add rust/wasm impl

1 files changed, 60 insertions, 2 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 66bafe7..223e28a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,11 +1,69 @@
-use log::{Level, error, info};
+use std::rc::Rc;
+use std::cell::RefCell;
+
+use log::{Level, info};
 use wasm_bindgen::prelude::*;
-use web_sys::js_sys;
+
+use state::State;
+
+mod line;
+mod point;
+mod state;
+
+struct RenderLoop {
+    animation_id: Option<i32>,
+    pub closure: Option<Closure<dyn FnMut(f64)>>,
+}
+
+impl RenderLoop {
+    pub fn new() -> Self {
+        Self {
+            animation_id: None,
+            closure: None,
+        }
+    }
+}
+
+fn window() -> web_sys::Window {
+    web_sys::window().expect("no window")
+}
 
 #[wasm_bindgen(start)]
 pub fn init() -> Result<(), JsValue> {
     console_log::init_with_level(Level::Debug).expect("couldn't init console log");
     info!("wasm init");
 
+    let mut s = State::new()?;
+    s.render_frame(0.0)?;
+
+    //
+    // from https://users.rust-lang.org/t/wasm-web-sys-how-to-use-window-request-animation-frame-resolved/20882
+    //
+
+    let render_loop: Rc<RefCell<RenderLoop>> = Rc::new(RefCell::new(RenderLoop::new()));
+    {
+        let closure: Closure<dyn FnMut(f64)> = {
+            let render_loop = render_loop.clone();
+            Closure::wrap(Box::new(move |t| {
+                s.render_frame(t).expect("should render frame");
+                if !s.paused {
+                    let mut render_loop = render_loop.borrow_mut();
+                    render_loop.animation_id = if let Some(ref closure) = render_loop.closure {
+                        Some(window().request_animation_frame(closure.as_ref().unchecked_ref()).expect("req anim frame"))
+                    } else {
+                        None
+                    }
+                }
+            }))
+        };
+        let mut render_loop = render_loop.borrow_mut();
+        render_loop.animation_id = Some(window().request_animation_frame(closure.as_ref().unchecked_ref()).expect("req anim frame"));
+        render_loop.closure = Some(closure);
+    }
+
+    //
+    //
+    //
+
     Ok(())
 }