Fix initial Android support (#778)

* Add force touches, fix ui focus system and touch screen system

* Fix examples README. Update rodio with Android support. Add Android build CI

* Alter android metadata in root Cargo.toml

.github/workflows/ci.yml

@@ -85,6 +85,17 @@ jobs:
           command: check
           args: --target wasm32-unknown-unknown --no-default-features --features bevy_winit,x11,hdr,bevy_gltf
 
+  build-android:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Android targets
+      run: rustup target add aarch64-linux-android armv7-linux-androideabi
+    - name: Install Cargo APK
+      run: cargo install cargo-apk
+    - name: Build APK
+      run: cargo apk build --example bevy_android
+
   clean:
     runs-on: ubuntu-latest
     steps:

Cargo.toml

@@ -30,21 +30,6 @@ default = [
     "x11",
 ]
 
-supported_android_features = [
-    # cpal is not supported yet
-    # "bevy_audio",
-    "bevy_dynamic_plugin",
-    "bevy_gilrs",
-    "bevy_gltf",
-    "bevy_wgpu",
-    "bevy_winit",
-    "render",
-    "png",
-    "hdr",
-    # "mp3",
-    "x11",
-]
-
 profiler = ["bevy_ecs/profiler", "bevy_diagnostic/profiler"]
 wgpu_trace = ["bevy_wgpu/trace"]
 
@@ -341,10 +326,6 @@ path = "examples/android/bevy_android.rs"
 crate-type = ["cdylib"]
 
 [package.metadata.android]
-build_targets = [ "aarch64-linux-android", "armv7-linux-androideabi" ]
-target_sdk_version = 28
-min_sdk_version = 28
-
-[[package.metadata.android.feature]]
-name = "android.hardware.vulkan.level"
-version = "1"
+build_targets = ["aarch64-linux-android", "armv7-linux-androideabi"]
+target_sdk_version = 29
+min_sdk_version = 16

crates/bevy_audio/Cargo.toml

@@ -22,7 +22,7 @@ bevy_utils = { path = "../bevy_utils", version = "0.2.1" }
 
 # other
 anyhow = "1.0"
-rodio = { version = "0.12", default-features = false }
+rodio = { version = "0.13", default-features = false }
 parking_lot = "0.11.0"
 
 [features]

crates/bevy_input/src/lib.rs

@@ -17,6 +17,7 @@ pub mod prelude {
         },
         keyboard::KeyCode,
         mouse::MouseButton,
+        touch::{TouchInput, Touches},
         Axis, Input,
     };
 }

crates/bevy_input/src/touch.rs

@@ -1,20 +1,73 @@
 use bevy_app::{EventReader, Events};
 use bevy_ecs::{Local, Res, ResMut};
 use bevy_math::Vec2;
-use bevy_utils::{HashMap, HashSet};
+use bevy_utils::HashMap;
+use core::ops::DerefMut;
 
-/// A touch input event
-#[derive(Debug, Clone)]
+/// Represents a touch event
+///
+/// Every time the user touches the screen, a new `Start` event with an unique
+/// identifier for the finger is generated. When the finger is lifted, an `End`
+/// event is generated with the same finger id.
+///
+/// After a `Start` event has been emitted, there may be zero or more `Move`
+/// events when the finger is moved or the touch pressure changes.
+///
+/// The finger id may be reused by the system after an `End` event. The user
+/// should assume that a new `Start` event received with the same id has nothing
+/// to do with the old finger and is a new finger.
+///
+/// A `Cancelled` event is emitted when the system has canceled tracking this
+/// touch, such as when the window loses focus, or on iOS if the user moves the
+/// device against their face.
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub struct TouchInput {
     pub phase: TouchPhase,
     pub position: Vec2,
+    /// Describes how hard the screen was pressed. May be `None` if the platform
+    /// does not support pressure sensitivity.
     ///
     /// ## Platform-specific
     ///
+    /// - Only available on **iOS** 9.0+ and **Windows** 8+.
+    pub force: Option<ForceTouch>,
     /// Unique identifier of a finger.
     pub id: u64,
 }
 
+/// Describes the force of a touch event
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ForceTouch {
+    /// On iOS, the force is calibrated so that the same number corresponds to
+    /// roughly the same amount of pressure on the screen regardless of the
+    /// device.
+    Calibrated {
+        /// The force of the touch, where a value of 1.0 represents the force of
+        /// an average touch (predetermined by the system, not user-specific).
+        ///
+        /// The force reported by Apple Pencil is measured along the axis of the
+        /// pencil. If you want a force perpendicular to the device, you need to
+        /// calculate this value using the `altitude_angle` value.
+        force: f64,
+        /// The maximum possible force for a touch.
+        ///
+        /// The value of this field is sufficiently high to provide a wide
+        /// dynamic range for values of the `force` field.
+        max_possible_force: f64,
+        /// The altitude (in radians) of the stylus.
+        ///
+        /// A value of 0 radians indicates that the stylus is parallel to the
+        /// surface. The value of this property is Pi/2 when the stylus is
+        /// perpendicular to the surface.
+        altitude_angle: Option<f64>,
+    },
+    /// If the platform reports the force as normalized, we have no way of
+    /// knowing how much pressure 1.0 corresponds to – we know it's the maximum
+    /// amount of force, but as to how much force, you might either have to
+    /// press really really hard, or not hard at all, depending on the device.
+    Normalized(f64),
+}
+
 /// Describes touch-screen input state.
 #[derive(Debug, Hash, PartialEq, Eq, Clone, Copy)]
 #[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
@@ -30,12 +83,15 @@ pub struct TouchSystemState {
     touch_event_reader: EventReader<TouchInput>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub struct Touch {
     pub id: u64,
     pub start_position: Vec2,
+    pub start_force: Option<ForceTouch>,
     pub previous_position: Vec2,
+    pub previous_force: Option<ForceTouch>,
     pub position: Vec2,
+    pub force: Option<ForceTouch>,
 }
 
 impl Touch {
@@ -48,47 +104,69 @@ impl Touch {
     }
 }
 
-#[derive(Default)]
+impl From<&TouchInput> for Touch {
+    fn from(input: &TouchInput) -> Touch {
+        Touch {
+            id: input.id,
+            start_position: input.position,
+            start_force: input.force,
+            previous_position: input.position,
+            previous_force: input.force,
+            position: input.position,
+            force: input.force,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Default)]
 pub struct Touches {
-    active_touches: HashMap<u64, Touch>,
-    just_pressed: HashSet<u64>,
-    just_released: HashSet<u64>,
-    just_cancelled: HashSet<u64>,
+    pressed: HashMap<u64, Touch>,
+    just_pressed: HashMap<u64, Touch>,
+    just_released: HashMap<u64, Touch>,
+    just_cancelled: HashMap<u64, Touch>,
 }
 
 impl Touches {
     pub fn iter(&self) -> impl Iterator<Item = &Touch> + '_ {
-        self.active_touches.values()
+        self.pressed.values()
+    }
+
+    pub fn get_pressed(&self, id: u64) -> Option<&Touch> {
+        self.pressed.get(&id)
     }
 
     pub fn just_pressed(&self, id: u64) -> bool {
-        self.just_pressed.contains(&id)
+        self.just_pressed.contains_key(&id)
     }
 
     pub fn iter_just_pressed(&self) -> impl Iterator<Item = &Touch> + '_ {
         self.just_pressed
             .iter()
-            .map(move |id| self.active_touches.get(id).unwrap())
+            .map(move |(id, _)| self.pressed.get(id).unwrap())
+    }
+
+    pub fn get_released(&self, id: u64) -> Option<&Touch> {
+        self.just_released.get(&id)
     }
 
     pub fn just_released(&self, id: u64) -> bool {
-        self.just_released.contains(&id)
+        self.just_released.contains_key(&id)
     }
 
     pub fn iter_just_released(&self) -> impl Iterator<Item = &Touch> + '_ {
         self.just_released
             .iter()
-            .map(move |id| self.active_touches.get(id).unwrap())
+            .map(move |(id, _)| self.pressed.get(id).unwrap())
     }
 
     pub fn just_cancelled(&self, id: u64) -> bool {
-        self.just_cancelled.contains(&id)
+        self.just_cancelled.contains_key(&id)
     }
 
     pub fn iter_just_cancelled(&self) -> impl Iterator<Item = &Touch> + '_ {
         self.just_cancelled
             .iter()
-            .map(move |id| self.active_touches.get(id).unwrap())
+            .map(move |(id, _)| self.pressed.get(id).unwrap())
     }
 }
 
@@ -98,45 +176,30 @@ pub fn touch_screen_input_system(
     mut touch_state: ResMut<Touches>,
     touch_input_events: Res<Events<TouchInput>>,
 ) {
-    let touch_state = &mut *touch_state;
-    for released_id in touch_state.just_released.iter() {
-        touch_state.active_touches.remove(&released_id);
-    }
-
-    for cancelled_id in touch_state.just_cancelled.iter() {
-        touch_state.active_touches.remove(&cancelled_id);
-    }
-
+    let touch_state = touch_state.deref_mut();
     touch_state.just_pressed.clear();
-    touch_state.just_cancelled.clear();
-
+    touch_state.just_released.clear();
     for event in state.touch_event_reader.iter(&touch_input_events) {
-        let active_touch = touch_state.active_touches.get(&event.id);
         match event.phase {
             TouchPhase::Started => {
-                touch_state.active_touches.insert(
-                    event.id,
-                    Touch {
-                        id: event.id,
-                        start_position: event.position,
-                        previous_position: event.position,
-                        position: event.position,
-                    },
-                );
-                touch_state.just_pressed.insert(event.id);
+                touch_state.pressed.insert(event.id, event.into());
+                touch_state.just_pressed.insert(event.id, event.into());
             }
             TouchPhase::Moved => {
-                let old_touch = active_touch.unwrap();
-                let mut new_touch = old_touch.clone();
+                let mut new_touch = touch_state.pressed.get(&event.id).cloned().unwrap();
                 new_touch.previous_position = new_touch.position;
+                new_touch.previous_force = new_touch.force;
                 new_touch.position = event.position;
-                touch_state.active_touches.insert(event.id, new_touch);
+                new_touch.force = event.force;
+                touch_state.pressed.insert(event.id, new_touch);
             }
             TouchPhase::Ended => {
-                touch_state.just_released.insert(event.id);
+                touch_state.just_released.insert(event.id, event.into());
+                touch_state.pressed.remove_entry(&event.id);
             }
             TouchPhase::Cancelled => {
-                touch_state.just_cancelled.insert(event.id);
+                touch_state.just_cancelled.insert(event.id, event.into());
+                touch_state.pressed.remove_entry(&event.id);
             }
         };
     }

crates/bevy_ui/src/focus.rs

@@ -2,7 +2,7 @@ use crate::Node;
 use bevy_app::{EventReader, Events};
 use bevy_core::FloatOrd;
 use bevy_ecs::prelude::*;
-use bevy_input::{mouse::MouseButton, Input};
+use bevy_input::{mouse::MouseButton, touch::Touches, Input};
 use bevy_math::Vec2;
 use bevy_transform::components::GlobalTransform;
 use bevy_window::CursorMoved;
@@ -43,6 +43,7 @@ pub fn ui_focus_system(
     mut state: Local<State>,
     mouse_button_input: Res<Input<MouseButton>>,
     cursor_moved_events: Res<Events<CursorMoved>>,
+    touches_input: Res<Touches>,
     mut node_query: Query<(
         Entity,
         &Node,
@@ -54,8 +55,11 @@ pub fn ui_focus_system(
     if let Some(cursor_moved) = state.cursor_moved_event_reader.latest(&cursor_moved_events) {
         state.cursor_position = cursor_moved.position;
     }
+    if let Some(touch) = touches_input.get_pressed(0) {
+        state.cursor_position = touch.position;
+    }
 
-    if mouse_button_input.just_released(MouseButton::Left) {
+    if mouse_button_input.just_released(MouseButton::Left) || touches_input.just_released(0) {
         for (_entity, _node, _global_transform, interaction, _focus_policy) in node_query.iter_mut()
         {
             if let Some(mut interaction) = interaction {
@@ -66,7 +70,8 @@ pub fn ui_focus_system(
         }
     }
 
-    let mouse_clicked = mouse_button_input.just_pressed(MouseButton::Left);
+    let mouse_clicked =
+        mouse_button_input.just_pressed(MouseButton::Left) || touches_input.just_released(0);
     let mut hovered_entity = None;
 
     {

crates/bevy_winit/src/converters.rs

@@ -1,7 +1,7 @@
 use bevy_input::{
     keyboard::{KeyCode, KeyboardInput},
     mouse::MouseButton,
-    touch::{TouchInput, TouchPhase},
+    touch::{ForceTouch, TouchInput, TouchPhase},
     ElementState,
 };
 use bevy_math::Vec2;
@@ -39,6 +39,18 @@ pub fn convert_touch_input(touch_input: winit::event::Touch) -> TouchInput {
             winit::event::TouchPhase::Cancelled => TouchPhase::Cancelled,
         },
         position: Vec2::new(touch_input.location.x as f32, touch_input.location.y as f32),
+        force: touch_input.force.map(|f| match f {
+            winit::event::Force::Calibrated {
+                force,
+                max_possible_force,
+                altitude_angle,
+            } => ForceTouch::Calibrated {
+                force,
+                max_possible_force,
+                altitude_angle,
+            },
+            winit::event::Force::Normalized(x) => ForceTouch::Normalized(x),
+        }),
         id: touch_input.id,
     }
 }

crates/bevy_winit/src/lib.rs

@@ -261,9 +261,15 @@ pub fn winit_runner(mut app: App) {
                         });
                     }
                 },
-                WindowEvent::Touch(touch) => {
+                WindowEvent::Touch(mut touch) => {
                     let mut touch_input_events =
                         app.resources.get_mut::<Events<TouchInput>>().unwrap();
+                    let windows = app.resources.get_mut::<Windows>().unwrap();
+                    // FIXME?: On Android window start is top while on PC/Linux/OSX on bottom
+                    if cfg!(target_os = "android") {
+                        let window_height = windows.get_primary().unwrap().height();
+                        touch.location.y = window_height as f64 - touch.location.y;
+                    }
                     touch_input_events.send(converters::convert_touch_input(touch));
                 }
                 _ => {}

examples/README.md

@@ -2,7 +2,8 @@
 
 These examples demonstrate the main features of Bevy and how to use them.
 To run an example, use the command `cargo run --example <Example>`, and add the option `--features x11` or `--features wayland` to force the example to run on a specific window compositor, e.g.
-```
+
+```sh
 cargo run --features wayland --example hello_world
 ```
 
@@ -119,47 +120,61 @@ Example | File | Description
 
 ## WASM
 
-#### pre-req
+#### Pre-requirements
 
-    $ rustup target add wasm32-unknown-unknown
-    $ cargo install wasm-bindgen-cli
+```sh
+rustup target add wasm32-unknown-unknown
+cargo install wasm-bindgen-cli
+```
 
-#### build & run
+#### Build & run
 
 Following is an example for `headless_wasm`. For other examples in wasm/ directory,
 change the `headless_wasm` in the following commands **and edit** `examples/wasm/index.html`
 to point to the correct `.js` file.
 
-    $ cargo build --example headless_wasm --target wasm32-unknown-unknown --no-default-features
-    $ wasm-bindgen --out-dir examples/wasm/target --target web target/wasm32-unknown-unknown/debug/examples/headless_wasm.wasm
+```sh
+cargo build --example headless_wasm --target wasm32-unknown-unknown --no-default-features
+wasm-bindgen --out-dir examples/wasm/target --target web target/wasm32-unknown-unknown/debug/examples/headless_wasm.wasm
+```
 
 Then serve `examples/wasm` dir to browser. i.e.
 
-    $ basic-http-server examples/wasm
+```sh
+basic-http-server examples/wasm
+```
 
 ## iOS
 
-#### pre-req
+#### Pre-requirements
 
-    $ rustup target add aarch64-apple-ios x86_64-apple-ios
-    $ cargo install cargo-lipo
+```sh
+rustup target add aarch64-apple-ios x86_64-apple-ios
+cargo install cargo-lipo
+```
 
-#### build & run
+#### Build & run
 
 Using bash:
 
-    $ cd examples/ios
-    $ make run
+```sh
+cd examples/ios
+make run
+```
 
 In an ideal world, this will boot up, install and run the app for the first
 iOS simulator in your `xcrun simctl devices list`. If this fails, you can
 specify the simulator device UUID via:
 
-    $ DEVICE_ID=${YOUR_DEVICE_ID} make run
+```sh
+DEVICE_ID=${YOUR_DEVICE_ID} make run
+```
 
 If you'd like to see xcode do stuff, you can run
 
-    $ open bevy_ios_example.xcodeproj/
+```sh
+open bevy_ios_example.xcodeproj/
+```
 
 which will open xcode. You then must push the zoom zoom play button and wait
 for the magic.
@@ -175,42 +190,46 @@ used for the `Makefile`.
 
 ## Android
 
-#### pre-req
+#### Pre-requirements
 
-    $ rustup target add aarch64-linux-android armv7-linux-androideabi
-    $ cargo install cargo-apk
+```sh
+rustup target add aarch64-linux-android armv7-linux-androideabi
+cargo install cargo-apk
+```
 
-The Android SDK 29 must be installed, and the environment variable `ANDROID_SDK_ROOT` set to the root Android `sdk` folder.
+The Android SDK must be installed, and the environment variable `ANDROID_SDK_ROOT` set to the root Android `sdk` folder.
 
 When using `NDK (Side by side)`, the environment variable `ANDROID_NDK_ROOT` must also be set to one of the NDKs in `sdk\ndk\[NDK number]`.
 
-#### build & run
+#### Build & run
 
 To run on a device setup for Android development, run:
 
-    $ cargo apk run --example bevy_android --features="supported_android_features" --no-default-features
+```sh
+cargo apk run --example bevy_android
+```
 
 :warning: At this time Bevy does not work in Android Emulator.
 
 When using Bevy as a library, the following fields must be added to `Cargo.toml`:
 
-    [package.metadata.android]
-    build_targets = [ "aarch64-linux-android", "armv7-linux-androideabi" ]
-    target_sdk_version = 29
-    min_sdk_version = 29
-
-    [[package.metadata.android.feature]]
-    name = "android.hardware.vulkan.level"
-    version = "1"
+```toml
+[package.metadata.android]
+build_targets = ["aarch64-linux-android", "armv7-linux-androideabi"]
+target_sdk_version = 29
+min_sdk_version = 16
+```
 
 Please reference `cargo-apk` [README](https://crates.io/crates/cargo-apk) for other Android Manifest fields.
 
-#### old phones
+#### Old phones
 
-Bevy by default requires Android API level 29 which is the [Play Store's minimum API to upload or update apps](https://developer.android.com/distribute/best-practices/develop/target-sdk). Users of older phones may want to use an older API when testing.
+Bevy by default targets Android API level 29 in its examples which is the [Play Store's minimum API to upload or update apps](https://developer.android.com/distribute/best-practices/develop/target-sdk). Users of older phones may want to use an older API when testing.
 
 To use a different API, the following fields must be updated in Cargo.toml:
 
-    [package.metadata.android]
-    target_sdk_version = >>API<<
-    min_sdk_version = >>API or less<<
+```toml
+[package.metadata.android]
+target_sdk_version = >>API<<
+min_sdk_version = >>API or less<<
+```