UnsafeUtility.SizeOf

Declaration

public static int SizeOf();

Declaration

public static int SizeOf(Type type);

Parameters

type The type whose byte size is to be determined.

Returns

int The total size in bytes of the specified type, including any alignment padding required for efficient memory access.

Description

Determines the size, in bytes, of a specified type, including padding for alignment.

The SizeOf method calculates the number of bytes needed to store a single instance of a provided type. This includes any padding necessary for proper memory alignment, which ensures efficient data access and hardware compliance.

Use this method when manually allocating memory or interfacing with lower-level systems in Unity. It is essential for tasks that require precise control over memory use, such as custom data structures or interaction with native plugins.

using UnityEngine;
using Unity.Collections.LowLevel.Unsafe;
using System.Runtime.InteropServices;
using Unity.Collections;

public class SizeOfExample : MonoBehaviour { [StructLayout(LayoutKind.Sequential)] struct ComplexStruct { public byte SmallValue; public double LargeValue; public short MediumValue; }

void Start() { // Calculate and log the size of ComplexStruct int structSize = UnsafeUtility.SizeOf<ComplexStruct>(); Debug.Log($"Size of ComplexStruct: {structSize} bytes");

// Using SizeOf to allocate memory for an array of ComplexStruct unsafe { void* structBuffer = UnsafeUtility.Malloc(structSize * 5, UnsafeUtility.AlignOf<ComplexStruct>(), Allocator.Temp);

// Cast the buffer to work with the ComplexStruct type ComplexStruct* structArray = (ComplexStruct*)structBuffer; for (int i = 0; i < 5; i++) { structArray[i].SmallValue = (byte)i; structArray[i].LargeValue = i * 2.2; structArray[i].MediumValue = (short)(i * 10); Debug.Log($"Struct[{i}]: SmallValue = {structArray[i].SmallValue}, LargeValue = {structArray[i].LargeValue}, MediumValue = {structArray[i].MediumValue}"); }

// Free the allocated memory UnsafeUtility.Free(structBuffer, Allocator.Temp); } } }

Did you find this page useful? Please give it a rating: