From 781a772d8a63db11ea0a202327cd356e363dc232 Mon Sep 17 00:00:00 2001
From: Jonathan <jonno.5000@gmail.com>
Date: Sun, 14 Aug 2022 07:33:41 -0400
Subject: [PATCH] move immediately instead of splicing after construction
 (probably compiles to the same code but whatever) don't add all of the
 `result_portals_onnode` one at a time; just directly copy-elision the result.

---
 include/qbsp/map.hh |  1 +
 qbsp/brush.cc       | 32 +++++++++++---------------------
 qbsp/map.cc         | 11 +++++++++++
 qbsp/portals.cc     | 10 +++-------
 4 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/include/qbsp/map.hh b/include/qbsp/map.hh
index f3a22917..48d6c0b9 100644
--- a/include/qbsp/map.hh
+++ b/include/qbsp/map.hh
@@ -91,6 +91,7 @@ public:
     contentflags_t contents {};
     int16_t lmshift = 0; /* lightmap scaling (qu/lightmap pixel), passed to the light util */
     mapentity_t *func_areaportal = nullptr;
+    bool is_hint = false; // whether we are a hint brush or not (at least one side is "hint" or SURF_HINT)
 };
 
 struct lumpdata
diff --git a/qbsp/brush.cc b/qbsp/brush.cc
index ee5c4f1a..79a1bb01 100644
--- a/qbsp/brush.cc
+++ b/qbsp/brush.cc
@@ -231,26 +231,6 @@ qvec3d FixRotateOrigin(mapentity_t *entity)
     return offset;
 }
 
-static bool MapBrush_IsHint(const mapbrush_t &brush)
-{
-    for (auto &f : brush.faces) {
-        if (f.flags.is_hint)
-            return true;
-    }
-
-    return false;
-}
-
-#if 0
-        if (hullnum <= 0 && Brush_IsHint(*hullbrush)) {
-            /* Don't generate hintskip faces */
-            const maptexinfo_t &texinfo = map.mtexinfos.at(mapface.texinfo);
-
-            if (qbsp_options.target_game->texinfo_is_hintskip(texinfo.flags, map.miptexTextureName(texinfo.miptex)))
-                continue;
-        }
-#endif
-
 //============================================================================
 
 /*
@@ -315,6 +295,16 @@ std::optional<bspbrush_t> LoadBrush(const mapentity_t *src, mapbrush_t *mapbrush
     for (size_t i = 0; i < mapbrush->faces.size(); i++) {
         auto &src = mapbrush->faces[i];
 
+        if (hullnum <= 0 && mapbrush->is_hint) {
+            /* Don't generate hintskip faces */
+            const maptexinfo_t &texinfo = map.mtexinfos.at(src.texinfo);
+
+            // any face that isn't a hint is assumed to be hintskip
+            if (!texinfo.flags.is_hint) {
+                continue;
+            }
+        }
+
         // don't add bevels for the point hull
         if (hullnum <= 0 && src.bevel) {
             continue;
@@ -511,7 +501,7 @@ static void Brush_LoadEntity(mapentity_t *dst, mapentity_t *src, const int hulln
         }
 
         /* "hint" brushes don't affect the collision hulls */
-        if (MapBrush_IsHint(mapbrush)) {
+        if (mapbrush.is_hint) {
             if (hullnum > 0)
                 continue;
             contents = qbsp_options.target_game->create_empty_contents();
diff --git a/qbsp/map.cc b/qbsp/map.cc
index 5a5fc84b..78104f41 100644
--- a/qbsp/map.cc
+++ b/qbsp/map.cc
@@ -2251,6 +2251,16 @@ inline void CalculateBrushBounds(mapbrush_t &ob)
 	}
 }
 
+inline bool MapBrush_IsHint(const mapbrush_t &brush)
+{
+    for (auto &f : brush.faces) {
+        if (f.flags.is_hint)
+            return true;
+    }
+
+    return false;
+}
+
 void ProcessMapBrushes()
 {
     logging::funcheader();
@@ -2295,6 +2305,7 @@ void ProcessMapBrushes()
             // set properties calculated above
             brush.lmshift = lmshift;
             brush.func_areaportal = areaportal;
+            brush.is_hint = MapBrush_IsHint(brush);
 
             // calculate brush bounds
             CalculateBrushBounds(brush);
diff --git a/qbsp/portals.cc b/qbsp/portals.cc
index b0f585d2..a3720dc8 100644
--- a/qbsp/portals.cc
+++ b/qbsp/portals.cc
@@ -448,8 +448,7 @@ static std::list<buildportal_t> ClipNodePortalsToTree_r(node_t *node, portaltype
     auto front_fragments = ClipNodePortalsToTree_r(node->children[0], type, std::move(boundary_portals_split.front), stats);
     auto back_fragments = ClipNodePortalsToTree_r(node->children[1], type, std::move(boundary_portals_split.back), stats);
 
-    std::list<buildportal_t> merged_result;
-    merged_result.splice(merged_result.end(), front_fragments);
+    std::list<buildportal_t> merged_result = std::move(front_fragments);
     merged_result.splice(merged_result.end(), back_fragments);
     return merged_result;
 }
@@ -496,14 +495,11 @@ std::list<buildportal_t> MakeTreePortals_r(tree_t *tree, node_t *node, portaltyp
         std::list<buildportal_t> half_clipped =
             ClipNodePortalsToTree_r(node->children[0], type, make_list(std::move(*nodeportal)), stats);
 
-        for (auto &clipped_p : ClipNodePortalsToTree_r(node->children[1], type, std::move(half_clipped), stats)) {
-            result_portals_onnode.push_back(std::move(clipped_p));
-        }
+        result_portals_onnode = ClipNodePortalsToTree_r(node->children[1], type, std::move(half_clipped), stats);
     }
 
     // all done, merge together the lists and return
-    std::list<buildportal_t> merged_result;
-    merged_result.splice(merged_result.end(), result_portals_front);
+    std::list<buildportal_t> merged_result = std::move(result_portals_front);
     merged_result.splice(merged_result.end(), result_portals_back);
     merged_result.splice(merged_result.end(), result_portals_onnode);
     return merged_result;