From 5f5e7e7f99fb87daf77524495825e5d988c62a3b Mon Sep 17 00:00:00 2001
From: Sally Knight <ffqq@danwin1210.de>
Date: Thu, 26 Mar 2026 03:10:10 +0300
Subject: [PATCH] feat(jui): add item switch tooltips

---
 Minecraft.Client/UI/Gui.cpp | 50 +++++++++++++++++++++++++++++++++++++
 Minecraft.Client/UI/Gui.h   |  4 +++
 2 files changed, 54 insertions(+)

diff --git a/Minecraft.Client/UI/Gui.cpp b/Minecraft.Client/UI/Gui.cpp
index 8d9d12071..728277092 100644
--- a/Minecraft.Client/UI/Gui.cpp
+++ b/Minecraft.Client/UI/Gui.cpp
@@ -56,6 +56,10 @@ Gui::Gui(Minecraft* minecraft) {
     tbr = 1.0f;
     fAlphaIncrementPerCent = 255.0f / 100.0f;
 
+    // 4jcraft: backported item switch tooltip display from 1.6.4
+    remainingHighlightTicks = 0;
+    highlightingItemStack = nullptr;
+
     this->minecraft = minecraft;
 
     lastTickA = 0.0f;
@@ -816,6 +820,31 @@ void Gui::render(float a, bool mouseFree, int xMouse, int yMouse) {
     }
 
 #if RENDER_HUD
+    // 4jcraft: backported item switch tooltip display from 1.6.4
+    if (remainingHighlightTicks > 0 && highlightingItemStack != nullptr) {
+        std::wstring displayName = highlightingItemStack->getHoverName();
+        int x = (screenWidth - font->width(displayName)) / 2;
+        int y = screenHeight - 89;
+
+        if (!minecraft->gameMode->canHurtPlayer()) {
+            y += 14;
+        }
+
+        int alpha = (int)((float)remainingHighlightTicks * 256.0f / 10.0f);
+        if (alpha > 255) alpha = 255;
+        if (alpha > 0) {
+            glPushMatrix();
+            glEnable(GL_BLEND);
+            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+            int color = 0xFFFFFF | (alpha << 24);
+            font->drawShadow(displayName, x, y, color);
+
+            glDisable(GL_BLEND);
+            glPopMatrix();
+        }
+    }
+
     // Moved so the opacity blend is applied to it
     if (bDisplayGui && minecraft->gameMode->hasExperience() &&
         minecraft->player->experienceLevel > 0) {
@@ -1334,6 +1363,27 @@ void Gui::tick() {
     if (overlayMessageTime > 0) overlayMessageTime--;
     tickCount++;
 
+    // 4jcraft: backported item switch tooltip display from 1.6.4
+    if (minecraft->player != nullptr) {
+        std::shared_ptr<ItemInstance> currentItem =
+            minecraft->player->inventory->getSelected();
+
+        if (currentItem == nullptr) {
+            remainingHighlightTicks = 0;
+        } else if (highlightingItemStack != nullptr &&
+                   currentItem->id == highlightingItemStack->id &&
+                   currentItem->sameItemWithTags(highlightingItemStack) &&
+                   (currentItem->isDamageableItem() ||
+                    currentItem->getDamageValue() ==
+                        highlightingItemStack->getDamageValue())) {
+            if (remainingHighlightTicks > 0) --remainingHighlightTicks;
+        } else {
+            remainingHighlightTicks = 40;
+        }
+
+        highlightingItemStack = currentItem;
+    }
+
     for (int iPad = 0; iPad < XUSER_MAX_COUNT; iPad++) {
         // 4J Stu - Fix for #10929 - MP LAB: Network Disconnects: Host does not
         // receive an error message stating the client left the game when
diff --git a/Minecraft.Client/UI/Gui.h b/Minecraft.Client/UI/Gui.h
index 81ee2b5f8..2ced840c3 100644
--- a/Minecraft.Client/UI/Gui.h
+++ b/Minecraft.Client/UI/Gui.h
@@ -34,6 +34,10 @@ private:
     float lastTickA;
     float fAlphaIncrementPerCent;
 
+    // 4jcraft: backported item switch tooltip display from 1.6.4
+    int remainingHighlightTicks;
+    std::shared_ptr<ItemInstance> highlightingItemStack;
+
 public:
     static float currentGuiBlendFactor;  // 4J added
     static float currentGuiScaleFactor;  // 4J added