Add RenderReloadCallback Event (#217)

fabric-rendering-v0/build.gradle

@@ -1,5 +1,5 @@
 archivesBaseName = "fabric-rendering-v0"
-version = getSubprojectVersion(project, "0.1.0")
+version = getSubprojectVersion(project, "0.1.1")
 
 dependencies {
 	compile project(path: ':fabric-api-base', configuration: 'dev')

fabric-rendering-v0/src/main/java/net/fabricmc/fabric/api/client/render/InvalidateRenderStateCallback.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.api.client.render;
+
+import net.fabricmc.fabric.api.event.Event;
+import net.fabricmc.fabric.api.event.EventFactory;
+
+/**
+ * Called when the world renderer reloads, usually as result of changing resource pack
+ * or video configuration, or when the player types F3+A in the debug screen.
+ * Afterwards all render chunks will be reset and reloaded.<p>
+ *     
+ * Render chunks and other render-related object instances will be made null
+ * or invalid after this event so do not use it to capture dependent state.
+ * Instead, use it to invalidate state and reinitialize lazily.
+ */
+public interface InvalidateRenderStateCallback {
+    public static final Event<InvalidateRenderStateCallback> EVENT = EventFactory.createArrayBacked(InvalidateRenderStateCallback.class,
+        (listeners) -> () -> {
+            for (InvalidateRenderStateCallback event : listeners) {
+                event.onInvalidate();
+            }
+        }
+    );
+    
+    void onInvalidate();
+}

fabric-rendering-v0/src/main/java/net/fabricmc/fabric/mixin/client/render/MixinWorldRenderer.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.mixin.client.render;
+
+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 net.fabricmc.fabric.api.client.render.InvalidateRenderStateCallback;
+import net.minecraft.client.render.WorldRenderer;
+
+@Mixin(WorldRenderer.class)
+public abstract class MixinWorldRenderer {
+    @Inject(method = "reload", at = @At("HEAD"))
+    private void onReload(CallbackInfo ci) {
+        InvalidateRenderStateCallback.EVENT.invoker().onInvalidate();
+    }
+}

fabric-rendering-v0/src/main/resources/fabric-rendering-v0.mixins.json

@@ -6,7 +6,8 @@
     "MixinBlockColorMap",
     "MixinBlockEntityRenderManager",
     "MixinEntityRenderManager",
-    "MixinItemColorMap"
+    "MixinItemColorMap",
+    "MixinWorldRenderer"
   ],
   "injectors": {
     "defaultRequire": 1