Assemble the group polygon ourselves when exporting a DXF; that

lets us export open curves, if the user drew them that way.

Also increase the limits on how many pwls we will generate for a
single curve.

[git-p4: depot-paths = "//depot/solvespace/": change = 1854]

drawentity.cpp

@@ -155,9 +155,9 @@ void Entity::BezierPwl(double ta, double tb,
     double d = max(pm1.DistanceToLine(pa, pb.Minus(pa)),
                    pm2.DistanceToLine(pa, pb.Minus(pa)));
 
-    double tol = 0.5*SS.chordTol/SS.GW.scale;
+    double tol = SS.chordTol/SS.GW.scale;
 
-    if((tb - ta) < 0.05 || d < tol) {
+    if((tb - ta) < 0.01 || d < tol) {
         LineDrawOrGetDistanceOrEdge(pa, pb);
     } else {
         double tm = (ta + tb) / 2;

export.cpp

@@ -2,9 +2,8 @@
 #include <png.h>
 
 void SolveSpace::ExportDxfTo(char *filename) {
-    SPolygon *sp;
-    SPolygon spa;
-    ZERO(&spa);
+    SPolygon sp;
+    ZERO(&sp);
 
     Vector gn = (SS.GW.projRight).Cross(SS.GW.projUp);
     gn = gn.WithMagnitude(1);
@@ -19,17 +18,21 @@ void SolveSpace::ExportDxfTo(char *filename) {
     Vector p, u, v, n;
     double d;
 
-    if(gs.n == 0 && !(g->poly.IsEmpty())) {
+    // Don't use the assembled polygon from the group data structure; that
+    // one gets cleared if the curves aren't all closed.
+    g->AssemblePolygon(&sp, NULL);
+
+    if(gs.n == 0 && !(sp.IsEmpty())) {
         // Easiest case--export the polygon drawn in this group
-        sp = &(g->poly);
-        p = sp->AnyPoint();
-        n = (sp->ComputeNormal()).WithMagnitude(1);
+        p = sp.AnyPoint();
+        n = (sp.ComputeNormal()).WithMagnitude(1);
         if(n.Dot(gn) < 0) n = n.ScaledBy(-1);
         u = n.Normal(0);
         v = n.Normal(1);
         d = p.Dot(n);
         goto havepoly;
     }
+    sp.Clear();
 
     if(g->runningMesh.l.n > 0 &&
        ((gs.n == 0 && g->activeWorkplane.v != Entity::FREE_IN_3D.v) ||
@@ -93,8 +96,7 @@ void SolveSpace::ExportDxfTo(char *filename) {
         SEdgeList el;
         ZERO(&el);
         root->MakeCertainEdgesInto(&el, false);
-        el.AssemblePolygon(&spa, NULL);
-        sp = &spa;
+        el.AssemblePolygon(&sp, NULL);
 
         el.Clear();
         m.Clear();
@@ -111,7 +113,7 @@ havepoly:
     FILE *f = fopen(filename, "wb");
     if(!f) {
         Error("Couldn't write to '%s'", filename);
-        spa.Clear();
+        sp.Clear();
         return;
     }
 
@@ -159,8 +161,8 @@ havepoly:
 "ENTITIES\r\n");
 
     int i, j;
-    for(i = 0; i < sp->l.n; i++) {
-        SContour *sc = &(sp->l.elem[i]);
+    for(i = 0; i < sp.l.n; i++) {
+        SContour *sc = &(sp.l.elem[i]);
 
         for(j = 1; j < sc->l.n; j++) {
             Vector p0 = sc->l.elem[j-1].p,
@@ -200,7 +202,7 @@ havepoly:
 "  0\r\n"
 "EOF\r\n" );
 
-    spa.Clear();
+    sp.Clear();
     fclose(f);
 }
 

groupmesh.cpp

@@ -2,22 +2,27 @@
 
 #define gs (SS.GW.gs)
 
+bool Group::AssemblePolygon(SPolygon *p, SEdge *error) {
+    SEdgeList edges; ZERO(&edges);
+    int i;
+    for(i = 0; i < SS.entity.n; i++) {
+        Entity *e = &(SS.entity.elem[i]);
+        if(e->group.v != h.v) continue;
+
+        e->GenerateEdges(&edges);
+    }
+    bool ret = edges.AssemblePolygon(p, error);
+    edges.Clear();
+    return ret;
+}
+
 void Group::GeneratePolygon(void) {
     poly.Clear();
 
     if(type == DRAWING_3D || type == DRAWING_WORKPLANE || 
        type == ROTATE || type == TRANSLATE)
     {
-        SEdgeList edges; ZERO(&edges);
-        int i;
-        for(i = 0; i < SS.entity.n; i++) {
-            Entity *e = &(SS.entity.elem[i]);
-            if(e->group.v != h.v) continue;
-
-            e->GenerateEdges(&edges);
-        }
-        SEdge error;
-        if(edges.AssemblePolygon(&poly, &error)) {
+        if(AssemblePolygon(&poly, &(polyError.notClosedAt))) {
             polyError.how = POLY_GOOD;
             poly.normal = poly.ComputeNormal();
             poly.FixContourDirections();
@@ -29,10 +34,8 @@ void Group::GeneratePolygon(void) {
             }
         } else {
             polyError.how = POLY_NOT_CLOSED;
-            polyError.notClosedAt = error;
             poly.Clear();
         }
-        edges.Clear();
     }
 }
 

sketch.h

@@ -197,6 +197,7 @@ public:
     void GenerateEquations(IdList<Equation,hEquation> *l);
 
     // Assembling piecewise linear sections into polygons
+    bool AssemblePolygon(SPolygon *p, SEdge *error);
     void GeneratePolygon(void);
     // And the mesh stuff
     SMesh *PreviousGroupMesh(void);

solvespace.cpp

@@ -129,7 +129,7 @@ int SolveSpace::CircleSides(double r) {
     double tol = chordTol/GW.scale;
     int n = 3 + (int)(PI/sqrt(2*tol/r));
 
-    return max(7, min(n, 40));
+    return max(7, min(n, 200));
 }
 
 char *SolveSpace::MmToString(double v) {

ttf.cpp

@@ -704,9 +704,9 @@ void TtfFont::BezierPwl(double ta, double tb, Vector p0, Vector p1, Vector p2) {
 
     Vector pm = BezierEval(tm, p0, p1, p2);
 
-    double tol = 0.5*SS.chordTol/SS.GW.scale;
+    double tol = SS.chordTol/SS.GW.scale;
 
-    if((tb - ta) < 0.05 || pm.DistanceToLine(pa, pb.Minus(pa)) < tol) {
+    if((tb - ta) < 0.01 || pm.DistanceToLine(pa, pb.Minus(pa)) < tol) {
         Entity *e = SS.GetEntity(entity);
         e->LineDrawOrGetDistanceOrEdge(pa, pb);
     } else {