Use ASM instead of inheritance to override methods in RenderGlobal

src/main/java/eu/crushedpixel/replaymod/renderer/ChunkLoadingRenderGlobal.java

@@ -1,7 +1,6 @@
 package eu.crushedpixel.replaymod.renderer;
 
 import eu.crushedpixel.replaymod.utils.JailingQueue;
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.RegionRenderCacheBuilder;
 import net.minecraft.client.renderer.RenderGlobal;
 import net.minecraft.client.renderer.chunk.ChunkCompileTaskGenerator;
@@ -12,31 +11,23 @@ import net.minecraft.client.renderer.culling.ICamera;
 import net.minecraft.entity.Entity;
 import net.minecraft.util.BlockPos;
 
+import java.lang.reflect.Field;
 import java.util.Iterator;
 import java.util.concurrent.BlockingQueue;
 
-public class ChunkLoadingRenderGlobal extends RenderGlobal {
-    public static void install(Minecraft mc) {
-        RenderGlobal org = mc.renderGlobal;
-        if (org instanceof ChunkLoadingRenderGlobal) {
-            ((ChunkLoadingRenderGlobal) org).uninstall();
-        }
-        mc.renderGlobal = new ChunkLoadingRenderGlobal(mc);
-    }
+public class ChunkLoadingRenderGlobal {
 
-    private final RenderGlobal originalRenderGlobal;
+    private final RenderGlobal hooked;
+    private final ChunkRenderDispatcher renderDispatcher;
     private final JailingQueue<?> workerJailingQueue;
     private final CustomChunkRenderWorker renderWorker;
     private int frame;
 
     @SuppressWarnings("unchecked")
-    private ChunkLoadingRenderGlobal(Minecraft mc) {
-        super(mc);
-        this.originalRenderGlobal = mc.renderGlobal;
+    public ChunkLoadingRenderGlobal(RenderGlobal renderGlobal) {
+        this.hooked = renderGlobal;
+        this.renderDispatcher = renderGlobal.renderDispatcher;
         this.renderWorker = new CustomChunkRenderWorker(renderDispatcher, new RegionRenderCacheBuilder());
-        if (mc.theWorld != null) {
-            setWorldAndLoadRenderers(mc.theWorld);
-        }
 
         int workerThreads = renderDispatcher.listThreadedWorkers.size();
         BlockingQueue<Object> queueChunkUpdates = renderDispatcher.queueChunkUpdates;
@@ -49,27 +40,35 @@ public class ChunkLoadingRenderGlobal extends RenderGlobal {
         }
         workerJailingQueue.jail(workerThreads);
         renderDispatcher.queueChunkUpdates = queueChunkUpdates;
+
+        try {
+            Field hookField = RenderGlobal.class.getField("hook");
+            hookField.set(hooked, this);
+        } catch (NoSuchFieldException e) {
+            throw new Error(e);
+        } catch (IllegalAccessException e) {
+            throw new Error(e);
+        }
     }
 
-    @Override
+    @SuppressWarnings("unused") // Method called by ASM hook
     public void setupTerrain(Entity viewEntity, double partialTicks, ICamera camera, int frameCount, boolean playerSpectator) {
         // There has to be a better way to force minecraft into queueing all chunks at once
         // Someone should probably find and implement it!
         do {
-            super.setupTerrain(viewEntity, partialTicks, camera, frame++, playerSpectator);
-        } while (displayListEntitiesDirty);
+            original_setupTerrain(viewEntity, partialTicks, camera, frame++, playerSpectator);
+        } while (hooked.displayListEntitiesDirty);
     }
 
-    @Override
-    public boolean isPositionInRenderChunk(BlockPos p_174983_1_, RenderChunk p_174983_2_) {
+    @SuppressWarnings("unused") // Method called by ASM hook
+    public boolean isPositionInRenderChunk(BlockPos pos, RenderChunk chunk) {
         return true;
     }
 
-    @Override
-    @SuppressWarnings("unchecked")
+    @SuppressWarnings({"unchecked", "unused"}) // Method called by ASM hook
     public void updateChunks(long finishTimeNano) {
         while (renderDispatcher.runChunkUploads(0)) {
-            displayListEntitiesDirty = true;
+            hooked.displayListEntitiesDirty = true;
         }
 
         while (!renderDispatcher.queueChunkUpdates.isEmpty()) {
@@ -78,7 +77,7 @@ public class ChunkLoadingRenderGlobal extends RenderGlobal {
             } catch (InterruptedException ignored) { }
         }
 
-        Iterator<RenderChunk> iterator = chunksToUpdate.iterator();
+        Iterator<RenderChunk> iterator = hooked.chunksToUpdate.iterator();
         while (iterator.hasNext()) {
             RenderChunk renderchunk = iterator.next();
 
@@ -89,9 +88,33 @@ public class ChunkLoadingRenderGlobal extends RenderGlobal {
         }
     }
 
+    @SuppressWarnings("unused")
+    private void original_setupTerrain(Entity viewEntity, double partialTicks, ICamera camera, int frameCount, boolean playerSpectator) {
+        // Method body generated by ASM
+    }
+
+    @SuppressWarnings("unused")
+    private boolean original_isPositionInRenderChunk(BlockPos pos, RenderChunk chunk) {
+        // Method body generated by ASM
+        return false;
+    }
+
+    @SuppressWarnings("unused")
+    private void original_updateChunks(long finishTimeNano) {
+        // Method body generated by ASM
+    }
+
     public void uninstall() {
         workerJailingQueue.freeAll();
-        Minecraft.getMinecraft().renderGlobal = originalRenderGlobal;
+
+        try {
+            Field hookField = RenderGlobal.class.getField("hook");
+            hookField.set(hooked, null);
+        } catch (NoSuchFieldException e) {
+            throw new Error(e);
+        } catch (IllegalAccessException e) {
+            throw new Error(e);
+        }
     }
 
     /**