Rasagar/Library/PackageCache/com.unity.inputsystem/InputSystem/Events/DeltaStateEvent.cs
2024-08-26 23:07:20 +03:00

106 lines
3.9 KiB
C#

using System;
using System.Runtime.InteropServices;
using Unity.Collections;
using Unity.Collections.LowLevel.Unsafe;
using UnityEngine.InputSystem.Utilities;
namespace UnityEngine.InputSystem.LowLevel
{
/// <summary>
/// Partial state update for an input device.
/// </summary>
/// <remarks>
/// Avoids having to send a full state memory snapshot when only a small
/// part of the state has changed.
/// </remarks>
[StructLayout(LayoutKind.Explicit, Pack = 1, Size = InputEvent.kBaseEventSize + 9)]
public unsafe struct DeltaStateEvent : IInputEventTypeInfo
{
public const int Type = 0x444C5441; // 'DLTA'
[FieldOffset(0)]
public InputEvent baseEvent;
[FieldOffset(InputEvent.kBaseEventSize)]
public FourCC stateFormat;
[FieldOffset(InputEvent.kBaseEventSize + 4)]
public uint stateOffset;
[FieldOffset(InputEvent.kBaseEventSize + 8)]
internal fixed byte stateData[1]; // Variable-sized.
public uint deltaStateSizeInBytes => baseEvent.sizeInBytes - (InputEvent.kBaseEventSize + 8);
public void* deltaState
{
get
{
fixed(byte* data = stateData)
{
return data;
}
}
}
public FourCC typeStatic => Type;
public InputEventPtr ToEventPtr()
{
fixed(DeltaStateEvent * ptr = &this)
{
return new InputEventPtr((InputEvent*)ptr);
}
}
public static DeltaStateEvent* From(InputEventPtr ptr)
{
if (!ptr.valid)
throw new ArgumentNullException(nameof(ptr));
if (!ptr.IsA<DeltaStateEvent>())
throw new InvalidCastException($"Cannot cast event with type '{ptr.type}' into DeltaStateEvent");
return FromUnchecked(ptr);
}
internal static DeltaStateEvent* FromUnchecked(InputEventPtr ptr)
{
return (DeltaStateEvent*)ptr.data;
}
public static NativeArray<byte> From(InputControl control, out InputEventPtr eventPtr, Allocator allocator = Allocator.Temp)
{
if (control == null)
throw new ArgumentNullException(nameof(control));
var device = control.device;
if (!device.added)
throw new ArgumentException($"Device for control '{control}' has not been added to system",
nameof(control));
ref var deviceStateBlock = ref device.m_StateBlock;
ref var controlStateBlock = ref control.m_StateBlock;
var stateFormat = deviceStateBlock.format; // The event is sent against the *device* so that's the state format we use.
var stateSize = 0u;
if (controlStateBlock.bitOffset != 0)
stateSize = (controlStateBlock.bitOffset + controlStateBlock.sizeInBits + 7) / 8;
else
stateSize = controlStateBlock.alignedSizeInBytes;
var stateOffset = controlStateBlock.byteOffset;
var statePtr = (byte*)control.currentStatePtr + (int)stateOffset;
var eventSize = InputEvent.kBaseEventSize + sizeof(int) * 2 + stateSize;
var buffer = new NativeArray<byte>((int)eventSize.AlignToMultipleOf(4), allocator);
var stateEventPtr = (DeltaStateEvent*)buffer.GetUnsafePtr();
stateEventPtr->baseEvent = new InputEvent(Type, (int)eventSize, device.deviceId, InputRuntime.s_Instance.currentTime);
stateEventPtr->stateFormat = stateFormat;
stateEventPtr->stateOffset = controlStateBlock.byteOffset - deviceStateBlock.byteOffset; // Make offset relative to device.
UnsafeUtility.MemCpy(stateEventPtr->deltaState, statePtr, stateSize);
eventPtr = stateEventPtr->ToEventPtr();
return buffer;
}
}
}