X-Git-Url: http://git.asbjorn.biz/?p=swftools.git;a=blobdiff_plain;f=lib%2Fgfxpoly%2Fconvert.c;h=f67699ed76458dee9ece58437b59dfe06c39ad8a;hp=5619f790fe2f8d76f2223c602243771b2c46efb6;hb=2391d7ae5d8a145a250a8b80ab8c93ba74eba030;hpb=3513ae007a04da02f11cdca9f0d08ddda9eac245

diff --git a/lib/gfxpoly/convert.c b/lib/gfxpoly/convert.c
index 5619f79..f67699e 100644
--- a/lib/gfxpoly/convert.c
+++ b/lib/gfxpoly/convert.c
@@ -4,55 +4,36 @@
 #include "../gfxdevice.h"
 #include "../mem.h"
 #include "poly.h"
+#include "convert.h"
+#include "wind.h"
 
 /* factor that determines into how many line fragments a spline is converted */
 #define SUBFRACTION (2.4)
 
-static edge_t*edge_new(int x1, int y1, int x2, int y2)
+static inline int32_t convert_coord(double x, double z)
 {
-    edge_t*s = rfx_calloc(sizeof(edge_t));
-    s->a.x = x1;
-    s->a.y = y1;
-    s->b.x = x2;
-    s->b.y = y2;
-    return s;
-}
-
-static inline int32_t convert_coord(double x)
-{
-    /* we clamp to 31 bit instead of 32 bit because we use
-       a (x1-x2) shortcut when comparing coordinates
+    /* we clamp to 26 bit because: 
+       a) we use a (x1-x2) shortcut when comparing coordinates
+       b) we need to be able to multiply two coordinates and store them in a double w/o loss of precision
     */
-    if(x < -0x40000000) x = -0x40000000;
-    if(x >  0x3fffffff) x =  0x3fffffff;
+    x *= z;
+    if(x < -0x2000000) x = -0x2000000;
+    if(x >  0x1ffffff) x =  0x1ffffff;
     return ceil(x);
 }
 
-static inline void gfxpoly_add_edge(gfxpoly_t*poly, double _x1, double _y1, double _x2, double _y2)
-{
-    int x1 = convert_coord(_x1);
-    int y1 = convert_coord(_y1);
-    int x2 = convert_coord(_x2);
-    int y2 = convert_coord(_y2);
-
-    if(x1!=x2 || y1!=y2) {
-        edge_t*s = edge_new(x1, y1, x2, y2);
-        s->next = poly->edges;
-        poly->edges = s;
-    }
-}
-
-static void convert_gfxline(gfxline_t*line, void*data, void(*moveto)(void*data, double x, double y), void(*lineto)(void*data, double x, double y), void(*setgridsize)(void*data, double g))
+static void convert_gfxline(gfxline_t*line, polywriter_t*w, double gridsize)
 {
     assert(!line || line[0].type == gfx_moveTo);
     double lastx=0,lasty=0;
+    double z = 1.0 / gridsize;
     while(line) {
         if(line->type == gfx_moveTo) {
 	    if(line->next && line->next->type != gfx_moveTo && (line->x!=lastx || line->y!=lasty)) {
-		moveto(data, line->x, line->y);
+		w->moveto(w, convert_coord(line->x,z), convert_coord(line->y,z));
 	    }
         } else if(line->type == gfx_lineTo) {
-            lineto(data, line->x, line->y);
+            w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
 	} else if(line->type == gfx_splineTo) {
             int parts = (int)(sqrt(fabs(line->x-2*line->sx+lastx) + 
                                    fabs(line->y-2*line->sy+lasty))*SUBFRACTION);
@@ -63,9 +44,9 @@ static void convert_gfxline(gfxline_t*line, void*data, void(*moveto)(void*data,
 		double t = (double)i*stepsize;
 		double sx = (line->x*t*t + 2*line->sx*t*(1-t) + lastx*(1-t)*(1-t));
 		double sy = (line->y*t*t + 2*line->sy*t*(1-t) + lasty*(1-t)*(1-t));
-		lineto(data, sx, sy);
+		w->lineto(w, convert_coord(sx,z), convert_coord(sy,z));
 	    }
-	    lineto(data, line->x, line->y);
+	    w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
         }
 	lastx = line->x;
 	lasty = line->y;
@@ -95,12 +76,13 @@ static char* readline(FILE*fi)
     }
 }
 
-static void convert_file(const char*filename, void*data, void(*moveto)(void*data, double x, double y), void(*lineto)(void*data, double x, double y),void(*setgridsize)(void*data, double gridsize))
+static void convert_file(const char*filename, polywriter_t*w, double gridsize)
 {
     FILE*fi = fopen(filename, "rb");
     if(!fi) {
         perror(filename);
     }
+    double z = 1.0 / gridsize;
     int count = 0;
     double g = 0;
     double lastx=0,lasty=0;
@@ -110,18 +92,20 @@ static void convert_file(const char*filename, void*data, void(*moveto)(void*data
             break;
         double x,y;
         char s[256];
-        if(sscanf(line, "%lf %lf %s", &x, &y, &s) == 3) {
+        if(sscanf(line, "%lf %lf %s", &x, &y, (char*)&s) == 3) {
             if(s && !strcmp(s,"moveto")) {
-		moveto(data, x, y);
+		w->moveto(w, convert_coord(x,z), convert_coord(y,z));
                 count++;
             } else if(s && !strcmp(s,"lineto")) {
-		lineto(data, x, y);
+		w->lineto(w, convert_coord(x,z), convert_coord(y,z));
                 count++;
             } else {
                 fprintf(stderr, "invalid command: %s\n", s);
             }
         } else if(sscanf(line, "%% gridsize %lf", &g) == 1) {
-	    setgridsize(data, g);
+	    gridsize = g;
+	    z = 1.0 / gridsize;
+	    w->setgridsize(w, g);
         }
         free(line);
     }
@@ -133,79 +117,28 @@ static void convert_file(const char*filename, void*data, void(*moveto)(void*data
     }
 }
 
-typedef struct _stdpoly {
-    gfxpoly_t*poly;
-    double lastx,lasty;
-    double z;
-} stdpoly_t;
-static void stdmoveto(void*data, double x, double y)
-{
-    stdpoly_t*d = (stdpoly_t*)data;
-    x *= d->z;
-    y *= d->z;
-    d->lastx = x;d->lasty = y;
-}
-static void stdlineto(void*data, double x, double y)
-{
-    stdpoly_t*d = (stdpoly_t*)data;
-    x *= d->z;
-    y *= d->z;
-    gfxpoly_add_edge(d->poly, d->lastx, d->lasty, x, y);
-    d->lastx = x;d->lasty = y;
-}
-static void stdsetgridsize(void*data, double gridsize)
-{
-    stdpoly_t*d = (stdpoly_t*)data;
-    d->poly->gridsize = gridsize;
-}
-gfxpoly_t* gfxpoly_from_gfxline(gfxline_t*line, double gridsize)
-{
-    stdpoly_t data;
-    data.poly = gfxpoly_new(gridsize);
-    data.z = 1.0 / gridsize;
-    data.lastx = data.lasty = 0;
-    convert_gfxline(line, &data, stdmoveto, stdlineto, stdsetgridsize);
-    return data.poly;
-}
-gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize)
-{
-    stdpoly_t data;
-    data.poly = gfxpoly_new(gridsize);
-    data.z = 1.0 / gridsize;
-    data.lastx = data.lasty = 0;
-    convert_file(filename, &data, stdmoveto, stdlineto, stdsetgridsize);
-    return data.poly;
-}
-
 typedef struct _compactpoly {
-    gfxcompactpoly_t*poly;
+    gfxpoly_t*poly;
     point_t last;
-    double z;
-    int strokes_size;
     point_t*points;
     int num_points;
     int points_size;
     segment_dir_t dir;
+    char new;
 } compactpoly_t;
 
-void add_segment(compactpoly_t*data, point_t start, segment_dir_t dir)
-{
-    if(data->poly->num_strokes == data->strokes_size) {
-	data->strokes_size <<= 1;
-	assert(data->strokes_size > data->poly->num_strokes);
-	data->poly->strokes = rfx_realloc(data->poly->strokes, data->strokes_size);
-    }
-    data->poly->strokes[data->poly->num_strokes].dir = dir;
-    data->points[0] = start;
-    data->num_points = 1;
-    data->dir = dir;
-}
 void finish_segment(compactpoly_t*data)
 {
     if(data->num_points <= 1)
 	return;
     point_t*p = malloc(sizeof(point_t)*data->num_points);
-    data->poly->strokes[data->poly->num_strokes-1].points = p;
+    gfxpolystroke_t*s = rfx_calloc(sizeof(gfxpolystroke_t));
+    s->next = data->poly->strokes;
+    data->poly->strokes = s;
+    s->num_points = s->points_size = data->num_points;
+    s->dir = data->dir;
+    s->points = p;
+    assert(data->dir != DIR_UNKNOWN);
     if(data->dir == DIR_UP) {
 	int t;
 	int s = data->num_points;
@@ -215,83 +148,392 @@ void finish_segment(compactpoly_t*data)
     } else {
 	memcpy(p, data->points, sizeof(point_t)*data->num_points);
     }
-    data->poly->num_strokes++;
+#ifdef CHECKS
+    int t;
+    for(t=0;t<data->num_points-1;t++) {
+	assert(p[t].y<=p[t+1].y);
+    }
+#endif
 }
-static void compactmoveto(void*_data, double _x, double _y)
+static void compactmoveto(polywriter_t*w, int32_t x, int32_t y)
 {
-    compactpoly_t*data = (compactpoly_t*)_data;
-    data->dir = DIR_UNKNOWN;
+    compactpoly_t*data = (compactpoly_t*)w->internal;
     point_t p;
-    p.x = convert_coord(_x);
-    p.y = convert_coord(_y);
+    p.x = x;
+    p.y = y;
+    if(p.x != data->last.x || p.y != data->last.y) {
+	data->new = 1;
+    }
     data->last = p;
 }
-static void compactlineto(void*_data, double _x, double _y)
+static void compactlineto(polywriter_t*w, int32_t x, int32_t y)
 {
-    compactpoly_t*data = (compactpoly_t*)_data;
+    compactpoly_t*data = (compactpoly_t*)w->internal;
     point_t p;
-    p.x = convert_coord(_x);
-    p.y = convert_coord(_y);
-    if(p.y < data->last.y && data->dir != DIR_UP ||
-       p.y > data->last.y && data->dir != DIR_DOWN) {
-	data->dir = p.y > data->last.y ? DIR_DOWN : DIR_UP;
+    p.x = x;
+    p.y = y;
+    if(p.x == data->last.x && p.y == data->last.y)
+	return;
+
+    if((p.y < data->last.y && data->dir != DIR_UP) ||
+       (p.y > data->last.y && data->dir != DIR_DOWN) || data->new) {
 	finish_segment(data);
-	add_segment(data, data->last, data->dir);
+	data->dir = p.y > data->last.y ? DIR_DOWN : DIR_UP;
+	data->points[0] = data->last;
+	data->num_points = 1;
     }
+    data->new = 0;
+
     if(data->points_size == data->num_points) {
 	data->points_size <<= 1;
 	assert(data->points_size > data->num_points);
-	data->points = rfx_realloc(data->points, data->points_size);
+	data->points = rfx_realloc(data->points, sizeof(point_t)*data->points_size);
     }
     data->points[data->num_points++] = p;
+    data->last = p;
 }
-static void compactsetgridsize(void*data, double gridsize)
+static void compactsetgridsize(polywriter_t*w, double gridsize)
 {
-    compactpoly_t*d = (compactpoly_t*)data;
+    compactpoly_t*d = (compactpoly_t*)w->internal;
     d->poly->gridsize = gridsize;
 }
-static void compactinit(compactpoly_t*data, double gridsize)
+/*static int compare_stroke(const void*_s1, const void*_s2)
+{
+    gfxpolystroke_t*s1 = (gfxpolystroke_t*)_s1;
+    gfxpolystroke_t*s2 = (gfxpolystroke_t*)_s2;
+    return s1->points[0].y - s2->points[0].y;
+}*/
+static void*compactfinish(polywriter_t*w)
 {
-    data->poly = rfx_calloc(sizeof(gfxcompactpoly_t));
-    data->poly->gridsize = gridsize;
-    data->z = 1.0 / gridsize;
+    compactpoly_t*data = (compactpoly_t*)w->internal;
+    finish_segment(data);
+    //qsort(data->poly->strokes, data->poly->num_strokes, sizeof(gfxpolystroke_t), compare_stroke);
+    free(data->points);
+    gfxpoly_t*poly = data->poly;
+    free(w->internal);w->internal = 0;
+    return (void*)poly;
+}
+void gfxpolywriter_init(polywriter_t*w)
+{
+    w->moveto = compactmoveto;
+    w->lineto = compactlineto;
+    w->setgridsize = compactsetgridsize;
+    w->finish = compactfinish;
+    compactpoly_t*data = w->internal = rfx_calloc(sizeof(compactpoly_t));
+    data->poly = rfx_calloc(sizeof(gfxpoly_t));
+    data->poly->gridsize = 1.0;
     data->last.x = data->last.y = 0;
-    data->strokes_size = 16;
     data->num_points = 0;
     data->points_size = 16;
+    data->new = 1;
+    data->dir = DIR_UNKNOWN;
     data->points = (point_t*)rfx_alloc(sizeof(point_t)*data->points_size);
-    data->poly->strokes = (gfxstroke_t*)rfx_alloc(sizeof(gfxstroke_t)*data->strokes_size);
+    data->poly->strokes = 0;
 }
-static gfxcompactpoly_t*compactfinish(compactpoly_t*data)
+
+gfxpoly_t* gfxpoly_from_fill(gfxline_t*line, double gridsize)
 {
-    finish_segment(data);
-    data->poly->strokes = rfx_realloc(data->poly->strokes, sizeof(gfxstroke_t)*data->poly->num_strokes);
-    free(data->points);
-    return data->poly;
+    polywriter_t writer;
+    gfxpolywriter_init(&writer);
+    writer.setgridsize(&writer, gridsize);
+    convert_gfxline(line, &writer, gridsize);
+    return (gfxpoly_t*)writer.finish(&writer);
 }
-gfxcompactpoly_t* gfxcompactpoly_from_gfxline(gfxline_t*line, double gridsize)
+gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize)
 {
-    compactpoly_t data;
-    compactinit(&data, gridsize);
-    data.poly->gridsize = gridsize;
-    convert_gfxline(line, &data, compactmoveto, compactlineto, compactsetgridsize);
-    return compactfinish(&data);
+    polywriter_t writer;
+    gfxpolywriter_init(&writer);
+    writer.setgridsize(&writer, gridsize);
+    convert_file(filename, &writer, gridsize);
+    return (gfxpoly_t*)writer.finish(&writer);
+}
+void gfxpoly_destroy(gfxpoly_t*poly)
+{
+    int t;
+    gfxpolystroke_t*stroke = poly->strokes;
+    while(stroke) {
+	gfxpolystroke_t*next = stroke->next;
+	free(stroke->points);
+	free(stroke);
+	stroke = next;
+    }
+    free(poly);
 }
-gfxcompactpoly_t* gfxcompactpoly_from_file(const char*filename, double gridsize)
+
+typedef struct _polydraw_internal
 {
-    compactpoly_t data;
-    compactinit(&data, gridsize);
-    data.poly->gridsize = gridsize;
-    convert_file(filename, &data, compactmoveto, compactlineto, compactsetgridsize);
-    return compactfinish(&data);
+    double lx, ly;
+    int32_t lastx, lasty;
+    int32_t x0, y0;
+    double z;
+    char last;
+    polywriter_t writer;
+} polydraw_internal_t;
+
+static void polydraw_moveTo(gfxdrawer_t*d, gfxcoord_t _x, gfxcoord_t _y)
+{
+    polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
+    int32_t x = convert_coord(_x, i->z);
+    int32_t y = convert_coord(_y, i->z);
+    if(i->lastx != x || i->lasty != y) {
+	i->writer.moveto(&i->writer, x, y);
+    }
+    i->lx = _x;
+    i->ly = _y;
+    i->x0 = x;
+    i->y0 = y;
+    i->lastx = x;
+    i->lasty = y;
+    i->last = 1;
 }
-void gfxcompactpoly_free(gfxcompactpoly_t*poly)
+static void polydraw_lineTo(gfxdrawer_t*d, gfxcoord_t _x, gfxcoord_t _y)
 {
+    polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
+    if(!i->last) {
+	polydraw_moveTo(d, _x, _y);
+	return;
+    }
+    int32_t x = convert_coord(_x, i->z);
+    int32_t y = convert_coord(_y, i->z);
+    if(i->lastx != x || i->lasty != y) {
+	i->writer.lineto(&i->writer, x, y);
+    }
+    i->lx = _x;
+    i->ly = _y;
+    i->lastx = x;
+    i->lasty = y;
+    i->last = 1;
+}
+static void polydraw_splineTo(gfxdrawer_t*d, gfxcoord_t sx, gfxcoord_t sy, gfxcoord_t x, gfxcoord_t y)
+{
+    polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
+    if(!i->last) {
+	polydraw_moveTo(d, x, y);
+	return;
+    }
+    double c = fabs(x-2*sx+i->lx) + fabs(y-2*sy+i->ly);
+    int parts = (int)(sqrt(c)*SUBFRACTION);
+    if(!parts) parts = 1;
     int t;
-    for(t=0;t<poly->num_strokes;t++) {
-	free(poly->strokes[t].points);
+    int32_t nx,ny;
+    for(t=0;t<parts;t++) {
+	nx = convert_coord((double)(t*t*x + 2*t*(parts-t)*sx + (parts-t)*(parts-t)*i->lx)/(double)(parts*parts), i->z);
+	ny = convert_coord((double)(t*t*y + 2*t*(parts-t)*sy + (parts-t)*(parts-t)*i->ly)/(double)(parts*parts), i->z);
+	if(nx != i->lastx || ny != i->lasty) {
+	    i->writer.lineto(&i->writer, nx, ny);
+	    i->lastx = nx; i->lasty = ny;
+	}
     }
-    free(poly->strokes);
-    free(poly);
+    nx = convert_coord(x,i->z);
+    ny = convert_coord(y,i->z);
+    if(nx != i->lastx || ny != i->lasty) {
+	i->writer.lineto(&i->writer, nx, ny);
+    }
+    i->lx = x;
+    i->ly = y;
+    i->lastx = nx; 
+    i->lasty = ny;
+    i->last = 1;
+}
+static void polydraw_close(gfxdrawer_t*d)
+{
+    polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
+    assert(!(i->last && (i->x0 == INVALID_COORD || i->y0 == INVALID_COORD)));
+    if(!i->last)
+	return;
+    if(i->lastx != i->x0 || i->lasty != i->y0) {
+	i->writer.lineto(&i->writer, i->x0, i->y0);
+	i->lastx = i->x0;
+	i->lasty = i->y0;
+    }
+    i->last = 0;
+    i->x0 = INVALID_COORD;
+    i->y0 = INVALID_COORD;
+}
+static void* polydraw_result(gfxdrawer_t*d)
+{
+    polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
+    void*result = i->writer.finish(&i->writer);
+    rfx_free(i);
+    memset(d, 0, sizeof(gfxdrawer_t));
+    return result;
+}
+
+void gfxdrawer_target_poly(gfxdrawer_t*d, double gridsize)
+{
+    polydraw_internal_t*i = (polydraw_internal_t*)rfx_calloc(sizeof(polydraw_internal_t));
+    d->internal = i;
+    i->lastx = INVALID_COORD; // convert_coord can never return this value
+    i->lasty = INVALID_COORD;
+    i->x0 = INVALID_COORD;
+    i->y0 = INVALID_COORD;
+    d->moveTo = polydraw_moveTo;
+    d->lineTo = polydraw_lineTo;
+    d->splineTo = polydraw_splineTo;
+    d->close = polydraw_close;
+    d->result = polydraw_result;
+    gfxpolywriter_init(&i->writer);
+    i->writer.setgridsize(&i->writer, gridsize);
+    i->z = 1.0 / gridsize;
+}
+
+#if 0
+gfxline_t*gfxline_from_gfxpoly(gfxpoly_t*poly)
+{
+    gfxpolystroke_t*stroke;
+    int count = 0;
+    for(stroke=poly->strokes;stroke;stroke=stroke->next) {
+	assert(stroke->num_points);
+	count += stroke->num_points;
+    }
+    if(!count) return 0;
+    gfxline_t*l = malloc(sizeof(gfxline_t)*count);
+    count = 0;
+    /* TODO: it might make sense to concatenate strokes */
+    for(stroke=poly->strokes;stroke;stroke=stroke->next) {
+	int t;
+	for(t=0;t<stroke->num_points;t++) {
+	    l[count+t].x = stroke->points[t].x * poly->gridsize;
+	    l[count+t].y = stroke->points[t].y * poly->gridsize;
+	    l[count+t].type = gfx_lineTo;
+	    l[count+t].next = &l[count+t+1];
+	}
+	l[count].type = gfx_moveTo;
+	count+=stroke->num_points;
+    }
+    l[count-1].next = 0;
+    return l;
+}
+#endif
+
+static gfxline_t*mkgfxline(gfxpoly_t*poly, char preserve_direction)
+{
+    gfxpolystroke_t*stroke;
+    int count = 0;
+    if(!poly->strokes)
+	return 0;
+    dict_t*d = dict_new2(&point_type);
+    dict_t*todo = dict_new2(&ptr_type);
+    gfxpolystroke_t*stroke_min= poly->strokes;
+    int32_t x_min=stroke_min->points[0].x;
+    int32_t y_min=stroke_min->points[0].y;
+    for(stroke=poly->strokes;stroke;stroke=stroke->next) {
+	dict_put(todo, stroke, stroke);
+	assert(stroke->num_points>1);
+	count += stroke->num_points;
+	if(stroke->dir == DIR_UP) {
+	    dict_put(d, &stroke->points[stroke->num_points-1], stroke);
+	    if(!preserve_direction)
+		dict_put(d, &stroke->points[0], stroke);
+	} else {
+	    dict_put(d, &stroke->points[0], stroke);
+	    if(!preserve_direction)
+		dict_put(d, &stroke->points[stroke->num_points-1], stroke);
+	}
+	if(stroke->points[0].y < y_min ||
+	   (stroke->points[0].y == y_min && stroke->points[0].x < x_min)) {
+	    y_min = stroke->points[0].y;
+	    stroke_min = stroke;
+	}
+    }
+    gfxpolystroke_t*next_todo = poly->strokes;
+    gfxline_t*l = malloc(sizeof(gfxline_t)*count);
+    count = 0;
+    stroke = stroke_min;
+    
+    point_t last = {INVALID_COORD, INVALID_COORD};
+    char should_connect = 0;
+    while(stroke) {
+	if(stroke && !preserve_direction) {
+	    char del1 = dict_del2(d, &stroke->points[0], stroke);
+	    char del2 = dict_del2(d, &stroke->points[stroke->num_points-1], stroke);
+	    assert(del1 && del2);
+	}
+	assert(dict_contains(todo, stroke));
+	int t;
+	int pos = 0;
+	int incr = 1;
+	if(preserve_direction) {
+	    if(stroke->dir == DIR_UP) {
+		pos = stroke->num_points-1;
+		incr = -1;
+	    }
+	} else {
+	    // try to find matching point on either end.
+	    // Prefer downward.
+	    if(last.x == stroke->points[stroke->num_points-1].x &&
+	       last.y == stroke->points[stroke->num_points-1].y) {
+		pos = stroke->num_points-1;
+		incr = -1;
+	    }
+	}
+	if(last.x != stroke->points[pos].x || last.y != stroke->points[pos].y) {
+	    l[count].x = stroke->points[pos].x * poly->gridsize;
+	    l[count].y = stroke->points[pos].y * poly->gridsize;
+	    l[count].type = gfx_moveTo;
+	    l[count].next = &l[count+1];
+	    count++;
+	    assert(!should_connect);
+	}
+	pos += incr;
+	for(t=1;t<stroke->num_points;t++) {
+	    l[count].x = stroke->points[pos].x * poly->gridsize;
+	    l[count].y = stroke->points[pos].y * poly->gridsize;
+	    l[count].type = gfx_lineTo;
+	    l[count].next = &l[count+1];
+	    count++;
+	    pos += incr;
+	}
+	last = stroke->points[pos-incr];
+	char del = dict_del(todo, stroke);
+	assert(del);
+	assert(!dict_contains(todo, stroke));
+
+	/* try to find a poly which starts at the point we drew last */
+	stroke = dict_lookup(d, &last);
+	should_connect = 1;
+	while(!dict_contains(todo, stroke)) {
+	    should_connect = 0;
+	    stroke = next_todo;
+	    if(!next_todo) {
+		stroke = 0;
+		break;
+	    }
+	    next_todo = next_todo->next;
+	}
+    }
+    l[count-1].next = 0;
+    dict_destroy(todo);
+    dict_destroy(d);
+    return l;
+}
+
+gfxline_t*gfxline_from_gfxpoly(gfxpoly_t*poly)
+{
+    return mkgfxline(poly, 0);
+}
+
+gfxline_t*gfxline_from_gfxpoly_updown(gfxpoly_t*poly)
+{
+    return mkgfxline(poly, 1);
+}
+
+static windcontext_t onepolygon = {1};
+gfxline_t* gfxpoly_circular_to_evenodd(gfxline_t*line, double gridsize)
+{
+    gfxpoly_t*poly = gfxpoly_from_fill(line, gridsize);
+    gfxpoly_t*poly2 = gfxpoly_process(poly, 0, &windrule_circular, &onepolygon);
+    gfxline_t*line2 = gfxline_from_gfxpoly(poly2);
+    gfxpoly_destroy(poly);
+    gfxpoly_destroy(poly2);
+    return line2;
+}
+
+gfxpoly_t* gfxpoly_createbox(double x1, double y1,double x2, double y2, double gridsize)
+{
+    gfxline_t* line = gfxline_makerectangle(x1, y1, x2, y2);
+    gfxpoly_t* poly = gfxpoly_from_fill(line, gridsize);
+    gfxline_free(line);
+    return poly;
 }