Not regenerate all the entities, only for DIRTY.

src/constrainteq.cpp

@@ -196,6 +196,7 @@ void ConstraintBase::Generate(IdList<Param,hParam> *l) const {
         case Type::PT_ON_LINE: {
             Param p = {};
             p.h = h.param(0);
+            p.group = group;
             l->Add(&p);
             break;
         }

src/generate.cpp

@@ -221,11 +221,13 @@ void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox)
 
     // Don't lose our numerical guesses when we regenerate.
     IdList<Param,hParam> prev = {};
-    SK.param.MoveSelfInto(&prev);
-    SK.param.ReserveMore(prev.n);
-    int oldEntityCount = SK.entity.n;
-    SK.entity.Clear();
-    SK.entity.ReserveMore(oldEntityCount);
+    SK.param.DeepCopyInto(&prev);
+    bool needRegenerateAllEntities = (type == Generate::ALL || type == Generate::REGEN);
+    if(needRegenerateAllEntities) {
+        SK.param.Clear();
+        SK.param.ReserveMore(prev.n);
+        SK.entity.Clear();
+    }
 
     for(i = 0; i < SK.groupOrder.n; i++) {
         Group *g = SK.GetGroup(SK.groupOrder.elem[i]);
@@ -236,19 +238,34 @@ void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox)
         if(PruneGroups(g->h))
             goto pruned;
 
-        for(j = 0; j < SK.request.n; j++) {
-            Request *r = &(SK.request.elem[j]);
-            if(r->group.v != g->h.v) continue;
+        if(i >= first && i <= last || type == Generate::REGEN) {
+            if(!needRegenerateAllEntities) {
+                // Remove all the entities from the current group
+                for(j = 0; j < SK.entity.n; j++) {
+                    SK.entity.elem[j].tag = (int)(SK.entity.elem[j].group.v == g->h.v);
+                }
+                SK.entity.RemoveTagged();
+                // Remove all the parameters from the current group
+                for(j = 0; j < SK.param.n; j++) {
+                    SK.param.elem[j].tag = (int)(SK.param.elem[j].group.v == g->h.v);
+                }
+                SK.param.RemoveTagged();
+            }
+            // Regenerate entities
+            for(j = 0; j < SK.request.n; j++) {
+                Request *r = &(SK.request.elem[j]);
+                if(r->group.v != g->h.v) continue;
 
-            r->Generate(&(SK.entity), &(SK.param));
-        }
-        for(j = 0; j < SK.constraint.n; j++) {
-            Constraint *c = &SK.constraint.elem[j];
-            if(c->group.v != g->h.v) continue;
+                r->Generate(&(SK.entity), &(SK.param));
+            }
+            for(j = 0; j < SK.constraint.n; j++) {
+                Constraint *c = &SK.constraint.elem[j];
+                if(c->group.v != g->h.v) continue;
 
-            c->Generate(&(SK.param));
+                c->Generate(&(SK.param));
+            }
+            g->Generate(&(SK.entity), &(SK.param));
         }
-        g->Generate(&(SK.entity), &(SK.param));
 
         // The requests and constraints depend on stuff in this or the
         // previous group, so check them after generating.

src/group.cpp

@@ -38,6 +38,7 @@ void Group::AddParam(IdList<Param,hParam> *param, hParam hp, double v) {
     Param pa = {};
     pa.h = hp;
     pa.val = v;
+    pa.group = h;
 
     param->Add(&pa);
 }

src/request.cpp

@@ -228,6 +228,7 @@ int Request::IndexOfPoint(hEntity he) const {
 hParam Request::AddParam(IdList<Param,hParam> *param, hParam hp) {
     Param pa = {};
     pa.h = hp;
+    pa.group = group;
     param->Add(&pa);
     return hp;
 }

src/sketch.h

@@ -224,7 +224,7 @@ class Group {
     std::string DescriptionString();
     void Clear();
 
-    static void AddParam(ParamList *param, hParam hp, double v);
+    void AddParam(ParamList *param, hParam hp, double v);
     void Generate(EntityList *entity, ParamList *param);
     bool IsSolvedOkay();
     void TransformImportedBy(Vector t, Quaternion q);
@@ -322,7 +322,7 @@ class Request {
     std::string font;
     double      aspectRatio;
 
-    static hParam AddParam(ParamList *param, hParam hp);
+    hParam AddParam(ParamList *param, hParam hp);
     void Generate(EntityList *entity, ParamList *param);
 
     std::string DescriptionString() const;
@@ -552,6 +552,7 @@ class Param {
 public:
     int         tag;
     hParam      h;
+    hGroup      group;
 
     double      val;
     bool        known;