diff --git a/3d-models.cpp b/3d-models.cpp
index dd848a6f..d85e84ce 100644
--- a/3d-models.cpp
+++ b/3d-models.cpp
@@ -879,7 +879,7 @@ void geometry_information::make_shadow(hpcshape& sh) {
 void geometry_information::make_3d_models() {
   if(GDIM == 2 || noGUI) return;
   eyepos = WDIM == 2 ? 0.875 : 0.925;
-  DEBBI(DF_POLY, ("make_3d_models"));
+  DEBBI(debug_poly, ("make_3d_models"));
   shcenter = tile_center();
 
 #if CAP_GL  
@@ -891,7 +891,7 @@ void geometry_information::make_3d_models() {
 #endif
   
   if(WDIM == 2 || euclid) {
-    DEBB(DF_POLY, ("shadows"));
+    DEBB(debug_poly, ("shadows"));
     for(hpcshape* sh: {&shBatWings, &shBugBody, &shBullBody, &shButterflyWing, &shCatBody, &shDogBody, &shDogTorso,
       &shEagle, &shFemaleBody, &shFlailMissile, &shGadflyWing, &shGargoyleWings, &shHawk, &shJiangShi, &shKnife,
       &shPBody, &shPHead, &shRaiderBody, &shReptileBody, &shSkeletonBody, &shTongue, &shTrapArrow, &shTrylobite,
@@ -903,7 +903,7 @@ void geometry_information::make_3d_models() {
     for(int i=0; i<8; i++) make_shadow(shAsteroid[i]);
     }
   
-  DEBB(DF_POLY, ("humanoids"));
+  DEBB(debug_poly, ("humanoids"));
   make_humanoid_3d(shPBody);
   make_humanoid_3d(shYeti);
   make_humanoid_3d(shFemaleBody);
@@ -918,7 +918,7 @@ void geometry_information::make_3d_models() {
   // shRaiderBody = shPBody;
   // shJiangShi = shPBody;
 
-  DEBB(DF_POLY, ("heads"));
+  DEBB(debug_poly, ("heads"));
   make_head_3d(shFemaleHair);
   make_head_3d(shPHead);
   make_head_3d(shTurban1);
@@ -942,7 +942,7 @@ void geometry_information::make_3d_models() {
   make_head_3d(shJiangShiCap2);
   make_head_3d(shTerraHead);
   
-  DEBB(DF_POLY, ("armors"));
+  DEBB(debug_poly, ("armors"));
   make_armor_3d(shKnightArmor);
   make_armor_3d(shKnightCloak, 2);
   make_armor_3d(shPrinceDress);
@@ -961,7 +961,7 @@ void geometry_information::make_3d_models() {
   
   make_armor_3d(shHood, 2);
   
-  DEBB(DF_POLY, ("feet and paws"));
+  DEBB(debug_poly, ("feet and paws"));
   make_foot_3d(shHumanFoot);
   make_foot_3d(shYetiFoot);
   make_skeletal(shSkeletalFoot, WDIM == 2 ? zc(0.5) + human_height/40 - FLOOR : 0);
@@ -983,7 +983,7 @@ void geometry_information::make_3d_models() {
   make_paw_3d(shDogFrontPaw, shDogFrontLeg);
   make_paw_3d(shDogRearPaw, shDogRearLeg);  
   
-  DEBB(DF_POLY, ("revolution"));
+  DEBB(debug_poly, ("revolution"));
   // make_abody_3d(shWolfBody, 0.01);
   // make_ahead_3d(shWolfHead);
   // make_ahead_3d(shFamiliarHead);
@@ -1076,7 +1076,7 @@ void geometry_information::make_3d_models() {
   make_revolution_cut(shButterflyWing, 180, 0, 0.05*S);
   finishshape();
   
-  DEBB(DF_POLY, ("animatebirds"));
+  DEBB(debug_poly, ("animatebirds"));
   animate_bird(shEagle, shAnimatedEagle, 0.05*S);
   animate_bird(shTinyBird, shAnimatedTinyEagle, 0.05*S/2);
 
@@ -1088,7 +1088,7 @@ void geometry_information::make_3d_models() {
   animate_bird(shBatWings, shAnimatedBat, 0.05*S);
   animate_bird(shBatBody, shAnimatedBat2, 0.05*S);
 
-  DEBB(DF_POLY, ("disablers"));
+  DEBB(debug_poly, ("disablers"));
 
   disable(shWolfRearLeg);
   disable(shWolfFrontLeg);
@@ -1123,7 +1123,7 @@ void geometry_information::make_3d_models() {
 
   make_head_only();
   
-  DEBB(DF_POLY, ("balls"));
+  DEBB(debug_poly, ("balls"));
   make_ball(shDisk, orbsize*.2, 2);
   make_ball(shHeptaMarker, zhexf*.2, 1);
   make_ball(shSnowball, zhexf*.1, 1);
@@ -1173,7 +1173,7 @@ void geometry_information::make_3d_models() {
   clone_shape(shRose, shRoseItem);
   shift_shape(shRose, FLOOR - human_height * 1/20);
 
-  DEBB(DF_POLY, ("slime"));
+  DEBB(debug_poly, ("slime"));
   bshape(shSlime, PPR::MONSTER_BODY);
   hyperpoint tip = xtangent(1);
   hyperpoint atip = xtangent(-1);
@@ -1197,7 +1197,7 @@ void geometry_information::make_3d_models() {
   shift_shape(shMagicSword, ABODY);
   shift_shape(shMagicShovel, ABODY);
   
-  DEBB(DF_POLY, ("eyes"));
+  DEBB(debug_poly, ("eyes"));
   adjust_eye(shSlimeEyes, shSlime, FLATEYE, 0, 2, 2);
   adjust_eye(shGhostEyes, shGhost, GHOST, GHOST, 2, WDIM == 2 ? 2 : 4);
   adjust_eye(shMiniEyes, shMiniGhost, GHOST, GHOST, 2, 2);
diff --git a/achievement.cpp b/achievement.cpp
index b49821d9..47206733 100644
--- a/achievement.cpp
+++ b/achievement.cpp
@@ -909,12 +909,14 @@ EX void check_total_victory() {
   hadtotalvictory = true;
   achievement_gain("TOTALVICTORY");
   }
-  
+
+EX debugflag debug_achievements = {"steam_achievements"};
+
 /** gain the victory achievements. 
  *  @param hyper true for the Hyperstone victory, and false for the Orb of Yendor victory.
  */
 EX void achievement_victory(bool hyper) {
-  DEBBI(DF_STEAM, ("achievement_victory"))
+  if(debug_achievements) println(hlog, "achievement_victory");
   if(offlineMode) return;
 #if CAP_ACHIEVE
   if(cheater) return;
@@ -931,7 +933,8 @@ EX void achievement_victory(bool hyper) {
   if(ineligible_starting_land) return;
   if(use_custom_land_list) return;
   LATE( achievement_victory(hyper); )
-  DEBB(DF_STEAM, ("after checks"))
+
+  if(debug_achievements) println(hlog, "after checks");
 
   int t = getgametime();
   
@@ -982,7 +985,8 @@ EX void achievement_victory(bool hyper) {
       }
     }
   
-  DEBB(DF_STEAM, ("uploading scores"))
+  if(debug_achievements) println(hlog, "uploading scores");
+
   upload_score(ih1, t);
   upload_score(ih2, turncount);
 #endif
diff --git a/arbitrile.cpp b/arbitrile.cpp
index 795b3397..6f6e2b0a 100644
--- a/arbitrile.cpp
+++ b/arbitrile.cpp
@@ -275,7 +275,7 @@ void shape::build_from_angles_edges(bool is_comb) {
   vector<transmatrix> matrices;
   for(int i=0; i<n; i++) {
     matrices.push_back(at);
-    if(debugflags & DF_GEOM) println(hlog, "at = ", at);
+    if(debug_geometry) println(hlog, "at = ", at);
     ctr += tC0(at);
     at = at * lxpush(in_edges[i]) * spin(in_angles[i]+M_PI);
     }
@@ -287,12 +287,12 @@ void shape::build_from_angles_edges(bool is_comb) {
   if(sqhypot_d(3, ctr) < 1e-2) {
     // this may happen for some spherical tilings
     // try to move towards the center
-    if(debugflags & DF_GEOM) println(hlog, "special case encountered");
+    if(debug_geometry) println(hlog, "special case encountered");
     for(int i=0; i<n; i++) {
       ctr += at * lxpush(in_edges[i]) * spin((in_angles[i]+M_PI)/2) * lxpush0(.01);
       at = at * lxpush(in_edges[i]) * spin(in_angles[i]);
       }
-    if(debugflags & DF_GEOM) println(hlog, "ctr = ", ctr);
+    if(debug_geometry) println(hlog, "ctr = ", ctr);
     }
   hyperpoint inf_point;
   if(apeirogonal) {
@@ -526,9 +526,9 @@ EX void unmirror(arbi_tiling& c) {
     if(sh[i].apeirogonal) {
       cycle(sh[i].edges);
       cycle(sh[i].vertices);
-      if(debugflags & DF_GEOM) println(hlog, "angles before = ", sh[i].angles);
+      if(debug_geometry) println(hlog, "angles before = ", sh[i].angles);
       cycle(sh[i].angles);
-      if(debugflags & DF_GEOM) println(hlog, "angles now = ", sh[i].angles);
+      if(debug_geometry) println(hlog, "angles now = ", sh[i].angles);
       cycle(sh[i].connections);
       }
     }
@@ -597,7 +597,7 @@ EX void compute_vertex_valence_prepare(arb::arbi_tiling& ac) {
         mirror_connection(ac, co);
         reduce_gcd(sh.cycle_length, k-co.eid);
         }
-      if(debugflags & DF_GEOM) 
+      if(debug_geometry)
         println(hlog, "tile ", i, " cycle_length = ", sh.cycle_length, " / ", n);
       }
     
@@ -658,7 +658,7 @@ EX bool compute_vertex_valence_flat(arb::arbi_tiling& ac) {
       sh.vertex_period[k] = pqty;
       sh.vertex_angles[k] = std::move(anglelist);
       }
-    if(debugflags & DF_GEOM) 
+    if(debug_geometry)
       println(hlog, "computed vertex_valence of ", i, " as ", ac.shapes[i].vertex_valence);
     }
   return false;
@@ -709,7 +709,7 @@ EX bool compute_vertex_valence_generic(arb::arbi_tiling& ac) {
       sh.vertex_valence[k] = qty;
       sh.vertex_valence_gluesub[k] = qty == OINF ? OINF : qty - subqty;
       }
-    if(debugflags & DF_GEOM)
+    if(debug_geometry)
       println(hlog, "computed vertex_valence of ", i, " as ", ac.shapes[i].vertex_valence);
     }
   return false;
@@ -899,7 +899,7 @@ EX void check_football_colorability(arbi_tiling& c) {
             }
 
           if((sh.cycle_length&1) && (t < 2) && !sh.apeirogonal) sh.cycle_length *= 2;
-          if(debugflags & DF_GEOM)
+          if(debug_geometry)
             println(hlog, tie(i,t), " becomes ", ni, " with connections ", sh.connections, " and cycle length = ", sh.cycle_length);
           }
 
@@ -1129,7 +1129,7 @@ EX void load(const string& fname, bool load_as_slided IS(false), bool keep_slide
       string tok = ep.next_token();
       ep.force_eat("=");
       ep.extra_params[tok] =ep.parsepar();
-      if(debugflags & DF_GEOM)
+      if(debug_geometry)
         println(hlog, "let ", tok, " = ", ep.extra_params[tok]);
       }
     else if(ep.eat("unittile(")) load_tile(ep, c, true);
@@ -1220,7 +1220,7 @@ EX void load(const string& fname, bool load_as_slided IS(false), bool keep_slide
             ld dist = hdist(sh.vertices[i], sh.vertices[j]);
             if(abs(dist - d) < eps) {
               sh.sublines.emplace_back(i, j);
-              if(debugflags & DF_GEOM) println(hlog, "add subline ", i, "-", j);
+              if(debug_geometry) println(hlog, "add subline ", i, "-", j);
               }
             }
         }
@@ -1996,7 +1996,7 @@ EX void convert_minimize(int N, vector<int>& old_shvids, map<int, int>& old_to_n
   
   int chg = 1;
   while(chg) {
-    if(debugflags & DF_GEOM) {
+    if(debug_geometry) {
       println(hlog, "current table of equals:");
       int eqid = 0;
       for(auto& eq: equal) {
@@ -2117,7 +2117,7 @@ EX void convert() {
       cyclefix(alpha, 0);
       sh.angles.push_back(alpha);
       }
-    if(debugflags & DF_GEOM) {
+    if(debug_geometry) {
       println(hlog, "shape ", i, ":");
       indenter indp(2);
       println(hlog, "vertices=", sh.vertices);
diff --git a/archimedean.cpp b/archimedean.cpp
index 227eaf84..6943256d 100644
--- a/archimedean.cpp
+++ b/archimedean.cpp
@@ -141,7 +141,7 @@ EX int gcd(int x, int y) { return x ? gcd(y%x, x) : y < 0 ? -y : y; }
 
 void archimedean_tiling::make_match(int a, int i, int b, int j) {
   if(isize(adjacent[a]) != isize(adjacent[b])) {
-    DEBB(DF_GEOM, ("(error here)"));
+    if(debug_geometry) println(hlog, "make_match error");
     errormsg = XLAT("polygons match incorrectly");
     errors++;
     }
@@ -291,9 +291,9 @@ void archimedean_tiling::prepare() {
     for(int oi=0; oi<1; oi++) {
       int at = (i+oi)%N;
       int inv = oi;
-      DEBB0(DF_GEOM, ("vertex "));
+      if(debug_geometry) print(hlog, "vertex ");
       for(int z=0; z<faces[i]; z++) {
-        DEBB0(DF_GEOM, (hr::format("[%d %d] " , at, inv)));
+        if(debug_geometry) print(hlog, tie(at, inv), " ");
         adjacent[2*i+oi].emplace_back(2*N+int(inv), inv ? (2*at+2*N-2) % (2*N) : 2*at);
         if(invert[at]) inv ^= 1;
         at = adj[at];
@@ -301,7 +301,7 @@ void archimedean_tiling::prepare() {
         else at = (at+N-1) % N;
         }
       if(!inv) make_match(2*i, 0, inv ? (2*at+2*N-1) % 2*N : 2*at, 0);
-      DEBB(DF_GEOM, (hr::format("-> [%d %d]\n", at, inv)));
+      if(debug_geometry) print(hlog, "-> ", tie(at, inv));
       }
     }
   for(int i=0; i<N; i++) {
@@ -325,14 +325,14 @@ void archimedean_tiling::prepare() {
       }
     }
   
-  if(debugflags & DF_GEOM) {
+  if(debug_geometry) {
     for(int i=0; i<M; i++) {
-      DEBB0(DF_GEOM, ("adjacent ", i, ":"));
+      print(hlog, "adjacent ", i, ":");
       for(int j=0; j<isize(adjacent[i]); j++) {
         auto p = adjacent[i][j];
-        DEBB0(DF_GEOM, (" ", p));
+        print(hlog, " ", p);
         }
-      DEBB(DF_GEOM, ("\n"));
+      println(hlog);
       }
     }
 
@@ -348,13 +348,13 @@ void archimedean_tiling::prepare() {
   for(int i=0; i<M; i++) {
     for(int j=0; j<isize(adjacent[i]); j++) {
       int ai = i, aj = j;
-      DEBB0(DF_GEOM, ("triangle "));
+      if(debug_geometry) print(hlog, "triangle ");
       for(int s=0; s<3; s++) {
-        DEBB0(DF_GEOM, (hr::format("[%d %d] ", ai, aj)));
+        if(debug_geometry) print(hlog, tie(ai, aj));
         tie(ai, aj) = adjacent[ai][aj];
         aj++; if(aj >= isize(adjacent[ai])) aj = 0;
         }
-      DEBB(DF_GEOM, (hr::format("-> [%d %d]\n", ai, aj)));
+      if(debug_geometry) println(hlog, "-> ", tie(ai, aj));
       make_match(i, j, ai, aj);
       }
     }
@@ -406,10 +406,9 @@ void archimedean_tiling::regroup() {
     for(int i=0; i<M; i++) if(tilegroup[i] == 0) flags[i] |= sfPH;
     }
   
-  if(debugflags & DF_GEOM) {
-    for(int i=0; i<M; i+=(have_symmetry?1:2)) {
-      DEBB(DF_GEOM, (hr::format("tiling group of %2d: [%2d]%2d+Z%2d\n", i, tilegroup[i], groupoffset[i], periods[i])));
-      }
+  if(debug_geometry) {
+    for(int i=0; i<M; i+=(have_symmetry?1:2))
+      print(hlog, hr::format("tiling group of %2d: [%2d]%2d+Z%2d", i, tilegroup[i], groupoffset[i], periods[i]));
     }
   }
 
@@ -437,7 +436,8 @@ void archimedean_tiling::compute_geometry() {
     set_flag(arr[gArchimedean].flags, qSMALL, gg.kind == gcSphere);
     }
 
-  DEBB(DF_GEOM, (hr::format("euclidean_angle_sum = %f\n", float(euclidean_angle_sum))));
+  if(debug_geometry)
+    println(hlog, "euclidean_angle_sum = ", euclidean_angle_sum);
 
   bool infake = fake::in_ext();
   
@@ -507,8 +507,7 @@ void archimedean_tiling::compute_geometry() {
       alpha_total += alphas[i];
       }
     
-    if(debugflags & DF_GEOM)
-    if(p < 10 || p == 99)
+    if(debug_geometry && (p < 10 || p == 99))
       println(hlog, "edgelength = ", edgelength, " angles = ", alphas, " inradius = ", inradius, " circumradius = ", circumradius);
     
     if(isnan(alpha_total)) elmax = edgelength;
@@ -518,9 +517,9 @@ void archimedean_tiling::compute_geometry() {
     }
 
   if(need_flip) geom3::light_flip(false);
-  
-  DEBB(DF_GEOM, (hr::format("computed edgelength = %f\n", float(edgelength))));
-  
+
+  if(debug_geometry) println(hlog, "computed edgelength = ", edgelength);
+
   triangles.clear();
   triangles.resize(2*N+2);
   for(int i=0; i<N; i++) for(int j=0; j<2; j++) 
@@ -539,10 +538,10 @@ void archimedean_tiling::compute_geometry() {
     for(auto& t: ts) tie(t.first, total) = make_pair(total, total + t.first);
     }
 
-  if(debugflags & DF_GEOM) for(auto& ts: triangles) {
-    DEBB0(DF_GEOM, ("T"));
-    for(auto& t: ts) DEBB0(DF_GEOM, (hr::format(" %f@%f", float(t.first), float(t.second))));
-    DEBB(DF_GEOM, ());
+  if(debug_geometry) for(auto& ts: triangles) {
+    print(hlog, "T");
+    for(auto& t: ts) print(hlog, " ", t.first, "@", t.second);
+    println(hlog);
     }
 
   regular = true;
@@ -691,7 +690,7 @@ struct hrmap_archimedean : hrmap {
       return h1;
       }
 
-    DEBB(DF_GEOM, (heptspin(h,d), " ~ ?"));
+    if(debug_geometry) println(hlog, heptspin(h,d), " ~ ?");
 
     dynamicval<geometryinfo1> gi(ginf[geometry].g, ginf[gArchimedean].g);
     
@@ -727,15 +726,15 @@ struct hrmap_archimedean : hrmap {
       alt = (heptagon*) s;
       }
       
-    DEBB(DF_GEOM, ("look for: ", alt, " / ", kz(T * C0)));
+    if(debug_geometry) println(hlog, "look for: ", alt, " / ", kz(T * C0));
   
     for(auto& p2: altmap[alt]) if(same_point_may_warn(p2.second * tile_center(), T * tile_center())) {
-      DEBB(DF_GEOM, ("cell found: ", p2.first));
+      if(debug_geometry) println(hlog, "cell found: ", p2.first);
       for(int d2=0; d2<p2.first->degree(); d2++) {
         heptspin hs(p2.first, d2);
         auto& t2 = current.get_triangle(p2.first, d2);
         transmatrix T1 = T * spin(M_PI + t2.first);
-        DEBB(DF_GEOM, ("compare: ", kz(T1 * lxpush0(1)), ":: ", kz(p2.second * lxpush0(1))));
+        if(debug_geometry) println(hlog, "compare: ", kz(T1 * lxpush0(1)), ":: ", kz(p2.second * lxpush0(1)));
         if(same_point_may_warn(T1 * lxpush0(1), p2.second * lxpush0(1))) {
         
           // T1 = p2.second
@@ -754,7 +753,7 @@ struct hrmap_archimedean : hrmap {
           return h->move(d);
           }
         }
-      DEBB(DF_GEOM, ("but rotation not found"));
+      if(debug_geometry) println(hlog, "but rotation not found");
       }
     
     auto& t2 = current.get_triangle(current.get_adj(hi));
@@ -904,10 +903,12 @@ struct hrmap_archimedean : hrmap {
 
 EX hrmap *new_map() { return new hrmap_archimedean; }
 
+EX debugflag debug_archimedean_map = {"archimedean_map"};
+
 heptagon *build_child(heptspin p, pair<int, int> adj) {
   indenter ind;
   auto h = buildHeptagon1(tailored_alloc<heptagon> (isize(current.adjacent[adj.first])), p.at, p.spin, hstate(1), 0);
-  DEBB(DF_GEOM, ("NEW ", p, " ~ ", heptspin(h, 0)));
+  if(debug_archimedean_map) println(hlog, "NEW ", p, " ~ ", heptspin(h, 0));
   id_of(h) = adj.first;
   parent_index_of(h) = adj.second;
   int nei = neighbors_of(h);
@@ -951,23 +952,21 @@ void connect_digons_too(heptspin h1, heptspin h2) {
     // no need to specify archimedean_gmatrix and altmap
     hnew->c.connect(1, h2);
     h1--, h2++;
-    DEBB(DF_GEOM, (hr::format("OL2 %p.%d ~ %p.%d\n", hr::voidp(h1.at), h1.spin, hr::voidp(h2.at), h2.spin)));
+    if(debug_archimedean_map) println(hlog, hr::format("OL2 %p.%d ~ %p.%d\n", hr::voidp(h1.at), h1.spin, hr::voidp(h2.at), h2.spin));
     h1.at->c.connect(h1.spin, h2);
     }
   }
 
 void connectHeptagons(heptspin hi, heptspin hs) {
-  DEBB(DF_GEOM, ("OLD ", hi, " ~ ", hs));
+  if(debug_archimedean_map) println(hlog, "OLD ", hi, " ~ ", hs);
   if(hi.at->move(hi.spin) == hs.at && hi.at->c.spin(hi.spin) == hs.spin) {
-    DEBB(DF_GEOM, (hr::format("WARNING: already connected\n")));
+    if(debug_map_warnings) println(hlog, "WARNING: already connected");
     return;
     }
   if(hi.peek()) {
-    DEBB(DF_GEOM, (hr::format("ERROR: already connected left\n")));
     throw hr_archimedean_error("Archimedean error: already connected left");
     }
   if(hs.peek()) {
-    DEBB(DF_GEOM, (hr::format("ERROR: already connected right\n")));
     throw hr_archimedean_error("Archimedean error: already connected right");
     }
   hi.at->c.connect(hi.spin, hs);
@@ -1095,7 +1094,7 @@ void archimedean_tiling::parse() {
 EX bool load_symbol(const string& s, bool switch_geom) {
   archimedean_tiling at; at.parse(s);
   if(at.errors) {
-    DEBB(DF_ERROR | DF_GEOM, ("error: ", at.errormsg));
+    if(debug_errors) println(hlog, "error: ", at.errormsg);
     return false;
     }
   if(!switch_geom && geometry != gArchimedean) return true;
@@ -1392,7 +1391,7 @@ EX void show() {
     archimedean_tiling tested;
     tested.parse(s);
     if(tested.errors) {
-      DEBB(DF_GEOM | DF_WARN, ("WARNING: ", tested.errors, " errors on ", s, " '", tested.errormsg, "'"));
+      if(debug_warnings) println(hlog, "WARNING: ", tested.errors, " errors on ", s, " '", tested.errormsg, "'");
       }
     else {
       tested.coloring = col;
diff --git a/asonov.cpp b/asonov.cpp
index 91e38d43..9d65899a 100644
--- a/asonov.cpp
+++ b/asonov.cpp
@@ -88,7 +88,7 @@ EX void prepare() {
   lambda[0] = b + sqrt(b*b-1);
   lambda[1] = b - sqrt(b*b-1);
   
-  DEBB(DF_GEOM, ("b = ", b, " lambda = ", lambda));
+  if(debug_geometry) println(hlog, "asonov: b = ", b, " lambda = ", lambda);
   
   transmatrix eigen = Id;
   
@@ -103,7 +103,7 @@ EX void prepare() {
   ty = point3(ieigen[0][1], ieigen[1][1], 0) * vid.binary_width;
   tz = -point3(0, 0, log(lambda[0]));
   
-  DEBB(DF_GEOM, ("tx = ", tx, " ty = ", ty, " tz = ", tz));
+  if(debug_geometry) println(hlog, "tx = ", tx, " ty = ", ty, " tz = ", tz);
   
   straighten = inverse(build_matrix(asonov::tx/2, asonov::ty/2, asonov::tz/2, C0));
   }
diff --git a/attack.cpp b/attack.cpp
index a9c447a5..25201180 100644
--- a/attack.cpp
+++ b/attack.cpp
@@ -476,7 +476,7 @@ EX bignum ivy_total() {
 
 EX void killMonster(cell *c, eMonster who, flagtype deathflags IS(0)) {
   eMonster m = c->monst;
-  DEBBI(DF_TURN, ("killmonster ", dnameof(m)));
+  DEBBI(debug_turn, ("killmonster ", dnameof(m)));
   
   if(!m) return;
   
diff --git a/basegraph.cpp b/basegraph.cpp
index 587c1d22..9b2815ee 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -251,6 +251,8 @@ EX vector<pair<string, string>> font_names = {
 EX int last_font_id = 0;
 EX int font_id = 0;
 
+EX debugflag debug_init_font = {"init_font", true};
+
 #ifdef FONTCONFIG
 TTF_Font* findfont(int siz) {
 
@@ -289,7 +291,7 @@ TTF_Font* findfont(int siz) {
   FcPatternDestroy(pat);
   FcFini();
   cfont->use_fontconfig = false;
-  if(debugflags & DF_INIT) println(hlog, "fontpath is: ", cfont->filename);
+  if(debug_init_font) println(hlog, "fontpath is: ", cfont->filename);
   return TTF_OpenFont(cfont->filename.c_str(), siz);
   }
 #endif
@@ -410,7 +412,7 @@ EX bool model_needs_depth() {
   }
 
 EX void setGLProjection(color_t col IS(backcolor)) {
-  DEBBI(DF_GRAPH, ("setGLProjection"));
+  DEBBI(debug_graph, ("setGLProjection"));
   GLERR("pre_setGLProjection");
 
   glClearColor(part(col, 2) / 255.0, part(col, 1) / 255.0, part(col, 0) / 255.0, 1);
@@ -568,7 +570,7 @@ void sdltogl(SDL_Surface *txt, glfont_t& f, int ch) {
   
 EX void init_glfont(int size) {
   if(cfont->glfont[size]) return;
-  DEBBI(DF_GRAPH, ("init GL font: ", size));
+  DEBBI(debug_init_font, ("init GL font: ", size));
   
 #if !CAP_TABFONT
   loadfont(size);
@@ -755,7 +757,7 @@ bool gl_print(int x, int y, int shift, int size, const char *s, color_t color, i
 EX purehookset hooks_resetGL;
 
 EX void resetGL() {
-  DEBBI(DF_INIT | DF_GRAPH, ("reset GL"))
+  DEBBI(debug_init_graph, ("reset GL"))
   callhooks(hooks_resetGL);
 #if CAP_GLFONT
   for(auto& cf: fontdatas)
@@ -1015,9 +1017,11 @@ void addMessageToLog(msginfo& m, vector<msginfo>& log) {
 
 EX void clearMessages() { msgs.clear(); }
 
+EX debugflag debug_messages = {"messages", true};
+
 EX void addMessage(string s, char spamtype) {
   LATE( addMessage(s, spamtype); )
-  DEBB(DF_MSG, ("addMessage: ", s));
+  DEBB(debug_messages, ("addMessage: ", s));
 
   msginfo m;
   m.msg = s; m.spamtype = spamtype; m.flashout = false; m.stamp = ticks;
@@ -1097,7 +1101,7 @@ EX void drawmessage(const string& s, int& y, color_t col) {
   }
 
 EX void drawmessages() {
-  DEBBI(DF_GRAPH, ("draw messages"));
+  DEBBI(debug_graph, ("draw messages"));
   int i = 0;
   int t = ticks;
   for(int j=0; j<isize(msgs); j++) {
@@ -1348,7 +1352,7 @@ EX int current_window_flags = -1;
 
 EX void setvideomode() {
 
-  DEBBI(DF_INIT | DF_GRAPH, ("setvideomode"));
+  DEBBI(debug_graph || debug_init, ("setvideomode"));
   
   vid.full = vid.want_fullscreen;
   
@@ -1631,16 +1635,14 @@ EX void init_graph() {
 
 EX void initialize_all() {
 
-  DEBBI(DF_INIT | DF_GRAPH, ("initgraph"));
+  DEBBI(debug_init || debug_graph, ("initialize_all"));
   
-  DEBB(DF_INIT, ("initconfig"));
   initConfig();
 
 #if CAP_SDLJOY
   joyx = joyy = 0; joydir.d = -1;
 #endif
   
-  DEBB(DF_INIT, ("restartGraph"));
   restartGraph();
   
   if(noGUI) {
@@ -1650,14 +1652,11 @@ EX void initialize_all() {
     return;
     }
 
-  DEBB(DF_INIT, ("preparesort"));
   preparesort();
 #if CAP_CONFIG
-  DEBB(DF_INIT, ("loadConfig"));
   loadConfig();
 #endif
 #if CAP_ARCM
-  DEBB(DF_INIT, ("parse symbol"));
   arcm::current.parse();
 #endif
   if(mhybrid) geometry = hybrid::underlying;
@@ -1666,14 +1665,10 @@ EX void initialize_all() {
   arg::read(2);
 #endif
 
-  DEBB(DF_INIT | DF_GRAPH, ("init graph"));
   init_graph();
-  DEBB(DF_INIT | DF_POLY, ("check CGI"));
   check_cgi();
-  DEBB(DF_INIT | DF_POLY, ("require basic"));
   cgi.require_basics();
   
-  DEBB(DF_INIT | DF_GRAPH, ("init font"));
   init_font();
 
 #if CAP_SDLJOY  
@@ -1681,15 +1676,12 @@ EX void initialize_all() {
 #endif
 
 #if CAP_SDLAUDIO
-  DEBB(DF_INIT, ("init audio"));
   initAudio();
 #endif
-
-  DEBB(DF_INIT, ("initialize_all done"));
   }
 
 EX void quit_all() {
-  DEBBI(DF_INIT, ("clear graph"));
+  DEBBI(debug_init, ("quit_all"));
 #if CAP_SDLJOY
   closeJoysticks();
 #endif
diff --git a/binary-tiling.cpp b/binary-tiling.cpp
index 9455ea6f..11e380a6 100644
--- a/binary-tiling.cpp
+++ b/binary-tiling.cpp
@@ -765,9 +765,7 @@ EX namespace bt {
       t[10] = it * t[6] * t[2];
       t[11] = it * t[1];
 
-      if(debugflags & DF_GEOM)
-        for(int a=0; a<12; a++) 
-          println(hlog, t[a]);
+      if(debug_geometry) for(int i=0; i<12; i++) println(hlog, "direct_tmatrix[", i, "] is ", t[i]);
 
       use_direct >>= 1;
       }
diff --git a/cell.cpp b/cell.cpp
index 61431550..116e914f 100644
--- a/cell.cpp
+++ b/cell.cpp
@@ -10,6 +10,8 @@
 #include "hyper.h"
 namespace hr {
 
+EX debugflag debug_map_warnings = {"map_warnings", true};
+
 #if HDR
 extern int default_levs();
 
@@ -570,9 +572,11 @@ EX cell *fractal_rep(cell *c) {
     }
   }
 
+EX debugflag debug_init_cells = {"init_cells", true};
+
 /** create a map in the current geometry */
 EX void initcells() {
-  DEBB(DF_INIT, ("initcells"));
+  indenter_finish dif(debug_init_cells, "initcells");
 
   if(embedded_plane) {
     geom3::swap_direction = -1;
@@ -627,19 +631,25 @@ EX void initcells() {
   // origin->emeraldval = 
   }
 
+EX debugflag debug_memory_cell = {"memory_cell"};
+
 EX void clearcell(cell *c) {
   if(!c) return;
-  DEBB(DF_MEMORY, (hr::format("c%d %p\n", c->type, hr::voidp(c))));
+  indenter_finish(debug_memory_cell, hr::format("memory_cell %d %p\n", c->type, hr::voidp(c)));
   for(int t=0; t<c->type; t++) if(c->move(t)) {
-    DEBB(DF_MEMORY, (hr::format("mov %p [%p] S%d\n", hr::voidp(c->move(t)), hr::voidp(c->move(t)->move(c->c.spin(t))), c->c.spin(t))));
+    if(debug_memory_cell)
+      println(hlog, hr::format("mov %p [%p] S%d\n", hr::voidp(c->move(t)), hr::voidp(c->move(t)->move(c->c.spin(t))), c->c.spin(t)));
     if(c->move(t)->move(c->c.spin(t)) != NULL &&
       c->move(t)->move(c->c.spin(t)) != c) {
-        DEBB(DF_MEMORY | DF_ERROR, (hr::format("cell error: type = %d %d -> %d\n", c->type, t, c->c.spin(t))));
-        if(worst_precision_error < 1e-3) exit(1);
+        if(debug_errors || debug_memory_cell)
+          println(hlog, hr::format("cell error: type = %d %d -> %d\n", c->type, t, c->c.spin(t)));
+        if(worst_precision_error < 1e-3)
+          throw hr_exception("clearcell");
         }
     c->move(t)->move(c->c.spin(t)) = NULL;
     }
-  DEBB(DF_MEMORY, (hr::format("DEL %p\n", hr::voidp(c))));
+  if(debug_memory_cell)
+    println(hlog, hr::format("DEL %p\n", hr::voidp(c)));
   gp::delete_mapped(c);
   destroy_cell(c);
   }
@@ -692,11 +702,12 @@ EX void clearfrom(heptagon *at) {
     at = q.front(); 
 //  if(q.size() > maxq) maxq = q.size();
     q.pop();
-    DEBB(DF_MEMORY, ("from %p", at));
+    if(debug_memory_cell) println(hlog, "from %p", at);
     if(!at->c7 && !ls::voronoi_structure()) {
       heptagon *h = dynamic_cast<heptagon*> ((cdata_or_heptagon*) at->cdata);
       if(h) {
-        if(h->alt != at) { DEBB(DF_MEMORY | DF_ERROR, ("alt error :: h->alt = ", h->alt, " expected ", at)); }
+        if(h->alt != at && (debug_memory_cell || debug_errors))
+          println(hlog, "alt error :: h->alt = ", h->alt, " expected ", at);
         cell *c = h->c7;
         subcell(c, destroycellcontents);
         h->alt = NULL;
@@ -710,12 +721,10 @@ EX void clearfrom(heptagon *at) {
         q.push(at->move(i));    
       unlink_cdata(at->move(i));
       at->move(i)->alt = &deletion_marker;
-      DEBB(DF_MEMORY, ("!mov ", at->move(i), " [", at->move(i)->move(at->c.spin(i)), "]"));
+      if(debug_memory_cell) println(hlog, "!mov ", at->move(i), " [", at->move(i)->move(at->c.spin(i)), "]");
       if(at->move(i)->move(at->c.spin(i)) != NULL &&
-        at->move(i)->move(at->c.spin(i)) != at) {
-          DEBB(DF_MEMORY | DF_ERROR, ("hept error"));
-          exit(1);
-          }
+        at->move(i)->move(at->c.spin(i)) != at)
+          throw hr_exception("hept error");
       at->move(i)->move(at->c.spin(i)) = NULL;
       at->move(i) = NULL;
       }
@@ -733,7 +742,7 @@ EX void verifycell(cell *c) {
       if(BITRUNCATED && c == c->master->c7) verifycell(c2);
       if(c2->move(c->c.spin(i)) && c2->move(c->c.spin(i)) != c) {
         printf("cell error %p:%d [%d] %p:%d [%d]\n", hr::voidp(c), i, c->type, hr::voidp(c2), c->c.spin(i), c2->type);
-        exit(1);
+        throw hr_exception("error during verifycell");
         }
       }
     }
@@ -1759,7 +1768,7 @@ EX int auto_compute_range(cell *c) {
   int z = isize(cl.dists);
   int d = cl.dists.back();
   while(cl.dists[z-1] == d) z--;
-  if(cgflags & DF_GEOM) {
+  if(debug_geometry) {
     println(hlog, "last distance = ", cl.dists.back());
     println(hlog, "ball size = ", isize(cl.dists));
     println(hlog, "previous ball size = ", z);
diff --git a/commandline.cpp b/commandline.cpp
index a90792e8..a7323550 100644
--- a/commandline.cpp
+++ b/commandline.cpp
@@ -187,42 +187,6 @@ int arg::readCommon() {
     PHASE(1);
     offlineMode = true;
     }
-  else if(argis("-no-stamp")) {
-    debugflags &=~ DF_TIME;
-    }
-  else if(argis("-debf")) {
-    shift(); 
-    string s = args();
-    for(char c: s) {
-      for(int i=0; i<int(strlen(DF_KEYS)); i++) {
-        if(DF_KEYS[i] == c) debugflags |= (1<<i);
-        else if(DF_KEYS[i] == (c ^ 32)) debugflags &= ~(1<<i);
-        }
-      if(c >= '0' && c <= '9') {
-        debugflags &= DF_TIME;
-        if(c >= '1')
-          debugflags |= DF_INIT | DF_WARN | DF_MSG | DF_ERROR;
-        if(c >= '2')
-          debugflags |= DF_GEOM | DF_GP | DF_LOG | DF_FIELD | DF_POLY;
-        if(c >= '3')
-          debugflags |= DF_TURN | DF_STEAM;
-        if(c >= '4')
-          debugflags |= DF_GRAPH | DF_MEMORY;
-        }
-      else if(c == '+') {
-        if(debugfile) fclose(debugfile);
-        shift(); 
-        println(hlog, "writing to ", argcs());
-        debugfile = fopen(argcs(), "at");  
-        }
-      else if(c == '@') {
-        if(debugfile) fclose(debugfile);
-        shift(); 
-        println(hlog, "writing to ", argcs());
-        debugfile = fopen(argcs(), "wt");  
-        }
-      }
-    }
   else if(argis("-run")) {
     PHASE(3); 
     start_game();
diff --git a/complex.cpp b/complex.cpp
index 3de3bb76..77073e7e 100644
--- a/complex.cpp
+++ b/complex.cpp
@@ -3594,9 +3594,9 @@ auto ccm = addHook(hooks_clearmemory, 0, [] () {
     eliminate_if(heat::offscreen_fire, is_cell_removed);
     eliminate_if(princess::infos, [] (princess::info*& i) { 
       if(is_cell_removed(i->princess) || is_cell_removed(i->prison)) { 
-        DEBB(DF_MEMORY, ("removing a princess"))
+        DEBB(debug_memory, ("removing a princess"))
         if(i->princess && !is_cell_removed(i->princess)) {
-          DEBB(DF_MEMORY, ("faking a princess"))
+          DEBB(debug_memory, ("faking a princess"))
           princess::newFakeInfo(i->princess);
           }
         delete i; 
diff --git a/config.cpp b/config.cpp
index f6c34b1b..c7a66103 100644
--- a/config.cpp
+++ b/config.cpp
@@ -1082,6 +1082,8 @@ EX void font_reaction() {
 
 EX void initConfig() {
   
+  DEBBI(debug_init_config, ("initconfig"));
+
   // basic config
   param_i(vid.flashtime, "flashtime", 8);
 
@@ -1939,8 +1941,11 @@ EX void resetConfig() {
 #endif
 
 #if CAP_CONFIG
+
+EX debugflag debug_init_config = {"init_config", true};
+
 EX void saveConfig() {
-  DEBB(DF_INIT, ("save config\n"));
+  indenter_finish(debug_init_config, "saveConfig");
   FILE *f = fopen(conffile, "wt");
   if(!f) {
     addMessage(s0 + "Could not open the config file: " + conffile);
@@ -2012,7 +2017,7 @@ EX void loadNewConfig(FILE *f) {
 
 EX void loadConfig() {
  
-  DEBB(DF_INIT, ("load config"));
+  indenter_finish(debug_init_config, "loadConfig");
   vid.xres = 9999; vid.yres = 9999; vid.framelimit = 999;
   FILE *f = fopen(conffile, "rt");
   if(f) {
@@ -2029,7 +2034,8 @@ EX void loadConfig() {
       }
   
     fclose(f);
-    DEBB(DF_INIT, ("Loaded configuration: %s\n", conffile));
+    if(debug_init_config)
+      println(hlog, "Loaded configuration: ", conffile);
     }
 
   geom3::apply_always3();
diff --git a/control.cpp b/control.cpp
index 707b0af3..65e25a71 100644
--- a/control.cpp
+++ b/control.cpp
@@ -146,7 +146,7 @@ EX int keybd_subdir = 1;
 EX bool keybd_subdir_enabled = 0;
 
 EX void movepckeydir(int d) {
-  DEBB(DF_GRAPH, ("movepckeydir\n"));
+  if(debug_graph) println(hlog, "movepckeydir(", d, ")");
   // EUCLIDEAN
   
   if(protect_memory()) return;
@@ -251,8 +251,12 @@ EX void initJoysticks_async() {
   #endif
   }
 
+EX debugflag debug_init_joy = {"init_joy"};
+EX debugflag debug_joy_error = {"joy_error"};
+EX debugflag debug_joy = {"joy"};
+
 EX void countJoysticks() {
-  DEBB(DF_INIT, ("opening joysticks"));
+  indenter_finish(debug_init_joy, "countJoysticks");
   #if SDLVER <= 2
   numsticks = SDL_NumJoysticks();
   #else
@@ -272,12 +276,11 @@ EX void countJoysticks() {
 
 EX void initJoysticks() {
 
-  DEBBI(DF_INIT, ("init joystick"));
+  indenter_finish(debug_init_joy, "initJoysticks");
 
-  DEBB(DF_INIT, ("init joystick subsystem"));
   if (SDL_error_in(SDL_InitSubSystem(SDL_INIT_JOYSTICK)))
   {
-    printf("Failed to initialize joysticks.\n");
+    if(debug_joy_error) println(hlog, "Failed to initialize joysticks.");
     numsticks = 0;
     return;
   }
@@ -287,7 +290,7 @@ EX void initJoysticks() {
   }
 
 EX void closeJoysticks() {
-  DEBB(DF_INIT, ("close joysticks"));
+  indenter_finish(debug_init_joy, "closeJoysticks");
   for(int i=0; i<numsticks; i++) {
     SDL_CloseJoystick(sticks[i]), sticks[i] = NULL;
     }
@@ -298,7 +301,7 @@ int joytime;
 EX bool joy_ignore_next = false;
 
 EX void checkjoy() {
-  DEBB(DF_GRAPH, ("check joy"));
+  indenter_finish(debug_joy, "checkjoy");
   if(!DEFAULTCONTROL) return;
   ld joyvalue1 = sqr(vid.joyvalue);
   ld joyvalue2 = sqr(vid.joyvalue2);
@@ -787,9 +790,11 @@ EX bool mouseaiming(bool shmupon) {
 
 EX purehookset hooks_control;
 
+EX debugflag debug_control = {"control"};
+
 EX void mainloopiter() {
+  indenter_finish(debug_control, "mainloopiter");
   GLWRAP;
-  DEBB(DF_GRAPH, ("main loop\n"));
 
   #if !CAP_SDLGFX && !CAP_GL 
   vid.wallmode = 0;
@@ -956,7 +961,8 @@ EX void mainloopiter() {
 #endif
   apply_memory_reserve();
   SDL_Event ev;
-  DEBB(DF_GRAPH, ("polling for events\n"));
+
+  if(debug_control) println(hlog, "polling for events");
   
   #if CAP_VR
   if(vrhr::active() && !shmup::on) {
@@ -1096,7 +1102,7 @@ EX bool need_refresh;
 
 EX void handle_event(SDL_Event& ev) {
   bool normal = cmode & sm::NORMAL;
-    DEBB(DF_GRAPH, ("got event type #%d\n", ev.type));
+    indenter_finish(debug_control, "got event type #" + its(ev.type));
     int sym = 0;
     int uni = 0;
     shiftmul = 1;
diff --git a/debug.cpp b/debug.cpp
index 8c81bcc1..714420e0 100644
--- a/debug.cpp
+++ b/debug.cpp
@@ -15,6 +15,19 @@ EX bool debug_cellnames = false;
 
 EX vector<cell*> buggycells;
 
+map<string, struct debugflag*> *all_debugflags;
+
+void add_debugflag(const string& s, debugflag *d) {
+  if(!all_debugflags) all_debugflags = new map<string, struct debugflag*>;
+  if(all_debugflags->count(s)) printf("warning: duplicate debugflag: %s\n", s.c_str());
+  (*all_debugflags)[s] = d;
+  }
+
+EX debugflag debug_errors = {"error", true};
+EX debugflag debug_warnings = {"warning", true};
+EX debugflag debug_memory = {"memory"};
+EX debugflag debug_init = {"init", true};
+
 #if HDR
 template<class... T>
 void limitgen(T... args) {
@@ -873,6 +886,35 @@ int read_cheat_args() {
     cheat();
     gen_wandering = false;
     }
+  else if(argis("-log")) {
+    shift(); auto s = args();
+    if(debug_init) println(hlog, "logging: '", s, "'");
+    for(auto& w: *all_debugflags) if(w.first.find(s) != string::npos) w.second->enabled = true;
+    }
+  else if(argis("-log-all")) {
+    if(debug_init) println(hlog, "logging all");
+    for(auto& w: *all_debugflags) w.second->enabled = true;
+    }
+  else if(argis("-no-log")) {
+    shift(); auto s = args();
+    if(debug_init) println(hlog, "not logging: '", s, "'");
+    for(auto& w: *all_debugflags) if(w.first.find(s) != string::npos) w.second->enabled = false;
+    }
+  else if(argis("-log-none")) {
+    for(auto& w: *all_debugflags) w.second->enabled = false;
+    }
+  else if(argis("-log-to")) {
+    shift();
+    if(debug_init) println(hlog, "writing to ", argcs());
+    if(debugfile) fclose(debugfile);
+    debugfile = fopen(argcs(), "wt");
+    }
+  else if(argis("-log-append")) {
+    shift();
+    if(debug_init) println(hlog, "writing to ", argcs());
+    if(debugfile) fclose(debugfile);
+    debugfile = fopen(argcs(), "at");
+    }
   else if(argis("-canvasfloor")) {
     shift(); canvasfloor = argi();
     for(int i=0; i<caflEND; i++) if(appears(mapeditor::canvasFloorName(i), args()))
diff --git a/drawing.cpp b/drawing.cpp
index d632f80b..eaa30987 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -180,7 +180,7 @@ vector<glhr::colored_vertex> line_vertices;
 #endif
 
 EX void glflush() {
-  DEBBI(DF_GRAPH, ("glflush"));
+  DEBBI(debug_graph, ("glflush"));
   #if MINIMIZE_GL_CALLS
   if(isize(triangle_vertices)) {
     // printf("%3d | %d shapes, %d/%d vertices\n", lprio, shapes_merged, isize(triangle_vertices), isize(line_vertices));
@@ -1817,10 +1817,12 @@ bool broken_projection(dqi_poly& p0) {
   return false;
   }
 
+EX debugflag debug_vertex = {"vertex"};
+
 void dqi_poly::draw() {
   if(flags & POLY_DEBUG) debug_this();
 
-  if(debugflags & DF_VERTEX) {
+  if(debug_vertex) {
     println(hlog, int(prio), ": V=", V, " o=", offset, " c=", cnt, " ot=", offset_texture, " ol=", outline, " lw=", linewidth, " f=", (color_t) flags, " i=", intester, " c=", cache, " ti=", (cell*) tinf);
     for(int i=0; i<cnt; i++) print(hlog, (*tab)[offset+i]);
     println(hlog);
@@ -2345,7 +2347,7 @@ void dqi_line::draw_back() {
   }
 
 EX void sort_drawqueue() {
-  DEBBI(DF_GRAPH, ("sort_drawqueue"));
+  DEBBI(debug_graph, ("sort_drawqueue"));
   
   for(int a=0; a<PMAX; a++) qp[a] = 0;
   
@@ -2399,7 +2401,7 @@ EX void reverse_side_priorities() {
 
 // on the sphere, parts on the back are drawn first
 EX void draw_backside() {
-  DEBBI(DF_GRAPH, ("draw_backside"));
+  DEBBI(debug_graph, ("draw_backside"));
   if(pmodel == mdHyperboloid && hyperbolic && pconf.show_hyperboloid_flat) {
     dynamicval<eModel> dv (pmodel, mdHyperboloidFlat);
     for(auto& ptd: ptds) 
@@ -2457,7 +2459,7 @@ EX void set_vr_sphere() {
 EX int hemi_side = 0;
 
 EX void draw_main() {
-  DEBBI(DF_GRAPH, ("draw_main"));
+  DEBBI(debug_graph, ("draw_main"));
   
   if(pconf.back_and_front == 1 && vid.consider_shader_projection) {
     dynamicval<int> pa(pconf.back_and_front);
@@ -2546,20 +2548,20 @@ EX void draw_main() {
     glflush();
     }
   else {
-    DEBB(DF_GRAPH, ("draw_main1"));
+    DEBB(debug_graph, ("draw_main1"));
     if(ray::in_use && !ray::comparison_mode) {
       ray::cast();
       reset_projection();
       }
 
-    DEBB(DF_GRAPH, ("outcircle"));
+    DEBB(debug_graph, ("outcircle"));
     for(auto& ptd: ptds) if(ptd->prio == PPR::OUTCIRCLE)
       ptd->draw();
     
     if(two_sided_model()) draw_backside();
   
     for(auto& ptd: ptds) if(ptd->prio != PPR::OUTCIRCLE) {
-      DEBBI(DF_VERTEX, ("prio: ", int(ptd->prio), " color ", ptd->color));
+      DEBBI(debug_vertex, ("prio: ", int(ptd->prio), " color ", ptd->color));
       dynamicval<int> ss(spherespecial, among(ptd->prio, PPR::MOBILE_ARROW, PPR::OUTCIRCLE, PPR::CIRCLE) ? 0 : spherespecial);
       ptd->draw();
       }
@@ -2582,7 +2584,7 @@ EX void draw_main() {
 
 EX void drawqueue() {
 
-  DEBBI(DF_GRAPH, ("drawqueue"));
+  DEBBI(debug_graph, ("drawqueue"));
   
   #if CAP_WRL
   if(wrl::in) { wrl::render(); return; }
@@ -2611,7 +2613,7 @@ EX void drawqueue() {
   
   sort_drawqueue();
 
-  DEBB(DF_GRAPH, ("sort walls"));
+  DEBB(debug_graph, ("sort walls"));
   
   if(GDIM == 2)
   for(PPR p: all_side_prios) {
diff --git a/environment.cpp b/environment.cpp
index d2142896..59802837 100644
--- a/environment.cpp
+++ b/environment.cpp
@@ -833,11 +833,11 @@ EX void monstersTurn() {
   reset_spill();
   checkSwitch();
   mirror::breakAll();
-  DEBB(DF_TURN, ("bfs"));
+  DEBB(debug_turn, ("bfs"));
   bfs();
-  DEBB(DF_TURN, ("charge"));
+  DEBB(debug_turn, ("charge"));
   if(elec::havecharge) elec::act();
-  DEBB(DF_TURN, ("mmo"));
+  DEBB(debug_turn, ("mmo"));
   int phase2 = (1 & items[itOrbSpeed]);
   if(!phase2) movemonsters();
 
@@ -858,11 +858,11 @@ EX void monstersTurn() {
       refreshFriend(dcal[i]);
       }
     }
-  DEBB(DF_TURN, ("rop"));
+  DEBB(debug_turn, ("rop"));
   if(!dual::state) reduceOrbPowers();
   int phase1 = (1 & items[itOrbSpeed]);
   if(dual::state && items[itOrbSpeed]) phase1 = !phase1;
-  DEBB(DF_TURN, ("lc"));
+  DEBB(debug_turn, ("lc"));
   if(!phase1) livecaves();
   if(!phase1) ca::simulate();
   if(!phase1) heat::processfires();
@@ -885,7 +885,7 @@ EX void monstersTurn() {
   crush_now = std::move(crush_next);
   crush_next.clear();
   
-  DEBB(DF_TURN, ("heat"));
+  DEBB(debug_turn, ("heat"));
   heat::processheat();
   // if(elec::havecharge) elec::drawcharges();
 
@@ -899,7 +899,7 @@ EX void monstersTurn() {
     for(cell *pc: player_positions())
       checkFreedom(pc);
 
-  DEBB(DF_TURN, ("check"));
+  DEBB(debug_turn, ("check"));
   checkmove();
   if(canmove) elec::checklightningfast();
 
diff --git a/fieldpattern.cpp b/fieldpattern.cpp
index 861f9790..c5903788 100644
--- a/fieldpattern.cpp
+++ b/fieldpattern.cpp
@@ -75,6 +75,8 @@ EX int btspin(int id, int d) {
   return groupspin(id, d, S7);
   }
 
+EX debugflag debug_field = {"geometry_field"};
+
 #if HDR
 
 static constexpr int ERR = -99;
@@ -529,7 +531,8 @@ bool fpattern::generate_all3() {
     if(isize(matrices) >= limitv) { println(hlog, "limitv exceeded"); return false; }
     }
   hashv = compute_hash();
-  DEBB(DF_FIELD, ("all = ", isize(matrices), "/", local_group, " = ", isize(matrices) / local_group, " hash = ", hashv, " count = ", ++hash_found[hashv]));
+  if(debug_field)
+    println(hlog, "all = ", isize(matrices), "/", local_group, " = ", isize(matrices) / local_group, " hash = ", hashv, " count = ", ++hash_found[hashv]);
   
   if(use_quotient_fp) 
     generate_quotientgroup();  
@@ -604,9 +607,11 @@ EX purehookset hooks_solve3;
 
 int fpattern::solve3() {
 
+  indenter_finish(debug_field, "fpattern::solve3");
+
   reg3::generate_fulls();
   
-  DEBB(DF_FIELD, ("generating isometries for ", Field));
+  if(debug_field) println(hlog, "generating isometries for ", Field);
   
   auto iso3 = generate_isometries();
   auto iso4 = generate_isometries3();
@@ -625,7 +630,8 @@ int fpattern::solve3() {
     if(check_order(M, 2)) 
       possible_P.push_back(M);
     
-  DEBB(DF_FIELD, ("field = ", Field, " #P = ", isize(possible_P), " #X = ", isize(possible_X), " #R = ", isize(possible_R), " r_order = ", cgi.r_order, " xp_order = ", cgi.xp_order));
+  if(debug_field)
+    println(hlog, "field = ", Field, " #P = ", isize(possible_P), " #X = ", isize(possible_X), " #R = ", isize(possible_R), " r_order = ", cgi.r_order, " xp_order = ", cgi.xp_order);
                                                                                                                                
   for(auto& xX: possible_X)
   for(auto& xP: possible_P) if(check_order(mmul(xP, xX), cgi.xp_order)) 
@@ -653,7 +659,8 @@ int fpattern::solve3() {
 
   ok:
 
-  DEBB(DF_FIELD, ("cmb = ", cmb, " for field = ", Field));
+  if(debug_field)
+    println(hlog, "cmb = ", cmb, " for field = ", Field);
   
   return cmb;
   }
@@ -802,8 +809,9 @@ vector<triplet_info> fpattern::find_triplets() {
     
     return transcript;
     };
-  
-  DEBB(DF_FIELD, ("looking for alternate solutions"));
+
+  if(debug_field) println(hlog, "looking for alternate solutions");
+
   auto orig_transcript = compute_transcript(1, S7);
   
   set<vector<int>> transcripts_seen;
@@ -824,7 +832,7 @@ vector<triplet_info> fpattern::find_triplets() {
     cc.push_back(i);
     }    
   
-  DEBB(DF_FIELD, ("conjugacy_classes = ", cc));
+  if(debug_field) println(hlog, "conjugacy_classes = ", cc);
   
   vector<triplet_info> tinf;
   triplet_info ti;
@@ -832,7 +840,7 @@ vector<triplet_info> fpattern::find_triplets() {
   tinf.push_back(ti);
   
   for(int i: conjugacy_classes) if(gorder(i) == S7) {
-    DEBB(DF_FIELD, ("checking i=", i));
+    if(debug_field) println(hlog, "checking i=", i);
     for(int j=1; j<N; j++) if(gorder(j) == 2 && gorder(gmul(i, j)) == S3) {
       auto t = compute_transcript(i, j);    
       if(!transcripts_seen.count(t)) {
@@ -844,7 +852,7 @@ vector<triplet_info> fpattern::find_triplets() {
       }
     }
   
-  DEBB(DF_FIELD, ("solutions found = ", isize(transcripts_seen)));
+  if(debug_field) println(hlog, "solutions found = ", isize(transcripts_seen));
   return tinf;
   }
 
@@ -879,10 +887,10 @@ void fpattern::build() {
     connections.push_back(matcode[PM]);
     }
 
-  DEBB(DF_FIELD, ("Computing inverses...\n"));
+  if(debug_field) println(hlog, "Computing inverses...\n");
   int N = isize(matrices);
 
-  DEBB(DF_FIELD, ("Number of heptagons: %d\n", N));
+  if(debug_field) println(hlog, "Number of heptagons: %d\n", N);
   
   if(WDIM == 3) return;
 
@@ -911,7 +919,7 @@ void fpattern::build() {
     if(i%S7 == S7-1) printf("\n");       
     }
   
-  DEBB(DF_FIELD, ("triplet_id = ", triplet_id, " N = ", N));
+  if(debug_field) println(hlog, "triplet_id = ", triplet_id, " N = ", N);
   if(triplet_id) {  
     auto triplets = find_triplets();
     if(triplet_id >= 0 && triplet_id < isize(triplets)) {
@@ -920,12 +928,12 @@ void fpattern::build() {
       P = matrices[ti.j];
       dynamicval<int> t(triplet_id, 0);
       build();
-      DEBB(DF_FIELD, ("triplet built successfully"));
+      if(debug_field) println(hlog, "triplet built successfully");
       return;
       }
     }
   
-  DEBB(DF_FIELD, ("Built.\n"));
+  if(debug_field) println(hlog, "Built.\n");
   }
 
 int fpattern::getdist(pair<int,bool> a, vector<char>& dists) {
@@ -991,7 +999,7 @@ void fpattern::analyze() {
       }
     }
     
-  DEBB(DF_FIELD, ("variation = %d\n", int(variation)));
+  if(debug_field) println(hlog, "variation = %d\n", int(variation));
   int N = isize(connections);
   
   markers.resize(N);
@@ -1039,7 +1047,7 @@ void fpattern::analyze() {
     if(disthep[connections[i]] < disthep[i] && disthep[connections[btspin(i,u)]] < disthep[i])
       circrad = disthep[i];
 
-  DEBB(DF_FIELD, ("maxdist = %d otherpole = %d circrad = %d\n", maxdist, otherpole, circrad));
+  if(debug_field) println(hlog, "maxdist = %d otherpole = %d circrad = %d\n", maxdist, otherpole, circrad);
   
   matrix PRRR = strtomatrix("PRRR");
   matrix PRRPRRRRR = strtomatrix("PRRPRRRRR");
@@ -1051,7 +1059,7 @@ void fpattern::analyze() {
   wallorder = order(Wall);
   wallid = matcode[Wall];
   
-  DEBB(DF_FIELD, ("wall order = %d\n", wallorder));
+  if(debug_field) println(hlog, "wall order = %d\n", wallorder);
 
 #define SETDIST(X, d, it) {int c = matcode[X]; indist[d].push_back(c); if(it == itNone) ; else if(markers[c] && markers[c] != it) markers[c] = itBuggy; else markers[c] = it; }
   
@@ -1067,8 +1075,7 @@ void fpattern::analyze() {
     }
   
   int walldist = dijkstra(distwall, indist);
-  DEBB(DF_FIELD, ("wall dist = %d\n", walldist));
-  
+  if(debug_field) println(hlog, "wall dist = %d\n", walldist);
   
   W = strtomatrix("RRRRPR");
   for(int j=0; j<wallorder; j++) {
@@ -1089,7 +1096,7 @@ void fpattern::analyze() {
     int ipush = gmul(rpushid, i);
     for(int k=0; k<wallorder; k++) {
       if(ipush == j) {
-        DEBB(DF_FIELD, ("River found at %d:%d\n", i, k));
+        if(debug_field) println(hlog, "River found at %d:%d\n", i, k);
         riverid = i;
         goto riveridfound;
         }
@@ -1131,7 +1138,7 @@ void fpattern::analyze() {
     W = mmul(W, Wall);
     }
   int riverdist = dijkstra(PURE ? distflower : distriver, indist);
-  DEBB(DF_FIELD, ("river dist = %d\n", riverdist));
+  if(debug_field) println(hlog, "river dist = %d\n", riverdist);
   
   for(int i=0; i<isize(matrices); i++)
     if(distflower[i] == 0) {
@@ -1194,8 +1201,8 @@ void fpattern::analyze() {
     dijkstra(distriverright, indist);
     }
 
-  DEBB(DF_FIELD, ("wall-river distance = %d\n", distwall[riverid]));
-  DEBB(DF_FIELD, ("river-wall distance = %d\n", distriver[0]));
+  if(debug_field) println(hlog, "wall-river distance = %d\n", distwall[riverid]);
+  if(debug_field) println(hlog, "river-wall distance = %d\n", distriver[0]);
   }
 
 int fpattern::orderstats() {
@@ -1229,7 +1236,7 @@ void fpattern::findsubpath() {
     if(gpow(i, Prime) == 0) {
       subpathid = i;
       subpathorder = Prime;
-      DEBB(DF_FIELD, ("Subpath found: %s\n", decodepath(i).c_str()));
+      if(debug_field) println(hlog, "Subpath found: %s\n", decodepath(i).c_str());
       return;
       }
   }
@@ -1416,7 +1423,7 @@ EX struct fpattern& getcurrfp() {
     static fpattern fp(0);
     if(fp.Prime) return fp;
     for(int p=2; p<20; p++) { fp.Prime = p; if(!fp.solve()) break; }
-    DEBB(DF_FIELD, ("set prime = ", fp.Prime));
+    if(debug_field) println(hlog, "set prime = ", fp.Prime);
     return fp;
     }
   if(S7 == 8 && S3 == 3 && !bt::in()) {
diff --git a/floorshapes.cpp b/floorshapes.cpp
index c1a59dd4..9385919b 100644
--- a/floorshapes.cpp
+++ b/floorshapes.cpp
@@ -232,7 +232,8 @@ void geometry_information::bshape2(hpcshape& sh, PPR prio, int shapeid, matrixli
   T = spin(m.o.bspi) * T;
   for(auto &pp: lst) pp = T * pp;
   
-  if(osym % rots && rots % osym && (debugflags & DF_GEOM)) printf("warning: rotation oddity (shapeid %d, osym=%d rots=%d)\n", shapeid, osym, rots);
+  if(osym % rots && rots % osym && debug_geometry)
+    printf("warning: rotation oddity (shapeid %d, osym=%d rots=%d)\n", shapeid, osym, rots);
 
   if(rots > osym && rots % osym == 0) {
     int rep = rots / osym;
@@ -260,7 +261,8 @@ void geometry_information::bshape2(hpcshape& sh, PPR prio, int shapeid, matrixli
           nh = m.second[r] * z, mapped++;
           }
         }
-      if(mapped == 0 && (debugflags & DF_GEOM)) printf("warning: not mapped (shapeid %d)\n", shapeid);
+      if(mapped == 0 && debug_geometry)
+        println(hlog, "warning: not mapped shapeid = ", shapeid);
       if(invalid) {
         apeirogonal = true;        
         for(auto h: head) tail.push_back(h);
@@ -395,7 +397,7 @@ void geometry_information::generate_floorshapes_for(int id, cell *c) {
 
   #if CAP_IRR
   else if(IRREGULAR) {
-    DEBBI(DF_POLY, ("generate_floorshapes: irregular"));
+    DEBBI(debug_poly, ("generate_floorshapes: irregular"));
 
     auto& vs = irr::cells[id];
     siid = vs.is_pseudohept;
@@ -444,7 +446,7 @@ void geometry_information::generate_floorshapes_for(int id, cell *c) {
     }
   #endif
 
-  DEBBI(DF_POLY, ("generate_floorshapes_for ", id));
+  DEBBI(debug_poly, ("generate_floorshapes_for ", id));
 
   for(auto pfsh: all_plain_floorshapes) {
     auto& fsh = *pfsh;
@@ -1383,7 +1385,7 @@ void geometry_information::make_floor_textures_here() {
 
 EX void make_floor_textures() {
   if(noGUI || !vid.usingGL) return;
-  DEBBI(DF_POLY, ("make_floor_textures"));
+  DEBBI(debug_poly, ("make_floor_textures"));
   dynamicval<euc::torus_config_full> geu(euc::eu, euc::eu);
   dynamicval<eGeometry> g(geometry, gEuclidSquare);
   dynamicval<eModel> gm(pmodel, mdDisk);
diff --git a/geometry.cpp b/geometry.cpp
index 0f7e84ed..663a0cda 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -8,6 +8,8 @@
 #include "hyper.h"
 namespace hr {
 
+EX debugflag debug_geometry = {"geometry"};
+
 #if HDR
 struct usershapelayer {
   vector<hyperpoint> list;
@@ -646,7 +648,7 @@ void geometry_information::generate_faces() {
 
 void geometry_information::prepare_basics() {
 
-  DEBBI(DF_INIT | DF_POLY | DF_GEOM, ("prepare_basics"));
+  indenter_finish dif(debug_geometry, "prepare_basics");
   
   hexshift = 0;
 
@@ -790,9 +792,9 @@ void geometry_information::prepare_basics() {
     if(BITRUNCATED) plevel_twisted = (M_PI - 2 * alpha6 - alpha7) * fake::around * 2;
     }
   
-  DEBB(DF_GEOM | DF_POLY,
-    (hr::format("S7=%d S6=%d hexf = " LDF" hcross = " LDF" tessf = " LDF" hexshift = " LDF " hexhex = " LDF " hexv = " LDF "\n", S7, S6, hexf, hcrossf, tessf, hexshift, 
-    hexhexdist, hexvdist)));  
+  if(debug_geometry) println(hlog,
+    hr::format("S7=%d S6=%d hexf = " LDF" hcross = " LDF" tessf = " LDF" hexshift = " LDF " hexhex = " LDF " hexv = " LDF "\n", S7, S6, hexf, hcrossf, tessf, hexshift, 
+    hexhexdist, hexvdist));
   
   hybrid_finish:
   
@@ -831,7 +833,6 @@ void geometry_information::prepare_basics() {
     geometry = gFake;
     ld our = xpush0(hcrossf)[0] / xpush0(hcrossf)[GDIM];
     fake::scale = our / orig;
-    // if(debugflags & DF_GEOM) 
     }
 
   if(fake::in() && WDIM == 3) {
@@ -918,7 +919,8 @@ void geometry_information::prepare_basics() {
       if(inv) psl_steps = 2 * S3;
       if(single_step < 0) single_step = -single_step;
       }
-    DEBB(DF_GEOM | DF_POLY, ("steps = ", psl_steps, " / ", single_step));
+
+    if(debug_geometry) println(hlog, "steps = ", psl_steps, " / ", single_step);
     plevel = M_PI * single_step / psl_steps;
     if(hybrid::underlying == gFake) {
       auto s3 = fake::around;
@@ -1067,7 +1069,7 @@ EX namespace geom3 {
   
   void geometry_information::prepare_compute3() {
     using namespace geom3;
-    DEBBI(DF_INIT | DF_POLY | DF_GEOM, ("geom3::compute"));
+    indenter_finish dig(debug_geometry, "prepare_compute3");
     // tanh(depth) / tanh(camera) == pconf.alpha
     
     if(GDIM == 3 || flipped || changing_embedded_settings);
@@ -1462,7 +1464,8 @@ EX void check_cgi() {
     for(auto& t: cgis) if(!t.second.use_count) timestamps.emplace_back(-t.second.timestamp, t.first);
     sort(timestamps.begin(), timestamps.end());
     while(isize(timestamps) > limit && timestamps.back().first != -ntimestamp) {
-      DEBB(DF_GEOM, ("erasing geometry ", timestamps.back().second));
+      if(debug_geometry)
+        println(hlog, "erasing geometry ", timestamps.back().second);
       cgis.erase(timestamps.back().second);
       timestamps.pop_back();
       }
diff --git a/goldberg.cpp b/goldberg.cpp
index 84881556..ffebd1a3 100644
--- a/goldberg.cpp
+++ b/goldberg.cpp
@@ -17,6 +17,8 @@ extern hrmap *currentmap;
 
 EX namespace gp {
 
+  EX debugflag debug_gp = {"graph_gp"};
+
   #if HDR
   struct loc : pair<int, int> {
     loc() {}
@@ -214,7 +216,7 @@ EX namespace gp {
       if(peek(wcw)) {
         auto wcw1 = get_localwalk(wc1, dir1);
         if(wcw + wstep != wcw1) {
-          DEBB(DF_GP, (at1, " : ", (wcw+wstep), " / ", wcw1, " (pull error from ", at, " :: ", wcw, ")") );
+          DEBB(debug_gp, (at1, " : ", (wcw+wstep), " / ", wcw1, " (pull error from ", at, " :: ", wcw, ")") );
           exit(1);
           }
         if(do_adjm) wc1.adjm = wc.adjm * get_adj(wcw.at, wcw.spin);
@@ -223,7 +225,7 @@ EX namespace gp {
       }
     if(peek(wcw)) {
       set_localwalk(wc1, dir1, wcw + wstep);
-      DEBB(DF_GP, (at1, " :", wcw+wstep, " (pulled from ", at, " :: ", wcw, ")"));
+      DEBB(debug_gp, (at1, " :", wcw+wstep, " (pulled from ", at, " :: ", wcw, ")"));
       if(do_adjm) wc1.adjm = wc.adjm * get_adj(wcw.at, wcw.spin);
       return true;
       }
@@ -236,12 +238,12 @@ EX namespace gp {
     auto& wc = get_mapping(at);
     auto wcw = get_localwalk(wc, dir);
     auto& wc1 = get_mapping(at + eudir(dir));
-    DEBB0(DF_GP, (hr::format("  md:%02d s:%d", wc.mindir, wc.cw.spin)); )
-    DEBB0(DF_GP, ("  connection ", at, "/", dir, " ", wc.cw+dir, "=", wcw, " ~ ", at+eudir(dir), "/", dir1, " "); )
+    DEBB0(debug_gp, (hr::format("  md:%02d s:%d", wc.mindir, wc.cw.spin)); )
+    DEBB0(debug_gp, ("  connection ", at, "/", dir, " ", wc.cw+dir, "=", wcw, " ~ ", at+eudir(dir), "/", dir1, " "); )
     if(!wc1.cw.at) {
       wc1.start = wc.start;
       if(peek(wcw)) {
-        DEBB0(DF_GP, (" (pulled) "); )
+        DEBB0(debug_gp, (" (pulled) "); )
         set_localwalk(wc1, dir1, wcw + wstep);
         if(do_adjm) wc1.adjm = wc.adjm * get_adj(wcw.at, wcw.spin);
         }
@@ -251,27 +253,25 @@ EX namespace gp {
         set_localwalk(wc1, dir1, wcw + wstep);
         if(do_adjm) wc1.adjm = wc.adjm;
         spawn++;
-        DEBB0(DF_GP, (" (created) "); )
+        DEBB0(debug_gp, (" (created) "); )
         }
       }
-    DEBB0(DF_GP, (wc1.cw+dir1, " "));
+    DEBB0(debug_gp, (wc1.cw+dir1, " "));
     auto wcw1 = get_localwalk(wc1, dir1);
     if(peek(wcw)) {
       if(wcw+wstep != wcw1) {
-        DEBB(DF_GP, ("FAIL: ", wcw, " connected to ", wcw+wstep, " not to ", wcw1); exit(1); )
+        DEBB(debug_gp, ("FAIL: ", wcw, " connected to ", wcw+wstep, " not to ", wcw1); exit(1); )
         }
       else {
-        DEBB(DF_GP, ("(was there)"));
+        DEBB(debug_gp, ("(was there)"));
         }
       }
     else {
-      DEBB(DF_GP, ("ok"));
+      DEBB(debug_gp, ("ok"));
       peek(wcw) = wcw1.at;
       wcw.at->c.setspin(wcw.spin, wcw1.spin, wcw.mirrored != wcw1.mirrored);
-      if(wcw+wstep != wcw1) {
-        DEBB(DF_GP | DF_ERROR, ("assertion failed"));
-        exit(1);
-        }
+      if(wcw+wstep != wcw1)
+        throw hr_exception("assertion failed in gp::conn1");
       }
     if(do_adjm) {
       get_adj(wcw.at, wcw.spin) = inverse(wc.adjm) * wc1.adjm;
@@ -295,18 +295,18 @@ EX namespace gp {
     auto& ac0 = get_mapping(at);
     ac0.cw = cellwalker(hs.at->c7, hs.spin, hs.mirrored);
     ac0.start = at;
-    DEBB(DF_GP, (at, " : ", ac0.cw));
+    DEBB(debug_gp, (at, " : ", ac0.cw));
     return ac0;
     }
 
   EX void extend_map(cell *c, int d) {
-    DEBB(DF_GP, ("EXTEND ",c, " ", d));
+    DEBB(debug_gp, ("EXTEND ",c, " ", d));
     indenter ind(2);
     if(c->master->c7 != c) {
       auto c1 = c;
       auto d1 = d;
       while(c->master->c7 != c) {
-        DEBB(DF_GP, (c, " direction 0 corresponds to ", c->move(0), " direction ", c->c.spin(0)); )
+        DEBB(debug_gp, (c, " direction 0 corresponds to ", c->move(0), " direction ", c->c.spin(0)); )
         d = c->c.spin(0);
         c = c->move(0);
         }
@@ -465,13 +465,13 @@ EX namespace gp {
     for(int i=0; i<S3; i++) {
       loc start = vc[i];
       loc end = vc[(i+1)%S3];
-      DEBB(DF_GP, ("from ", start, " to ", end); )
+      DEBB(debug_gp, ("from ", start, " to ", end); )
       loc rel = param;
       auto build = [&] (loc& at, int dx, bool forward) {
         int dx0 = fixg6(dx + SG2*i);
         auto at1 = at + eudir(dx0);
         auto dx1 = fixg6(dx0 + SG3);
-        DEBB(DF_GP, (at, " .. ", make_pair(at1, dx1)));
+        DEBB(debug_gp, (at, " .. ", make_pair(at1, dx1)));
         conn(at, dx0);
         if(forward) { get_mapping(at).rdir = dx0; get_mapping(at1).rdir1 = dx1; }
         else { get_mapping(at).rdir1 = dx0; get_mapping(at1).rdir = dx1; }
@@ -506,8 +506,11 @@ EX namespace gp {
         }
       for(int k=0; k<SG6; k++)
         if(start + eudir(k+SG2*i) == end)
-          build(start, k, true);                         
-      if(start != end) { DEBB(DF_GP | DF_ERROR, ("assertion failed: start ", start, " == end ", end)); exit(1); }
+          build(start, k, true);
+      if(start != end) {
+        DEBB(debug_gp || debug_errors, ("assertion failed: start ", start, " == end ", end));
+        throw hr_exception("assertion failed in extend_map");
+        }
       }
 
     // now we can fill the interior of our big equilateral triangle
@@ -533,7 +536,7 @@ EX namespace gp {
         visit(at1);
         }
       }
-    DEBB(DF_GP, ("DONE"))
+    DEBB(debug_gp, ("DONE"))
     }
   
   EX hyperpoint loctoh_ort(loc at) {
@@ -719,7 +722,7 @@ EX namespace gp {
 //    spin = spintox(next);
 //    ispin = rspintox(next);
       cgi.gpdata->alpha = -atan2(next[1], next[0]) * 6 / S7;
-      DEBB(DF_GEOM | DF_POLY, ("scale = ", scale));
+      DEBB(debug_geometry, ("scale = ", scale));
       }
     }
 
diff --git a/graph-player.cpp b/graph-player.cpp
index 303ad76c..32ea8a9b 100644
--- a/graph-player.cpp
+++ b/graph-player.cpp
@@ -752,9 +752,11 @@ EX void draw_movement_arrows(cell *c, const transmatrix& V, int df) {
   if(keylist != "") queuestr(shiftless(V), keysize * mapfontscale / 100, keylist, col >> 8, 1);
   }
 
+debugflag debug_movestar = {"graph_movestar"};
+
 EX void drawmovestar(double dx, double dy) {
 
-  DEBBI(DF_GRAPH, ("draw movestar"));
+  indenter_finish(debug_movestar, "drawmovestar");
   if(viewdists) return;
   if(GDIM == 3) return;
 
diff --git a/graph.cpp b/graph.cpp
index 11a4b968..adeedb3d 100644
--- a/graph.cpp
+++ b/graph.cpp
@@ -289,8 +289,12 @@ void sumaura(int v) {
 vector<glhr::colored_vertex> auravertices;
 #endif
 
+EX debugflag debug_graph = {"graph"};
+
+EX debugflag debug_aura = {"graph_aura"};
+
 EX void drawaura() {
-  DEBBI(DF_GRAPH, ("draw aura"));
+  indenter_finish(debug_aura, "drawaura");
   if(!haveaura()) return;
   if(vid.stereo_mode) return;
   double rad = current_display->radius;
@@ -1359,11 +1363,13 @@ EX void center_multiplayer_map(const vector<hyperpoint>& hs) {
     }
   }
 
+EX debugflag debug_map = {"graph_map"};
+
 EX void drawthemap() {
+  indenter_finish(debug_map, "drawthemap");
+
   check_cgi();
   cgi.require_shapes();
-
-  DEBBI(DF_GRAPH, ("draw the map"));
   
   last_firelimit = firelimit;
   firelimit = 0;
@@ -1546,9 +1552,11 @@ EX ld get_stereo_param() {
   return 0;
   }
 
+EX debugflag debug_calcparam = {"graph_param"};
+
 EX void calcparam() {
 
-  DEBBI(DF_GRAPH, ("calc param"));
+  indenter_finish(debug_calcparam, "calcparam");
   auto cd = current_display;
   
   cd->xtop = vid.xres * cd->xmin;
@@ -1623,9 +1631,8 @@ EX function<void()> wrap_drawfullmap = drawfullmap;
 bool force_sphere_outline = false;
 
 EX void drawfullmap() {
+  indenter_finish(debug_map, "drawfullmap");
 
-  DEBBI(DF_GRAPH, ("draw full map"));
-    
   check_cgi();
   cgi.require_shapes();
 
@@ -1916,7 +1923,7 @@ EX color_t titlecolor;
 
 EX void drawscreen() {
 
-  DEBBI(DF_GRAPH, ("drawscreen"));
+  indenter_finish(debug_map, "drawscreen");
   #if CAP_GL
   GLWRAP;
   #endif
@@ -2025,7 +2032,7 @@ EX void drawscreen() {
   // SDL_UnlockSurface(s);
 
   glflush();
-  DEBB(DF_GRAPH, ("swapbuffers"));
+  if(debug_map) println(hlog, "swapbuffers");
 
   #if CAP_VR
   vrhr::submit();
@@ -2042,15 +2049,19 @@ EX void drawscreen() {
 //printf("\ec");
   }
 
+EX debugflag debug_init_graph = {"init_graph"};
+
 EX void restartGraph() {
-  DEBBI(DF_INIT, ("restartGraph"));
+  indenter_finish di(debug_init_graph, "restartGraph");
   
   if(!autocheat) linepatterns::clearAll();
   if(currentmap) resetview();
   }
 
+EX debugflag debug_graph_memory = {"graph_memory"};
+
 auto graphcm = addHook(hooks_clearmemory, 0, [] () {
-  DEBBI(DF_MEMORY, ("clear graph memory"));
+  indenter_finish di(debug_graph_memory, "graph_memory");
   mouseover = centerover = lmouseover = NULL;  
   gmatrix.clear(); gmatrix0.clear(); current_display->all_drawn_copies.clear();
   clearAnimations();
diff --git a/help.cpp b/help.cpp
index f0a17b1e..58a44508 100644
--- a/help.cpp
+++ b/help.cpp
@@ -89,7 +89,7 @@ EX hookset<bool()> hooks_build_help;
 
 EX void buildHelpText() {
   if(callhandlers(0, hooks_build_help)) return;
-  DEBBI(DF_GRAPH, ("buildHelpText"));
+  DEBBI(debug_graph, ("buildHelpText"));
 
   help = XLAT("Welcome to HyperRogue");
 #if ISANDROID  
@@ -911,7 +911,7 @@ template<class T> void set_help_to(T t) {
   }
 
 EX void describeMouseover() {
-  DEBBI(DF_GRAPH, ("describeMouseover"));
+  DEBBI(debug_graph, ("describeMouseover"));
 
   if(callhandlers(0, hooks_global_mouseover)) return;
 
diff --git a/hprint.cpp b/hprint.cpp
index 0dccde33..c3465e4b 100644
--- a/hprint.cpp
+++ b/hprint.cpp
@@ -10,27 +10,6 @@ namespace hr {
 
 EX FILE *debugfile;
 
-#if HDR
-#define DF_INIT              1 // always display these
-#define DF_MSG               2 // always display these
-#define DF_WARN              4 // always display these
-#define DF_ERROR             8 // always display these
-#define DF_STEAM            16
-#define DF_GRAPH            32
-#define DF_TURN             64
-#define DF_FIELD           128
-#define DF_GEOM            256
-#define DF_MEMORY          512
-#define DF_TIME           1024 // a flag to display timestamps
-#define DF_GP             2048
-#define DF_POLY           4096
-#define DF_LOG            8192
-#define DF_VERTEX        16384
-#define DF_KEYS "imwesxufgbtoplv"
-#endif
-
-EX int debugflags = DF_INIT | DF_ERROR | DF_WARN | DF_MSG | DF_TIME | DF_LOG;
-
 EX string s0;
 
 EX string its(int i) { return hr::format("%d", i); }
@@ -321,15 +300,23 @@ struct indenter_finish : indenter {
     indenter tmp(-2);
     println(hlog, s);
     }
+  explicit indenter_finish(bool b, string s): indenter(b ? 2 : 0) {
+    if(b) {
+      indenter tmp(-2);
+      println(hlog, s);
+      }
+    }
   ~indenter_finish() { if(hlog.indentation != ind.backup) println(hlog, "(done)"); }
   };
 
 #endif
 
+EX debugflag debug_stamps = {"stamps", true};
+
 void logger::write_char(char c) { 
   if(doindent) { 
     doindent = false; 
-    if(debugflags & DF_TIME) { 
+    if(debug_stamps) {
       string s = get_stamp(); 
       if(s != "") { for(char c: s) special_log(c); special_log(' '); }
       }
@@ -538,9 +525,9 @@ EX string as_nice_cstring(string o) {
 #define DEBB0(r,x)
 #define DEBBI(r,x)
 #else
-#define DEBB(r,x) { if(debugflags & (r)) { println_log x; } }
-#define DEBB0(r,x) { if(debugflags & (r)) { print_log x; } }
-#define DEBBI(r,x) { if(debugflags & (r)) { println_log x; } } indenter_finish _debbi(debugflags & (r));
+#define DEBB(r,x) { if(r) { println_log x; } }
+#define DEBB0(r,x) { if(r) { print_log x; } }
+#define DEBBI(r,x) { if(r) { println_log x; } } indenter_finish _debbi(r);
 #endif
 #endif
 
diff --git a/hyper.h b/hyper.h
index 49b63295..5ffac2eb 100644
--- a/hyper.h
+++ b/hyper.h
@@ -950,6 +950,24 @@ static inline void set_flag(flagtype& f, flagtype which, bool b) {
   else f &= ~which;
   }
 
+void add_debugflag(const string& s, struct debugflag *d);
+
+/** Flags to enable debugging.
+ *  A debugflag can be defined with e.g.: debugflag memory_cell("memory_cell")
+ *  and used as in: if(memory_cell) { ... output debugging info ... }
+ *  Then a commandline parameter '-debug memory' will enable all flags with 'memory' in its name
+ */
+
+struct debugflag {
+  bool enabled;
+  debugflag(string s, bool initial = false) {
+    add_debugflag(s, this);
+    enabled = initial;
+    }
+  operator bool() { return enabled; }
+  void flip() { enabled = !enabled; }
+  };
+
 }
 
 /** this macro is used to delay performing the action in case if everything is rolled back */
diff --git a/hypgraph.cpp b/hypgraph.cpp
index bb660be9..11b4b899 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -2327,7 +2327,6 @@ EX void centerpc(ld aspd) {
   
   if(ors::mode == 2 && vid.sspeed < 5) return;
   if(vid.sspeed >= 4.99) aspd = 1000;
-  DEBBI(DF_GRAPH, ("center pc"));
 
   auto mam = move_affected_matrices(0);
   for(auto pV: mam) ors::unrotate(*pV);
@@ -2458,7 +2457,7 @@ void ballgeometry() {
   }
 
 EX void resetview() {
-  DEBBI(DF_GRAPH, ("reset view"));
+  indenter_finish dif(debug_graph, "resetview");
   // EUCLIDEAN
   decide_lpu();
   NLP = Id;
diff --git a/legacy.cpp b/legacy.cpp
index b3707df1..a6e9f459 100644
--- a/legacy.cpp
+++ b/legacy.cpp
@@ -428,6 +428,65 @@ int read_legacy_args() {
   return 0;
   }
 
+struct legacy_flag {
+  char key;
+  int level;
+  debugflag *df;
+  };
+
+vector<legacy_flag> legacy_flags = {
+  // INIT
+  legacy_flag{'i', 1, &debug_init},
+  legacy_flag{'i', 1, &debug_init_music},
+  legacy_flag{'i', 1, &debug_init_graph},
+  legacy_flag{'i', 1, &debug_init_joy},
+  legacy_flag{'i', 1, &debug_init_cells},
+  legacy_flag{'i', 1, &debug_init_config},
+  legacy_flag{'i', 1, &debug_init_font},
+  // MSG
+  legacy_flag{'m', 1, &debug_messages},
+  // WARN
+  legacy_flag{'w', 1, &debug_warnings},
+  legacy_flag{'w', 1, &debug_map_warnings},
+  // ERROR
+  legacy_flag{'e', 1, &debug_errors},
+  legacy_flag{'e', 1, &debug_music_error},
+  legacy_flag{'e', 1, &debug_joy_error},
+  // STEAM
+  legacy_flag{'s', 3, &debug_achievements},
+  // GRAPH
+  legacy_flag{'x', 4, &debug_aura},
+  legacy_flag{'x', 4, &debug_map},
+  legacy_flag{'x', 4, &debug_calcparam},
+  legacy_flag{'x', 4, &debug_graph},
+  legacy_flag{'x', 4, &debug_joy},
+  legacy_flag{'x', 4, &debug_control},
+  // TURN
+  legacy_flag{'u', 3, &debug_turn},
+  // FIELD
+  legacy_flag{'f', 2, &fieldpattern::debug_field},
+  // GEOM
+  legacy_flag{'g', 2, &debug_geometry},
+  legacy_flag{'g', 4, &arcm::debug_archimedean_map},
+  // MEMORY
+  legacy_flag{'b', 4, &debug_memory},
+  legacy_flag{'b', 4, &debug_graph_memory},
+  legacy_flag{'b', 4, &debug_memory_cell},
+  // TIME
+  legacy_flag{'t', 9, &debug_stamps},
+  // GP
+  legacy_flag{'o', 2, &gp::debug_gp},
+  // POLY
+  legacy_flag{'p', 2, &debug_poly},
+  // VERTEX
+  legacy_flag{'v', 9, &debug_vertex}
+  };
+
+void set_legacy_flags(char key = 0, int level = 0, bool val = true) {
+  for(auto& lf: legacy_flags) if((!key || lf.key == key) && lf.level <= level && lf.df)
+    lf.df->enabled = val;
+  }
+
 int read_legacy_args_anim() {
   using namespace anims;
   using namespace arg;
@@ -529,6 +588,33 @@ int read_legacy_args_anim() {
     #endif
     vid.stereo_mode = sStereographic;
     }
+  else if(argis("-debf")) {
+    shift();
+    string s = args();
+    for(char c: s) {
+      if(c >= 'a' && c <= 'z')
+        set_legacy_flags(c, 0, true);
+      else if(c >= '0' && c <= '9') {
+        set_legacy_flags(0, 8, false);
+        set_legacy_flags(0, c - '0', true);
+        }
+      else if(c == '+') {
+        if(debugfile) fclose(debugfile);
+        shift();
+        println(hlog, "writing to ", argcs());
+        debugfile = fopen(argcs(), "at");
+        }
+      else if(c == '@') {
+        if(debugfile) fclose(debugfile);
+        shift();
+        println(hlog, "writing to ", argcs());
+        debugfile = fopen(argcs(), "wt");
+        }
+      }
+    }
+  else if(argis("-no-stamp")) {
+    debug_stamps.flip();
+    }
   else return 1;
   return 0;
   }
diff --git a/menus.cpp b/menus.cpp
index 2c9cb32f..a2ebd28c 100644
--- a/menus.cpp
+++ b/menus.cpp
@@ -22,8 +22,8 @@ int PREC(ld x) {
   }
 
 EX void showOverview() {
-  cmode = sm::ZOOMABLE | sm::OVERVIEW;  
-  DEBBI(DF_GRAPH, ("show overview"));
+  cmode = sm::ZOOMABLE | sm::OVERVIEW;
+  indenter_finish dif(debug_graph, "show overview");
 
   if(dialog::infix != "")
     mouseovers = dialog::infix;
@@ -1254,7 +1254,7 @@ EX string gettimestamp(msginfo& m) {
   }
   
 EX void showMessageLog() {
-  DEBBI(DF_GRAPH, ("show message log"));
+  indenter_finish dif(debug_graph, "showMessageLog");
 
   int lines = vid.yres / vid.fsize - 2;
   int maxpos = isize(gamelog) - lines;
diff --git a/monstermove.cpp b/monstermove.cpp
index 4036748a..38813aaa 100644
--- a/monstermove.cpp
+++ b/monstermove.cpp
@@ -1698,11 +1698,11 @@ EX void movegolems(flagtype flags) {
 
       auto recorduse = orbused;
 
-      DEBB(DF_TURN, ("stayval"));
+      DEBB(debug_turn, ("stayval"));
       int bestv = stayvalue(m, c);
       vector<int> bdirs;
 
-      DEBB(DF_TURN, ("moveval"));
+      DEBB(debug_turn, ("moveval"));
       for(int k=0; k<c->type; k++) if(c->move(k)) {
         int val = movevalue(m, c, k, flags);
 
@@ -1752,7 +1752,7 @@ EX void movegolems(flagtype flags) {
         }
       else {
         passable_for(m, c2, c, P_DEADLY);
-        DEBB(DF_TURN, ("move"));
+        DEBB(debug_turn, ("move"));
         moveMonster(mi);
         if(m != moTameBomberbird && m != moFriendlyGhost) 
           moveBoatIfUsingOne(mi);
@@ -1769,7 +1769,7 @@ EX void movegolems(flagtype flags) {
 
         empathyMove(mi);
         }
-      DEBB(DF_TURN, ("other"));
+      DEBB(debug_turn, ("other"));
       }
     }
   achievement_count("GOLEM", qg, 0);
@@ -2048,7 +2048,7 @@ EX void movemonsters() {
   ambush::distance = 0;
   #endif
 
-  DEBB(DF_TURN, ("lava1"));
+  DEBB(debug_turn, ("lava1"));
   orboflava(1);
   
   #if CAP_COMPLEX2
@@ -2060,80 +2060,80 @@ EX void movemonsters() {
 
   specialMoves();
 
-  DEBB(DF_TURN, ("jumpers"));
+  DEBB(debug_turn, ("jumpers"));
   if(havewhat & HF_JUMP) {
     groupmove(moFrog, 0);
     groupmove(moVaulter, 0);
     groupmove(moPhaser, 0);
     }
 
-  DEBB(DF_TURN, ("ghosts"));
+  DEBB(debug_turn, ("ghosts"));
   moveghosts();
     
-  DEBB(DF_TURN, ("butterflies"));
+  DEBB(debug_turn, ("butterflies"));
   moveButterflies();
 
-  DEBB(DF_TURN, ("normal"));
+  DEBB(debug_turn, ("normal"));
   moveNormals(moYeti);
 
-  DEBB(DF_TURN, ("slow"));
+  DEBB(debug_turn, ("slow"));
   if(havewhat & HF_SLOW) moveNormals(moTortoise);
   
   if(sagefresh) sagephase = 0;
   
-  DEBB(DF_TURN, ("ivy"));
+  DEBB(debug_turn, ("ivy"));
   moveivy();
-  DEBB(DF_TURN, ("slimes"));
+  DEBB(debug_turn, ("slimes"));
   groupmove(moSlime, 0);
-  DEBB(DF_TURN, ("sharks"));
+  DEBB(debug_turn, ("sharks"));
   if(havewhat & HF_SHARK) groupmove(moShark, 0);
-  DEBB(DF_TURN, ("eagles"));
+  DEBB(debug_turn, ("eagles"));
   if(havewhat & HF_BIRD) groupmove(moEagle, 0);
   if(havewhat & HF_EAGLES) groupmove(moEagle, MF_NOATTACKS | MF_ONLYEAGLE);
-  DEBB(DF_TURN, ("eagles"));
+  DEBB(debug_turn, ("eagles"));
   if(havewhat & HF_REPTILE) groupmove(moReptile, 0);
-  DEBB(DF_TURN, ("air"));
+  DEBB(debug_turn, ("air"));
   if(havewhat & HF_AIR) {
     airmap.clear();
     groupmove(moAirElemental, 0); 
     buildAirmap();
     }
-  DEBB(DF_TURN, ("earth"));
+  DEBB(debug_turn, ("earth"));
   if(havewhat & HF_EARTH) groupmove(moEarthElemental, 0);
-  DEBB(DF_TURN, ("water"));
+  DEBB(debug_turn, ("water"));
   if(havewhat & HF_WATER) groupmove(moWaterElemental, 0);
-  DEBB(DF_TURN, ("void"));
+  DEBB(debug_turn, ("void"));
   if(havewhat & HF_VOID) groupmove(moVoidBeast, 0);
-  DEBB(DF_TURN, ("leader"));
+  DEBB(debug_turn, ("leader"));
   if(havewhat & HF_LEADER) groupmove(moPirate, 0);
-  DEBB(DF_TURN, ("mutant"));
+  DEBB(debug_turn, ("mutant"));
   if((havewhat & HF_MUTANT) || (closed_or_bounded && among(specialland, laOvergrown, laClearing))) movemutant();
-  DEBB(DF_TURN, ("bugs"));
+  DEBB(debug_turn, ("bugs"));
   if(havewhat & HF_BUG) hive::movebugs();
-  DEBB(DF_TURN, ("whirlpool"));
+  DEBB(debug_turn, ("whirlpool"));
   if(havewhat & HF_WHIRLPOOL) whirlpool::move();
-  DEBB(DF_TURN, ("whirlwind"));
+  DEBB(debug_turn, ("whirlwind"));
   if(havewhat & HF_WHIRLWIND) whirlwind::move();
   #if CAP_COMPLEX2
-  DEBB(DF_TURN, ("westwall"));
+  DEBB(debug_turn, ("westwall"));
   if(havewhat & HF_WESTWALL) westwall::move();
   #endif
   for(cell *pc: player_positions())
     if(pc->item == itOrbSafety) 
       return;
-  DEBB(DF_TURN, ("river"));
+  DEBB(debug_turn, ("river"));
   if(havewhat & HF_RIVER) prairie::move();
-  /* DEBB(DF_TURN, ("magnet"));
+  /* DEBB(debug_turn, ("magnet"));
   if(havewhat & HF_MAGNET) 
     groupmove(moSouthPole, 0),
     groupmove(moNorthPole, 0); */
-  DEBB(DF_TURN, ("bugs"));
+  DEBB(debug_turn, ("bugs"));
   if(havewhat & HF_HEXD) groupmove(moHexDemon, 0);
   if(havewhat & HF_DICE) groupmove(moAnimatedDie, 0);    
   if(havewhat & HF_ALT) groupmove(moAltDemon, 0);
   if(havewhat & HF_MONK) groupmove(moMonk, 0);
 
-  DEBB(DF_TURN, ("worm"));
+  DEBB(debug_turn, ("worm"));
   cell *savepos[MAXPLAYER];
   
   for(int i=0; i<numplayers(); i++)
@@ -2147,22 +2147,22 @@ EX void movemonsters() {
   if(havewhat & HF_DRAGON) groupmove(moDragonHead, MF_NOFRIEND);
   if(haveMount()) groupmove(moDragonHead, MF_MOUNT);
 
-  DEBB(DF_TURN, ("golems"));
+  DEBB(debug_turn, ("golems"));
   movegolems(0);
   
-  DEBB(DF_TURN, ("fresh"));
+  DEBB(debug_turn, ("fresh"));
   moverefresh();
   
-  DEBB(DF_TURN, ("lava2"));
+  DEBB(debug_turn, ("lava2"));
   orboflava(2);
 
-  DEBB(DF_TURN, ("shadow"));
+  DEBB(debug_turn, ("shadow"));
   moveshadow();
   
-  DEBB(DF_TURN, ("wandering"));
+  DEBB(debug_turn, ("wandering"));
   wandering();
   
-  DEBB(DF_TURN, ("rosemap"));
+  DEBB(debug_turn, ("rosemap"));
   if(havewhat & HF_ROSE) buildRosemap();
 
   for(int i=0; i<numplayers(); i++)
diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index b712826a..3cf9c1dc 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -1477,14 +1477,17 @@ EX namespace hybrid {
 
         disc_quotient = abs(cycle_discrepancy(final));
 
-        if(debugflags & DF_GEOM) for(cell *c: ac) for(int i=0; i<c->type; i++) {
-          cellwalker cw(c, i);
-          if(cycle_discrepancy(cw)) println(hlog, cw, " ", cycle_discrepancy(cw));
-          }
-        if(debugflags & DF_GEOM) for(cell *c: ac) for(int i=0; i<c->type; i++) {
-          auto err = get_shift(cellwalker(c, i)) + get_shift(cellwalker(c, i)+wstep);
-          if(err)
-            println(hlog, "two-side error: ", err, " on ", cellwalker(c, i));
+        if(debug_geometry) {
+          indenter_finish in("fix_bounded_cycles");
+          for(cell *c: ac) for(int i=0; i<c->type; i++) {
+            cellwalker cw(c, i);
+            if(cycle_discrepancy(cw)) println(hlog, cw, " ", cycle_discrepancy(cw));
+            }
+          for(cell *c: ac) for(int i=0; i<c->type; i++) {
+            auto err = get_shift(cellwalker(c, i)) + get_shift(cellwalker(c, i)+wstep);
+            if(err)
+              println(hlog, "two-side error: ", err, " on ", cellwalker(c, i));
+            }
           }
         });
       }
diff --git a/pcmove.cpp b/pcmove.cpp
index 77b43d11..e6c210ca 100644
--- a/pcmove.cpp
+++ b/pcmove.cpp
@@ -9,6 +9,8 @@
 
 namespace hr {
 
+EX debugflag debug_turn = {"turn"};
+
 EX int illegal_moves;
 
 EX bool keepLightning = false;
@@ -366,7 +368,7 @@ bool pcmove::movepcto() {
     flipplayer = false;
     if(multi::players > 1) multi::flipped[multi::cpid] = false;
     }
-  DEBBI(checkonly ? 0 : DF_TURN, ("movepc"));
+  DEBBI(checkonly ? 0 : debug_turn, ("movepc"));
   if(!checkonly) invismove = false;  
   boatmove = false;
   
@@ -486,7 +488,7 @@ bool pcmove::after_move() {
     achievement_gain("SEVENMINE");
     }
 
-  DEBB(DF_TURN, ("done"));
+  DEBB(debug_turn, ("done"));
   return true;
   }
 
diff --git a/polygons.cpp b/polygons.cpp
index f7a94be7..02dd0d1d 100644
--- a/polygons.cpp
+++ b/polygons.cpp
@@ -10,6 +10,8 @@
 
 namespace hr {
 
+EX debugflag debug_poly = {"graph_poly"};
+
 #if HDR
 static constexpr ld NEWSHAPE = (-13.5);
 #endif
@@ -1185,7 +1187,7 @@ void geometry_information::prepare_shapes() {
 
   symmetriesAt.clear();
   allshapes.clear();
-  DEBBI(DF_POLY, ("buildpolys"));
+  DEBBI(debug_poly, ("buildpolys"));
 
   if(WDIM == 3 && !mhybrid) {
     if(sphere) SD3 = 3, SD7 = 5;
diff --git a/reg3.cpp b/reg3.cpp
index 7f9a5064..e36345a7 100644
--- a/reg3.cpp
+++ b/reg3.cpp
@@ -161,7 +161,7 @@ EX namespace reg3 {
         ld f0 = 0.5;
         ld f1 = binsearch(0.5, 1, [&] (ld d) {
           hyperpoint c = lerp(b, a, d);
-          if(debugflags & DF_GEOM) 
+          if(debug_geometry)
             println(hlog, "d=", d, " c= ", c, " material = ", material(c));
           return material(c) <= 0;
           });
@@ -174,7 +174,7 @@ EX namespace reg3 {
         for(int it=0; it<100; it++) {
           ld fa = (f0*2+f1) / 3;
           ld fb = (f0*1+f1*2) / 3;
-          if(debugflags & DF_GEOM) 
+          if(debug_geometry)
             println(hlog, "f(", fa, ") = ", f(fa), " f(", fb, ") = ", f(fb));
           if(f(fa) > f(fb)) f0 = fa;
           else f1 = fb;
@@ -234,10 +234,10 @@ EX namespace reg3 {
     cgi.adjmoves[0] = cpush(0, between_centers) * cspin180(0, 2);
     for(int i=1; i<S7; i++) cgi.adjmoves[i] = spins[i] * cgi.adjmoves[0];
 
-    for(int a=0; a<S7; a++)
-      DEBB(DF_GEOM, ("center of ", a, " is ", kz(tC0(cgi.adjmoves[a]))));
-
-    DEBB(DF_GEOM, ("doublemove = ", kz(tC0(cgi.adjmoves[0] * cgi.adjmoves[0]))));
+    if(debug_geometry) {
+      for(int a=0; a<S7; a++) println(hlog, "center of ", a, " is ", kz(tC0(cgi.adjmoves[a])));
+      println(hlog, "doublemove = ", kz(tC0(cgi.adjmoves[0] * cgi.adjmoves[0])));
+      }
 
     cgi.adjcheck = hdist(tC0(cgi.adjmoves[0]), tC0(cgi.adjmoves[1])) * 1.0001;
 
@@ -269,7 +269,7 @@ EX namespace reg3 {
     if(S7 == 20) mid = 5;
     /* icosahedron not implemented */
     loop = ginf[geometry].tiling_name[5] - '0';
-    DEBB(DF_GEOM, ("face = ", face, " loop = ", loop, " S7 = ", S7));    
+    if(debug_geometry) println(hlog, "face = ", face, " loop = ", loop, " S7 = ", S7);
     
     ld angle_between_faces, hcrossf;
     
@@ -341,7 +341,7 @@ EX namespace reg3 {
     for(int i=0; i<face; i++) midface += cspin(1, 2, TAU * i/face) * v2;
     midface = normalize(midface);
     ld between_centers = 2 * hdist0(midface);
-    DEBB(DF_GEOM, ("between_centers = ", between_centers));
+    if(debug_geometry) println(hlog, "between_centers = ", between_centers);
 
     build_regular_spins(between_centers, angle_between_faces);
     
@@ -1135,10 +1135,11 @@ EX namespace reg3 {
     
     
     void create_patterns() {
-      DEBB(DF_GEOM, ("creating pattern = ", isize(allh)));
+      indenter_finish(debug_geometry, "creating pattern = " + its(isize(allh)));
       
       if(!PURE) {
-         println(hlog, "create_patterns not implemented");
+         if(debug_errors || debug_geometry)
+           println(hlog, "create_patterns not implemented");
          return;
          }
 
@@ -1174,7 +1175,7 @@ EX namespace reg3 {
         
         // Vineyard in 435
         make_plane(cellwalker(gamestart(), 0));
-        DEBB(DF_GEOM, ("plane size = ", isize(plane)));
+        if(debug_geometry) println(hlog, "plane size = ", isize(plane));
         
         set<int> plane_indices;
         for(auto cw: plane) plane_indices.insert(cw.at->master->fieldval);
@@ -1255,10 +1256,10 @@ EX namespace reg3 {
       
       for(int index = 5; index >= 0; index--) {
         for(auto k: boundaries) println(hlog, k);
-        DEBB(DF_GEOM, ("simplifying..."));
+        if(debug_geometry) println(hlog, "simplifying...");
         
         for(auto by: boundaries) if(among(by[index], 1, -1)) {
-          DEBB(DF_GEOM, ("simplifying by ", by));
+          if(debug_geometry) println(hlog, "simplifying by ", by);
           periods.push_back(by);
           set<coord> nb;
       
@@ -1266,7 +1267,8 @@ EX namespace reg3 {
             if(v == by) ;
             else if(v[index] % by[index] == 0)
               nb.insert(v - by * (v[index] / by[index]));
-            else println(hlog, "error");    
+            else if(debug_errors || debug_geometry)
+              println(hlog, "simplification error");
           
           boundaries = std::move(nb);
           break;
@@ -1935,7 +1937,7 @@ EX namespace reg3 {
       for(int i=0; i<qty; i++) 
         bfs.emplace_back(i, root[i]);
       int qstate = isize(childpos) - 1;
-      DEBB(DF_GEOM, ("qstate = ", qstate));
+      DEBB(debug_geometry, ("qstate = ", qstate));
       for(int i=0; i<isize(bfs); i++) {
         address last = bfs[i];
         int state = last.second;
@@ -1976,7 +1978,7 @@ EX namespace reg3 {
           }
         }
       
-      DEBB(DF_GEOM, ("removed cases = ", isize(bfs)));
+      DEBB(debug_geometry, ("removed cases = ", isize(bfs)));
 
       /* remove non-branching states */
 
diff --git a/renderbuffer.cpp b/renderbuffer.cpp
index 65a9990b..e1935335 100644
--- a/renderbuffer.cpp
+++ b/renderbuffer.cpp
@@ -137,7 +137,7 @@ renderbuffer::renderbuffer(int x, int y, bool gl) : x(x), y(y) {
     else
       valid = true;
 
-    DEBB(DF_GRAPH, ("Framebuffer remains = ", int(FramebufferName), " (", int(valid), ")"));
+    DEBB(debug_graph, ("Framebuffer remains = ", int(FramebufferName), " (", int(valid), ")"));
     GLERR("initialization");
     
     rb.reset();
diff --git a/rogueviz/banachtarski.cpp b/rogueviz/banachtarski.cpp
index 06cfb59e..36b6cfc3 100644
--- a/rogueviz/banachtarski.cpp
+++ b/rogueviz/banachtarski.cpp
@@ -204,6 +204,8 @@ tuple<ld,bool,ld> quality(bantar_config cp) {
 
 int notry = 0;
 
+debugflags debug_bantar = {"demo_bantar"};
+
 void bantar() {
   if(!on) return;
   cwt = cellwalker(currentmap->gamestart(), 0);
@@ -234,8 +236,8 @@ void bantar() {
       bool tres = test_uniq(cwt, -1, 15, NULL);
       auto q = quality(bc);
       if(tres) {
-        DEBB(DF_LOG, ("gens = ", gens));
-        DEBB(DF_LOG, ("testing quality ", q, " ", make_pair(celldist(bc.first), celldist(bc.second)), ", result = ", tres));
+        DEBB(debug_bantar, ("gens = ", gens));
+        DEBB(debug_bantar, ("testing quality ", q, " ", make_pair(celldist(bc.first), celldist(bc.second)), ", result = ", tres));
         lnotry--; if(lnotry <= 0) goto picked;
         }
       // if(tres) goto picked;
diff --git a/rogueviz/som/kohonen.cpp b/rogueviz/som/kohonen.cpp
index 6c69f9ba..dfaf9844 100644
--- a/rogueviz/som/kohonen.cpp
+++ b/rogueviz/som/kohonen.cpp
@@ -5,6 +5,10 @@
 
 namespace rogueviz { namespace kohonen {
 
+debugflag debug_kohonen("kohonen", true);
+debugflag debug_kohonen_dispersion("kohonen_dispersion");
+debugflag debug_kohonen_error("kohonen_error", true);
+
 int columns;
 
 vector<sample> data;
@@ -65,19 +69,13 @@ bool noshow = false;
 vector<int> samples_to_show;
 
 void loadsamples(const string& fname) {
+  DEBBI(debug_kohonen, ("Loading samples: ", fname));
   data.clear();
   samples_to_show.clear();
   clear();
   fhstream f(fname, "rt");
-  if(!f.f) {
-    fprintf(stderr, "Could not load samples: %s\n", fname.c_str());
-    return;
-    }
-  if(!scan(f, columns)) { 
-    printf("Bad format: %s\n", fname.c_str());
-    return; 
-    }
-  printf("Loading samples: %s\n", fname.c_str());
+  if(!f.f) return file_error(fname);
+  if(!scan(f, columns)) return file_format_error(fname);
   while(true) {
     sample s;
     bool shown = false;
@@ -509,7 +507,7 @@ void buildcellcrawler(cell *c, cellcrawler& cr, int dir) {
     
     d.clear();
     
-    // DEBBI(DF_LOG, ("Building dispersion, precision = ", dispersion_precision, " end_at = ", dispersion_end_at, "...\n"));
+    DEBBI(debug_kohonen_dispersion, ("Building dispersion, precision = ", dispersion_precision, " end_at = ", dispersion_end_at, "...\n"));
     
     for(iter=0; dispersion_count ? true : vmax > vmin * dispersion_end_at; iter++) {
       if(iter % dispersion_each == 0) {
@@ -535,13 +533,14 @@ void buildcellcrawler(cell *c, cellcrawler& cr, int dir) {
       }
     if(!dispersion_count) {
       if(!dispersion_long) dispersion_count = isize(d);
-      DEBB(DF_LOG, ("Dispersion count = ", isize(d), " celldist = ", celldist(c)));
+      DEBB(debug_kohonen_dispersion, ("Dispersion count = ", isize(d), " celldist = ", celldist(c)));
+      }
+
+    if(debug_kohonen_dispersion) {
+      println(hlog, "dlast = ", d.back());
+      println(hlog, "dlast2 = ", d[d.size()-2]);
+      println(hlog, "vmin=", vmin, " vmax=",vmax, " end_at=", dispersion_end_at);
       }
-    /*
-    println(hlog, "dlast = ", d.back());
-    println(hlog, "dlast2 = ", d[d.size()-2]);
-    println(hlog, "vmin=", vmin, " vmax=",vmax, " end_at=", dispersion_end_at);
-    */
     }
   }
 
@@ -607,20 +606,22 @@ void verify_crawlers() {
   
   int uniq = 0, failures = 0;
   
-  printf("Verifying crawlers...\n");  
+  if(debug_kohonen) printf("Verifying crawlers...\n");  
   for(cell *c: allcells) {
     auto id = get_cellcrawler_id(c);
     if(allcrawlers.count(id.first)) {
       bool b = verify_crawler(allcrawlers[id.first], cellwalker(c, id.second));
       if(!b) {
-        printf("cell %p: type = %d id = %d dir = %d / earlier crawler failed\n", hr::voidp(c), c->type, id.first, id.second);
+        if(debug_kohonen_dispersion)
+          printf("cell %p: type = %d id = %d dir = %d / earlier crawler failed\n", hr::voidp(c), c->type, id.first, id.second);
         failures++;
         }
       }
     else {
       for(int i=0; i<c->type; i++)
       for(auto& cc: allcrawlers) if(verify_crawler(cc.second, cellwalker(c, i))) {
-        printf("cell %p: type = %d id = %d dir = %d / also works id %d in direction %d\n", hr::voidp(c), c->type, id.first, id.second, cc.first, i);
+        if(debug_kohonen_dispersion)
+          printf("cell %p: type = %d id = %d dir = %d / also works id %d in direction %d\n", hr::voidp(c), c->type, id.first, id.second, cc.first, i);
         uniq--;
         goto breakcheck;
         }
@@ -631,9 +632,10 @@ void verify_crawlers() {
       uniq++;
       }
     }
-  printf("Crawlers constructed: %d (%d unique, %d failures)\n", isize(allcrawlers), uniq, failures);
+  if(debug_kohonen)
+    printf("Crawlers constructed: %d (%d unique, %d failures)\n", isize(allcrawlers), uniq, failures);
   setindex(false);
-  if(failures) exit(1);
+  if(failures) throw hr_exception("verify_crawler error");
   }
   
 bool finished() { return t == 0; }
@@ -809,7 +811,8 @@ vector<cell*> gen_neuron_cells() {
     while(at < isize(allcells) && hdist0(tC0(ggmatrix(allcells[at]))) < dist + 1e-6) at++;
     int at1 = kohrestrict;
     while(at1 > 0 && hdist0(tC0(ggmatrix(allcells[at1-1]))) > dist - 1e-6) at1--;
-    printf("Cells numbered [%d,%d) are in the same distance\n", at1, at);
+    if(debug_kohonen)
+      println(hlog, "Cells numbered [", at1, ",", at, ") are in the same distance");
     allcells.resize(kohrestrict);
     for(int i=kohrestrict; i<isize(allcells); i++) {
       setdist(allcells[i], 0, nullptr);
@@ -823,14 +826,12 @@ vector<cell*> gen_neuron_cells() {
 void create_neurons() {
   initialize_rv();
   
-  if(!samples) {
-    fprintf(stderr, "Error: SOM without samples\n");
-    exit(1);
-    }
+  if(!samples)
+    throw hr_exception("SOM without samples");
   
   weight_label = "quantity";
   
-  DEBBI(DF_LOG, ("Creating neurons"));
+  DEBBI(debug_kohonen, ("Creating neurons"));
   
   auto allcells = gen_neuron_cells();
 
@@ -844,12 +845,12 @@ void create_neurons() {
     }
     
   for(neuron& n: net) for(int d=BARLEV; d>=7; d--) setdist(n.where, d, NULL);
-  DEBB(DF_LOG, ("number of neurons = ", cells));
+  DEBB(debug_kohonen, ("number of neurons = ", cells));
   }
 
 void set_neuron_initial() {
   initialize_neurons();
-  DEBBI(DF_LOG, ("Setting initial neuron values"));
+  DEBBI(debug_kohonen, ("Setting initial neuron values"));
   for(int i=0; i<cells; i++) {
     alloc(net[i].net);
     for(int k=0; k<columns; k++)
@@ -870,7 +871,7 @@ void initialize_samples_to_show() {
   if(state & KS_SAMPLES) return;
   if(noshow) return;
 
-  DEBBI(DF_LOG, ("Initializing samples-to-show (", isize(samples_to_show), " samples", ")"));
+  DEBBI(debug_kohonen, ("Initializing samples-to-show (", isize(samples_to_show), " samples", ")"));
   if(!noshow) for(int s: samples_to_show) {
     int vdid = isize(vdata);
     sample_vdata_id[s] = vdid;
@@ -892,36 +893,36 @@ void initialize_dispersion() {
   
   initialize_neurons();
 
-  DEBBI(DF_LOG, ("Initializing dispersion"));
+  DEBBI(debug_kohonen, ("Initializing dispersion"));
 
   if(gaussian || true) {
-    DEBB(DF_LOG, ("dist = ", fts(mydistance(net[0].where, net[1].where))));
+    DEBB(debug_kohonen, ("dist = ", fts(mydistance(net[0].where, net[1].where))));
     cell *c1 = net[cells/2].where;
     vector<double> mapdist;
     for(neuron &n2: net) mapdist.push_back(mydistance(c1,n2.where));
     sort(mapdist.begin(), mapdist.end());
     maxdist = mapdist[isize(mapdist)*5/6] * distmul;
-    DEBB(DF_LOG, ("maxdist = ", fts(maxdist)));
+    DEBB(debug_kohonen, ("maxdist = ", fts(maxdist)));
     }
 
   dispersion_count = 0;  
 
   if(!gaussian)
-    DEBB(DF_LOG, ("dispersion precision = ", dispersion_precision, " end_at = ", dispersion_end_at, "...\n"));
+    DEBB(debug_kohonen, ("dispersion precision = ", dispersion_precision, " end_at = ", dispersion_end_at, "...\n"));
 
-  DEBB(DF_LOG, ("building crawlers...\n"));
+  DEBB(debug_kohonen, ("building crawlers...\n"));
 
   scc.clear();
   for(int i=0; i<cells; i++) {
     cell *c = net[i].where;
     auto cid = get_cellcrawler_id(c);
     if(!scc.count(cid.first)) {
-      // DEBB(DF_LOG, ("Building cellcrawler id = ", itsh(cid.first)));
+      DEBB(debug_kohonen_dispoersion, ("Building cellcrawler id = ", itsh(cid.first)));
       buildcellcrawler(c, scc[cid.first], cid.second);
       }
     }
 
-  DEBB(DF_LOG, ("crawlers constructed = ", isize(scc), "\n"));
+  DEBB(debug_kohonen, ("crawlers constructed = ", isize(scc), "\n"));
 
   lpct = -46130;
   state |= KS_DISPERSION;
@@ -1081,12 +1082,10 @@ namespace levelline {
   }
 
 void ksave(const string& fname) {
+  DEBBI(debug_kohonen, ("ksave"));
   initialize_neurons_initial();
   FILE *f = fopen(fname.c_str(), "wt");
-  if(!f) {
-    fprintf(stderr, "Could not save the network\n");
-    return;
-    }
+  if(!f) return file_error(fname);
   fprintf(f, "%d %d\n", cells, t);
   for(neuron& n: net) {
     for(int k=0; k<columns; k++)
@@ -1097,21 +1096,16 @@ void ksave(const string& fname) {
   }
 
 void kload(const string& fname) {
+  DEBBI(debug_kohonen, ("kload"));
   initialize_neurons();
   int xcells;
   fhstream f(fname.c_str(), "rt");
-  if(!f.f) {
-    fprintf(stderr, "Could not load the network: %s\n", fname.c_str());
-    return;
-    }
-  if(!scan(f, xcells, t)) {
-    fprintf(stderr, "Bad network format: %s\n", fname.c_str());
-    return;
-    }
-  printf("Loading the network %s...\n", fname.c_str());
+  if(!f.f) return file_error(fname);
+  if(!scan(f, xcells, t)) return file_format_error(fname);
   if(xcells != cells) {
-    fprintf(stderr, "Error: bad number of cells (x=%d c=%d)\n", xcells, cells);
-    exit(1);
+    if(debug_kohonen_error)
+      println(hlog, "Error: bad number of cells ", tie(xcells, cells));
+    throw hr_exception("bad number of SOM cells");
     }
   for(neuron& n: net) {
     for(int k=0; k<columns; k++) if(!scan(f, n.net[k])) return;
@@ -1120,23 +1114,19 @@ void kload(const string& fname) {
   }
 
 void ksavew(const string& fname) {
+  DEBBI(debug_kohonen, ("Saving the network weights to ", fname));
   FILE *f = fopen(fname.c_str(), "wt");
-  if(!f) {
-    fprintf(stderr, "Could not save the weights: %s\n", fname.c_str());
-    return;
-    }
-  printf("Saving the network to %s...\n", fname.c_str());
+  if(!f) return file_error(fname);
   for(int i=0; i<columns; i++)
     fprintf(f, "%s=%.9lf\n", colnames[i].c_str(), weights[i]);
   fclose(f);
   }
 
 void kloadw(const string& fname) {
+  if(debug_kohonen)
+    println(hlog, "Loading the network weights from ", fname);
   FILE *f = fopen(fname.c_str(), "rt");
-  if(!f) {
-    fprintf(stderr, "Could not load the weights\n");
-    return;
-    }
+  if(!f) return file_error(fname);
   for(int i=0; i<columns; i++) {
     string s1, s2;
     char kind = 0;
diff --git a/rulegen.cpp b/rulegen.cpp
index b7e5330e..7b36f159 100644
--- a/rulegen.cpp
+++ b/rulegen.cpp
@@ -558,7 +558,7 @@ EX void shortcut_found(tcell *c, tcell *alt, vector<twalker> &walkers, vector<tw
     return;
     }
 
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "new shortcut found, pre =  ", pre, " post = ", post, " pre reaches ", walkers[wpos], " post reaches ", walkers2.back(), " of type ", walkers[wpos].at->id, " sample = ", c);
 
   if(isize(pre) > max_shortcut_length) {
@@ -575,7 +575,7 @@ EX void shortcut_found(tcell *c, tcell *alt, vector<twalker> &walkers, vector<tw
   sh->last_dir = c->any_nearer;
   auto& sh1 = *sh;
 
-  if(debugflags & DF_GEOM) println(hlog, "exhaustive search:");
+  if(debug_geometry) println(hlog, "exhaustive search:");
   indenter ind(2);
   tcell* c1 = first_tcell;
   while(c1) {
@@ -595,11 +595,11 @@ EX void find_new_shortcuts(tcell *c, int d, tcell *alt, int newdir, int delta) {
   if(flags & w_known_distances) return;
 
   ufindc(c);
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "solid ", c, " changes ", c->dist, " to ", d, " alt=", alt);
 
   if(newdir == c->any_nearer) {
-    if(debugflags & DF_GEOM)
+    if(debug_geometry)
       println(hlog, "same direction");
     return;
     }
@@ -785,7 +785,7 @@ EX void be_solid(tcell *c) {
   look_for_shortcuts(c);
   ufindc(c);
   if(c->dist == MYSTERY) {
-    if(debugflags & DF_GEOM)
+    if(debug_geometry)
       println(hlog, "set solid but no dist ", c);
     debuglist = { c };
     throw rulegen_failure("set solid but no dist");
@@ -832,7 +832,7 @@ EX void look_for_shortcuts(tcell *c, shortcut& sh) {
 
     process_fix_queue();
     if(tw.at->dist < c->dist) {
-      if(debugflags & DF_GEOM)
+      if(debug_geometry)
         println(hlog, "smart shortcut updated ", c->dist, " to ", tw.at->dist);
       }
     push_unify(tw, tw0);
@@ -1236,7 +1236,7 @@ int get_side(twalker what) {
       cw = get_parent_dir(cw);
       if(cw.peek()->dist >= cw.at->dist) {
         handle_distance_errors();
-        if(debugflags & DF_GEOM)
+        if(debug_geometry)
           println(hlog, "get_parent_dir error at ", cw, " and ", cw.at->move(cw.spin), ": ", cw.at->dist, "::", cw.at->move(cw.spin)->dist);
         throw rulegen_failure("get_parent_dir error");
         }
@@ -1513,7 +1513,7 @@ EX void rules_iteration_for(twalker& cw) {
   else if(ts.rules != cids) {
     handle_distance_errors();
     auto& r = ts.rules;
-    if(debugflags & DF_GEOM) {
+    if(debug_geometry) {
       println(hlog, "merging ", ts.rules, " vs ", cids);
       }
     int mismatches = 0;
@@ -1555,7 +1555,7 @@ EX void rules_iteration_for(twalker& cw) {
 
 void minimize_rules() {
   states_premini = isize(treestates);
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "minimizing rules...");
   int next_id = isize(treestates);
 
@@ -1599,7 +1599,7 @@ void minimize_rules() {
       }
     }
 
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "final new_ids = ", new_ids, " / ", next_id);
 
   if(1) {
@@ -1686,7 +1686,7 @@ void find_possible_parents() {
   
   int pp = 0;
   for(auto& ts: treestates) if(ts.is_possible_parent) pp++;
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, pp, " of ", isize(treestates), " states are possible_parents");
   }
 
@@ -1756,10 +1756,10 @@ void verified_treewalk(twalker& tw, int id, int dir) {
       if((flags & w_examine_all) || !branch_conflicts_seen.count(conflict_id)) {
         branch_conflicts_seen.insert(conflict_id);
         important.push_back(tw.at);
-        if(debugflags & DF_GEOM)
+        if(debug_geometry)
           println(hlog, "branch conflict ", conflict_id, " found");
         }
-      else if(debugflags & DF_GEOM)
+      else if(debug_geometry)
         println(hlog, "branch conflict ", conflict_id, " found again");
       debuglist = {tw, tw+wstep};
       throw verify_advance_failed();
@@ -1772,7 +1772,7 @@ bool examine_branch(int id, int left, int right) {
   if(WDIM == 3) return true;
   auto rg = treestates[id].giver;
 
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "need to examine branches ", tie(left, right), " of ", id, " starting from ", rg, " step = ", rg+left+wstep, " vs ", rg+right+wstep);
 
   indenter ind(2);
@@ -1972,10 +1972,10 @@ EX void rules_iteration() {
     }
   
   handle_distance_errors();
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "number of treestates = ", isize(treestates));
   rule_root = get_treestate_id(t_origin[0]).second;
-  if(debugflags & DF_GEOM)
+  if(debug_geometry)
     println(hlog, "rule_root = ", rule_root);
 
   for(int id=0; id<isize(treestates); id++) {
@@ -2064,7 +2064,7 @@ EX void rules_iteration() {
         }
     if(qbranches == 2) double_live_branches++;
     if((flags & w_slow_side) && first_live_branch == last_live_branch && treestates[id].is_root) {
-      if(debugflags & DF_GEOM)
+      if(debug_geometry)
         println(hlog, "for id ", id, " we have a single live branch");
       single_live_branches++;
       indenter ind(2);
@@ -2074,7 +2074,7 @@ EX void rules_iteration() {
     if(isize(single_live_branch_close_to_root) != q) {
       vector<tcell*> v;
       for(auto c: single_live_branch_close_to_root) v.push_back(c);
-      if(debugflags & DF_GEOM) 
+      if(debug_geometry)
         println(hlog, "changed single_live_branch_close_to_root from ", q, " to ", v);
       debuglist = { treestates[id].giver };
       clear_sidecache_and_codes();
@@ -2506,7 +2506,7 @@ EX bool prepare_rules() {
     rules_known_for = arb::current.name;
     rule_status = XLAT("rules generated successfully: %1 states using %2-%3 cells", 
       its(isize(treestates)), its(tcellcount), its(tunified));
-    if(debugflags & DF_GEOM) println(hlog, rule_status);
+    if(debug_geometry) println(hlog, rule_status);
     return true;
     }
   catch(rulegen_retry& e) {
@@ -2518,7 +2518,7 @@ EX bool prepare_rules() {
   catch(rulegen_failure& e) {
     rule_status = XLAT("bug: %1", e.what());
     }
-  if(debugflags & DF_GEOM) println(hlog, rule_status);
+  if(debug_geometry) println(hlog, rule_status);
   return false;
   }
 
@@ -2612,9 +2612,9 @@ EX void parse_treestate(arb::arbi_tiling& c, exp_parser& ep) {
   if(qparent > 1) throw hr_parse_exception("multiple parent at " + ep.where());
   if(qparent == 1) {
     ts.parent_dir = sumparent;
-    if(debugflags & DF_GEOM) println(hlog, "before: ", ts.rules);
+    if(debug_geometry) println(hlog, "before: ", ts.rules);
     std::rotate(ts.rules.begin(), ts.rules.begin() + sumparent, ts.rules.end());
-    if(debugflags & DF_GEOM) println(hlog, "after : ", ts.rules);
+    if(debug_geometry) println(hlog, "after : ", ts.rules);
     }
   ep.force_eat(")");
   }
diff --git a/savemem.cpp b/savemem.cpp
index 10da4564..101bc115 100644
--- a/savemem.cpp
+++ b/savemem.cpp
@@ -69,13 +69,13 @@ void recursive_delete(heptagon *h, int i) {
     if(h2->move(i) && h2->move(i)->move(0) == h2)
       recursive_delete(h2, i); }
   if(h2->alt && h2->alt->alt == h2->alt) {
-    DEBB(DF_MEMORY, ("destroying alternate map ", h2->alt));
+    DEBB(debug_memory, ("destroying alternate map ", h2->alt));
     for(hrmap *& hm: allmaps) {
       if(hm->getOrigin() == h2->alt) {
         delete hm;
         hm = allmaps.back();
         allmaps.pop_back();
-        DEBB(DF_MEMORY, ("map found (", isize(allmaps), " altmaps total)"));
+        DEBB(debug_memory, ("map found (", isize(allmaps), " altmaps total)"));
         break;
         }
       }
@@ -155,7 +155,7 @@ EX void save_memory() {
   if(last_cleared && celldist(at->c7) < celldist(last_cleared->c7))
     return;
 
-  DEBB(DF_MEMORY, ("celldist = ", make_pair(celldist(cwt.at), celldist(at->c7))));
+  DEBB(debug_memory, ("celldist = ", make_pair(celldist(cwt.at), celldist(at->c7))));
   
   heptagon *at1 = at;
   while(at != last_cleared && at != orig) {
@@ -168,7 +168,7 @@ EX void save_memory() {
     }
   
   last_cleared = at1;
-  DEBB(DF_MEMORY, ("current cellcount = ", cellcount));
+  DEBB(debug_memory, ("current cellcount = ", cellcount));
   
   sort(removed_cells.begin(), removed_cells.end());
   callhooks(hooks_removecells);
diff --git a/sound.cpp b/sound.cpp
index eb125a9e..6c34553b 100644
--- a/sound.cpp
+++ b/sound.cpp
@@ -101,8 +101,11 @@ EX hookset<void(eLand&)> hooks_sync_music;
 
 EX bool music_out_of_focus = false;
 
+EX debugflag debug_music = {"music"};
+EX debugflag debug_music_error = {"music_error"};
+
 EX void handlemusic() {
-  DEBBI(DF_GRAPH, ("handle music"));
+  indenter_finish hm(debug_music, "handlemusic");
   if(audio && musicvolume) {
     eLand id = getCurrentLandForMusic();
     if(callhandlers(false, hooks_music, id)) return;
@@ -120,7 +123,7 @@ EX void handlemusic() {
       if(!music[id]) {
         memory_for_lib();
         music[id] = Mix_LoadMUS(musfname[id].c_str());
-        if(!music[id]) {
+        if(!music[id] && debug_music_error) {
            printf("Mix_LoadMUS: %s\n", Mix_GetError());
            }
         }
@@ -159,8 +162,10 @@ EX void resetmusic() {
 constexpr eLand mfcode(const char* buf) { return eLand((buf[0] - '0') * 10 + buf[1] - '0'); }
 #endif
 
+EX debugflag debug_init_music = {"init_music", true};
+
 EX bool loadMusicInfo(string dir) {
-  DEBBI(DF_INIT, ("load music info"));
+  indenter_finish hm(debug_init_music, "loadMusicInfo");
   if(dir == "") return false;
   FILE *f = fopen(dir.c_str(), "rt");
   if(f) {
@@ -178,7 +183,7 @@ EX bool loadMusicInfo(string dir) {
           else musfname[id] = buf+5;
           music_available = true;
           }
-        else {
+        else if(debug_music_error) {
           fprintf(stderr, "warning: bad soundtrack id, use the following format:\n");
           fprintf(stderr, "[##] */filename\n");
           fprintf(stderr, "where ## are two digits, and */ is optional and replaced by path to the music\n");
diff --git a/system.cpp b/system.cpp
index 7eee49de..7d1cf6dc 100644
--- a/system.cpp
+++ b/system.cpp
@@ -191,7 +191,7 @@ EX void reset_cheats() {
 
 /** \brief initialize the game */
 EX void initgame() {
-  DEBBI(DF_INIT, ("initGame"));
+  DEBBI(debug_init, ("initGame"));
   if(!safety) reset_cheats();
 
   callhooks(hooks_initgame);
@@ -1095,7 +1095,7 @@ scores::score scorebox;
 EX bool save_cheats;
 
 EX void saveStats(bool emergency IS(false)) {
-  DEBBI(DF_INIT, ("saveStats [", scorefile, "]"));
+  DEBBI(debug_init, ("saveStats [", scorefile, "]"));
 
   if(autocheat && !save_cheats) return;
   if(scorefile == "") return;
@@ -1232,7 +1232,7 @@ EX void saveStats(bool emergency IS(false)) {
   fprintf(f, "\n\n\n");
 
 #if !ISMOBILE
-  DEBB(DF_INIT, ("Game statistics saved to ", scorefile));
+  DEBB(debug_init, ("Game statistics saved to ", scorefile));
   addMessage(XLAT("Game statistics saved to %1", scorefile));
 #endif
   fclose(f);
@@ -1247,7 +1247,7 @@ EX void loadsave() {
 #if CAP_TOUR
   if(tour::on) return;
 #endif
-  DEBBI(DF_INIT, ("loadSave"));
+  DEBBI(debug_init, ("loadSave"));
 
   FILE *f = fopen(scorefile.c_str(), "rt");
   havesave = f;
@@ -1440,7 +1440,7 @@ EX void load_last_save() {
 EX void stop_game() {
   if(!game_active) return;
   if(dual::split(stop_game)) return;
-  DEBBI(DF_INIT, ("stop_game"));
+  DEBBI(debug_init, ("stop_game"));
   achievement_final(true);
   save_if_needed();
   for(int i=0; i<ittypes; i++) items[i] = 0;
@@ -1557,7 +1557,7 @@ EX void set_variation(eVariation target) {
   }
 
 EX void switch_game_mode(char switchWhat) {
-  DEBBI(DF_INIT, ("switch_game_mode ", switchWhat));
+  DEBBI(debug_init, ("switch_game_mode ", switchWhat));
   switch(switchWhat) {
     case rg::peace:
       peace::on = !peace::on;
@@ -1688,7 +1688,7 @@ EX void switch_game_mode(char switchWhat) {
 
 EX void start_game() {
   if(game_active) return;
-  DEBBI(DF_INIT, ("start_game"));
+  DEBBI(debug_init, ("start_game"));
   if(dual::state == 1) dual::assign_landsides();
   if(dual::split(start_game)) return;
   restart:
diff --git a/usershapes.cpp b/usershapes.cpp
index 3dca8b3f..2b344a2a 100644
--- a/usershapes.cpp
+++ b/usershapes.cpp
@@ -76,7 +76,7 @@ void geometry_information::pushShape(usershapelayer& ds) {
 void geometry_information::prepare_usershapes() {
   hpc.resize(prehpc);
   last = NULL;
-  DEBB(DF_POLY, ("hpc = ", prehpc));
+  DEBB(debug_poly, ("hpc = ", prehpc));
 
   user_triangles_texture.tvertices.clear();
   
@@ -92,7 +92,7 @@ void geometry_information::prepare_usershapes() {
   
   static int qhpc0;
   int qhpc = isize(hpc);
-  if(qhpc != qhpc0 && (debugflags & (DF_GEOM | DF_POLY))) {
+  if(qhpc != qhpc0 && debug_poly) {
     println(hlog, "qhpc = ", qhpc0=qhpc, " (", prehpc, "+", qhpc-prehpc, ")");
     println(hlog, "shapes = ", isize(allshapes));
     int inve=0, issi=0, vcon=0, ccon=0;
diff --git a/util.cpp b/util.cpp
index dfe51944..83b0f889 100644
--- a/util.cpp
+++ b/util.cpp
@@ -1031,6 +1031,14 @@ EX string find_file(string s) {
   return s;
   }
 
+EX void file_error(const char* fname) {
+  throw hr_exception("missing file error");
+  }
+
+EX void file_format_error(const char* fname) {
+  throw hr_exception("file format error");
+  }
+
 EX void open_url(string s) {
   #if ISWEB
   EM_ASM_({
diff --git a/yendor.cpp b/yendor.cpp
index 126a49cb..a3339e67 100644
--- a/yendor.cpp
+++ b/yendor.cpp
@@ -709,7 +709,7 @@ EX namespace yendor {
     }) + addHook(hooks_removecells, 0, [] () {
     eliminate_if(yendor::yi, [] (yendorinfo& i) {
       for(int j=0; j<YDIST; j++) if(is_cell_removed(i.path[j])) {
-        DEBB(DF_MEMORY, ("removing a Yendor"));
+        DEBB(debug_memory, ("removing a Yendor"));
         if(&yi[yii] == &i) yii = NOYENDOR;
         return true;
         }