IT WORKS!!!!!!

src/main/java/me/cortex/voxy/client/core/VoxelCore.java

@@ -75,6 +75,8 @@ public class VoxelCore {
         this.postProcessing = new PostProcessing();
 
         System.out.println("Voxy core initialized");
+
+        //this.verifyTopNodeChildren(0,0,0);
     }
 
 

src/main/java/me/cortex/voxy/client/core/rendering/PrintfDebugUtil.java

@@ -3,6 +3,7 @@ package me.cortex.voxy.client.core.rendering;
 import me.cortex.voxy.client.Voxy;
 import me.cortex.voxy.client.core.gl.shader.IShaderProcessor;
 import me.cortex.voxy.client.core.gl.shader.PrintfInjector;
+import me.cortex.voxy.client.core.gl.shader.ShaderType;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -12,8 +13,8 @@ public final class PrintfDebugUtil {
 
     private static final List<String> printfQueue2 = new ArrayList<>();
     private static final List<String> printfQueue = new ArrayList<>();
-    private static final IShaderProcessor PRINTF;
+    public static final IShaderProcessor PRINTF_processor;
-    public static final PrintfInjector PRINTF_object;
+    private static final PrintfInjector PRINTF_object;
 
 
     static {
@@ -24,11 +25,18 @@ public final class PrintfDebugUtil {
                 }
                 printfQueue.add(line);
             }, printfQueue::clear);
-            PRINTF = PRINTF_object;
+            PRINTF_processor = PRINTF_object;
         } else {
             PRINTF_object = null;
             //Todo add a dummy processor that just removes all the printf calls
-            PRINTF = null;
+            PRINTF_processor = new IShaderProcessor() {
+                @Override
+                public String process(ShaderType type, String src) {
+                    //TODO: replace with https://stackoverflow.com/questions/47162098/is-it-possible-to-match-nested-brackets-with-a-regex-without-using-recursion-or/47162099#47162099
+                    // to match on printf with balanced bracing
+                    return src.replace("printf", "//printf");
+                }
+            };
         }
     }
 

src/main/java/me/cortex/voxy/client/core/rendering/building/BuiltSection.java

@@ -9,20 +9,22 @@ import java.util.Arrays;
 public final class BuiltSection {
     public static final boolean VERIFY_BUILT_SECTION_OFFSETS = VoxyCommon.isVerificationFlagOn("verifyBuiltSectionOffsets");
     public final long position;
+    public final byte childExistence;
     public final int aabb;
     public final MemoryBuffer geometryBuffer;
     public final int[] offsets;
 
     private BuiltSection(long position) {
-        this(position, -1, null, null);
+        this(position, (byte) 0, -1, null, null);
     }
 
     public static BuiltSection empty(long position) {
         return new BuiltSection(position);
     }
 
-    public BuiltSection(long position, int aabb, MemoryBuffer geometryBuffer, int[] offsets) {
+    public BuiltSection(long position, byte childExistence, int aabb, MemoryBuffer geometryBuffer, int[] offsets) {
         this.position = position;
+        this.childExistence = childExistence;
         this.aabb = aabb;
         this.geometryBuffer = geometryBuffer;
         this.offsets = offsets;
@@ -37,7 +39,7 @@ public final class BuiltSection {
     }
 
     public BuiltSection clone() {
-        return new BuiltSection(this.position, this.aabb, this.geometryBuffer!=null?this.geometryBuffer.copy():null, this.offsets!=null?Arrays.copyOf(this.offsets, this.offsets.length):null);
+        return new BuiltSection(this.position, this.childExistence, this.aabb, this.geometryBuffer!=null?this.geometryBuffer.copy():null, this.offsets!=null?Arrays.copyOf(this.offsets, this.offsets.length):null);
     }
 
     public void free() {

src/main/java/me/cortex/voxy/client/core/rendering/building/RenderDataFactory.java

@@ -321,7 +321,7 @@ public class RenderDataFactory {
         aabb |= (this.maxY-this.minY)<<20;
         aabb |= (this.maxZ-this.minZ)<<25;
 
-        return new BuiltSection(section.key, aabb, buff, offsets);
+        return new BuiltSection(section.key, section.getNonEmptyChildren(), aabb, buff, offsets);
     }
 
 

src/main/java/me/cortex/voxy/client/core/rendering/building/SectionUpdateRouter.java

@@ -44,8 +44,9 @@ public class SectionUpdateRouter {
             if (set.containsKey(position)) {
                 current = set.get(position);
             }
-            delta = (byte) ((current&types)^types);
+            delta = (byte) (current&types);
             current |= (byte) types;
+            delta ^= (byte) (current&types);
             set.put(position, current);
         }
         if ((delta&UPDATE_TYPE_BLOCK_BIT)!=0) {

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/HierarchicalNodeManager.java

@@ -240,7 +240,7 @@ public class HierarchicalNodeManager {
             nodeId &= ~ID_TYPE_MSK;
             if (type == ID_TYPE_REQUEST) {
                 //Doesnt result in an invalidation as we must wait for geometry to create a child
-                this.requests.get(nodeId).putChildResult(getChildIdx(position), childExistence);
+                this.requests.get(nodeId).setChildMesh(getChildIdx(position), childExistence);
             } else if (type == ID_TYPE_LEAF || type == ID_TYPE_INNER) {// || type == ID_TYPE_TOP
                 if (this.nodeData.getNodeChildExistence(nodeId) == childExistence) {
                     //Dont need to update the internal state since it is the same
@@ -345,7 +345,7 @@ public class HierarchicalNodeManager {
                 var request = this.requests.get(nodeId);
                 //Update for section part of a request, the request may be a leaf request update or an inner node update
                 int child = getChildIdx(position);
-                int prev = request.putChildResult(child, this.geometryManager.uploadSection(section));
+                int prev = request.setChildMesh(child, this.geometryManager.uploadSection(section));
                 if (prev != -1) {
                     this.geometryManager.removeSection(prev);
                 }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/HierarchicalOcclusionTraverser.java

@@ -15,7 +15,7 @@ import org.joml.Matrix4f;
 import org.joml.Vector3f;
 import org.lwjgl.system.MemoryUtil;
 
-import static me.cortex.voxy.client.core.rendering.PrintfDebugUtil.PRINTF_object;
+import static me.cortex.voxy.client.core.rendering.PrintfDebugUtil.PRINTF_processor;
 import static org.lwjgl.opengl.GL11.*;
 import static org.lwjgl.opengl.GL12.GL_UNPACK_IMAGE_HEIGHT;
 import static org.lwjgl.opengl.GL12.GL_UNPACK_SKIP_IMAGES;
@@ -56,7 +56,7 @@ public class HierarchicalOcclusionTraverser {
     private final HiZBuffer hiZBuffer = new HiZBuffer();
     private final int hizSampler = glGenSamplers();
 
-    private final Shader traversal = Shader.make(PRINTF_object)
+    private final Shader traversal = Shader.make(PRINTF_processor)
             .defineIf("DEBUG", Voxy.SHADER_DEBUG)
             .define("MAX_ITERATIONS", MAX_ITERATIONS)
             .define("LOCAL_SIZE_BITS", LOCAL_WORK_SIZE_BITS)
@@ -103,6 +103,7 @@ public class HierarchicalOcclusionTraverser {
         MemoryUtil.memPutInt(ptr, sx); ptr += 4;
         MemoryUtil.memPutInt(ptr, sy); ptr += 4;
         MemoryUtil.memPutInt(ptr, sz); ptr += 4;
+
         MemoryUtil.memPutInt(ptr, viewport.width); ptr += 4;
 
         var innerTranslation = new Vector3f((float) (viewport.cameraX-(sx<<5)), (float) (viewport.cameraY-(sy<<5)), (float) (viewport.cameraZ-(sz<<5)));
@@ -175,7 +176,7 @@ public class HierarchicalOcclusionTraverser {
         //Set the first entry
         glClearNamedBufferSubData(this.queueMetaBuffer.id, GL_RGBA32UI, 0, 16, GL_RGBA, GL_UNSIGNED_INT, new int[]{firstDispatchSize,1,1,initialQueueSize});
          */
-        {
+        {//TODO:FIXME: THIS IS BULLSHIT BY INTEL need to fix the clearing
             long ptr = UploadStream.INSTANCE.upload(this.queueMetaBuffer, 0, 16*5);
             MemoryUtil.memPutInt(ptr +  0, firstDispatchSize);
             MemoryUtil.memPutInt(ptr +  4, 1);
@@ -187,6 +188,12 @@ public class HierarchicalOcclusionTraverser {
                 MemoryUtil.memPutInt(ptr + (i*16)+ 8, 1);
                 MemoryUtil.memPutInt(ptr + (i*16)+12, 0);
             }
+            //TODO: Move the first queue to a persistent list so its not updated every frame
+
+            ptr = UploadStream.INSTANCE.upload(this.scratchQueueA, 0, 4L*initialQueueSize);
+            for (int i = 0; i < initialQueueSize; i++) {
+                MemoryUtil.memPutInt(ptr + 4L*i, 0);
+            }
 
             UploadStream.INSTANCE.commit();
         }
@@ -229,7 +236,7 @@ public class HierarchicalOcclusionTraverser {
     }
 
     private void forwardDownloadResult(long ptr, long size) {
-        int count = MemoryUtil.memGetInt(ptr);
+        int count = MemoryUtil.memGetInt(ptr);ptr += 8;//its 8 since we need to skip the second value (which is empty)
         if (count < 0 || count > 50000) {
             throw new IllegalStateException("Count unexpected extreme value: " + count);
         }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/NodeChildRequest.java

@@ -10,28 +10,44 @@ class NodeChildRequest {
 
     private byte results;
     private byte mask;
+    private byte existenceMask = 0;
 
     NodeChildRequest(long nodePos) {
         this.nodePos = nodePos;
     }
 
-    public int getChildMeshResult(int childIdx) {
+    public int getChildMesh(int childIdx) {
         if ((this.mask&(1<<childIdx))==0) {
             throw new IllegalStateException("Tried getting mesh result of child not in mask");
         }
         return this.childStates[childIdx];
     }
 
-    public void putChildChildExistence(int childIdx, byte childExistence) {
+    public void setChildChildExistence(int childIdx, byte childExistence) {
         if ((this.mask&(1<<childIdx))==0) {
-            throw new IllegalStateException("Tried putting child into request which isnt in mask");
+            throw new IllegalStateException("Tried setting child child existence in request when child isnt in mask");
         }
         this.childChildExistence[childIdx] = childExistence;
+        this.existenceMask |= (byte) (1<<childIdx);
     }
 
-    public int putChildResult(int childIdx, int mesh) {
+    public boolean hasChildChildExistence(int childId) {
+        if ((this.mask&(1<<childId))==0) {
+            throw new IllegalStateException("Tried getting child child existence set of child not in mask");
+        }
+        return (this.existenceMask&(1<<childId))!=0;
+    }
+
+    public byte getChildChildExistence(int childIdx) {
+        if (!this.hasChildChildExistence(childIdx)) {
+            throw new IllegalStateException("Tried getting child child existence when child child existence for child was not set");
+        }
+        return this.childChildExistence[childIdx];
+    }
+
+    public int setChildMesh(int childIdx, int mesh) {
         if ((this.mask&(1<<childIdx))==0) {
-            throw new IllegalStateException("Tried putting child into request which isnt in mask");
+            throw new IllegalStateException("Tried setting child mesh when child isnt in mask");
         }
         //Note the mesh can be -ve meaning empty mesh, but we should still mark that node as having a result
         boolean isFirstInsert = (this.results&(1<<childIdx))==0;
@@ -54,6 +70,7 @@ class NodeChildRequest {
         byte prev = this.results;
         this.results &= (byte) ~MSK;
         this.mask &= (byte) ~MSK;
+        this.existenceMask &= (byte) ~MSK;
         int mesh = this.childStates[childIdx];
         this.childStates[childIdx] = -1;
         if ((prev&MSK)==0) {
@@ -82,4 +99,5 @@ class NodeChildRequest {
     public byte getMsk() {
         return this.mask;
     }
+
 }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/NodeManager2.java

@@ -2,7 +2,6 @@ package me.cortex.voxy.client.core.rendering.hierachical2;
 
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
 import it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap;
-import me.cortex.voxy.client.core.VoxelCore;
 import me.cortex.voxy.client.core.gl.GlBuffer;
 import me.cortex.voxy.client.core.rendering.building.BuiltSection;
 import me.cortex.voxy.client.core.rendering.building.SectionUpdateRouter;
@@ -11,11 +10,7 @@ import me.cortex.voxy.client.core.rendering.util.UploadStream;
 import me.cortex.voxy.client.core.util.ExpandingObjectAllocationList;
 import me.cortex.voxy.common.Logger;
 import me.cortex.voxy.common.world.WorldEngine;
-import me.cortex.voxy.commonImpl.VoxyCommon;
 import me.jellysquid.mods.sodium.client.util.MathUtil;
-import org.lwjgl.system.MemoryUtil;
-
-import static me.cortex.voxy.client.core.rendering.hierachical2.NodeStore.NODE_ID_MSK;
 
 public class NodeManager2 {
     //Assumptions:
@@ -27,7 +22,10 @@ public class NodeManager2 {
     // For the queue processing, will need a redirect node-value type
     //      since for inner node child resize gpu could take N frames to update
 
+    public static final int NULL_GEOMETRY_ID = -1;
+    public static final int EMPTY_GEOMETRY_ID = -2;
 
+    public static final int NODE_ID_MSK = ((1<<24)-1);
     private static final int NODE_TYPE_MSK = 0b11<<30;
     private static final int NODE_TYPE_LEAF = 0b00<<30;
     private static final int NODE_TYPE_INNER = 0b01<<30;
@@ -95,28 +93,82 @@ public class NodeManager2 {
         if ((nodeId&NODE_TYPE_MSK)==NODE_TYPE_REQUEST) {
             //For a request
             if ((nodeId&REQUEST_TYPE_MSK)==REQUEST_TYPE_SINGLE) {
+                var request = this.singleRequests.get(nodeId&NODE_ID_MSK);
+                request.setMesh(this.uploadReplaceSection(request.getMesh(), sectionResult));
 
+                //sectionResult has a cheeky childExistence field that we can use to set the request too, this is just
+                // because processChildChange is only ever invoked when child existence changes, so we still need to
+                // populate the request somehow, it will only set it if it hasnt been set before
+                if (!request.hasChildExistenceSet()) {
+                    request.setChildExistence(sectionResult.childExistence);
+                }
+
+                if (request.isSatisfied()) {
+                    this.singleRequests.release(nodeId&NODE_ID_MSK);
+                    this.finishRequest(request);
+                }
             } else if ((nodeId&REQUEST_TYPE_MSK)==REQUEST_TYPE_CHILD) {
+                var request = this.childRequests.get(nodeId&NODE_ID_MSK);
+                int childId = getChildIdx(pos);
+                request.setChildMesh(childId, this.uploadReplaceSection(request.getChildMesh(childId), sectionResult));
+                if (!request.hasChildChildExistence(childId)) {
+                    request.setChildChildExistence(childId, sectionResult.childExistence);
+                }
 
+                if (request.isSatisfied()) {
+                    this.finishRequest(nodeId&NODE_ID_MSK, request);
+                }
             } else {
                 throw new IllegalStateException();
             }
         } else if ((nodeId&NODE_TYPE_MSK)==NODE_TYPE_INNER || (nodeId&NODE_TYPE_MSK)==NODE_TYPE_LEAF) {
             // Just doing a geometry update
+            if (this.updateNodeGeometry(nodeId&NODE_ID_MSK, sectionResult) != 0) {
+                this.nodeUpdates.add(nodeId&NODE_ID_MSK);
+            }
+        }
     }
 
+    private int uploadReplaceSection(int meshId, BuiltSection section) {
+        if (section.isEmpty()) {
+            if (meshId != NULL_GEOMETRY_ID && meshId != EMPTY_GEOMETRY_ID) {
+                this.geometryManager.removeSection(meshId);
+            }
+            section.free();
+            return EMPTY_GEOMETRY_ID;
+        }
+        if (meshId != NULL_GEOMETRY_ID && meshId != EMPTY_GEOMETRY_ID) {
+            return this.geometryManager.uploadReplaceSection(meshId, section);
+        }
+        return this.geometryManager.uploadSection(section);
     }
 
-    //==================================================================================================================
+    private int updateNodeGeometry(int node, BuiltSection geometry) {
-    public void processRequest(long pos) {
+        int previousGeometry = this.nodeData.getNodeGeometry(node);
-        int nodeId = this.activeSectionMap.get(pos);
+        int newGeometry = EMPTY_GEOMETRY_ID;
-        if (nodeId == -1) {
+        if (previousGeometry != EMPTY_GEOMETRY_ID && previousGeometry != NULL_GEOMETRY_ID) {
-            Logger.error("Got request for pos " + WorldEngine.pprintPos(pos) + " but it was not in active map, ignoring!");
+            if (!geometry.isEmpty()) {
-            return;
+                newGeometry = this.geometryManager.uploadReplaceSection(previousGeometry, geometry);
+            } else {
+                this.geometryManager.removeSection(previousGeometry);
+            }
+        } else {
+            if (!geometry.isEmpty()) {
+                newGeometry = this.geometryManager.uploadSection(geometry);
+            }
         }
 
+        if (previousGeometry != newGeometry) {
+            this.nodeData.setNodeGeometry(node, newGeometry);
+        }
+        if (previousGeometry == newGeometry) {
+            return 0;//No change
+        } else if (previousGeometry == EMPTY_GEOMETRY_ID || previousGeometry == NULL_GEOMETRY_ID) {
+            return 1;//Became non-empty/non-null
+        } else {
+            return 2;//Became empty
+        }
     }
-
     //==================================================================================================================
 
     public void processChildChange(long pos, byte childExistence) {
@@ -126,6 +178,159 @@ public class NodeManager2 {
             return;
         }
 
+
+        if ((nodeId&NODE_TYPE_MSK)==NODE_TYPE_REQUEST) {
+            //For a request
+            if ((nodeId&REQUEST_TYPE_MSK)==REQUEST_TYPE_SINGLE) {
+                var request = this.singleRequests.get(nodeId&NODE_ID_MSK);
+                request.setChildExistence(childExistence);
+                if (request.isSatisfied()) {
+                    this.singleRequests.release(nodeId&NODE_ID_MSK);
+                    this.finishRequest(request);
+                }
+            } else if ((nodeId&REQUEST_TYPE_MSK)==REQUEST_TYPE_CHILD) {
+                var request = this.childRequests.get(nodeId&NODE_ID_MSK);
+                request.setChildChildExistence(getChildIdx(pos), childExistence);
+                if (request.isSatisfied()) {
+                    this.finishRequest(nodeId&NODE_ID_MSK, request);
+                }
+            } else {
+                throw new IllegalStateException();
+            }
+        } else if ((nodeId&NODE_TYPE_MSK)==NODE_TYPE_INNER) {
+            //Very complex and painful operation
+
+        } else if ((nodeId&NODE_TYPE_MSK)==NODE_TYPE_LEAF) {
+            //Just need to update the child node data, nothing else
+            this.nodeData.setNodeChildExistence(nodeId&NODE_ID_MSK, childExistence);
+        }
+    }
+
+    //==================================================================================================================
+
+    private void finishRequest(SingleNodeRequest request) {
+        int id = this.nodeData.allocate();
+        this.nodeData.setNodePosition(id, request.getPosition());
+        this.nodeData.setNodeGeometry(id, request.getMesh());
+        this.nodeData.setNodeChildExistence(id, request.getChildExistence());
+        //TODO: this (or remove)
+        //this.nodeData.setNodeType();
+        this.activeSectionMap.put(request.getPosition(), id|NODE_TYPE_LEAF);//Assume that the result of any single request type is a leaf node
+        this.nodeUpdates.add(id);
+    }
+
+    private void finishRequest(int requestId, NodeChildRequest request) {
+        int parentNodeId = this.activeSectionMap.get(request.getPosition());
+        if (parentNodeId == -1 || (parentNodeId&NODE_TYPE_MSK)==NODE_TYPE_REQUEST) {
+            throw new IllegalStateException("CRITICAL BAD STATE!!! finishRequest tried to finish for a node that no longer exists in the map or has become a request type somehow?!!?!!" + WorldEngine.pprintPos(request.getPosition()) + " " + parentNodeId);
+        }
+
+        if ((parentNodeId&NODE_TYPE_MSK)==NODE_TYPE_LEAF) {
+            int msk = Byte.toUnsignedInt(request.getMsk());
+            int base = this.nodeData.allocate(Integer.bitCount(msk));
+            int offset = -1;
+            for (int childIdx = 0; childIdx < 8; childIdx++) {
+                if ((msk&(1<<childIdx)) == 0) {
+                    continue;
+                }
+                offset++;
+
+                long childPos = makeChildPos(request.getPosition(), childIdx);
+                int childNodeId = base+offset;
+                //Fill in node
+                this.nodeData.setNodePosition(childNodeId, childPos);
+                this.nodeData.setNodeChildExistence(childNodeId, request.getChildChildExistence(childIdx));
+                this.nodeData.setNodeGeometry(childNodeId, request.getChildMesh(childIdx));
+                //Mark for update
+                this.nodeUpdates.add(childNodeId);
+                //Put in map
+                int pid = this.activeSectionMap.put(childPos, childNodeId|NODE_TYPE_LEAF);
+                if ((pid&NODE_TYPE_MSK) != NODE_TYPE_REQUEST) {
+                    throw new IllegalStateException("Put node in map from request but type was not request: " + pid + " " + WorldEngine.pprintPos(childPos));
+                }
+            }
+            //Free request
+            this.childRequests.release(requestId);
+            //Update the parent
+            this.nodeData.setChildPtr(parentNodeId, base);
+            this.nodeData.setChildPtrCount(parentNodeId, offset+1);
+            this.nodeData.setNodeRequest(parentNodeId, 0);//TODO: create a better null request
+            this.nodeData.unmarkRequestInFlight(parentNodeId);
+            this.nodeUpdates.add(parentNodeId);
+        } else if ((parentNodeId&NODE_TYPE_MSK)==NODE_TYPE_INNER) {
+            System.err.println("TODO: FIXME FINISH: finishRequest NODE_TYPE_INNER");
+        } else {
+            throw new IllegalStateException();
+        }
+    }
+
+    //==================================================================================================================
+    public void processRequest(long pos) {
+        int nodeId = this.activeSectionMap.get(pos);
+        if (nodeId == -1) {
+            Logger.error("Got request for pos " + WorldEngine.pprintPos(pos) + " but it was not in active map, ignoring!");
+            return;
+        }
+        int nodeType = nodeId&NODE_TYPE_MSK;
+        nodeId &= NODE_ID_MSK;
+        if (nodeType == NODE_TYPE_REQUEST) {
+            Logger.error("Tried processing request for pos: " + WorldEngine.pprintPos(pos) + " but its type was a request, ignoring!");
+            return;
+        } else if (nodeType != NODE_TYPE_LEAF && nodeType != NODE_TYPE_INNER ) {
+            throw new IllegalStateException("Unknown node type: " + nodeType);
+        }
+
+        if (this.nodeData.isNodeRequestInFlight(nodeId)) {
+            Logger.warn("Tried processing a node that already has a request in flight: " + nodeId + " pos: " + WorldEngine.pprintPos(pos) + " ignoring");
+            return;
+        }
+        this.nodeData.markRequestInFlight(nodeId);
+
+        if (nodeType == NODE_TYPE_LEAF) {
+            //The hard one of processRequest, spin up a new request for the node
+            this.makeLeafChildRequest(nodeId);
+
+        } else {//nodeType == NODE_TYPE_INNER
+            //TODO: assert that the node isnt already being watched for geometry, if it is, just spit out a warning? and ignore
+
+            if (!this.updateRouter.watch(pos, WorldEngine.UPDATE_TYPE_BLOCK_BIT)) {
+                //FIXME: i think this can occur accidently? when removing nodes or something creating leaf nodes
+                // or other, the node might be wanted to be watched by gpu, but cpu already started watching it a few frames ago
+                Logger.warn("Node: " + nodeId + " at pos: " + WorldEngine.pprintPos(pos) + " got update request, but geometry was already being watched");
+            }
+        }
+    }
+
+    private void makeLeafChildRequest(int nodeId) {
+        long pos = this.nodeData.nodePosition(nodeId);
+        byte childExistence = this.nodeData.getNodeChildExistence(nodeId);
+
+        //Enqueue a leaf expansion request
+        var request = new NodeChildRequest(pos);
+        int requestId = this.childRequests.put(request);
+
+        //Only request against the childExistence mask, since the guarantee is that if childExistence bit is not set then that child is guaranteed to be empty
+        for (int i = 0; i < 8; i++) {
+            if ((childExistence&(1<<i))==0) {
+                //Dont watch or enqueue the child node cause it doesnt exist
+                continue;
+            }
+            long childPos = makeChildPos(pos, i);
+            request.addChildRequirement(i);
+
+            //Insert all the children into the tracking map with the node id
+            int pid = this.activeSectionMap.put(childPos, requestId|NODE_TYPE_REQUEST|REQUEST_TYPE_CHILD);
+            if (pid != -1) {
+                throw new IllegalStateException("Leaf request creation failed to insert child into map as a mapping already existed for the node! pos: " + WorldEngine.pprintPos(childPos) + " id: " + pid);
+            }
+
+            //Watch and request the child node at the given position
+            if (!this.updateRouter.watch(childPos, WorldEngine.UPDATE_FLAGS)) {
+                throw new IllegalStateException("Failed to watch childPos");
+            }
+        }
+
+        this.nodeData.setNodeRequest(nodeId, requestId);
     }
 
     //==================================================================================================================
@@ -141,4 +346,25 @@ public class NodeManager2 {
         this.nodeUpdates.clear();
         return true;
     }
+
+
+
+    //==================================================================================================================
+    private static int getChildIdx(long pos) {
+        int x = WorldEngine.getX(pos);
+        int y = WorldEngine.getY(pos);
+        int z = WorldEngine.getZ(pos);
+        return (x&1)|((y&1)<<2)|((z&1)<<1);
+    }
+
+    private static long makeChildPos(long basePos, int addin) {
+        int lvl = WorldEngine.getLevel(basePos);
+        if (lvl == 0) {
+            throw new IllegalArgumentException("Cannot create a child lower than lod level 0");
+        }
+        return WorldEngine.getWorldSectionId(lvl-1,
+                (WorldEngine.getX(basePos)<<1)|(addin&1),
+                (WorldEngine.getY(basePos)<<1)|((addin>>2)&1),
+                (WorldEngine.getZ(basePos)<<1)|((addin>>1)&1));
+    }
 }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/NodeStore.java

@@ -8,9 +8,9 @@ public final class NodeStore {
     public static final int NODE_ID_MSK = ((1<<24)-1);
     public static final int REQUEST_ID_MSK = ((1<<16)-1);
     public static final int GEOMETRY_ID_MSK = (1<<24)-1;
-    public static final int MAX_GEOMETRY_ID = GEOMETRY_ID_MSK-2;
+    public static final int MAX_GEOMETRY_ID = (1<<24)-3;
-    public static final int ABSENT_GEOMETRY_ID = GEOMETRY_ID_MSK-1;//Value for if want to clear geometry and make gpu request it if its needed
+    private static final int SENTINEL_NULL_GEOMETRY_ID = (1<<24)-1;
-    private static final int SENTINEL_EMPTY_GEOMETRY_ID = GEOMETRY_ID_MSK;
+    private static final int SENTINEL_EMPTY_GEOMETRY_ID = (1<<24)-2;
     private static final int SENTINEL_NULL_NODE_ID = NODE_ID_MSK -1;
     private static final int SENTINEL_REQUEST_ID = REQUEST_ID_MSK -1;
     private static final int LONGS_PER_NODE = 4;
@@ -104,20 +104,33 @@ public final class NodeStore {
     public int getNodeGeometry(int node) {
         long data = this.localNodeData[id2idx(node)+1];
         int geometryPtr = (int) (data&GEOMETRY_ID_MSK);
-        if (geometryPtr == SENTINEL_EMPTY_GEOMETRY_ID) {
+        if (geometryPtr == SENTINEL_NULL_GEOMETRY_ID) {
             return -1;
         }
+        if (geometryPtr == SENTINEL_EMPTY_GEOMETRY_ID) {
+            return -2;
+        }
         return geometryPtr;
     }
 
     public void setNodeGeometry(int node, int geometryId) {
-        if (geometryId>MAX_GEOMETRY_ID || geometryId<-1) {
+
-            throw new IllegalArgumentException("Geometry ptr greater than MAX_GEOMETRY_ID or less than -1 : " + geometryId);
+        if (geometryId>MAX_GEOMETRY_ID) {
+            throw new IllegalArgumentException("Geometry ptr greater than MAX_GEOMETRY_ID: " + geometryId);
         }
+
         if (geometryId == -1) {
+            geometryId = SENTINEL_NULL_GEOMETRY_ID;
+        }
+
+        if (geometryId == -2) {
             geometryId = SENTINEL_EMPTY_GEOMETRY_ID;
         }
 
+        if (geometryId < 0) {
+            throw new IllegalArgumentException("Geometry ptr less than -1 : " + geometryId);
+        }
+
         int idx = id2idx(node)+1;
         long data = this.localNodeData[idx];
         data &= ~GEOMETRY_ID_MSK;
@@ -165,6 +178,9 @@ public final class NodeStore {
         this.localNodeData[id2idx(nodeId)+1] |= 1L<<63;
     }
 
+    public void unmarkRequestInFlight(int nodeId) {
+        this.localNodeData[id2idx(nodeId)+1] &= ~(1L<<63);
+    }
     public boolean isNodeRequestInFlight(int nodeId) {
         return ((this.localNodeData[id2idx(nodeId)+1]>>63)&1)!=0;
     }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical2/SingleNodeRequest.java

@@ -8,6 +8,7 @@ class SingleNodeRequest {
 
     SingleNodeRequest(long nodePos) {
         this.nodePos = nodePos;
+        this.mesh = -1;
     }
 
     public void setChildExistence(byte childExistence) {
@@ -37,4 +38,8 @@ class SingleNodeRequest {
     public byte getChildExistence() {
         return this.childExistence;
     }
+
+    public boolean hasChildExistenceSet() {
+        return (this.setMsk&2)!=0;
+    }
 }

src/main/java/me/cortex/voxy/common/world/WorldEngine.java

@@ -6,6 +6,7 @@ import me.cortex.voxy.common.world.service.SectionSavingService;
 import me.cortex.voxy.common.world.service.VoxelIngestService;
 import me.cortex.voxy.common.storage.StorageBackend;
 import me.cortex.voxy.common.thread.ServiceThreadPool;
+import me.cortex.voxy.commonImpl.VoxyCommon;
 
 import java.util.Arrays;
 import java.util.function.Consumer;
@@ -151,6 +152,7 @@ public class WorldEngine {
                         long oldId = worldSection.set(x, y, z, newId);
                         nonAirCountDelta += Mapper.isAir(oldId)==Mapper.isAir(newId)?0:(Mapper.isAir(newId)?-1:1 );
                         didStateChange |= newId != oldId;
+                        //if (newId != oldId) {VoxyCommon.breakpoint();}
                     }
                 }
             }
@@ -163,9 +165,7 @@ public class WorldEngine {
             }
 
             if (didStateChange||(emptinessStateChange!=0)) {
-                //Mark the section as dirty (enqueuing saving and geometry rebuild) and move to parent mip level
+                this.markDirty(worldSection, (didStateChange?UPDATE_TYPE_BLOCK_BIT:0)|(emptinessStateChange!=0?UPDATE_TYPE_CHILD_EXISTENCE_BIT:0));
-                //TODO: have an update type! so that then e.g. if the child empty set changes it doesnt cause chunk rebuilds!
-                this.markDirty(worldSection);
             }
 
             //Need to release the section after using it

src/main/resources/assets/voxy/shaders/lod/hierarchical/node.glsl

@@ -29,6 +29,7 @@ struct UnpackedNode {
 
 #define NULL_NODE ((1<<24)-1)
 #define NULL_MESH ((1<<24)-1)
+#define EMPTY_MESH ((1<<24)-2)
 
 void unpackNode(out UnpackedNode node, uint nodeId) {
     uvec4 compactedNode = nodes[nodeId];
@@ -55,7 +56,7 @@ bool hasMesh(in UnpackedNode node) {
 }
 
 bool isEmptyMesh(in UnpackedNode node) {
-    return node.meshPtr == (NULL_MESH-1);//Specialcase
+    return node.meshPtr == EMPTY_MESH;//Specialcase
 }
 
 bool hasChildren(in UnpackedNode node) {

src/main/resources/assets/voxy/shaders/lod/hierarchical/screenspace.glsl

@@ -64,14 +64,14 @@ void setupScreenspace(in UnpackedNode node) {
 
     //printf("Screenspace MIN: %f, %f, %f  MAX: %f, %f, %f", minBB.x,minBB.y,minBB.z, maxBB.x,maxBB.y,maxBB.z);
 
-    size = maxBB.xy - minBB.xy;
+    size = (maxBB.xy - minBB.xy)*0.5f;//We half it for implicit conversion to screenspace
 
 }
 
 //Checks if the node is implicitly culled (outside frustum)
 bool outsideFrustum() {
-    //printf("Cull point (%f %f %f)x(%f %f %f)", maxBB.x, maxBB.y, maxBB.z, minBB.x, minBB.y, minBB.z);
+    printf("Cull point (%f %f %f)x(%f %f %f)", maxBB.x, maxBB.y, maxBB.z, minBB.x, minBB.y, minBB.z);
-    return any(lessThanEqual(maxBB, vec3(-1f, -1f, 0f))) || any(lessThanEqual(vec3(1f, 1f, 1f), minBB));
+    return any(lessThanEqual(maxBB, vec3(-1.0f, -1.0f, 0.0f))) || any(lessThanEqual(vec3(1.0f, 1.0f, 1.0f), minBB));
 }
 
 bool isCulledByHiz() {
@@ -80,12 +80,12 @@ bool isCulledByHiz() {
     }
     vec2 ssize = size.xy * vec2(ivec2(screenW, screenH));
     float miplevel = ceil(log2(max(max(ssize.x, ssize.y),1)));
-    vec2 midpoint = (maxBB.xy + minBB.xy)*0.5;
+    vec2 midpoint = (maxBB.xy + minBB.xy)*0.5f;
-    return textureLod(hizDepthSampler, vec3(midpoint, minBB.z), miplevel) > 0.0001;
+    return textureLod(hizDepthSampler, vec3(midpoint, minBB.z), miplevel) > 0.0001f;
 }
 
 //Returns if we should decend into its children or not
 bool shouldDecend() {
-    printf("Screen area %f: %f, %f", (size.x*size.y*float(screenW)*float(screenH)), float(screenW), float(screenH));
+    printf("Screen area %f: %f, %f", (size.x*size.y*float(screenW)*float(screenH)), float(size.x), float(size.y));
     return (size.x*size.y*screenW*screenH) > minSSS;
 }