cellular sim determinism

src/main/c/includes/fluid/queue/chunk.h

@@ -24,6 +24,11 @@
  */
 #define DIM 18
 
+/**
+ * The spacing between chunks
+ */
+#define CHUNK_SPACING 16
+
 /**
  * A chunk
 */

src/main/c/src/fluid/env/environment.c

@@ -8,7 +8,7 @@
  * Creates an environment
  */
 LIBRARY_API Environment * fluid_environment_create(){
-    Environment * rVal = (Environment *)malloc(sizeof(Environment));
+    Environment * rVal = (Environment *)calloc(1,sizeof(Environment));
     rVal->queue.cellularQueue = NULL;
     rVal->queue.gridQueue = NULL;
     return rVal;

src/main/c/src/fluid/queue/islandsolver.c

@@ -16,7 +16,7 @@
  * Creates a fluid island solver
  */
 LIBRARY_API FluidIslandSolver * fluid_island_solver_create(){
-    FluidIslandSolver * rVal = (FluidIslandSolver *)malloc(sizeof(FluidIslandSolver));
+    FluidIslandSolver * rVal = (FluidIslandSolver *)calloc(1,sizeof(FluidIslandSolver));
 
     rVal->sparseArray = fluid_sparse_array_create();
     rVal->remaining = NULL;

src/main/c/src/fluid/queue/javainterface.c

@@ -203,7 +203,7 @@ int readInChunks(JNIEnv * env, jobject chunkList, Environment * environment){
         if(cSideArrPos >= stbds_arrlen(chunkViewC)){
             // printf("allocate chunk %d\n",i);
             // fflush(stdout);
-            newChunk = (Chunk *)malloc(sizeof(Chunk));
+            newChunk = (Chunk *)calloc(1,sizeof(Chunk));
             // printf("new chunk %p\n",newChunk);
             // fflush(stdout);
             stbds_arrput(chunkViewC,newChunk);

src/main/c/src/fluid/queue/metadatacalc.c

@@ -94,6 +94,6 @@ void updateMetadata(JNIEnv * env, int numChunks, Chunk ** passedInChunks, Enviro
 
 
     //update frame state
-    environment->state.frame += 1;
+    environment->state.frame = environment->state.frame + 1;
 }
 

src/main/c/src/fluid/queue/sparse.c

@@ -16,7 +16,7 @@ int solveOffset(int chunkPos);
 LIBRARY_API SparseChunkArray * fluid_sparse_array_create(){
 
     //allocate the object itself
-    SparseChunkArray * rVal = (SparseChunkArray *)malloc(sizeof(SparseChunkArray));
+    SparseChunkArray * rVal = (SparseChunkArray *)calloc(1,sizeof(SparseChunkArray));
     if(rVal == NULL){
         return NULL;
     }

src/main/c/src/fluid/sim/cellular/cellular.c

@@ -33,11 +33,16 @@ LIBRARY_API void fluid_cellular_simulate(Environment * environment){
 
     Chunk ** chunks = environment->queue.cellularQueue;
     int chunkCount = stbds_arrlen(chunks);
+    int worldX, worldY, worldZ;
+    int permuteX, permuteY, permuteZ;
 
     for(int cellIndex = 0; cellIndex < chunkCount; cellIndex++){
         Chunk * currentChunk = chunks[cellIndex];
-        //simulate here
+        worldX = currentChunk->x;
+        worldY = currentChunk->y;
+        worldZ = currentChunk->z;
 
+        //simulate here
         float *d  = currentChunk->d[CENTER_LOC];
         float * bounds = currentChunk->bounds[CENTER_LOC];
         float density;
@@ -45,8 +50,17 @@ LIBRARY_API void fluid_cellular_simulate(Environment * environment){
 
         // printf("%f %f %f %d %d %d\n",bounds[IX(0,1,1)],bounds[IX(1,0,1)],bounds[IX(1,1,0)],currentChunk->x,currentChunk->y,currentChunk->z);
         for(int y = 0; y < DIM; y++){
-            int shift = randutils_map(randutils_rand2(environment->state.frame,y),0,FLUID_CELLULAR_KERNEL_PERMUTATIONS - 1);
-            int permutation = randutils_map(randutils_rand2(environment->state.frame,y + 1),0,FLUID_CELLULAR_KERNEL_PERMUTATIONS - 1);
+            if(y == 0){
+                permuteY = DIM-2 + (CHUNK_SPACING * (worldY - 1));
+
+            } else if(y == DIM-1){
+                permuteY = 1 + (CHUNK_SPACING * (worldY + 1));
+
+            } else {
+                permuteY = y + (CHUNK_SPACING * worldY);
+            }
+            int shift = randutils_map(randutils_rand2(environment->state.frame,permuteY),0,FLUID_CELLULAR_KERNEL_PERMUTATIONS - 1);
+            // int permutation = randutils_map(randutils_rand2(environment->state.frame,y + 1),0,FLUID_CELLULAR_KERNEL_PERMUTATIONS - 1);
             for(int x = 0; x < DIM; x++){
                 for(int z = 0; z < DIM; z++){
 
@@ -119,15 +133,35 @@ LIBRARY_API void fluid_cellular_simulate(Environment * environment){
                             }
                         }
                         //transfer laterally
-                        // int permutation = (z % (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2)) + ((x % (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2)) * (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2));
+                        //calculate permutation based on the location of the cell
+                        if(x == 0){
+                            permuteX = DIM-2 + (CHUNK_SPACING * (worldX - 1));
+
+                        } else if(x == DIM-1){
+                            permuteX = 1 + (CHUNK_SPACING * (worldX + 1));
+
+                        } else {
+                            permuteX = x + (CHUNK_SPACING * worldX);
+                        }
+                        if(z == 0){
+                            permuteZ = DIM-2 + (CHUNK_SPACING * (worldZ - 1));
+
+                        } else if(z == DIM-1){
+                            permuteZ = 1 + (CHUNK_SPACING * (worldZ + 1));
+                            
+                        } else {
+                            permuteZ = z + (CHUNK_SPACING * worldZ);
+                        }
+                        int permutation = (permuteZ % (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2)) + ((permuteX % (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2)) * (FLUID_CELLULAR_KERNEL_PERMUTATIONS / 2));
                         // for(int j = 0; j < FLUID_CELLULAR_KERNEL_SIZE; j++){
-                            int nX = x + fluid_cellular_kernel_x[permutation][shift];
-                            int nZ = z + fluid_cellular_kernel_z[permutation][shift];
+                            int nX = x + fluid_cellular_kernel_x[shift][permutation];
+                            int nZ = z + fluid_cellular_kernel_z[shift][permutation];
                             if(nX < 0 || nX >= DIM || nZ < 0 || nZ >= DIM){
                                 continue;
                             }
                             if(bounds[IX(nX,y,nZ)] <= BOUND_CUTOFF_VALUE){
                                 if(d[IX(nX,y,nZ)] <= MIN_FLUID_VALUE){
+                                    // printf("%d %d %d --> %d %d %d \n",x,y,z,nX,y,nZ);
                                     d[IX(nX,y,nZ)] = d[IX(x,y,z)];
                                     d[IX(x,y,z)] = MIN_FLUID_VALUE;
                                     break;

src/main/c/src/mem/pool.c

@@ -13,7 +13,7 @@
  * @return The pool
  */
 POOL * pool_create(int blockSize){
-    POOL * p = (POOL*)malloc(sizeof(POOL) );
+    POOL * p = (POOL*)calloc(1,sizeof(POOL) );
     p->table = NULL;
     p->blockSize = blockSize;
     p->posCurr = 0;

src/test/c/fluid/sim/cellular/cellular_tests.c

@@ -90,6 +90,7 @@ int fluid_sim_cellular_bounds_test1(){
         rVal += assertEqualsFloat(transferedVal,CELLULAR_TEST_PLACE_VAL,"Value was overwritten on border! -- %f %f \n");
     }
 
+    printf("\n");
     return rVal;
 }
 
@@ -98,6 +99,7 @@ int fluid_sim_cellular_bounds_test2(){
     printf("fluid_sim_cellular_bounds_test2\n");
 
     Environment * env = fluid_environment_create();
+    env->state.frame += 10;
 
     int chunkCount =  27;
 
@@ -140,14 +142,65 @@ int fluid_sim_cellular_bounds_test2(){
 
     //assert that the density moved
     {
-        float borderVal = queue[0]->d[CENTER_LOC][IX(1,1,DIM-2)];
-        float orderBorderVal = queue[0]->d[CENTER_LOC][IX(1,1,DIM-3)];
+        float borderOldVal = queue[0]->d[CENTER_LOC][IX(1,1,DIM-1)];
+        float borderNewVal = queue[0]->d[CENTER_LOC][IX(1,1,DIM-2)];
         float transferedVal = queue[1]->d[CENTER_LOC][IX(1,1,0)];
-        rVal += assertEqualsFloat(borderVal,MIN_FLUID_VALUE,"Border value has not changed! -- %f %f \n");
-        rVal += assertEqualsFloat(orderBorderVal,CELLULAR_TEST_PLACE_VAL,"Border value has not moved! -- %f %f \n");
+        rVal += assertEqualsFloat(borderOldVal,MIN_FLUID_VALUE,"Border old val has not changed! -- %f %f \n");
+        rVal += assertEqualsFloat(borderNewVal,CELLULAR_TEST_PLACE_VAL,"Border new val not occupied! -- %f %f \n");
         rVal += assertEqualsFloat(transferedVal,CELLULAR_TEST_PLACE_VAL,"Value was overwritten on border! -- %f %f \n");
     }
 
+    printf("\n");
+    return rVal;
+}
+
+int fluid_sim_cellular_stability_test1(){
+    int rVal = 0;
+    printf("fluid_sim_cellular_stability_test1\n");
+
+    Environment * env = fluid_environment_create();
+
+    int chunkCount =  27;
+
+    Chunk ** queue = NULL;
+    for(int i = 0; i < chunkCount; i++){
+        arrput(queue,chunk_create(
+            fluid_sim_cellular_cellular_tests_kernelx[i],
+            fluid_sim_cellular_cellular_tests_kernely[i],
+            fluid_sim_cellular_cellular_tests_kernelz[i]
+        ));
+    }
+
+    //link neighbors
+    chunk_link_neighbors(queue);
+
+    //fill them with values
+    for(int i = 0; i < chunkCount; i++){
+        chunk_fill(queue[i],0);
+    }
+    
+    //set border of 0,0,0 to push a value into z
+    queue[1]->d[CENTER_LOC][IX(1,1,1)] = CELLULAR_TEST_PLACE_VAL;
+
+    //check sum beforehand
+    float originalSum = chunk_queue_sum(queue);
+
+
+    //dispatch and simulate
+    int frameCount = 50;
+    for(int i = 0; i < frameCount; i++){
+        fluid_solve_bounds(chunkCount,queue,env);
+        fluid_dispatch(chunkCount,queue,env);
+        fluid_simulate(env);
+        env->state.frame++;
+    }
+
+    //check sum beforehand
+    float afterSum = chunk_queue_sum(queue);
+
+    rVal += assertEqualsFloat(originalSum,afterSum,"cellular sim was unstable! %f %f \n");
+
+    printf("\n");
     return rVal;
 }
 
@@ -157,6 +210,7 @@ int fluid_sim_cellular_cellular_tests(int argc, char **argv){
 
     rVal += fluid_sim_cellular_bounds_test1();
     rVal += fluid_sim_cellular_bounds_test2();
+    rVal += fluid_sim_cellular_stability_test1();
 
     return rVal;
 }

src/test/c/util/chunk_test_utils.c

@@ -214,6 +214,25 @@ void chunk_link_neighbors(Chunk ** chunks){
     }
 }
 
+/**
+ * Sums all chunks in a queue
+ */
+float chunk_queue_sum(Chunk ** chunks){
+    float sum = 0;
+    int num = arrlen(chunks);
+    for(int i = 0; i < num; i++){
+        Chunk * current = chunks[i];
+        for(int x = 1; x < DIM - 2; x++){
+            for(int y = 1; y < DIM - 2; y++){
+                for(int z = 1; z < DIM - 2; z++){
+                    sum = sum + current->d[CENTER_LOC][IX(x,y,z)];
+                }
+            }
+        }
+    }
+    return sum;
+}
+
 /**
  * Empty test launcher
  */

src/test/c/util/chunk_test_utils.h

@@ -88,4 +88,9 @@ void chunk_free_queue(Chunk ** chunks);
  */
 void chunk_link_neighbors(Chunk ** chunks);
 
+/**
+ * Sums all chunks in a queue
+ */
+float chunk_queue_sum(Chunk ** chunks);
+
 #endif