generate: add minor optimisation to request and constraint pruning

For request pruning, iterate over requests rather than over entities,
and for constraint pruning look up in the requests list where possible,
as it should be much shorter.

While at it, combine them into a single operation. This saves us one
potential recursion for every group, since there's no reason to wait for
the next recursion to do constraint pruning when requests were pruned.

Author: iscgar

src/generate.cpp

@@ -86,46 +86,53 @@ bool SolveSpaceUI::PruneGroups(hGroup hg) {
     return true;
 }
 
-bool SolveSpaceUI::PruneRequests(hGroup hg) {
-    const int requests = SK.request.n;
-    for(Entity &e : SK.entity) {
-        if(e.group != hg) {
-            continue;
+bool SolveSpaceUI::PruneRequestsAndConstraints(hGroup hg) {
+    auto entityRequestExists = [](hEntity he, bool checkEntity = false) {
+        if(he == Entity::NO_ENTITY) {
+            return true;
+        }
+
+        if(he.isFromRequest()) {
+            if(SK.request.FindByIdNoOops(he.request()) != nullptr) {
+                return true;
+            }
+        } else if(!checkEntity || SK.entity.FindByIdNoOops(he) != nullptr) {
+            return true;
         }
 
-        if(!e.h.isFromRequest()) {
+        return false;
+    };
+
+    const int requests = SK.request.n;
+    for(Request &r : SK.request) {
+        if(r.group != hg) {
             continue;
         }
 
-        if(EntityExists(e.workplane)) {
+        if(entityRequestExists(r.workplane)) {
             continue;
         }
 
-        Request *r = SK.GetRequest(e.h.request());
-        r->tag = 1;
+        r.tag = 1;
     }
     SK.request.RemoveTagged();
     deleted.requests += requests - SK.request.n;
 
-    return requests > SK.request.n;
-}
-
-bool SolveSpaceUI::PruneConstraints(hGroup hg) {
     const int constraints = SK.constraint.n;
     for(Constraint &c : SK.constraint) {
-        if(c.group != hg) continue;
-
-        if(EntityExists(c.workplane) &&
-           EntityExists(c.ptA) &&
-           EntityExists(c.ptB) &&
-           EntityExists(c.entityA) &&
-           EntityExists(c.entityB) &&
-           EntityExists(c.entityC) &&
-           EntityExists(c.entityD)) {
+        if(c.group != hg)
+            continue;
+
+        if(entityRequestExists(c.workplane, true) &&
+           entityRequestExists(c.ptA, true) &&
+           entityRequestExists(c.ptB, true) &&
+           entityRequestExists(c.entityA, true) &&
+           entityRequestExists(c.entityB, true) &&
+           entityRequestExists(c.entityC, true) &&
+           entityRequestExists(c.entityD, true)) {
             continue;
         }
 
-        (deleted.constraints)++;
         if(c.type != Constraint::Type::POINTS_COINCIDENT &&
            c.type != Constraint::Type::HORIZONTAL &&
            c.type != Constraint::Type::VERTICAL) {
@@ -134,10 +141,10 @@ bool SolveSpaceUI::PruneConstraints(hGroup hg) {
 
         c.tag = 1;
     }
-
     SK.constraint.RemoveTagged();
+    deleted.constraints += constraints - SK.constraint.n;
 
-    return constraints > SK.constraint.n;
+    return (requests > SK.request.n) || (constraints > SK.constraint.n);
 }
 
 void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox) {
@@ -215,8 +222,7 @@ void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox)
     // Remove any requests or constraints that refer to a nonexistent
     // group; can check those immediately, since we know what the list
     // of groups should be.
-    while(PruneOrphans())
-        ;
+    PruneOrphans();
 
     // Don't lose our numerical guesses when we regenerate.
     IdList<Param,hParam> prev = {};
@@ -254,7 +260,7 @@ void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox)
 
         // The requests and constraints depend on stuff in this or the
         // previous group, so check them after generating.
-        if(PruneRequests(hg) || PruneConstraints(hg))
+        if(PruneRequestsAndConstraints(hg))
             goto pruned;
 
         // Use the previous values for params that we've seen before, as

src/solvespace.h

@@ -765,8 +765,7 @@ class SolveSpaceUI {
     bool EntityExists(hEntity he);
     bool GroupsInOrder(hGroup before, hGroup after);
     bool PruneGroups(hGroup hg);
-    bool PruneRequests(hGroup hg);
-    bool PruneConstraints(hGroup hg);
+    bool PruneRequestsAndConstraints(hGroup hg);
     static void ShowNakedEdges(bool reportOnlyWhenNotOkay);
 
     enum class Generate : uint32_t {