d, &s->b)) {
+ dict_put(d, &s->b, (void*)(ptroff_t)1);
+ } else {
+ int count = (ptroff_t)dict_lookup(d, &s->b);
+ dict_del(d, &s->b);
+ count++;
+ dict_put(d, &s->b, (void*)(ptroff_t)count);
+ }
+ s = s->next;
+ }
+ 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;
+ edge_t* s = poly->edges;
+ double g = poly->gridsize;
while(s) {
- fprintf(stderr, "(%d,%d) -> (%d,%d)\n", s->a.x, s->a.y, s->b.x, s->b.y);
+ fprintf(stderr, "(%f,%f) -> (%f,%f)\n", s->a.x*g, s->a.y*g, s->b.x*g, s->b.y*g);
s = s->next;
}
}
+gfxpoly_t* gfxpoly_save(gfxpoly_t*poly, const char*filename)
+{
+ FILE*fi = fopen(filename, "wb");
+ fprintf(fi, "%% begin\n");
+ edge_t* s = poly->edges;
+ while(s) {
+ fprintf(fi, "%g setgray\n", s->b.y < s->a.y ? 0.7 : 0);
+ fprintf(fi, "%d %d moveto\n", s->a.x, s->a.y);
+ fprintf(fi, "%d %d lineto\n", s->b.x, s->b.y);
+ fprintf(fi, "stroke\n");
+ s = s->next;
+ }
+ fprintf(fi, "showpage\n");
+ fclose(fi);
+}
+
inline static event_t event_new()
{
event_t e;
void event_dump(event_t*e)
{
- if(e->type == EVENT_START) {
+ 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);
+ } 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);
} 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);
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;}
-void segment_init(segment_t*s, int x1, int y1, int x2, int y2)
+void segment_dump(segment_t*s)
+{
+ fprintf(stderr, "(%d,%d)->(%d,%d) ", 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);
+}
+
+void segment_init(segment_t*s, int x1, int y1, int x2, int y2, windstate_t windstate, int polygon_nr)
{
- assert(y1!=y2);
if(y1<y2) {
s->dir = DIR_DOWN;
- } else {
+ } else if(y1>y2) {
int x = x1;x1=x2;x2=x;
int y = y1;y1=y2;y2=y;
s->dir = DIR_UP;
+ } else {
+ /* 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) {
+ s->dir = DIR_DOWN;
+ int x = x1;x1=x2;x2=x;
+ int y = y1;y1=y2;y2=y;
+ }
}
s->a.x = x1;
s->a.y = y1;
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;
-#ifdef DEBUG
- static int segment_count=0; //for debugging
+ s->polygon_nr = polygon_nr;
+#define XDEBUG
+#ifdef XDEBUG
+ static int segment_count=0;
s->nr = segment_count++;
#endif
assert(LINE_EQ(s->a, s) == 0);
assert(LINE_EQ(s->b, s) == 0);
-
+
/* check that all signs are in order:
a a
|\ /|
dict_init2(&s->scheduled_crossings, &ptr_type, 0);
}
-segment_t* segment_new(int32_t x1, int32_t y1, int32_t x2, int32_t y2)
+segment_t* segment_new(int32_t x1, int32_t y1, int32_t x2, int32_t y2, windstate_t initial, int polygon_nr)
{
segment_t*s = (segment_t*)rfx_calloc(sizeof(segment_t));
- segment_init(s, x1, y1, x2, y2);
+ segment_init(s, x1, y1, x2, y2, initial, polygon_nr);
return s;
}
void segment_destroy(segment_t*s)
free(s);
}
-void gfxpoly_enqueue(edge_t*list, heap_t*queue)
+void gfxpoly_enqueue(edge_t*list, heap_t*queue, windstate_t initial, int polygon_nr)
{
- edge_t*l = list;
- while(l) {
- segment_t*s = segment_new(l->a.x, l->a.y, l->b.x, l->b.y);
+ 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, initial, polygon_nr);
+ if(l->tmp)
+ s->nr = l->tmp;
#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.type = s->delta.y ? EVENT_START : EVENT_HORIZONTAL;
e.p = s->a;
e.s1 = s;
e.s2 = 0;
heap_put(queue, &e);
- l = l->next;
}
}
/* 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);
- /* we probably could precompute these */
- int32_t minx1 = min32(s1->a.x,s1->b.x);
+#ifdef CHECKS
+ assert(s1!=s2);
+ 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) {
/* bounding boxes don't intersect */
return;
}
-
+
if(dict_contains(&s1->scheduled_crossings, s2)) {
- // we already know about this one
- return;
+ /* FIXME: this whole segment hashing thing is really slow */
+ //fprintf(stderr, "Encountered crossing between [%d] and [%d] twice\n", s1->nr, s2->nr);
+ return; // we already know about this one
}
double adx = s1->delta.x;
p.y = (int32_t)ceil((+lb*ady -la*bdy) / 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;
assert(!dict_contains(status->seen_crossings, &pair));
dict_put(status->seen_crossings, &pair, 0);
+#endif
+#ifdef DEBUG
fprintf(stderr, "schedule crossing between [%d] and [%d] at (%d,%d)\n", s1->nr, s2->nr, p.x, p.y);
#endif
//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))
schedule_crossing(status, s1, right);
}
-void insert_point_into_segment(status_t*status, segment_t*s, point_t p)
-{
-#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);
- }
-#endif
- assert(s->pos.x != p.x || s->pos.y != p.y);
-#ifdef DEBUG
- 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;
-}
-
typedef struct _box {
point_t left1, left2, right1, right2;
} box_t;
box.left2.y = box.right2.y = y;
return box;
}
-
-/* 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)
-*/
+
+
+static void insert_point_into_segment(status_t*status, segment_t*s, point_t p)
+{
+ assert(s->pos.x != p.x || s->pos.y != p.y);
+
+#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
+ 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
+ // omit horizontal lines
+ if(s->pos.y != p.y) {
+ edge_t*e = rfx_calloc(sizeof(edge_t));
+ e->tmp = s->nr;
+ e->a = s->pos;
+ e->b = p;
+ assert(e->a.y != e->b.y);
+ e->next = status->output;
+ status->output = e;
+ }
+ } else {
+#ifdef DEBUG
+ fprintf(stderr, "[%d] receives next point (%d,%d) (omitting)\n", s->nr, p.x, p.y);
+#endif
+ }
+ s->pos = p;
+}
+
+/* by restricting the recalculation of line segments to a range between the lowest
+ and the highest modified segment, we only do about a 33% overprocessing of fill
+ styles. (update: that statistic might be outdated now that xmin/xmax are double) */
+typedef struct _segrange {
+ double xmin;
+ segment_t*segmin;
+ double xmax;
+ segment_t*segmax;
+} segrange_t;
+
+static inline char xpos_eq(segment_t*s1, segment_t*s2, int y)
+{
+ if(XPOS_EQ(s1, s2, y)) {
+ return 1;
+ }
+ return 0;
+}
+
+void segrange_adjust_endpoints(segrange_t*range, int y)
+{
+#ifdef CHECK
+ /* this would mean that the segment left/right of the minimum/maximum
+ intersects the current segment exactly at the scanline, but somehow
+ wasn't found to be passing through the same snapping box */
+ assert(!min || !min->left || !XPOS_EQ(min, min->left, y));
+ assert(!max || !max->right || !XPOS_EQ(max, max->right, y));
+#endif
+
+ segment_t*min = range->segmin;
+ segment_t*max = range->segmax;
+ 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;
+}
+void segrange_test_segment_min(segrange_t*range, segment_t*seg, int 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.
+ TODO: might be faster to use XPOS_COMPARE here (see also _max)
+ */
+ double x = XPOS(seg, y);
+ if(!range->segmin || x<range->xmin) {
+ range->segmin = seg;
+ range->xmin = x;
+ }
+}
+void segrange_test_segment_max(segrange_t*range, segment_t*seg, int y)
+{
+ if(!seg) return;
+ double x = XPOS(seg, y);
+ if(!range->segmax || x>range->xmax) {
+ range->segmax = seg;
+ range->xmax = x;
+ }
+}
+
/*
SLOPE_POSITIVE:
- + \ +
------- I \I
- -I\---- I
+ \+ \ +
+------ I \I
+ -I\---- I
I \ --I\---
I \ I \ -------
+ \ + \
*/
-void add_points_to_positively_sloped_segments(status_t*status, xrow_t*xrow, 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<xrow->num;t++) {
- box_t box = box_new(xrow->x[t], y);
+ 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);
- if(seg)
- seg = seg->right;
- else
- seg = actlist_leftmost(status->actlist);
+
+ 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) {
-#ifdef DEBUG
- dict_put(status->segs_with_point, seg, 0);
-#endif
+ 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 = seg->right;
+ seg = actlist_right(status->actlist, seg);
}
}
+ segrange_test_segment_min(range, first, y);
+ segrange_test_segment_max(range, last, y);
}
/* SLOPE_NEGATIVE:
| + /| + / /
| I | /I /
| /+ |/ + /
*/
-void add_points_to_negatively_sloped_segments(status_t*status, xrow_t*xrow, 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=xrow->num-1;t>=0;t--) {
- box_t box = box_new(xrow->x[t], y);
+ 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) {
-#ifdef DEBUG
- dict_put(status->segs_with_point, seg, 0);
-#endif
+ seg->changed = 1;
insert_point_into_segment(status, seg, box.right2);
} else {
+ //break;
+ }
+ }
+ seg = actlist_left(status->actlist, seg);
+ }
+ }
+ 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)
+*/
+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
+ 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 = seg->left;
+
+#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 recalculate_windings(status_t*status, segrange_t*range)
+{
+ 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) {
+ 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 = actlist_right(status->actlist, s);
+ }
+ s = actlist_rightmost(status->actlist);
+ while(s && s!=range->segmax) {
+ assert(!s->changed);
+ s = actlist_left(status->actlist, s);
+ }
+ /* 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 = actlist_right(status->actlist, end);
+ while(s!=end) {
+#ifndef CHECK
+ if(s->changed)
+#endif
+ {
+ segment_t* left = actlist_left(status->actlist, s);
+ windstate_t wind = left?left->wind:status->windrule->start(status->num_polygons);
+ s->wind = status->windrule->add(wind, s->fs, s->dir, s->polygon_nr);
+ fillstyle_t*fs_old = s->fs_out;
+ s->fs_out = status->windrule->diff(&wind, &s->wind);
+
+ assert(!(!s->changed && fs_old!=s->fs_out));
+ s->changed = 0;
+
+ s->fs_out_ok = 1;
+#ifdef DEBUG
+ fprintf(stderr, "[%d] %s/%d/%s/%s ", s->nr, s->dir==DIR_UP?"up":"down", s->wind.wind_nr, s->wind.is_filled?"fill":"nofill", s->fs_out?"draw":"omit");
+#endif
+ }
+ s = actlist_right(status->actlist, s);
+ }
+#ifdef DEBUG
+ fprintf(stderr, "\n");
+#endif
+}
+
+/* we need to handle horizontal lines in order to add points to segments
+ we otherwise would miss during the windrule re-evaluation */
+void intersect_with_horizontal(status_t*status, segment_t*h)
+{
+ segment_t* left = actlist_find(status->actlist, h->a, h->a);
+ segment_t* right = actlist_find(status->actlist, h->b, h->b);
+
+ /* not strictly necessary, also done by the event */
+ xrow_add(status->xrow, h->a.x);
+ point_t o = h->a;
+
+ left = actlist_right(status->actlist, left);
+ right = actlist_right(status->actlist, right);
+ segment_t* s = left;
+
+ while(s!=right) {
+ assert(s);
+ int x = XPOS_INT(s, status->y);
+#ifdef DEBUG
+ 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,
+ x, status->y
+ );
+#endif
+ 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_right(status->actlist, s);
}
}
void event_apply(status_t*status, event_t*e)
{
switch(e->type) {
+ case EVENT_HORIZONTAL: {
+#ifdef DEBUG
+ event_dump(e);
+#endif
+ intersect_with_horizontal(status, e->s1);
+ segment_destroy(e->s1);e->s1=0;
+ break;
+ }
case EVENT_END: {
//delete segment from list
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);
actlist_delete(status->actlist, s);
if(left && right)
schedule_crossing(status, left, right);
- segment_destroy(s);e->s1=0;
+
+ s->left = 0; s->right = status->ending_segments;
+ status->ending_segments = s;
break;
}
case EVENT_START: {
schedule_crossing(status, left, s);
if(right)
schedule_crossing(status, s, right);
-
schedule_endpoint(status, e->s1);
break;
}
case EVENT_CROSS: {
- // exchange two (or more) segments
+ // exchange two segments
+#ifdef DEBUG
+ event_dump(e);
+#endif
if(actlist_right(status->actlist, e->s1) == e->s2 &&
actlist_left(status->actlist, e->s2) == e->s1) {
exchange_two(status, e);
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
+#ifdef CHECKS
point_t pair;
pair.x = e->s1->nr;
pair.y = e->s2->nr;
}
}
-#ifdef DEBUG
+#ifdef CHECKS
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)
+{
+ /*
+ |..| |...........| | |
+ |..| |...........| | |
+ |..+ + +..| +--+ +--+
+ |...........| |..| | |
+ |...........| |..| | |
+ */
+
+#ifdef DEBUG
+ fprintf(stderr, "========================================================================\n");
+#endif
+ heap_t* queue = heap_new(sizeof(event_t), compare_events_simple);
+ gfxpoly_enqueue(poly->edges, queue, windrule->start(1), 0);
+
+ actlist_t* actlist = actlist_new();
+
+ event_t*e = heap_chopmax(queue);
+ while(e) {
+ int y = e->p.y;
+ int x = 0;
+ char fill = 0;
+#ifdef DEBUG
+ fprintf(stderr, "----------------------------------- %d\n", y);
+ actlist_dump(actlist, y-1);
+#endif
+#ifdef CHECKS
+ /* FIXME: this actually fails sometimes */
+ 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
+ edge_t*l= malloc(sizeof(edge_t));
+ l->a.y = l->b.y = y;
+ l->a.x = x;
+ l->b.x = e->p.x;
+ l->next = poly->edges;
+ poly->edges = l;
+ }
+ segment_t*left = 0;
+ segment_t*s = e->s1;
+
+ windstate_t before,after;
+ switch(e->type) {
+ case EVENT_START: {
+ actlist_insert(actlist, e->p, s);
+ event_t e;
+ e.type = EVENT_END;
+ e.p = s->b;
+ e.s1 = s;
+ e.s2 = 0;
+ heap_put(queue, &e);
+ left = actlist_left(actlist, s);
+
+ before = left?left->wind:windrule->start(1);
+ after = s->wind = windrule->add(before, s->fs, s->dir, s->polygon_nr);
+ break;
+ }
+ case EVENT_END: {
+ left = actlist_left(actlist, s);
+ actlist_delete(actlist, s);
+
+ before = s->wind;
+ after = left?left->wind:windrule->start(1);
+ break;
+ }
+ default: assert(0);
+ }
+
+ x = e->p.x;
+ fill ^= 1;//(before.is_filled != after.is_filled);
+#ifdef DEBUG
+ fprintf(stderr, "%d) event=%s[%d] left:[%d] x:%d before:%d after:%d\n",
+ y, e->type==EVENT_START?"start":"end",
+ s->nr,
+ left?left->nr:-1,
+ x,
+ before.is_filled, after.is_filled);
+#endif
+
+ if(e->type == EVENT_END)
+ segment_destroy(s);
+
+ free(e);
+ e = heap_chopmax(queue);
+ } while(e && y == e->p.y);
+
+ assert(!fill); // check that polygon is not bleeding
+ }
+ actlist_destroy(actlist);
+ heap_destroy(queue);
+}
+
+gfxpoly_t* gfxpoly_process(gfxpoly_t*poly, windrule_t*windrule)
{
+ current_polygon = poly;
heap_t* queue = heap_new(sizeof(event_t), compare_events);
- gfxpoly_enqueue(poly, queue);
+
+ gfxpoly_enqueue(poly->edges, queue, windrule->start(1), /*polygon nr*/0);
+
status_t status;
memset(&status, 0, sizeof(status_t));
+ status.num_polygons = 1;
status.queue = queue;
+ status.windrule = windrule;
status.actlist = actlist_new();
-#ifdef DEBUG
+#ifdef CHECKS
status.seen_crossings = dict_new2(&point_type);
- gfxpoly_dump(poly);
#endif
-
- xrow_t*xrow = xrow_new();
+
+ status.xrow = xrow_new();
event_t*e = heap_chopmax(queue);
while(e) {
status.y = e->p.y;
-#ifdef DEBUG
+#ifdef CHECKS
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
- xrow_reset(xrow);
+#ifdef CHECKS
+ actlist_verify(status.actlist, status.y-1);
+#endif
+ xrow_reset(status.xrow);
do {
- xrow_add(xrow, e->p.x);
+ xrow_add(status.xrow, e->p.x);
event_apply(&status, e);
free(e);
e = heap_chopmax(queue);
} while(e && status.y == e->p.y);
- xrow_sort(xrow);
- add_points_to_positively_sloped_segments(&status, xrow, status.y);
- add_points_to_negatively_sloped_segments(&status, xrow, status.y);
+ xrow_sort(status.xrow);
+ 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);
- xrow_destroy(xrow);
+ xrow_destroy(status.xrow);
+
+ gfxpoly_t*p = gfxpoly_new(poly->gridsize);
+ p->edges = status.output;
- return status.output;
+ add_horizontals(p, &windrule_evenodd); // output is always even/odd
+ return p;
}
git.asbjorn.biz / swftools.git / blobdiff