Singularity/Library/PackageCache/com.unity.burst@1.8.4/Documentation~/csharp-calling-burst-code.md
2024-05-06 11:45:45 -07:00

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# Calling Burst-compiled code
You can call Burst-compiled methods direct from managed code. Calling generic methods or methods whose declaring type is generic isn't supported, otherwise the rules as for [function pointers](csharp-function-pointers.md) apply. However, you don't need to worry about the extra boiler plate needed for function pointers.
The following example shows a Burst-compiled utility class. Because it uses structs, it passes by reference per the [function pointer](csharp-function-pointers.md) rules.
```c#
[BurstCompile]
public static class MyBurstUtilityClass
{
[BurstCompile]
public static void BurstCompiled_MultiplyAdd(in float4 mula, in float4 mulb, in float4 add, out float4 result)
{
result = mula * mulb + add;
}
}
```
Use this method from managed code like so:
```c#
public class MyMonoBehaviour : MonoBehaviour
{
void Start()
{
var mula = new float4(1, 2, 3, 4);
var mulb = new float4(-1,1,-1,1);
var add = new float4(99,0,0,0);
MyBurstUtilityClass.BurstCompiled_MultiplyAdd(mula, mulb, add, out var result);
Debug.Log(result);
}
}
```
If you attach this script to an object and run it, `float4(98f, 2f, -3f, 4f)` is printed to the log.
## Code transformation
Burst uses IL Post Processing to automatically transform the code into a function pointer and call. For more information, see the documentation on [Function pointers](csharp-function-pointers.md).
To disable the direct call transformation, add`DisableDirectCall = true` to the BurstCompile options. This prevents the Post Processor from running on the code:
```c#
[BurstCompile]
public static class MyBurstUtilityClass
{
[BurstCompile(DisableDirectCall = true)]
public static void BurstCompiled_MultiplyAdd(in float4 mula, in float4 mulb, in float4 add, out float4 result)
{
result = mula * mulb + add;
}
}
```