qbsp: optimize FindTexinfo

include/qbsp/map.hh

@@ -80,6 +80,9 @@ typedef struct mapdata_s {
     std::vector<miptex_t> miptex;
     std::vector<mtexinfo_t> mtexinfos;
     
+    /* quick lookup for texinfo */
+    std::map<mtexinfo_t, int> mtexinfo_lookup;
+    
     /* map from plane hash code to list of indicies in `planes` vector */
     std::unordered_map<int, std::vector<int>> planehash;
     

include/qbsp/qbsp.hh

@@ -200,6 +200,29 @@ typedef struct mtexinfo_s {
     float vecs[2][4];           /* [s/t][xyz offset] */
     int32_t miptex;
     uint64_t flags;
+    
+    bool operator<(const mtexinfo_s &other) const {
+        if (this->miptex < other.miptex)
+            return true;
+        if (this->miptex > other.miptex)
+            return false;
+        
+        if (this->flags < other.flags)
+            return true;
+        if (this->flags > other.flags)
+            return false;
+        
+        for (int i=0; i<2; i++) {
+            for (int j=0; j<4; j++) {
+                if (this->vecs[i][j] < other.vecs[i][j])
+                    return true;
+                if (this->vecs[i][j] > other.vecs[i][j])
+                    return false;
+            }
+        }
+        
+        return false;
+    }
 } mtexinfo_t;
 
 typedef struct visfacet_s {

qbsp/map.cc

@@ -23,6 +23,7 @@
 #include <memory>
 #include <list>
 #include <utility>
+#include <cassert>
 
 #include <ctype.h>
 #include <string.h>
@@ -236,38 +237,31 @@ Returns a global texinfo number
 int
 FindTexinfo(mtexinfo_t *texinfo, uint64_t flags)
 {
-    const size_t num_texinfo = map.mtexinfos.size();
-
     /* Set the texture flags */
     texinfo->flags = flags;
-
-    for (size_t index = 0; index < num_texinfo; index++) {
-        const mtexinfo_t *target = &map.mtexinfos.at(index);
-        if (texinfo->miptex != target->miptex)
-            continue;
-        if (texinfo->flags != target->flags)
-            continue;
-
-        /* Don't worry about texture alignment on skip or hint surfaces */
-        if (texinfo->flags & (TEX_SKIP | TEX_HINT))
-            return index;
-
-        int j;
-        for (j = 0; j < 4; j++) {
-            if (texinfo->vecs[0][j] != target->vecs[0][j])
-                break;
-            if (texinfo->vecs[1][j] != target->vecs[1][j])
-                break;
-        }
-        if (j != 4)
-            continue;
-
-        return static_cast<int>(index);
+    
+    /* Don't worry about texture alignment on skip or hint surfaces */
+    if (texinfo->flags & (TEX_SKIP | TEX_HINT)) {
+        for (int i=0; i<2; i++)
+            for (int j=0; j<4; j++)
+                texinfo->vecs[i][j] = 0.0f;
     }
-
+    
+    // check for an exact match in the reverse lookup
+    const auto it = map.mtexinfo_lookup.find(*texinfo);
+    if (it != map.mtexinfo_lookup.end()) {
+        return it->second;
+    }
+    
     /* Allocate a new texinfo at the end of the array */
+    const int num_texinfo = static_cast<int>(map.mtexinfos.size());
     map.mtexinfos.push_back(*texinfo);
-    return static_cast<int>(num_texinfo);
+    map.mtexinfo_lookup[*texinfo] = num_texinfo;
+    
+    // catch broken < implementations in mtexinfo_t
+    assert(map.mtexinfo_lookup.find(*texinfo) != map.mtexinfo_lookup.end());
+    
+    return num_texinfo;
 }
 
 /* detect colors with components in 0-1 and scale them to 0-255 */