From 9cf6f3497db9e59ea431d6b8970f842ef84204cc Mon Sep 17 00:00:00 2001
From: PJB3005 <pieterjan.briers+git@gmail.com>
Date: Tue, 7 Apr 2026 21:43:38 +0200
Subject: [PATCH] Fix JUTResFont performance

Just store the GXTexObjs in a separately allocated hashmap, so they can be persisted cross-frame. Easy.

Fixes #227
---
 .../include/JSystem/JUtility/JUTResFont.h     |  8 ++++
 libs/JSystem/src/JUtility/JUTResFont.cpp      | 45 +++++++++++++++++--
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/libs/JSystem/include/JSystem/JUtility/JUTResFont.h b/libs/JSystem/include/JSystem/JUtility/JUTResFont.h
index 09d3303da0..8709822d7b 100644
--- a/libs/JSystem/include/JSystem/JUtility/JUTResFont.h
+++ b/libs/JSystem/include/JSystem/JUtility/JUTResFont.h
@@ -18,6 +18,10 @@ struct BlockHeader {
     BE(u32) size;
 };
 
+#if TARGET_PC
+struct GlyphTextures;
+#endif
+
 /**
 * @ingroup jsystem-jutility
 * 
@@ -64,7 +68,11 @@ public:
     // some types uncertain, may need to be fixed
     /* 0x1C */ int mWidth;
     /* 0x20 */ int mHeight;
+#if TARGET_PC
+    GlyphTextures* mGlyphTextures;
+#else
     /* 0x24 */ TGXTexObj mTexObj;
+#endif
     /* 0x44 */ int mTexPageIdx;
     /* 0x48 */ const ResFONT* mResFont;
     /* 0x4C */ ResFONT::INF1* mInf1Ptr;
diff --git a/libs/JSystem/src/JUtility/JUTResFont.cpp b/libs/JSystem/src/JUtility/JUTResFont.cpp
index e6410defdc..10443d6404 100644
--- a/libs/JSystem/src/JUtility/JUTResFont.cpp
+++ b/libs/JSystem/src/JUtility/JUTResFont.cpp
@@ -6,19 +6,39 @@
 #include "JSystem/JUtility/JUTAssert.h"
 #include "JSystem/JUtility/JUTConsole.h"
 #include <gx.h>
+#include "absl/container/node_hash_map.h"
+
+#if TARGET_PC
+struct GlyphTextures {
+    absl::node_hash_map<int, TGXTexObj> textures;
+};
+#endif
 
 JUTResFont::JUTResFont() {
+#if TARGET_PC
+    mGlyphTextures = new GlyphTextures();
+#endif
     initialize_state();
     JUTFont::initialize_state();
 }
 
 JUTResFont::JUTResFont(const ResFONT* pFont, JKRHeap* pHeap) {
+#if TARGET_PC
+    mGlyphTextures = new GlyphTextures();
+#endif
     initialize_state();
     JUTFont::initialize_state();
     initiate(pFont, pHeap);
 }
 
 JUTResFont::~JUTResFont() {
+#if TARGET_PC
+    for (auto& pair : mGlyphTextures->textures) {
+        pair.second.reset();
+    }
+    delete mGlyphTextures;
+#endif
+
     if (mValid) {
         delete_and_initialize();
         JUTFont::initialize_state();
@@ -414,12 +434,30 @@ void JUTResFont::loadImage(int code, GXTexMapID id){
         mWidth = cellCol * cellW;
         mHeight = cellRow * cellH;
 
+#if TARGET_PC
+        const auto found = mGlyphTextures->textures.find(code);
+        GXTexObj* texObj;
+        if (found == mGlyphTextures->textures.end()) {
+            texObj = &mGlyphTextures->textures[code];
+            void* pImg = &mpGlyphBlocks[i]->data[pageIdx * mpGlyphBlocks[i]->textureSize];
+            GXInitTexObj(texObj, pImg, mpGlyphBlocks[i]->textureWidth,
+                         mpGlyphBlocks[i]->textureHeight, (GXTexFmt)(u16)mpGlyphBlocks[i]->textureFormat,
+                         GX_CLAMP, GX_CLAMP, 0);
+
+            GXInitTexObjLOD(texObj, GX_LINEAR, GX_LINEAR, 0.0f, 0.0f, 0.0f, 0U, 0U, GX_ANISO_1);
+        } else {
+            texObj = &found->second;
+        }
+
+        GXLoadTexObj(texObj, id);
+
+        // Gets used by some other code.
+        mTexPageIdx = pageIdx;
+        field_0x66 = i;
+#else
         if (pageIdx != mTexPageIdx || i != field_0x66)
         {
             void* pImg = &mpGlyphBlocks[i]->data[pageIdx * mpGlyphBlocks[i]->textureSize];
-#ifdef TARGET_PC
-            mTexObj.reset();
-#endif
             GXInitTexObj(&mTexObj, pImg, mpGlyphBlocks[i]->textureWidth,
                          mpGlyphBlocks[i]->textureHeight, (GXTexFmt)(u16)mpGlyphBlocks[i]->textureFormat,
                          GX_CLAMP, GX_CLAMP, 0);
@@ -430,6 +468,7 @@ void JUTResFont::loadImage(int code, GXTexMapID id){
         }
 
         GXLoadTexObj(&mTexObj, id);
+#endif
     }
 }