Jolt: add 6 public hashing methods

src/main/java/com/github/stephengold/joltjni/Jolt.java

@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2024 Stephen Gold
+Copyright (c) 2024-2025 Stephen Gold
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -21,6 +21,8 @@ of this software and associated documentation files (the "Software"), to deal
  */
 package com.github.stephengold.joltjni;
 
+import com.github.stephengold.joltjni.readonly.ConstBodyId;
+import com.github.stephengold.joltjni.readonly.RVec3Arg;
 import com.github.stephengold.joltjni.readonly.Vec3Arg;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
@@ -165,6 +167,84 @@ public static long hashBytes(RVec3 vector, long oldHash) {
         return result;
     }
 
+    /**
+     * Combine the specified character ID with the specified hash code.
+     *
+     * @param id the ID to combine (not null, unaffected)
+     * @param oldHash the old hash code
+     * @return the new hash code
+     */
+    public static long hashCombine(long oldHash, CharacterId id) {
+        long idVa = id.va();
+        long result = hashCombineCharacterId(oldHash, idVa);
+
+        return result;
+    }
+
+    /**
+     * Combine the specified body ID with the specified hash code.
+     *
+     * @param id the ID to combine (not null, unaffected)
+     * @param oldHash the old hash code
+     * @return the new hash code
+     */
+    public static long hashCombine(long oldHash, ConstBodyId id) {
+        long idVa = id.targetVa();
+        long result = hashCombineBodyId(oldHash, idVa);
+
+        return result;
+    }
+
+    /**
+     * Combine the specified 32-bit integer with the specified hash code.
+     *
+     * @param oldHash the old hash code
+     * @param iValue the integer value to combine
+     * @return the new hash code
+     */
+    native public static long hashCombine(long oldHash, int iValue);
+
+    /**
+     * Combine the specified 64-bit integer with the specified hash code.
+     *
+     * @param oldHash the old hash code
+     * @param lValue the integer value to combine
+     * @return the new hash code
+     */
+    native public static long hashCombine(long oldHash, long lValue);
+
+    /**
+     * Combine the specified location vector with the specified hash code.
+     *
+     * @param rvec the vector to combine (not null, unaffected)
+     * @param oldHash the old hash code
+     * @return the new hash code
+     */
+    public static long hashCombine(long oldHash, RVec3Arg rvec) {
+        double xx = rvec.xx();
+        double yy = rvec.yy();
+        double zz = rvec.zz();
+        long result = hashCombineRVec3(oldHash, xx, yy, zz);
+
+        return result;
+    }
+
+    /**
+     * Combine the specified vector with the specified hash code.
+     *
+     * @param vec the vector to combine (not null, unaffected)
+     * @param oldHash the old hash code
+     * @return the new hash code
+     */
+    public static long hashCombine(long oldHash, Vec3Arg vec) {
+        float x = vec.getX();
+        float y = vec.getY();
+        float z = vec.getZ();
+        long result = hashCombineVec3(oldHash, x, y, z);
+
+        return result;
+    }
+
     /**
      * Test whether the native library implements debug rendering. (native
      * macro: JPH_DEBUG_RENDERER)
@@ -427,6 +507,16 @@ native private static long hashBytes(
     native private static long hashBytes(
             float qx, float qy, float qz, float qw, long oldHash);
 
+    native private static long hashCombineBodyId(long oldHash, long idVa);
+
+    native private static long hashCombineCharacterId(long oldHash, long idVa);
+
+    native private static long hashCombineRVec3(
+            long oldHash, double xx, double yy, double zz);
+
+    native private static long hashCombineVec3(
+            long oldHash, float x, float y, float z);
+
     native private static boolean rayAaBoxHits(float startX, float startY,
             float startZ, float offsetX, float offsetY, float offsetZ,
             float minX, float minY, float minZ, float maxX, float maxY,

src/main/native/glue/j/Jolt.cpp

@@ -26,9 +26,12 @@ SOFTWARE.
 #include "Jolt/Jolt.h"
 #include "Jolt/ConfigurationString.h"
 #include "Jolt/Core/Factory.h"
+#include "Jolt/Core/HashCombine.h"
 #include "Jolt/Core/Profiler.h"
 #include "Jolt/Core/TempAllocator.h"
 #include "Jolt/Geometry/RayAABox.h"
+#include "Jolt/Physics/Body/BodyID.h"
+#include "Jolt/Physics/Character/CharacterID.h"
 #include "Jolt/Physics/DeterminismLog.h"
 #include "Jolt/RegisterTypes.h"
 #include "TestFramework/External/Perlin.h"
@@ -115,6 +118,30 @@ JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashBytes__JI
     return result;
 }
 
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombine
+ * Signature: (JI)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombine__JI
+  (JNIEnv *, jclass, jlong oldHash, jint iValue) {
+    uint64 result = oldHash;
+    HashCombine(result, iValue);
+    return result;
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombine
+ * Signature: (JJ)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombine__JJ
+  (JNIEnv *, jclass, jlong oldHash, jlong lValue) {
+    uint64 result = oldHash;
+    HashCombine(result, (uint64)lValue);
+    return result;
+}
+
 /*
  * Class:     com_github_stephengold_joltjni_Jolt
  * Method:    implementsDebugRendering
@@ -374,6 +401,58 @@ JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashBytes__FFFF
     return result;
 }
 
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombineBodyId
+ * Signature: (JJ)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombineBodyId
+  (JNIEnv *, jclass, jlong oldHash, jlong idVa) {
+    uint64 result = oldHash;
+    const BodyID * const pId = reinterpret_cast<BodyID *> (idVa);
+    HashCombine(result, *pId);
+    return result;
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombineCharacterId
+ * Signature: (JJ)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombineCharacterId
+  (JNIEnv *, jclass, jlong oldHash, jlong idVa) {
+    uint64 result = oldHash;
+    const CharacterID * const pId = reinterpret_cast<CharacterID *> (idVa);
+    HashCombine(result, *pId);
+    return result;
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombineRVec3
+ * Signature: (JDDD)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombineRVec3
+  (JNIEnv *, jclass, jlong oldHash, jdouble xx, jdouble yy, jdouble zz) {
+    uint64 result = oldHash;
+    const RVec3 rvec(xx, yy, zz);
+    HashCombine(result, rvec);
+    return result;
+}
+
+/*
+ * Class:     com_github_stephengold_joltjni_Jolt
+ * Method:    hashCombineVec3
+ * Signature: (JFFF)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_stephengold_joltjni_Jolt_hashCombineVec3
+  (JNIEnv *, jclass, jlong oldHash, jfloat x, jfloat y, jfloat z) {
+    uint64 result = oldHash;
+    const Vec3 vec(x, y, z);
+    HashCombine(result, vec);
+    return result;
+}
+
 /*
  * Class:     com_github_stephengold_joltjni_Jolt
  * Method:    rayAaBoxHits