From 6d4088a17328603cbc7c85c8bacb49d064875e48 Mon Sep 17 00:00:00 2001
From: Serge Bazanski <q3k@q3k.org>
Date: Sun, 4 Apr 2021 15:46:29 +0000
Subject: [PATCH] engine: add input module

---
 engine/BUILD             |  2 +
 engine/src/input.rs      | 68 +++++++++++++++++++++++++++++++
 engine/src/main.rs       | 10 ++++-
 engine/src/render/mod.rs | 88 ++++++++++++++++++++++++++++++++++++----
 4 files changed, 158 insertions(+), 10 deletions(-)
 create mode 100644 engine/src/input.rs

diff --git a/engine/BUILD b/engine/BUILD
index 43bf509..c2cadca 100644
--- a/engine/BUILD
+++ b/engine/BUILD
@@ -13,6 +13,8 @@ rust_binary(
     srcs = [
         "src/main.rs",
 
+        "src/input.rs",
+
         "src/physics/mod.rs",
         "src/physics/color.rs",
 
diff --git a/engine/src/input.rs b/engine/src/input.rs
new file mode 100644
index 0000000..f7a4aff
--- /dev/null
+++ b/engine/src/input.rs
@@ -0,0 +1,68 @@
+use std::collections::{BTreeMap,BTreeSet};
+
+#[derive(Clone, Debug)]
+pub struct Input {
+    pub devices: BTreeMap<u64, Device>,
+    highest_no: u64,
+}
+impl ecs::Global for Input {}
+
+impl Input {
+    pub fn allocate_device(&mut self) -> u64 {
+        self.highest_no += 1;
+        self.highest_no
+    }
+    pub fn new() -> Self {
+        Self {
+            devices: BTreeMap::new(),
+            highest_no: 0,
+        }
+    }
+    pub fn mouse_cursor(&self) -> Option<&MouseCursor> {
+        for dev in self.devices.values() {
+            if let &Device::MouseCursor(cursor) = &dev {
+                return Some(&cursor);
+            }
+        }
+        None
+    }
+}
+
+#[derive(Clone, Debug)]
+pub enum Device {
+    MouseCursor(MouseCursor),
+}
+
+#[derive(Clone, Debug)]
+pub struct MouseCursor {
+    // x and y coordinates [0.0, 1.0), top left at (0, 0).
+    pub x: f32,
+    pub y: f32,
+
+    pressed: BTreeSet<MouseButton>,
+}
+
+impl MouseCursor {
+    pub fn new() -> Self {
+        Self {
+            x: 0., y: 0.,
+            pressed: BTreeSet::new(),
+        }
+    }
+
+    pub fn set_mouse_pressed(&mut self, button: MouseButton) {
+        self.pressed.insert(button);
+    }
+
+    pub fn set_mouse_released(&mut self, button: MouseButton) {
+        self.pressed.remove(&button);
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq)]
+pub enum MouseButton {
+    Left,
+    Middle,
+    Right,
+    Other,
+}
diff --git a/engine/src/main.rs b/engine/src/main.rs
index abc2315..6bdaa04 100644
--- a/engine/src/main.rs
+++ b/engine/src/main.rs
@@ -21,6 +21,7 @@ use std::time;
 
 use cgmath as cgm;
 
+pub mod input;
 mod render;
 mod util;
 mod physics;
@@ -158,13 +159,17 @@ impl Main {
 struct MainData<'a> {
     scene_info: ecs::ReadWriteGlobal<'a, render::SceneInfo>,
     time: ecs::ReadGlobal<'a, Time>,
+    input: ecs::ReadGlobal<'a, input::Input>,
     transforms: ecs::ReadWriteComponent<'a, Transform>,
 }
 
 impl<'a> ecs::System <'a> for Main {
     type SystemData = MainData<'a>;
     fn run(&mut self, sd: Self::SystemData) {
-        let position = (sd.time.get().instant() / 10.0) * 3.14 * 2.0;
+        let position: f32 = match sd.input.get().mouse_cursor() {
+            Some(cursor) => cursor.x,
+            _ => (sd.time.get().instant() / 10.0) * 3.14 * 2.0,
+        };
 
         let camera = cgm::Point3::new(
             7.0 + (position / 4.0).sin(),
@@ -209,10 +214,11 @@ fn main() {
     p.add_system(renderer);
 
     let start = time::Instant::now();
-    world.set_global(Time{
+    world.set_global(Time {
         start,
         now: start,
     });
+    world.set_global(input::Input::new());
     loop {
         world.global_mut::<Time>().get().now = time::Instant::now();
 
diff --git a/engine/src/render/mod.rs b/engine/src/render/mod.rs
index 2aaf6fb..149c665 100644
--- a/engine/src/render/mod.rs
+++ b/engine/src/render/mod.rs
@@ -48,6 +48,8 @@ pub use mesh::Mesh;
 pub use renderable::{Transform, Renderable};
 pub use resource::{Resource, ResourceID};
 
+use crate::input;
+
 const WIDTH: u32 = 800;
 const HEIGHT: u32 = 600;
 
@@ -57,9 +59,11 @@ pub struct Renderer {
     rm: resource::Manager,
 }
 
+
 #[derive(Clone, Debug)]
 pub struct Status {
     pub closed: bool,
+    pub input_device_id: u64,
 }
 impl ecs::Global for Status {}
 
@@ -76,15 +80,19 @@ impl<'a> ecs::System<'a> for Renderer {
         ecs::ReadComponent<'a, Renderable>,
         ecs::ReadWriteGlobal<'a, Status>,
         ecs::ReadGlobal<'a, SceneInfo>,
+        ecs::ReadWriteGlobal<'a, input::Input>,
     );
 
     fn run(&mut self,
         ( transforms
         , renderables
         , status
-        , scene): Self::SystemData,
+        , scene
+        , input): Self::SystemData,
     ) {
         let transformedRenderables = (transforms, renderables);
+        let mut input = input.get();
+        let mut status = status.get();
 
         let mut rd = vulkan::RenderData {
             meshes: BTreeMap::new(),
@@ -106,12 +114,38 @@ impl<'a> ecs::System<'a> for Renderer {
         let view = &scene.get().view;
         self.instance.flip(camera, view, &rd, &self.rm);
 
-        if self.poll_close() {
-            status.get().closed = true;
+        if status.input_device_id == 0 {
+            status.input_device_id = input.allocate_device();
+        }
+
+        let (close, events) = self.poll_close();
+        if close {
+            status.closed = true;
+        } else {
+            let mut device = input.devices.entry(status.input_device_id).or_insert(input::Device::MouseCursor(input::MouseCursor::new()));
+            if let &mut input::Device::MouseCursor(cursor) = &mut device {
+                for event in events {
+                    match event {
+                        InternalEvent::MousePressed(button) => cursor.set_mouse_pressed(button),
+                        InternalEvent::MouseReleased(button) => cursor.set_mouse_released(button),
+                        InternalEvent::MouseMoved(x, y) => {
+                            cursor.x = x as f32;
+                            cursor.y = y as f32;
+                        },
+                    }
+                }
+            }
         }
     }
 }
 
+#[derive(Clone,Debug)]
+enum InternalEvent {
+    MousePressed(input::MouseButton),
+    MouseReleased(input::MouseButton),
+    MouseMoved(f64, f64),
+}
+
 impl Renderer {
     pub fn initialize(world: &mut ecs::World) -> Self {
         world.set_global(SceneInfo {
@@ -120,6 +154,7 @@ impl Renderer {
         });
         world.set_global(Status {
             closed: false,
+            input_device_id: 0,
         });
 
         let mut instance = vulkan::Instance::new("abrasion".to_string());
@@ -143,16 +178,53 @@ impl Renderer {
         (events_loop, surface)
     }
 
-    fn poll_close(&mut self) -> bool {
+    fn poll_close(&mut self) -> (bool, Vec<InternalEvent>) {
         let mut close = false;
+
+        let mut events = vec![];
         // TODO(q3k): migrate to EventLoop::run
         self.events_loop.run_return(|ev, _, control_flow| {
-            if let Event::WindowEvent { event: WindowEvent::CloseRequested, .. } = ev {
-                close = true;
+            match ev {
+                Event::WindowEvent {
+                    event: WindowEvent::CloseRequested,
+                    ..
+                } => {
+                    close = true;
+                },
+                Event::MainEventsCleared => {
+                    *control_flow = winit::event_loop::ControlFlow::Exit;
+                },
+                Event::WindowEvent {
+                    event:  WindowEvent::CursorMoved { position, .. },
+                    ..
+                } => {
+                    events.push(InternalEvent::MouseMoved(position.x, position.y));
+                },
+                Event::WindowEvent { 
+                    event:  WindowEvent::MouseInput { state, button, .. },
+                    ..
+                } => {
+                    let button = match button {
+                        winit::event::MouseButton::Left => input::MouseButton::Left,
+                        winit::event::MouseButton::Middle => input::MouseButton::Middle,
+                        winit::event::MouseButton::Right => input::MouseButton::Right,
+                        _ => input::MouseButton::Other,
+                    };
+                    match state {
+                        winit::event::ElementState::Pressed => {
+                            events.push(InternalEvent::MousePressed(button));
+                        },
+                        winit::event::ElementState::Released => {
+                            events.push(InternalEvent::MouseReleased(button));
+                        },
+                    }
+                },
+                _ => {
+                    *control_flow = winit::event_loop::ControlFlow::Poll;
+                },
             }
-            *control_flow = winit::event_loop::ControlFlow::Exit;
         });
-        return close;
+        return (close, events);
     }
 
     pub fn add_resource<T: Resource>(&mut self, r: T) -> ResourceID<T> {