actual fluid sim in bounded level

.vscode/settings.json

@@ -10,6 +10,11 @@
     "files.associations": {
         "electrosphere_fluidsim.h": "c",
         "jni.h": "c",
-        "electrosphere_server_fluid_simulator_fluidacceleratedsimulator.h": "c"
+        "electrosphere_server_fluid_simulator_fluidacceleratedsimulator.h": "c",
+        "utilities.h": "c",
+        "simulation.h": "c",
+        "chunk.h": "c",
+        "chunkmask.h": "c",
+        "metadatacalc.h": "c"
     }
 }

buildNumber.properties

@@ -1,3 +1,3 @@
 #maven.buildNumber.plugin properties file
-#Sat Nov 30 18:07:55 EST 2024
-buildNumber=427
+#Sat Nov 30 19:02:40 EST 2024
+buildNumber=435

src/fluid/compile.sh

@@ -68,12 +68,17 @@ INPUT_FILES="./src/fluidsim.c"
 OUTPUT_FILE="./fluidsim.o"
 gcc $COMPILE_FLAGS -I"$BASE_INCLUDE_DIR" -I"$OS_INCLUDE_DIR" $INPUT_FILES -o $OUTPUT_FILE
 
+COMPILE_FLAGS="-c -fPIC -m64 -mavx -mavx2 -march=native -Ofast -DSAVE_STEPS=$SAVE_STEPS"
+INPUT_FILES="./src/metadatacalc.c"
+OUTPUT_FILE="./metadatacalc.o"
+gcc $COMPILE_FLAGS -I"$BASE_INCLUDE_DIR" -I"$OS_INCLUDE_DIR" $INPUT_FILES -o $OUTPUT_FILE
+
 
 
 #compile shared object file
 OUTPUT_FILE="libfluidsim$LIB_ENDING"
 COMPILE_FLAGS="-shared"
-INPUT_FILES="fluidsim.o javainterface.o"
+INPUT_FILES="fluidsim.o javainterface.o metadatacalc.o"
 gcc $COMPILE_FLAGS $INPUT_FILES -o $OUTPUT_FILE
 
 #move to resources

src/fluid/includes/electrosphere_server_fluid_simulator_FluidAcceleratedSimulator.h

@@ -7,6 +7,18 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+#undef electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_SIMULATE_TIMESTEP
+#define electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_SIMULATE_TIMESTEP 0.01f
+#undef electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_GRAVITY_CONST
+#define electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_GRAVITY_CONST 1000.0f
+/*
+ * Class:     electrosphere_server_fluid_simulator_FluidAcceleratedSimulator
+ * Method:    init
+ * Signature: (F)V
+ */
+JNIEXPORT void JNICALL Java_electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_init
+  (JNIEnv *, jclass, jfloat);
+
 /*
  * Class:     electrosphere_server_fluid_simulator_FluidAcceleratedSimulator
  * Method:    simulate

src/fluid/includes/environment.h

@@ -0,0 +1,11 @@
+#ifndef ENVIRONMENT_H
+#define ENVIRONMENT_H
+
+/**
+ * Stores data about the simulation environment
+*/
+typedef struct {
+    float gravity;
+} Environment;
+
+#endif

src/fluid/includes/metadatacalc.h

@@ -0,0 +1,18 @@
+#ifndef METADATACALC
+#define METADATACALC
+
+#include "./chunk.h"
+#include "./environment.h"
+
+
+/**
+ * Updates the metadata for all chunks
+ * @param numChunks The number of chunks
+ * @param passedInChunks The chunks that were passed in
+ * @param environment The environment data
+ */
+void updateMetadata(int numChunks, Chunk ** passedInChunks, Environment * environment);
+
+
+
+#endif

src/fluid/includes/simulation.h

@@ -2,7 +2,15 @@
 #define SIMULATION_H
 
 #include "./chunk.h"
+#include "./environment.h"
 
-void simulate(int numChunks, Chunk ** passedInChunks, float timestep);
+/**
+ * Performs the main simulation
+ * @param numChunks The number of chunks
+ * @param passedInChunks The chunks to simulate
+ * @param environment The environment data
+ * @param timestep The timestep to simulate by
+ */
+void simulate(int numChunks, Chunk ** passedInChunks, Environment * environment, float timestep);
 
 #endif

src/fluid/src/fluidsim.c

@@ -31,10 +31,12 @@ Chunk ** chunks = NULL;
 //https://stackoverflow.com/questions/39823375/clarification-about-getfieldid
 
 static inline void saveStep(float * values, const char * name);
+static inline void applyGravity(Chunk * currentChunk, Environment * environment);
 
 void simulate(
     int numChunks,
     Chunk ** passedInChunks,
+    Environment * environment,
     jfloat timestep
 ){
     chunks = passedInChunks;
@@ -50,6 +52,7 @@ void simulate(
     //solve chunk mask
     for(int i = 0; i < numChunks; i++){
         Chunk * currentChunk = chunks[i];
+        applyGravity(currentChunk,environment);
         addSourceToVectors(
             DIM,
             currentChunk->chunkMask,
@@ -540,3 +543,19 @@ static inline void saveStep(float * values, const char * name){
         fclose(fp);
     }
 }
+
+/**
+ * Applies gravity to the chunk
+ * @param currentChunk The chunk to apply on
+ * @param environment The environment data of the world
+ */
+static inline void applyGravity(Chunk * currentChunk, Environment * environment){
+    int N = DIM;
+    for(int x = 0; x < DIM; x++){
+        for(int y = 0; y < DIM; y++){
+            for(int z = 0; z < DIM; z++){
+                GET_ARR_RAW(currentChunk->v0,CENTER_LOC)[IX(x,y,z)] = GET_ARR_RAW(currentChunk->d,CENTER_LOC)[IX(x,y,z)] * environment->gravity;
+            }
+        }
+    }
+}

src/fluid/src/javainterface.c

@@ -10,6 +10,7 @@
 #include "../includes/chunkmask.h"
 #include "../includes/utilities.h"
 #include "../includes/simulation.h"
+#include "../includes/metadatacalc.h"
 
 
 //defines
@@ -35,6 +36,9 @@ Chunk ** javaChunkView = NULL;
 //the number of chunks
 int numChunks = 0;
 
+//the environment data
+Environment * environment = NULL;
+
 
 JNIEXPORT void JNICALL Java_electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_simulate(
     JNIEnv * env,
@@ -43,7 +47,8 @@ JNIEXPORT void JNICALL Java_electrosphere_server_fluid_simulator_FluidAccelerate
     jfloat dt
     ){
     readInChunks(env,chunkList);
-    simulate(numChunks,javaChunkView,dt);
+    simulate(numChunks,javaChunkView,environment,dt);
+    updateMetadata(numChunks,javaChunkView,environment);
 }
 
 /**
@@ -66,6 +71,19 @@ JNIEXPORT void JNICALL Java_electrosphere_server_fluid_simulator_FluidAccelerate
     numChunks = 0;
 }
 
+/**
+ * Initializes the library
+ */
+JNIEXPORT void JNICALL Java_electrosphere_server_fluid_simulator_FluidAcceleratedSimulator_init(
+    JNIEnv * env,
+    jclass fluidSimClass,
+    jfloat gravity
+    ){
+    if(environment == NULL){
+        environment = (Environment *)malloc(sizeof(Environment));
+    }
+    environment->gravity = gravity;
+}
 
 /**
  * Reads chunks into the dynamic array

src/fluid/src/metadatacalc.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <immintrin.h>
+#include <stdint.h>
+
+#include "../includes/utilities.h"
+#include "../includes/chunkmask.h"
+#include "../includes/metadatacalc.h"
+
+/**
+ * Updates the metadata for all chunks
+ * @param numChunks The number of chunks
+ * @param passedInChunks The chunks that were passed in
+ * @param environment The environment data
+ */
+void updateMetadata(int numChunks, Chunk ** passedInChunks, Environment * environment){
+
+}
+

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

@@ -8,8 +8,6 @@ import java.nio.FloatBuffer;
 import org.joml.Vector3f;
 import org.joml.Vector3i;
 
-import electrosphere.server.terrain.manager.ServerTerrainChunk;
-
 
 /**
  * Is a single chunk of terrain on the server
@@ -405,7 +403,7 @@ public class ServerFluidChunk {
      * @return The index
      */
     public int IX(int x, int y, int z){
-        return x * ServerTerrainChunk.CHUNK_DIMENSION * ServerTerrainChunk.CHUNK_DIMENSION + y * ServerTerrainChunk.CHUNK_DIMENSION  + z;
+        return x * ServerFluidChunk.BUFFER_DIM * ServerFluidChunk.BUFFER_DIM + y * ServerFluidChunk.BUFFER_DIM  + z;
     }
 
     /**

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

@@ -27,6 +27,16 @@ import org.joml.Vector3i;
  */
 public class ServerFluidManager {
 
+    /**
+     * DEfault size of the cache
+     */
+    static final int DEFAULT_CACHE_SIZE = 500;
+
+    /**
+     * The number of frames to wait between updates
+     */
+    static final int UPDATE_RATE = 0;
+        
     //the seed for the water    
     long seed;
     
@@ -38,7 +48,7 @@ public class ServerFluidManager {
     //Basic idea is we associate string that contains chunk x&y&z with elevation
     //While we incur a penalty with converting ints -> string, think this will
     //offset regenerating the array every time we want a new one
-    int cacheSize = 500;
+    int cacheSize = DEFAULT_CACHE_SIZE;
     @Exclude
     Map<String, ServerFluidChunk> chunkCache = new HashMap<String, ServerFluidChunk>();
     @Exclude
@@ -86,6 +96,12 @@ public class ServerFluidManager {
      */
     List<ServerFluidChunk> broadcastQueue = new LinkedList<ServerFluidChunk>();
 
+    @Exclude
+    /**
+     * The update frame-skipping tracking variable
+     */
+    int updatePhase = 0;
+    
     
     /**
      * Constructor
@@ -263,7 +279,9 @@ public class ServerFluidManager {
      * @param worldZ The world z coordinate of the chunk
      */
     public void queue(int worldX, int worldY, int worldZ){
-        this.simulationQueue.add(this.getChunk(worldX, worldY, worldZ));
+        ServerFluidChunk fluidChunk = this.getChunk(worldX, worldY, worldZ);
+        fluidChunk.updated = true;
+        this.simulationQueue.add(fluidChunk);
     }
 
     /**
@@ -273,10 +291,18 @@ public class ServerFluidManager {
         Globals.profiler.beginAggregateCpuSample("ServerFluidManager.simulate");
         lock.lock();
         if(simulate){
+            if(updatePhase == UPDATE_RATE){
                 if(this.serverFluidSimulator != null){
                     this.serverFluidSimulator.simulate(this.simulationQueue,this.broadcastQueue);
                 }
+            }
+            
             this.simulationQueue.clear();
+
+            updatePhase++;
+            if(updatePhase > UPDATE_RATE){
+                updatePhase = 0;
+            }
         }
         lock.unlock();
         Globals.profiler.endCpuSample();

src/main/java/electrosphere/server/fluid/simulator/FluidAcceleratedSimulator.java

@@ -26,6 +26,11 @@ public class FluidAcceleratedSimulator implements ServerFluidSimulator {
      */
     public static final float SIMULATE_TIMESTEP = 0.01f;
 
+    /**
+     * The gravity constant
+     */
+    public static final float GRAVITY_CONST = -1000;
+
     /**
      * Load fluid sim library
      */
@@ -49,8 +54,29 @@ public class FluidAcceleratedSimulator implements ServerFluidSimulator {
      * Starts up the simulator
      */
     public FluidAcceleratedSimulator(){
+        FluidAcceleratedSimulator.init(FluidAcceleratedSimulator.GRAVITY_CONST);
     }
 
+    /**
+     * Initializes the data for the fluid sim library
+     */
+    private static native void init(float gravity);
+
+    /**
+     * Main native simulation function
+     * @param chunks The list of chunks to simulate with
+     * @param timestep The timestep to simulate
+     */
+    private static native void simulate(List<ServerFluidChunk> chunks, float timestep);
+
+    /**
+     * Frees all native memory
+     */
+    private static native void free();
+
+
+
+
     @Override
     public void simulate(List<ServerFluidChunk> fluidChunks, List<ServerFluidChunk> broadcastQueue){
         FluidAcceleratedSimulator.simulate(fluidChunks, SIMULATE_TIMESTEP);
@@ -61,13 +87,6 @@ public class FluidAcceleratedSimulator implements ServerFluidSimulator {
         }
     }
 
-    /**
-     * Main native simulation function
-     * @param chunks The list of chunks to simulate with
-     * @param timestep The timestep to simulate
-     */
-    private static native void simulate(List<ServerFluidChunk> chunks, float timestep);
-
 
     /**
      * Cleans up the simulator's native state
@@ -76,9 +95,22 @@ public class FluidAcceleratedSimulator implements ServerFluidSimulator {
         FluidAcceleratedSimulator.free();
     }
 
+
     /**
-     * Frees all native memory
+     * Sums the density for a chunk
+     * @param fluidChunk The chunk
+     * @return The total density of the chunk
      */
-    private static native void free();
+    private static double sumAllDensity(ServerFluidChunk fluidChunk){
+        double rVal = 0;
+        for(int x = 0; x < ServerFluidChunk.BUFFER_DIM; x++){
+            for(int y = 0; y < ServerFluidChunk.BUFFER_DIM; y++){
+                for(int z = 0; z < ServerFluidChunk.BUFFER_DIM; z++){
+                    rVal = rVal + fluidChunk.getWeight(x, y, z);
+                }
+            }
+        }
+        return rVal;
+    }
     
 }