using System;
using System.Runtime.InteropServices;
using Unity.Collections;
using UnityEngine.InputSystem.Utilities;
using Unity.Collections.LowLevel.Unsafe;
namespace UnityEngine.InputSystem.LowLevel
{
/// <summary>
/// A complete state snapshot for an entire input device.
/// </summary>
/// <remarks>
/// This is a variable-sized event.
/// </remarks>
[StructLayout(LayoutKind.Explicit, Size = InputEvent.kBaseEventSize + 4 + kStateDataSizeToSubtract, Pack = 1)]
public unsafe struct StateEvent : IInputEventTypeInfo
{
public const int Type = 0x53544154; // 'STAT'
internal const int kStateDataSizeToSubtract = 1;
[FieldOffset(0)]
public InputEvent baseEvent;
/// <summary>
/// Type code for the state stored in the event.
/// </summary>
[FieldOffset(InputEvent.kBaseEventSize)]
public FourCC stateFormat;
[FieldOffset(InputEvent.kBaseEventSize + sizeof(int))]
internal fixed byte stateData[kStateDataSizeToSubtract]; // Variable-sized.
public uint stateSizeInBytes => baseEvent.sizeInBytes - (InputEvent.kBaseEventSize + sizeof(int));
public void* state
{
get
{
fixed(byte* data = stateData)
{
return data;
}
}
}
public InputEventPtr ToEventPtr()
{
fixed(StateEvent * ptr = &this)
{
return new InputEventPtr((InputEvent*)ptr);
}
}
public FourCC typeStatic => Type;
/// <summary>
/// Retrieve the state stored in the event.
/// </summary>
/// <typeparam name="TState">Type of state expected to be stored in the event. <see cref="IInputStateTypeInfo.format"/>
/// must match <see cref="stateFormat"/>.</typeparam>
/// <returns>Copy of the state stored in the event.</returns>
/// <exception cref="InvalidOperationException"><see cref="stateFormat"/> does not match <see cref="IInputStateTypeInfo.format"/>
/// of <typeparamref name="TState"/>.</exception>
/// <remarks>
/// The event may contain less or more data than what is found in the struct. Only the data found in the event
/// is copied. The remainder of the struct is left at default values.
/// </remarks>
/// <seealso cref="GetState{T}(InputEventPtr)"/>
public TState GetState<TState>()
where TState : struct, IInputStateTypeInfo
{
var result = default(TState);
if (stateFormat != result.format)
throw new InvalidOperationException($"Expected state format '{result.format}' but got '{stateFormat}' instead");
UnsafeUtility.MemCpy(UnsafeUtility.AddressOf(ref result), state, Math.Min(stateSizeInBytes, UnsafeUtility.SizeOf<TState>()));
return result;
}
/// <summary>
/// Retrieve the state stored in the event.
/// </summary>
/// <typeparam name="TState">Type of state expected to be stored in the event. <see cref="IInputStateTypeInfo.format"/>
/// must match <see cref="stateFormat"/>.</typeparam>
/// <param name="ptr">A pointer to an input event. The pointer is checked for <c>null</c> and
/// for whether the type of event it refers to is indeed a StateEvent.</param>
/// <returns>Copy of the state stored in the event.</returns>
/// <remarks>
/// The event may contain less or more data than what is found in the struct. Only the data found in the event
/// is copied. The remainder of the struct is left at default values.
/// </remarks>
/// <exception cref="InvalidOperationException"><see cref="stateFormat"/> does not match <see cref="IInputStateTypeInfo.format"/>
/// of <typeparamref name="TState"/>.</exception>
/// <exception cref="ArgumentNullException"><paramref name="ptr"/> is <c>default(InputEventPtr)</c>.</exception>
/// <exception cref="InvalidCastException"><paramref name="ptr"/> does not refer to a StateEvent.</exception>
/// <seealso cref="GetState{T}()"/>
public static TState GetState<TState>(InputEventPtr ptr)
where TState : struct, IInputStateTypeInfo
{
return From(ptr)->GetState<TState>();
}
public static int GetEventSizeWithPayload<TState>()
where TState : struct
{
return UnsafeUtility.SizeOf<TState>() + InputEvent.kBaseEventSize + sizeof(int);
}
/// <summary>
/// Return the given <see cref="InputEventPtr"/> as a StateEvent pointer.
/// </summary>
/// <param name="ptr">A pointer to an input event. The pointer is checked for <c>null</c> and
/// for whether the type of event it refers to is indeed a StateEvent.</param>
/// <returns>Pointer <paramref name="ptr"/> converted to a StateEvent pointer.</returns>
/// <exception cref="ArgumentNullException"><paramref name="ptr"/> is <c>default(InputEventPtr)</c>.</exception>
/// <exception cref="InvalidCastException"><paramref name="ptr"/> does not refer to a StateEvent.</exception>
public static StateEvent* From(InputEventPtr ptr)
{
if (!ptr.valid)
throw new ArgumentNullException(nameof(ptr));
if (!ptr.IsA<StateEvent>())
throw new InvalidCastException($"Cannot cast event with type '{ptr.type}' into StateEvent");
return FromUnchecked(ptr);
}
internal static StateEvent* FromUnchecked(InputEventPtr ptr)
{
return (StateEvent*)ptr.data;
}
/// <summary>
/// Read the current state of <paramref name="device"/> and create a state event from it.
/// </summary>
/// <param name="device">Device to grab the state from. Must be a device that has been added to the system.</param>
/// <param name="eventPtr">Receives a pointer to the newly created state event.</param>
/// <param name="allocator">Which native allocator to allocate memory for the event from. By default, the buffer is
/// allocated as temporary memory (<see cref="Allocator.Temp"/>. Note that this means the buffer will not be valid
/// past the current frame. Use <see cref="Allocator.Persistent"/> if the buffer for the state event is meant to
/// persist for longer.</param>
/// <returns>Buffer of unmanaged memory allocated for the event.</returns>
/// <exception cref="ArgumentException"><paramref name="device"/> has not been added to the system.</exception>
/// <exception cref="ArgumentNullException"><paramref name="device"/> is <c>null</c>.</exception>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", MessageId = "1#")]
public static NativeArray<byte> From(InputDevice device, out InputEventPtr eventPtr, Allocator allocator = Allocator.Temp)
{
return From(device, out eventPtr, allocator, useDefaultState: false);
}
/// <summary>
/// Create a state event for the given <paramref name="device"/> and copy the default state of the device
/// into the event.
/// </summary>
/// <param name="device">Device to create a state event for. Must be a device that has been added to the system.</param>
/// <param name="eventPtr">Receives a pointer to the newly created state event.</param>
/// <param name="allocator">Which native allocator to allocate memory for the event from. By default, the buffer is
/// allocated as temporary memory (<see cref="Allocator.Temp"/>. Note that this means the buffer will not be valid
/// past the current frame. Use <see cref="Allocator.Persistent"/> if the buffer for the state event is meant to
/// persist for longer.</param>
/// <returns>Buffer of unmanaged memory allocated for the event.</returns>
/// <exception cref="ArgumentException"><paramref name="device"/> has not been added to the system.</exception>
/// <exception cref="ArgumentNullException"><paramref name="device"/> is <c>null</c>.</exception>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", MessageId = "1#")]
public static NativeArray<byte> FromDefaultStateFor(InputDevice device, out InputEventPtr eventPtr, Allocator allocator = Allocator.Temp)
{
return From(device, out eventPtr, allocator, useDefaultState: true);
}
private static NativeArray<byte> From(InputDevice device, out InputEventPtr eventPtr, Allocator allocator, bool useDefaultState)
{
if (device == null)
throw new ArgumentNullException(nameof(device));
if (!device.added)
throw new ArgumentException($"Device '{device}' has not been added to system",
nameof(device));
var stateFormat = device.m_StateBlock.format;
var stateSize = device.m_StateBlock.alignedSizeInBytes;
var stateOffset = device.m_StateBlock.byteOffset;
var statePtr = (byte*)(useDefaultState ? device.defaultStatePtr : device.currentStatePtr) + (int)stateOffset;
var eventSize = InputEvent.kBaseEventSize + sizeof(int) + stateSize;
var buffer = new NativeArray<byte>((int)eventSize.AlignToMultipleOf(4), allocator);
var stateEventPtr = (StateEvent*)buffer.GetUnsafePtr();
stateEventPtr->baseEvent = new InputEvent(Type, (int)eventSize, device.deviceId, InputRuntime.s_Instance.currentTime);
stateEventPtr->stateFormat = stateFormat;
UnsafeUtility.MemCpy(stateEventPtr->state, statePtr, stateSize);
eventPtr = stateEventPtr->ToEventPtr();
return buffer;
}
}
}