Sort out loading errors

src/main/java/com/minelittlepony/client/FabMod.java

@@ -9,6 +9,7 @@ import net.minecraft.client.render.entity.EntityRenderDispatcher;
 import net.minecraft.client.render.entity.EntityRenderer;
 import net.minecraft.entity.Entity;
 
+import com.minelittlepony.client.gui.hdskins.MineLPHDSkins;
 import com.minelittlepony.client.settings.ClientPonyConfig;
 import com.minelittlepony.hdskins.mixin.MixinEntityRenderDispatcher;
 import com.minelittlepony.settings.SensibleJsonConfig;
@@ -18,12 +19,17 @@ import java.util.function.Function;
 
 public class FabMod implements ClientModInitializer, IModUtilities {
 
-    private final MineLPClient mlp = new MineLPClient(this);
-
     @Override
     public void onInitializeClient() {
-        mlp.init(SensibleJsonConfig.of(getConfigDirectory(), ClientPonyConfig::new));
+        MineLPClient mlp;
-        mlp.postInit(MinecraftClient.getInstance());
+
+        if (FabricLoader.getInstance().isModLoaded("hdskins")) {
+            mlp = new MineLPHDSkins(this);
+        } else {
+            mlp = new MineLPClient(this);
+        }
+
+        mlp.init(SensibleJsonConfig.of(getConfigDirectory().resolve("minelp.json"), ClientPonyConfig::new));
     }
 
     @Override

src/main/java/com/minelittlepony/client/MineLPClient.java

@@ -2,14 +2,9 @@ package com.minelittlepony.client;
 
 import com.minelittlepony.MineLittlePony;
 import com.minelittlepony.client.gui.GuiPonySettings;
-import com.minelittlepony.client.gui.hdskins.GuiSkinsMineLP;
 import com.minelittlepony.client.pony.PonyManager;
 import com.minelittlepony.client.render.tileentities.skull.PonySkullRenderer;
 import com.minelittlepony.common.client.gui.GuiHost;
-import com.minelittlepony.hdskins.HDSkins;
-import com.minelittlepony.hdskins.net.LegacySkinServer;
-import com.minelittlepony.hdskins.net.SkinServer;
-import com.minelittlepony.hdskins.net.ValhallaSkinServer;
 import com.minelittlepony.settings.PonyConfig;
 
 import net.minecraft.ChatFormat;
@@ -30,9 +25,6 @@ import org.lwjgl.glfw.GLFW;
  */
 public class MineLPClient extends MineLittlePony {
 
-    private static final String MINELP_VALHALLA_SERVER = "http://skins.minelittlepony-mod.com";
-    private static final String MINELP_LEGACY_SERVER = "http://minelpskins.voxelmodpack.com";
-    private static final String MINELP_LEGACY_GATEWAY = "http://minelpskinmanager.voxelmodpack.com";
 
     static final KeyBinding SETTINGS_GUI = new KeyBinding("Settings", GLFW.GLFW_KEY_F9, "Mine Little Pony");
 
@@ -54,36 +46,20 @@ public class MineLPClient extends MineLittlePony {
         utilities = utils;
     }
 
-    void init(PonyConfig newConfig) {
+    protected void init(PonyConfig newConfig) {
         config = newConfig;
         ponyManager = new PonyManager(config);
-
-        ReloadableResourceManager irrm = (ReloadableResourceManager) MinecraftClient.getInstance().getResourceManager();
-        irrm.registerListener(ponyManager);
-
-        // This also makes it the default gateway server.
-        SkinServer.defaultServers.add(new LegacySkinServer(MINELP_LEGACY_SERVER, MINELP_LEGACY_GATEWAY));
-        SkinServer.defaultServers.add(0, new ValhallaSkinServer(MINELP_VALHALLA_SERVER));
     }
 
     /**
      * Called when the game is ready.
      */
-    void postInit(MinecraftClient minecraft) {
+    public void postInit(MinecraftClient minecraft) {
-
-        HDSkins manager = HDSkins.getInstance();
-//        manager.setSkinUrl(SKIN_SERVER_URL);
-//        manager.setGatewayURL(GATEWAY_URL);
-        manager.addSkinModifier(new PonySkinModifier());
-        manager.addSkinParser(new PonySkinParser());
-//        logger.info("Set MineLP skin server URL.");
-        manager.addClearListener(ponyManager);
-
-        manager.setSkinsGui(GuiSkinsMineLP::new);
-
         EntityRenderDispatcher rm = minecraft.getEntityRenderManager();
-
         renderManager.initialiseRenderers(rm);
+
+        ReloadableResourceManager irrm = (ReloadableResourceManager) MinecraftClient.getInstance().getResourceManager();
+        irrm.registerListener(ponyManager);
     }
 
     void onTick(MinecraftClient minecraft, boolean inGame) {

src/main/java/com/minelittlepony/client/gui/hdskins/MineLPHDSkins.java

@@ -0,0 +1,57 @@
+package com.minelittlepony.client.gui.hdskins;
+
+import net.minecraft.client.MinecraftClient;
+
+import com.minelittlepony.client.IModUtilities;
+import com.minelittlepony.client.MineLPClient;
+import com.minelittlepony.client.PonySkinModifier;
+import com.minelittlepony.client.PonySkinParser;
+
+import com.minelittlepony.hdskins.HDSkins;
+import com.minelittlepony.hdskins.net.LegacySkinServer;
+import com.minelittlepony.hdskins.net.SkinServer;
+import com.minelittlepony.hdskins.net.ValhallaSkinServer;
+import com.minelittlepony.settings.PonyConfig;
+
+/**
+ * All the interactions with HD Skins.
+ */
+public class MineLPHDSkins extends MineLPClient {
+    private static final String MINELP_VALHALLA_SERVER = "http://skins.minelittlepony-mod.com";
+
+    private static final String MINELP_LEGACY_SERVER = "http://minelpskins.voxelmodpack.com";
+    private static final String MINELP_LEGACY_GATEWAY = "http://minelpskinmanager.voxelmodpack.com";
+
+    public MineLPHDSkins(IModUtilities utils) {
+        super(utils);
+    }
+
+    @Override
+    protected void init(PonyConfig newConfig) {
+        super.init(newConfig);
+
+        // Register pony servers
+        SkinServer.defaultServers.add(new LegacySkinServer(MINELP_LEGACY_SERVER, MINELP_LEGACY_GATEWAY));
+        // And make valhalla the default
+        SkinServer.defaultServers.add(0, new ValhallaSkinServer(MINELP_VALHALLA_SERVER));
+    }
+
+    /**
+     * Called when the game is ready.
+     */
+    @Override
+    public void postInit(MinecraftClient minecraft) {
+        super.postInit(minecraft);
+
+        HDSkins manager = HDSkins.getInstance();
+
+        // Convert legacy pony skins
+        manager.addSkinModifier(new PonySkinModifier());
+        // Parse trigger pixel data
+        manager.addSkinParser(new PonySkinParser());
+        // Clear ponies when skins are cleared
+        manager.addClearListener(getManager());
+        // Ponify the skins GUI.
+        manager.setSkinsGui(GuiSkinsMineLP::new);
+    }
+}

src/main/java/com/minelittlepony/client/mixin/MixinMinecraftClient.java

@@ -0,0 +1,24 @@
+package com.minelittlepony.client.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.minelittlepony.client.MineLPClient;
+
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.WindowEventHandler;
+import net.minecraft.util.NonBlockingThreadExecutor;
+import net.minecraft.util.snooper.SnooperListener;
+
+@Mixin(MinecraftClient.class)
+public abstract class MixinMinecraftClient extends NonBlockingThreadExecutor<Runnable> implements SnooperListener, WindowEventHandler, AutoCloseable {
+
+    public MixinMinecraftClient() { super(null); }
+
+    @Inject(method = "init()V", at = @At("RETURN"))
+    private void onInit(CallbackInfo info) {
+        MineLPClient.getInstance().postInit(MinecraftClient.getInstance());
+    }
+}

src/main/resources/minelp.mixin.json

@@ -10,6 +10,7 @@
         "MixinFirstPersonRenderer",
         "MixinGlStateManager",
         "MixinItemRenderer",
+        "MixinMinecraftClient",
         "MixinRenderManager",
         "MixinThreadDownloadImageData"
     ]