From a96aa4de701037477083b99efe290d748bbc8b9b Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Tue, 1 Nov 2016 12:48:46 -0600
Subject: [PATCH] qbsp: fix stupid perf bug in BuildSurfaces that I introduced

(unnecessary insertions and redundant lookups to a map)
---
 qbsp/csg4.cc | 23 ++++++++---------------
 qbsp/qbsp.hh |  2 +-
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/qbsp/csg4.cc b/qbsp/csg4.cc
index 0cf13cc4..9bd9402f 100644
--- a/qbsp/csg4.cc
+++ b/qbsp/csg4.cc
@@ -377,26 +377,19 @@ visible face.
 ==================
 */
 surface_t *
-BuildSurfaces(std::map<int, face_t *> &planefaces)
+BuildSurfaces(const std::map<int, face_t *> &planefaces)
 {
-    int i;
-    surface_t *surf, *surfaces;
-    face_t *face;
-
-    surfaces = NULL;
-    for (i = 0; i < map.numplanes(); i++) {
-        if (planefaces[i] == nullptr)
-            continue;
-
+    surface_t *surfaces = NULL;
+    for (const auto &entry : planefaces) {
         /* create a new surface to hold the faces on this plane */
-        surf = (surface_t *)AllocMem(SURFACE, 1, true);
-        surf->planenum = i;
+        surface_t *surf = (surface_t *)AllocMem(SURFACE, 1, true);
+        surf->planenum = entry.first;
         surf->next = surfaces;
         surfaces = surf;
-        surf->faces = planefaces[i];
-        for (face = surf->faces; face; face = face->next)
+        surf->faces = entry.second;
+        for (const face_t *face = surf->faces; face; face = face->next)
             csgmergefaces++;
-
+        
         /* Calculate bounding box and flags */
         CalcSurfaceInfo(surf);
     }
diff --git a/qbsp/qbsp.hh b/qbsp/qbsp.hh
index ae29bb81..160dfc9a 100644
--- a/qbsp/qbsp.hh
+++ b/qbsp/qbsp.hh
@@ -368,7 +368,7 @@ int PlaneInvEqual(const plane_t *p1, const plane_t *p2);
 extern int csgmergefaces;
 
 // build surfaces is also used by GatherNodeFaces
-surface_t *BuildSurfaces(std::map<int, face_t *> &planefaces);
+surface_t *BuildSurfaces(const std::map<int, face_t *> &planefaces);
 face_t *NewFaceFromFace(face_t *in);
 void SplitFace(face_t *in, const plane_t *split, face_t **front, face_t **back);
 void UpdateFaceSphere(face_t *in);