Copy CCGuiTextures into a generic util class.

src/main/java/codechicken/lib/gui/modular/sprite/CCGuiTextures.java

@@ -14,6 +14,7 @@
  * <p>
  * Created by brandon3055 on 21/10/2023
  */
+// TODO 1.20.4, use GuiTextures instance.
 public class CCGuiTextures {
     private static final ModAtlasHolder ATLAS_HOLDER = new ModAtlasHolder(CodeChickenLib.MOD_ID, "textures/atlas/gui.png", "gui");
     private static final Map<String, Material> MATERIAL_CACHE = new HashMap<>();
@@ -56,4 +57,4 @@ public static Supplier<Material> getter(Supplier<String> texture) {
     public static Material getUncached(String texture) {
         return new Material(ATLAS_HOLDER.atlasLocation(), new ResourceLocation(CodeChickenLib.MOD_ID, "gui/" + texture), ATLAS_HOLDER::getSprite);
     }
-}
+}

src/main/java/codechicken/lib/gui/modular/sprite/GuiTextures.java

@@ -0,0 +1,88 @@
+package codechicken.lib.gui.modular.sprite;
+
+import net.minecraft.resources.ResourceLocation;
+import net.minecraftforge.client.event.RegisterClientReloadListenersEvent;
+import net.minecraftforge.data.loading.DatagenModLoader;
+import net.minecraftforge.eventbus.api.IEventBus;
+
+import javax.annotation.Nullable;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Supplier;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Gui texture handler implementation.
+ * This sets up a custom atlas that will be populated with all textures in "modid:textures/gui/"
+ * <p>
+ * Created by brandon3055 on 21/10/2023
+ */
+public class GuiTextures {
+
+    private final String modId;
+    private final @Nullable ModAtlasHolder atlasHolder;
+    private final Map<String, Material> materialCache = new HashMap<>();
+
+    public GuiTextures(String modId) {
+        this.modId = modId;
+        if (DatagenModLoader.isRunningDataGen()) {
+            atlasHolder = null;
+        } else {
+            atlasHolder = new ModAtlasHolder(modId, "textures/atlas/gui.png", "gui");
+        }
+    }
+
+    /**
+     * Called to initialize the {@link GuiTextures} helper
+     *
+     * @param bus Your mod event bus.
+     */
+    public void init(IEventBus bus) {
+        bus.addListener(this::onRegisterReloadListeners);
+    }
+
+    private void onRegisterReloadListeners(RegisterClientReloadListenersEvent event) {
+        getAtlasHolder().init();
+        event.registerReloadListener(getAtlasHolder());
+    }
+
+    /**
+     * @return The underlying {@link ModAtlasHolder} instance.
+     */
+    public ModAtlasHolder getAtlasHolder() {
+        return requireNonNull(atlasHolder, "AtlasHolder not available when datagen is running.");
+    }
+
+    /**
+     * Returns a cached Material for the specified gui texture.
+     * Warning: Do not use this if you intend to use the material with multiple render types.
+     * The material will cache the first render type it is used with.
+     * Instead use {@link #getUncached(String)}
+     *
+     * @param texture The texture path relative to "modid:gui/"
+     */
+    public Material get(String texture) {
+        return materialCache.computeIfAbsent(modId + ":" + texture, e -> getUncached(texture));
+    }
+
+    public Material get(Supplier<String> texture) {
+        return get(texture.get());
+    }
+
+    public Supplier<Material> getter(Supplier<String> texture) {
+        return () -> get(texture.get());
+    }
+
+    /**
+     * Use this to retrieve a new uncached material for the specified gui texture.
+     * Feel free to hold onto the returned material.
+     * Storing it somewhere is more efficient than recreating it every render frame.
+     *
+     * @param texture The texture path relative to "modid:gui/"
+     * @return A new Material for the specified gui texture.
+     */
+    public Material getUncached(String texture) {
+        return new Material(getAtlasHolder().atlasLocation(), new ResourceLocation(modId, "gui/" + texture), getAtlasHolder()::getSprite);
+    }
+}

src/main/java/codechicken/lib/gui/modular/sprite/ModAtlasHolder.java

@@ -4,6 +4,7 @@
 import net.minecraft.client.renderer.texture.SpriteLoader;
 import net.minecraft.client.renderer.texture.TextureAtlas;
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
+import net.minecraft.client.renderer.texture.TextureManager;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.PackResources;
 import net.minecraft.server.packs.resources.PreparableReloadListener;
@@ -22,6 +23,7 @@
  * Created by brandon3055 on 20/08/2023
  */
 public class ModAtlasHolder implements PreparableReloadListener, AutoCloseable {
+
     private final TextureAtlas textureAtlas;
     private final ResourceLocation atlasLocation;
     private final ResourceLocation atlasInfoLocation;
@@ -42,6 +44,14 @@ public ModAtlasHolder(String modid, String atlasLocation, String atlasInfoLocati
         this.atlasLocation = new ResourceLocation(modid, atlasLocation);
         this.textureAtlas = new TextureAtlas(this.atlasLocation);
         this.modid = modid;
+        // TODO remove in 1.20.4
+        TextureManager textureManager = Minecraft.getInstance().getTextureManager();
+        if (textureManager != null) {
+            textureManager.register(this.textureAtlas.location(), this.textureAtlas);
+        }
+    }
+
+    public void init() {
         Minecraft.getInstance().getTextureManager().register(this.textureAtlas.location(), this.textureAtlas);
     }
 
@@ -77,6 +87,7 @@ public void close() {
     }
 
     public static class ModResourceManager implements ResourceManager {
+
         private final ResourceManager wrapped;
         private final String modid;
 

src/main/java/codechicken/lib/internal/ClientInit.java

@@ -82,7 +82,7 @@ private static void onRegisterGeometryLoaders(ModelEvent.RegisterGeometryLoaders
         event.register("class", new ClassModelLoader());
     }
 
-    public static void onResourceReload(RegisterClientReloadListenersEvent event) {
+    private static void onResourceReload(RegisterClientReloadListenersEvent event) {
         event.registerReloadListener(CCGuiTextures.getAtlasHolder());
         event.registerReloadListener((ResourceManagerReloadListener) e -> CursorHelper.onResourceReload());
     }