chore: call common djb2 implementations in game hashing funcs

src/Common/Game/IW4/CommonIW4.cpp

@@ -2,26 +2,8 @@
 
 #include "Utils/Pack.h"
 
-#include <cctype>
-
 using namespace IW4;
 
-int Common::StringTable_HashString(const char* str)
-{
-    if (!str)
-        return 0;
-
-    auto result = 0;
-    auto offset = 0;
-    while (str[offset])
-    {
-        const auto c = tolower(str[offset++]);
-        result = c + 31 * result;
-    }
-
-    return result;
-}
-
 PackedTexCoords Common::Vec2PackTexCoords(const float (&in)[2])
 {
     return PackedTexCoords{pack32::Vec2PackTexCoordsVU(in)};

src/Common/Game/IW4/CommonIW4.h

@@ -1,33 +1,41 @@
 #pragma once
 
 #include "IW4.h"
+#include "Utils/Djb2.h"
+
+#include <cctype>
 
 namespace IW4
 {
     class Common
     {
     public:
-        static constexpr uint32_t R_HashString(const char* string, const uint32_t hash)
+        static constexpr int StringTable_HashString(const char* str)
         {
-            const char* v2 = string; // edx@1
-            char v3 = *string;       // cl@1
-            uint32_t result = hash;
+            if (!str)
+                return 0;
 
-            for (; *v2; v3 = *v2)
-            {
-                ++v2;
-                result = 33 * result ^ (v3 | 0x20);
-            }
-            return result;
+            // Lets do djb2 with 31 instead of 33 because why not
+            // and leave out the starting value while we are at it
+            uint32_t hash = 0;
+            for (char c = *str; c; c = *++str)
+                hash = hash * 31 + std::tolower(c);
+
+            return static_cast<int>(hash);
+        }
+
+        static constexpr uint32_t R_HashString(const char* str, const uint32_t hash)
+        {
+            return djb2_xor_nocase(str, hash);
         }
 
         static constexpr uint32_t R_HashString(const char* string)
         {
+            // Using djb2 with a 0 starting value makes a worse hash func apparently
+            // but who am I to judge
             return R_HashString(string, 0u);
         }
 
-        static int StringTable_HashString(const char* str);
-
         static PackedTexCoords Vec2PackTexCoords(const float (&in)[2]);
         static PackedUnitVec Vec3PackUnitVec(const float (&in)[3]);
         static GfxColor Vec4PackGfxColor(const float (&in)[4]);