ci: better build scripts

src/emscripten.rs

@@ -0,0 +1,44 @@
+// taken from https://github.com/Gigoteur/PX8/blob/master/src/px8/emscripten.rs
+#[cfg(target_os = "emscripten")]
+pub mod emscripten {
+    use std::cell::RefCell;
+    use std::ptr::null_mut;
+    use std::os::raw::{c_int, c_void, c_char, c_float};
+    use std::ffi::{CStr, CString};
+
+    #[allow(non_camel_case_types)]
+    type em_callback_func = unsafe extern "C" fn();
+
+    extern "C" {
+        // void emscripten_set_main_loop(em_callback_func func, int fps, int simulate_infinite_loop)
+        pub fn emscripten_set_main_loop(func: em_callback_func,
+                                        fps: c_int,
+                                        simulate_infinite_loop: c_int);
+
+        pub fn emscripten_cancel_main_loop();
+        pub fn emscripten_pause_main_loop();
+        pub fn emscripten_get_now() -> c_float;
+    }
+
+    thread_local!(static MAIN_LOOP_CALLBACK: RefCell<*mut c_void> = RefCell::new(null_mut()));
+
+    pub fn set_main_loop_callback<F>(callback: F)
+        where F: FnMut()
+    {
+        MAIN_LOOP_CALLBACK
+            .with(|log| { *log.borrow_mut() = &callback as *const _ as *mut c_void; });
+
+        unsafe {
+            emscripten_set_main_loop(wrapper::<F>, -1, 1);
+        }
+
+        unsafe extern "C" fn wrapper<F>()
+            where F: FnMut()
+        {
+            MAIN_LOOP_CALLBACK.with(|z| {
+                let closure = *z.borrow_mut() as *mut F;
+                (*closure)();
+            });
+        }
+    }
+}

src/main.rs

@@ -5,6 +5,9 @@ use sdl2::keyboard::{Keycode, Mod};
 use std::time::Duration;
 use crate::constants::{WINDOW_WIDTH, WINDOW_HEIGHT};
 
+#[cfg(target_os = "emscripten")]
+pub mod emscripten;
+
 mod constants;
 mod board;
 mod game;
@@ -19,27 +22,34 @@ pub fn main() {
         .expect("Could not initialize window");
 
     let mut canvas = window.into_canvas().build().expect("Could not build canvas");
-    let texture_creator= canvas.texture_creator();
+    let texture_creator = canvas.texture_creator();
 
     let map_texture = texture_creator.load_texture("assets/map.png").expect("Could not load pacman texture");
     canvas.copy(&map_texture, None, None).expect("Could not render texture on canvas");
 
     let mut event_pump = sdl_context.event_pump().expect("Could not get SDL EventPump");
-    'main: loop {
+    let mut main_loop = || {
         for event in event_pump.poll_iter() {
             match event {
                 Event::Quit { .. } |
-                Event::KeyDown { keycode: Some(Keycode::Q), .. } => {
-                    break 'main;
-                }
-                event @ Event::KeyDown {  .. } => {
+                Event::KeyDown { keycode: Some(Keycode::Q), .. } => break,
+                event @ Event::KeyDown { .. } => {
                     println!("{:?}", event);
-                },
+                }
                 _ => {}
             }
         }
 
         canvas.present();
         ::std::thread::sleep(Duration::from_millis(10));
-    }
+    };
+
+    #[cfg(target_os = "emscripten")]
+    use emscripten::{emscripten};
+
+    #[cfg(target_os = "emscripten")]
+    emscripten::set_main_loop_callback(main_loop);
+
+    #[cfg(not(target_os = "emscripten"))]
+    loop { main_loop(); }
 }