fix fluid sim null ptr bug

buildNumber.properties

@@ -1,3 +1,3 @@
 #maven.buildNumber.plugin properties file
-#Sun Dec 01 12:58:18 EST 2024
+#Sun Dec 01 15:41:36 EST 2024
-buildNumber=462
+buildNumber=471

docs/src/progress/renderertodo.md

@@ -1207,6 +1207,7 @@ Add more debugging tools for fluids
 Remove conditional update check in fluid sim
 Explicit memory management of fluid chunk cache buffers
 Fix GriddedDataCellManager memory leak caused by physics and ConcurrentHashMap
+Fix fluid sim null pointer bug with unallocated chunks
 
 
 

src/fluid/includes/solver_consts.h

@@ -2,5 +2,6 @@
 #define SOLVER_CONSTS_H
 
 #define LINEARSOLVERTIMES 5
+#define VECTOR_DIFFUSE_TIMES 1
 
 #endif

src/fluid/src/fluidsim.c

@@ -118,7 +118,7 @@ void simulate(
     // printLayer(chunks[0]->u0[CENTER_LOC],targetLayer);
     //solve vector diffusion
     {
-        for(int l = 0; l < LINEARSOLVERTIMES; l++){
+        for(int l = 0; l < VECTOR_DIFFUSE_TIMES; l++){
             //solve vector diffusion
             for(int i = 0; i < numChunks; i++){
                 Chunk * currentChunk = chunks[i];

src/fluid/src/javainterface.c

@@ -148,13 +148,22 @@ void readInChunks(JNIEnv * env, jobject chunkList, Environment * environment){
     int chunkMask;
 
     //solve chunk mask
+    int cSideArrPos = 0;
     for(int i = 0; i < numChunks; i++){
         chunkJRaw = getChunk(i);
         chunkMask = calculateChunkMask(env,getBuffArr(dJId));
         (*env)->SetIntField(env,chunkJRaw,chunkmaskJId,chunkMask);
 
+        //skip this chunk if the center array is not allocated (must not have been removed yet?)
+        if(
+            (*env)->GetObjectArrayElement(env,(*env)->GetObjectField(env,chunkJRaw,dJId),CENTER_LOC) == NULL ||
+            (*env)->GetDirectBufferAddress(env,(*env)->GetObjectArrayElement(env,(*env)->GetObjectField(env,chunkJRaw,dJId),CENTER_LOC)) == NULL
+        ){
+            continue;
+        }
+
         Chunk * newChunk;
-        if(i >= stbds_arrlen(chunkViewC)){
+        if(cSideArrPos >= stbds_arrlen(chunkViewC)){
             // printf("allocate chunk %d\n",i);
             // fflush(stdout);
             newChunk = (Chunk *)malloc(sizeof(Chunk));
@@ -164,10 +173,11 @@ void readInChunks(JNIEnv * env, jobject chunkList, Environment * environment){
             // printf("new chunk %p\n",chunks[i]);
             // fflush(stdout);
         } else {
-            newChunk = chunkViewC[i];
+            newChunk = chunkViewC[cSideArrPos];
             // printf("get chunk %d: %p\n",i,newChunk);
             // fflush(stdout);
         }
+        cSideArrPos++;
         jd = (*env)->GetObjectField(env,chunkJRaw,dJId);
         jd0 = (*env)->GetObjectField(env,chunkJRaw,d0JId);
         u = (*env)->GetObjectField(env,chunkJRaw,uJId);

src/main/java/electrosphere/client/fluid/cells/FluidCellManager.java

@@ -58,7 +58,7 @@ public class FluidCellManager {
     int drawStepdownInterval = 3;
     int drawStepdownValue = 25;
 
-    double drawRadius = 50;
+    double drawRadius = 5 * ServerTerrainChunk.CHUNK_PLACEMENT_OFFSET;
     
     int physicsRadius = 3;
     

src/main/java/electrosphere/server/fluid/manager/ServerFluidChunk.java

@@ -460,6 +460,14 @@ public class ServerFluidChunk {
         }
     }
 
+    /**
+     * Checks if this chunk is allocated or not
+     * @return true if it is allocated, false otherwise
+     */
+    public boolean isAllocated(){
+        return this.bWeights[CENTER_BUFF] != null;
+    }
+
     /**
      * Allocates the central arrays for this chunk
      */

src/main/java/electrosphere/server/fluid/manager/ServerFluidManager.java

@@ -72,7 +72,7 @@ public class ServerFluidManager {
     ServerTerrainManager serverTerrainManager;
 
     //controls whether fluid simulation should actually happen or not
-    boolean simulate = false;
+    boolean simulate = true;
 
     @Exclude
     /**
@@ -291,7 +291,9 @@ public class ServerFluidManager {
     public void queue(int worldX, int worldY, int worldZ){
         if(simulate){
             ServerFluidChunk fluidChunk = this.getChunk(worldX, worldY, worldZ);
-            this.simulationQueue.add(fluidChunk);
+            if(fluidChunk.isAllocated()){
+                this.simulationQueue.add(fluidChunk);
+            }
         }
     }