IndieGame/client/Packages/com.unity.inputsystem@1.7.0/Samples~/CustomDevice/CustomDevice.cs

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2024-10-11 10:12:15 +08:00
using System.Linq;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.Controls;
using UnityEngine.InputSystem.Layouts;
using UnityEngine.InputSystem.LowLevel;
using UnityEngine.InputSystem.Utilities;
#if UNITY_EDITOR
using UnityEditor;
#endif
// The input system stores a chunk of memory for each device. What that
// memory looks like we can determine ourselves. The easiest way is to just describe
// it as a struct.
//
// Each chunk of memory is tagged with a "format" identifier in the form
// of a "FourCC" (a 32-bit code comprised of four characters). Using
// IInputStateTypeInfo we allow the system to get to the FourCC specific
// to our struct.
public struct CustomDeviceState : IInputStateTypeInfo
{
// We use "CUST" here as our custom format code. It can be anything really.
// Should be sufficiently unique to identify our memory format, though.
public FourCC format => new FourCC('C', 'U', 'S', 'T');
// Next we just define fields that store the state for our input device.
// The only thing really interesting here is the [InputControl] attributes.
// These automatically attach InputControls to the various memory bits that
// we define.
//
// To get started, let's say that our device has a bitfield of buttons. Each
// bit indicates whether a certain button is pressed or not. For the sake of
// demonstration, let's say our device has 16 possible buttons. So, we define
// a ushort field that contains the state of each possible button on the
// device.
//
// On top of that, we need to tell the input system about each button. Both
// what to call it and where to find it. The "name" property tells the input system
// what to call the control; the "layout" property tells it what type of control
// to create ("Button" in our case); and the "bit" property tells it which bit
// in the bitfield corresponds to the button.
//
// We also tell the input system about "display names" here. These are names
// that get displayed in the UI and such.
[InputControl(name = "firstButton", layout = "Button", bit = 0, displayName = "First Button")]
[InputControl(name = "secondButton", layout = "Button", bit = 1, displayName = "Second Button")]
[InputControl(name = "thirdButton", layout = "Button", bit = 2, displayName = "Third Button")]
public ushort buttons;
// Let's say our device also has a stick. However, the stick isn't stored
// simply as two floats but as two unsigned bytes with the midpoint of each
// axis located at value 127. We can simply define two consecutive byte
// fields to represent the stick and annotate them like so.
//
// First, let's introduce stick control itself. This one is simple. We don't
// yet worry about X and Y individually as the stick as whole will itself read the
// component values from those controls.
//
// We need to set "format" here too as InputControlLayout will otherwise try to
// infer the memory format from the field. As we put this attribute on "X", that
// would come out as "BYTE" -- which we don't want. So we set it to "VC2B" (a Vector2
// of bytes).
[InputControl(name = "stick", format = "VC2B", layout = "Stick", displayName = "Main Stick")]
// So that's what we need next. By default, both X and Y on "Stick" are floating-point
// controls so here we need to individually configure them the way they work for our
// stick.
//
// NOTE: We don't mention things as "layout" and such here. The reason is that we are
// modifying a control already defined by "Stick". This means that we only need
// to set the values that are different from what "Stick" stick itself already
// configures. And since "Stick" configures both "X" and "Y" to be "Axis" controls,
// we don't need to worry about that here.
//
// Using "format", we tell the controls how their data is stored. As bytes in our case
// so we use "BYTE" (check the documentation for InputStateBlock for details on that).
//
// NOTE: We don't use "SBYT" (signed byte) here. Our values are not signed. They are
// unsigned. It's just that our "resting" (i.e. mid) point is at 127 and not at 0.
//
// Also, we use "defaultState" to tell the system that in our case, setting the
// memory to all zeroes will *NOT* result in a default value. Instead, if both x and y
// are set to zero, the result will be Vector2(-1,-1).
//
// And then, using the various "normalize" parameters, we tell the input system how to
// deal with the fact that our midpoint is located smack in the middle of our value range.
// Using "normalize" (which is equivalent to "normalize=true") we instruct the control
// to normalize values. Using "normalizeZero=0.5", we tell it that our midpoint is located
// at 0.5 (AxisControl will convert the BYTE value to a [0..1] floating-point value with
// 0=0 and 255=1) and that our lower limit is "normalizeMin=0" and our upper limit is
// "normalizeMax=1". Put another way, it will map [0..1] to [-1..1].
//
// Finally, we also set "offset" here as this is already set by StickControl.X and
// StickControl.Y -- which we inherit. Note that because we're looking at child controls
// of the stick, the offset is relative to the stick, not relative to the beginning
// of the state struct.
[InputControl(name = "stick/x", defaultState = 127, format = "BYTE",
offset = 0,
parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5")]
public byte x;
[InputControl(name = "stick/y", defaultState = 127, format = "BYTE",
offset = 1,
parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5")]
// The stick up/down/left/right buttons automatically use the state set up for X
// and Y but they have their own parameters. Thus we need to also sync them to
// the parameter settings we need for our BYTE setup.
// NOTE: This is a shortcoming in the current layout system that cannot yet correctly
// merge parameters. Will be fixed in a future version.
[InputControl(name = "stick/up", parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5,clamp=2,clampMin=0,clampMax=1")]
[InputControl(name = "stick/down", parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5,clamp=2,clampMin=-1,clampMax=0,invert")]
[InputControl(name = "stick/left", parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5,clamp=2,clampMin=-1,clampMax=0,invert")]
[InputControl(name = "stick/right", parameters = "normalize,normalizeMin=0,normalizeMax=1,normalizeZero=0.5,clamp=2,clampMin=0,clampMax=1")]
public byte y;
}
// Now that we have the state struct all sorted out, we have a way to lay out the memory
// for our device and we have a way to map InputControls to pieces of that memory. What
// we're still missing, however, is a way to represent our device as a whole within the
// input system.
//
// For that, we start with a class derived from InputDevice. We could also base this
// on something like Mouse or Gamepad in case our device is an instance of one of those
// specific types but for this demonstration, let's assume our device is nothing like
// those devices (if we base our devices on those layouts, we have to correctly map the
// controls we inherit from those devices).
//
// Other than deriving from InputDevice, there are two other noteworthy things here.
//
// For one, we want to ensure that the call to InputSystem.RegisterLayout happens as
// part of startup. Doing so ensures that the layout is known to the input system and
// thus appears in the control picker. So we use [InitializeOnLoad] and [RuntimeInitializeOnLoadMethod]
// here to ensure initialization in both the editor and the player.
//
// Also, we use the [InputControlLayout] attribute here. This attribute is optional on
// types that are used as layouts in the input system. In our case, we have to use it
// to tell the input system about the state struct we are using to define the memory
// layout we are using and the controls tied to it.
#if UNITY_EDITOR
[InitializeOnLoad] // Call static class constructor in editor.
#endif
[InputControlLayout(stateType = typeof(CustomDeviceState))]
public class CustomDevice : InputDevice, IInputUpdateCallbackReceiver
{
// [InitializeOnLoad] will ensure this gets called on every domain (re)load
// in the editor.
#if UNITY_EDITOR
static CustomDevice()
{
// Trigger our RegisterLayout code in the editor.
Initialize();
}
#endif
// In the player, [RuntimeInitializeOnLoadMethod] will make sure our
// initialization code gets called during startup.
[RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
private static void Initialize()
{
// Register our device with the input system. We also register
// a "device matcher" here. These are used when a device is discovered
// by the input system. Each device is described by an InputDeviceDescription
// and an InputDeviceMatcher can be used to match specific properties of such
// a description. See the documentation of InputDeviceMatcher for more
// details.
//
// NOTE: In case your device is more dynamic in nature and cannot have a single
// static layout, there is also the possibility to build layouts on the fly.
// Check out the API documentation for InputSystem.onFindLayoutForDevice and
// for InputSystem.RegisterLayoutBuilder.
InputSystem.RegisterLayout<CustomDevice>(
matches: new InputDeviceMatcher()
.WithInterface("Custom"));
}
// While our device is fully functional at this point, we can refine the API
// for it a little bit. One thing we can do is expose the controls for our
// device directly. While anyone can look up our controls using strings, exposing
// the controls as properties makes it simpler to work with the device in script.
public ButtonControl firstButton { get; protected set; }
public ButtonControl secondButton { get; protected set; }
public ButtonControl thirdButton { get; protected set; }
public StickControl stick { get; protected set; }
// FinishSetup is where our device setup is finalized. Here we can look up
// the controls that have been created.
protected override void FinishSetup()
{
base.FinishSetup();
firstButton = GetChildControl<ButtonControl>("firstButton");
secondButton = GetChildControl<ButtonControl>("secondButton");
thirdButton = GetChildControl<ButtonControl>("thirdButton");
stick = GetChildControl<StickControl>("stick");
}
// We can also expose a '.current' getter equivalent to 'Gamepad.current'.
// Whenever our device receives input, MakeCurrent() is called. So we can
// simply update a '.current' getter based on that.
public static CustomDevice current { get; private set; }
public override void MakeCurrent()
{
base.MakeCurrent();
current = this;
}
// When one of our custom devices is removed, we want to make sure that if
// it is the '.current' device, we null out '.current'.
protected override void OnRemoved()
{
base.OnRemoved();
if (current == this)
current = null;
}
// So, this is all great and nice. But we have one problem. No one is actually
// creating an instance of our device yet. Which means that while we can bind
// to controls on the device from actions all we want, at runtime we will never
// actually receive input from our custom device. For that to happen, we need
// to make sure that an instance of the device is created at some point.
//
// This one's a bit tricky. Because it really depends on how the device is
// actually discovered in practice. In most real-world scenarios, there will be
// some external API that notifies us when a device under its domain is added or
// removed. In response, we would report a device being added (using
// InputSystem.AddDevice(new InputDeviceDescription { ... }) or removed
// (using DeviceRemoveEvent).
//
// In this demonstration, we don't have an external API to query. And we don't
// really have another criteria by which to determine when a device of our custom
// type should be added.
//
// So, let's fake it here. First, to create the device, we simply add a menu entry
// in the editor. Means that in the player, this device will never be functional
// but this serves as a demonstration only anyway.
//
// NOTE: Nothing of the following is necessary if you have a device that is
// detected and sent input for by the Unity runtime itself, i.e. that is
// picked up from the underlying platform APIs by Unity itself. In this
// case, when your device is connected, Unity will automatically report an
// InputDeviceDescription and all you have to do is make sure that the
// InputDeviceMatcher you supply to RegisterLayout matches that description.
//
// Also, IInputUpdateCallbackReceiver and any other manual queuing of input
// is unnecessary in that case as Unity will queue input for the device.
#if UNITY_EDITOR
[MenuItem("Tools/Custom Device Sample/Create Device")]
private static void CreateDevice()
{
// This is the code that you would normally run at the point where
// you discover devices of your custom type.
InputSystem.AddDevice(new InputDeviceDescription
{
interfaceName = "Custom",
product = "Sample Product"
});
}
// For completeness sake, let's also add code to remove one instance of our
// custom device. Note that you can also manually remove the device from
// the input debugger by right-clicking in and selecting "Remove Device".
[MenuItem("Tools/Custom Device Sample/Remove Device")]
private static void RemoveDevice()
{
var customDevice = InputSystem.devices.FirstOrDefault(x => x is CustomDevice);
if (customDevice != null)
InputSystem.RemoveDevice(customDevice);
}
#endif
// So the other part we need is to actually feed input for the device. Notice
// that we already have the IInputUpdateCallbackReceiver interface on our class.
// What this does is to add an OnUpdate method that will automatically be called
// by the input system whenever it updates (actually, it will be called *before*
// it updates, i.e. from the same point that InputSystem.onBeforeUpdate triggers).
//
// Here, we can feed input to our devices.
//
// NOTE: We don't have to do this here. InputSystem.QueueEvent can be called from
// anywhere, including from threads. So if, for example, you have a background
// thread polling input from your device, that's where you can also queue
// its input events.
//
// Again, we don't have actual input to read here. So we just make up some stuff
// here for the sake of demonstration. We just poll the keyboard
//
// NOTE: We poll the keyboard here as part of our OnUpdate. Remember, however,
// that we run our OnUpdate from onBeforeUpdate, i.e. from where keyboard
// input has not yet been processed. This means that our input will always
// be one frame late. Plus, because we are polling the keyboard state here
// on a frame-to-frame basis, we may miss inputs on the keyboard.
//
// NOTE: One thing we could instead is to actually use OnScreenControls that
// represent the controls of our device and then use that to generate
// input from actual human interaction.
public void OnUpdate()
{
var keyboard = Keyboard.current;
if (keyboard == null)
return;
var state = new CustomDeviceState();
state.x = 127;
state.y = 127;
// WARNING: It may be tempting to simply store some state related to updates
// directly on the device. For example, let's say we want scale the
// vector from WASD to a certain length which can be adjusted with
// the scroll wheel of the mouse. It seems natural to just store the
// current strength as a private field on CustomDevice.
//
// This will *NOT* work correctly. *All* input state must be stored
// under the domain of the input system. InputDevices themselves
// cannot private store their own separate state.
//
// What you *can* do however, is simply add fields your state struct
// (CustomDeviceState in our case) that contain the state you want
// to keep. It is not necessary to expose these as InputControls if
// you don't want to.
// Map WASD to stick.
var wPressed = keyboard.wKey.isPressed;
var aPressed = keyboard.aKey.isPressed;
var sPressed = keyboard.sKey.isPressed;
var dPressed = keyboard.dKey.isPressed;
if (aPressed)
state.x -= 127;
if (dPressed)
state.x += 127;
if (wPressed)
state.y += 127;
if (sPressed)
state.y -= 127;
// Map buttons to 1, 2, and 3.
if (keyboard.digit1Key.isPressed)
state.buttons |= 1 << 0;
if (keyboard.digit2Key.isPressed)
state.buttons |= 1 << 1;
if (keyboard.digit3Key.isPressed)
state.buttons |= 1 << 2;
// Finally, queue the event.
// NOTE: We are replacing the current device state wholesale here. An alternative
// would be to use QueueDeltaStateEvent to replace only select memory contents.
InputSystem.QueueStateEvent(this, state);
}
}