From 70ffe740c6c042ff093bcdc5f7fcbb71e24ccb8a Mon Sep 17 00:00:00 2001
From: ah-OOG-ah <75745146+ah-OOG-ah@users.noreply.github.com>
Date: Tue, 26 Nov 2024 19:12:27 -0500
Subject: [PATCH] Add stack.malloc

---
 .../client/lwjgl3/CompatMemoryUtil.java        | 18 ++++++++++++++++++
 .../gtnhlib/client/lwjgl3/MemoryStack.java     | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/CompatMemoryUtil.java b/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/CompatMemoryUtil.java
index 5fd3100..0219a40 100644
--- a/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/CompatMemoryUtil.java
+++ b/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/CompatMemoryUtil.java
@@ -33,6 +33,8 @@ public class CompatMemoryUtil {
 
     static final sun.misc.Unsafe UNSAFE;
 
+    static final ByteOrder NATIVE_ORDER = ByteOrder.nativeOrder();
+
     private static final Class<? extends ByteBuffer> BUFFER_BYTE;
     private static final Class<? extends IntBuffer> BUFFER_INT;
     private static final Class<? extends FloatBuffer> BUFFER_FLOAT;
@@ -341,6 +343,22 @@ private static long getCapacityOffset() {
         return getFieldOffsetInt(bb, MAGIC_CAPACITY);
     }
 
+    static ByteBuffer wrapBufferByte(long address, int capacity) {
+        ByteBuffer buffer;
+        try {
+            buffer = (ByteBuffer)UNSAFE.allocateInstance(BUFFER_BYTE);
+        } catch (InstantiationException e) {
+            throw new UnsupportedOperationException(e);
+        }
+
+        UNSAFE.putLong(buffer, ADDRESS, address);
+        UNSAFE.putInt(buffer, MARK, -1);
+        UNSAFE.putInt(buffer, LIMIT, capacity);
+        UNSAFE.putInt(buffer, CAPACITY, capacity);
+
+        return buffer.order(NATIVE_ORDER);
+    }
+
     static IntBuffer wrapBufferInt(long address, int capacity) {
         IntBuffer buffer;
         try {
diff --git a/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/MemoryStack.java b/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/MemoryStack.java
index 2c1ba65..0b7b79a 100644
--- a/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/MemoryStack.java
+++ b/src/main/java/com/gtnewhorizon/gtnhlib/client/lwjgl3/MemoryStack.java
@@ -11,6 +11,7 @@
 import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.memPutLong;
 import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.memPutShort;
 import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.memSet;
+import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.wrapBufferByte;
 import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.wrapBufferFloat;
 import static com.gtnewhorizon.gtnhlib.client.lwjgl3.CompatMemoryUtil.wrapBufferInt;
 
@@ -329,6 +330,23 @@ public long ncalloc(int alignment, int num, int size) {
 
     // -------------------------------------------------
 
+    /**
+     * Allocates an aligned {@link ByteBuffer} on the stack.
+     *
+     * @param alignment the required buffer alignment
+     * @param size      the number of elements in the buffer
+     *
+     * @return the allocated buffer
+     */
+    public ByteBuffer malloc(int alignment, int size) {
+        if (/*DEBUG*/ false) {
+            checkAlignment(alignment);
+        }
+        return wrapBufferByte(nmalloc(alignment, size), size);
+    }
+
+    // -------------------------------------------------
+
     /** Unsafe version of {@link #shorts(short)}. */
     public long nshort(short value) {
         long a = nmalloc(2, 2);