Put input sources for bevy_input under features

Cargo.toml

@@ -599,6 +599,21 @@ libm = ["bevy_internal/libm"]
 # Enables use of browser APIs. Note this is currently only applicable on `wasm32` architectures.
 web = ["bevy_internal/web"]
 
+# Mouse support. Automatically enabled by `bevy_window`.
+mouse = ["bevy_internal/mouse"]
+
+# Keyboard support. Automatically enabled by `bevy_window`.
+keyboard = ["bevy_internal/keyboard"]
+
+# Gamepad support. Automatically enabled by `bevy_gilrs`.
+gamepad = ["bevy_internal/gamepad"]
+
+# Touch support. Automatically enabled by `bevy_window`.
+touch = ["bevy_internal/touch"]
+
+# Gestures support. Automatically enabled by `bevy_window`.
+gestures = ["bevy_internal/gestures"]
+
 # Enable hotpatching of Bevy systems
 hotpatching = ["bevy_internal/hotpatching"]
 

crates/bevy_gilrs/Cargo.toml

@@ -12,7 +12,9 @@ keywords = ["bevy"]
 # bevy
 bevy_app = { path = "../bevy_app", version = "0.18.0-dev" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.18.0-dev" }
-bevy_input = { path = "../bevy_input", version = "0.18.0-dev" }
+bevy_input = { path = "../bevy_input", version = "0.18.0-dev", features = [
+  "gamepad",
+] }
 bevy_time = { path = "../bevy_time", version = "0.18.0-dev" }
 bevy_platform = { path = "../bevy_platform", version = "0.18.0-dev", default-features = false, features = [
   "std",

crates/bevy_input/Cargo.toml

@@ -13,6 +13,13 @@ default = ["std", "bevy_reflect", "bevy_ecs/async_executor", "smol_str"]
 
 # Functionality
 
+## Input sources
+mouse = []
+keyboard = []
+gamepad = []
+touch = []
+gestures = []
+
 ## Adds runtime reflection support using `bevy_reflect`.
 bevy_reflect = [
   "dep:bevy_reflect",

crates/bevy_input/src/lib.rs

@@ -21,10 +21,20 @@ mod axis;
 mod button_input;
 /// Common run conditions
 pub mod common_conditions;
+
+#[cfg(feature = "gamepad")]
 pub mod gamepad;
+
+#[cfg(feature = "gestures")]
 pub mod gestures;
+
+#[cfg(feature = "keyboard")]
 pub mod keyboard;
+
+#[cfg(feature = "mouse")]
 pub mod mouse;
+
+#[cfg(feature = "touch")]
 pub mod touch;
 
 pub use axis::*;
@@ -35,28 +45,47 @@ pub use button_input::*;
 /// This includes the most common types in this crate, re-exported for your convenience.
 pub mod prelude {
     #[doc(hidden)]
-    pub use crate::{
-        gamepad::{Gamepad, GamepadAxis, GamepadButton, GamepadSettings},
-        keyboard::KeyCode,
-        mouse::MouseButton,
-        touch::{TouchInput, Touches},
-        Axis, ButtonInput,
-    };
+    pub use crate::{Axis, ButtonInput};
+
+    #[doc(hidden)]
+    #[cfg(feature = "gamepad")]
+    pub use crate::gamepad::{Gamepad, GamepadAxis, GamepadButton, GamepadSettings};
+
+    #[doc(hidden)]
+    #[cfg(feature = "keyboard")]
+    pub use crate::keyboard::KeyCode;
+
+    #[doc(hidden)]
+    #[cfg(feature = "mouse")]
+    pub use crate::mouse::MouseButton;
+
+    #[doc(hidden)]
+    #[cfg(feature = "touch")]
+    pub use crate::touch::{TouchInput, Touches};
 }
 
 use bevy_app::prelude::*;
 use bevy_ecs::prelude::*;
 #[cfg(feature = "bevy_reflect")]
 use bevy_reflect::Reflect;
+
+#[cfg(feature = "gestures")]
 use gestures::*;
+
+#[cfg(feature = "keyboard")]
 use keyboard::{keyboard_input_system, Key, KeyCode, KeyboardFocusLost, KeyboardInput};
+
+#[cfg(feature = "mouse")]
 use mouse::{
     accumulate_mouse_motion_system, accumulate_mouse_scroll_system, mouse_button_input_system,
     AccumulatedMouseMotion, AccumulatedMouseScroll, MouseButton, MouseButtonInput, MouseMotion,
     MouseWheel,
 };
+
+#[cfg(feature = "touch")]
 use touch::{touch_screen_input_system, TouchInput, Touches};
 
+#[cfg(feature = "gamepad")]
 use gamepad::{
     gamepad_connection_system, gamepad_event_processing_system, GamepadAxisChangedEvent,
     GamepadButtonChangedEvent, GamepadButtonStateChangedEvent, GamepadConnectionEvent,
@@ -67,7 +96,7 @@ use gamepad::{
 #[cfg(all(feature = "serialize", feature = "bevy_reflect"))]
 use bevy_reflect::{ReflectDeserialize, ReflectSerialize};
 
-/// Adds keyboard and mouse input to an App
+/// Adds input from various sources to an App
 #[derive(Default)]
 pub struct InputPlugin;
 
@@ -80,18 +109,22 @@ pub struct InputSystems;
 pub type InputSystem = InputSystems;
 
 impl Plugin for InputPlugin {
+    #[expect(clippy::allow_attributes, reason = "this is only sometimes unused")]
+    #[allow(unused, reason = "all features could be disabled")]
     fn build(&self, app: &mut App) {
-        app
-            // keyboard
-            .add_message::<KeyboardInput>()
+        #[cfg(feature = "keyboard")]
+        app.add_message::<KeyboardInput>()
             .add_message::<KeyboardFocusLost>()
             .init_resource::<ButtonInput<KeyCode>>()
             .init_resource::<ButtonInput<Key>>()
-            .add_systems(PreUpdate, keyboard_input_system.in_set(InputSystems))
-            // mouse
-            .add_message::<MouseButtonInput>()
+            .add_systems(PreUpdate, keyboard_input_system.in_set(InputSystems));
+
+        #[cfg(feature = "mouse")]
+        app.add_message::<MouseButtonInput>()
             .add_message::<MouseMotion>()
             .add_message::<MouseWheel>()
+            .init_resource::<AccumulatedMouseMotion>()
+            .init_resource::<AccumulatedMouseScroll>()
             .init_resource::<ButtonInput<MouseButton>>()
             .add_systems(
                 PreUpdate,
@@ -101,13 +134,16 @@ impl Plugin for InputPlugin {
                     accumulate_mouse_scroll_system,
                 )
                     .in_set(InputSystems),
-            )
-            .add_message::<PinchGesture>()
+            );
+
+        #[cfg(feature = "gestures")]
+        app.add_message::<PinchGesture>()
             .add_message::<RotationGesture>()
             .add_message::<DoubleTapGesture>()
-            .add_message::<PanGesture>()
-            // gamepad
-            .add_message::<GamepadEvent>()
+            .add_message::<PanGesture>();
+
+        #[cfg(feature = "gamepad")]
+        app.add_message::<GamepadEvent>()
             .add_message::<GamepadConnectionEvent>()
             .add_message::<GamepadButtonChangedEvent>()
             .add_message::<GamepadButtonStateChangedEvent>()
@@ -116,18 +152,17 @@ impl Plugin for InputPlugin {
             .add_message::<RawGamepadAxisChangedEvent>()
             .add_message::<RawGamepadButtonChangedEvent>()
             .add_message::<GamepadRumbleRequest>()
-            .init_resource::<AccumulatedMouseMotion>()
-            .init_resource::<AccumulatedMouseScroll>()
             .add_systems(
                 PreUpdate,
                 (
                     gamepad_connection_system,
                     gamepad_event_processing_system.after(gamepad_connection_system),
                 )
                     .in_set(InputSystems),
-            )
-            // touch
-            .add_message::<TouchInput>()
+            );
+
+        #[cfg(feature = "touch")]
+        app.add_message::<TouchInput>()
             .init_resource::<Touches>()
             .add_systems(PreUpdate, touch_screen_input_system.in_set(InputSystems));
     }

crates/bevy_internal/Cargo.toml

@@ -426,6 +426,13 @@ async_executor = [
 # Note this is currently only applicable on `wasm32` architectures.
 web = ["bevy_app/web", "bevy_platform/web", "bevy_reflect/web"]
 
+# Input sources.
+mouse = ["bevy_input/mouse"]
+keyboard = ["bevy_input/keyboard"]
+gamepad = ["bevy_input/gamepad"]
+touch = ["bevy_input/touch"]
+gestures = ["bevy_input/gestures"]
+
 hotpatching = ["bevy_app/hotpatching", "bevy_ecs/hotpatching"]
 
 debug = ["bevy_utils/debug"]

crates/bevy_window/Cargo.toml

@@ -50,7 +50,12 @@ libm = ["bevy_math/libm"]
 # bevy
 bevy_app = { path = "../bevy_app", version = "0.18.0-dev", default-features = false }
 bevy_ecs = { path = "../bevy_ecs", version = "0.18.0-dev", default-features = false }
-bevy_input = { path = "../bevy_input", version = "0.18.0-dev", default-features = false }
+bevy_input = { path = "../bevy_input", version = "0.18.0-dev", default-features = false, features = [
+  "gestures",
+  "keyboard",
+  "mouse",
+  "touch",
+] }
 bevy_math = { path = "../bevy_math", version = "0.18.0-dev", default-features = false }
 bevy_platform = { path = "../bevy_platform", version = "0.18.0-dev", default-features = false }
 

docs/cargo_features.md

@@ -105,6 +105,8 @@ The default feature set enables most of the expected features of a game engine,
 |flac|FLAC audio format support|
 |force_disable_dlss|Forcibly disable DLSS so that cargo build --all-features works without the DLSS SDK being installed. Not meant for users.|
 |free_cam|Enables the free cam from bevy_camera_controller|
+|gamepad|Gamepad support. Automatically enabled by `bevy_gilrs`.|
+|gestures|Gestures support. Automatically enabled by `bevy_window`.|
 |ghost_nodes|Experimental support for nodes that are ignored for UI layouting|
 |gif|GIF image format support|
 |glam_assert|Enable assertions to check the validity of parameters passed to glam|
@@ -113,9 +115,11 @@ The default feature set enables most of the expected features of a game engine,
 |https|Enables downloading assets from HTTPS sources. Warning: there are security implications. Read the docs on WebAssetPlugin.|
 |ico|ICO image format support|
 |jpeg|JPEG image format support|
+|keyboard|Keyboard support. Automatically enabled by `bevy_window`.|
 |libm|Uses the `libm` maths library instead of the one provided in `std` and `core`.|
 |meshlet|Enables the meshlet renderer for dense high-poly scenes (experimental)|
 |meshlet_processor|Enables processing meshes into meshlet meshes for bevy_pbr|
+|mouse|Mouse support. Automatically enabled by `bevy_window`.|
 |mp3|MP3 audio format support|
 |pbr_anisotropy_texture|Enable support for anisotropy texture in the `StandardMaterial`, at the risk of blowing past the global, per-shader texture limit on older/lower-end GPUs|
 |pbr_clustered_decals|Enable support for Clustered Decals|
@@ -143,6 +147,7 @@ The default feature set enables most of the expected features of a game engine,
 |symphonia-wav|WAV audio format support (through symphonia)|
 |tga|TGA image format support|
 |tiff|TIFF image format support|
+|touch|Touch support. Automatically enabled by `bevy_window`.|
 |trace|Tracing support|
 |trace_chrome|Tracing support, saving a file in Chrome Tracing format|
 |trace_tracy|Tracing support, exposing a port for Tracy|

release-content/migration-guides/bevy_input_features.md

@@ -0,0 +1,27 @@
+---
+title: Put input sources for `bevy_input` under features
+pull_requests: [21447]
+---
+
+`bevy_input` provides primitives for all kinds of input. But on
+consoles you usually don't have things like touch. On more obscure
+platforms, like GBA, only gamepad input is needed.
+
+If you use `bevy_window` or `bevy_gilrs`, they will automatically
+enable the necessary features on `bevy_input`. If you don't depend
+on them (for example, if you are developing for a platform that
+isn't supported by these crates), you need to enable the required
+input sources on `bevy_input` manually:
+
+```toml
+# Before:
+bevy = { version = "0.17", default-features = false }
+# After (enable sources that you actually use):
+bevy = { version = "0.18", default-features = false, features = [
+  "mouse",
+  "keyboard",
+  "gamepad",
+  "touch",
+  "gestures",
+] }
+```