working sdl2 example, albeit messy

src/bin/example.rs

@@ -6,8 +6,12 @@ use rustro::retro::ffi::GameGeometry;
 use rustro::retro::ffi::SystemAvInfo;
 
 use std::ffi::CStr;
+use std::io::Write;
+use std::ops::Deref;
 use std::path::{PathBuf, Path};
-use std::time::Duration;
+use std::pin::Pin;
+use std::thread::sleep;
+use std::time::{Duration, Instant};
 
 use structopt::StructOpt;
 
@@ -16,7 +20,6 @@ use sdl2::rect::Rect;
 use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
 use sdl2::video::WindowContext;
-use std::io::Write;
 
 struct MyEmulator {
     retro: retro::wrapper::LibretroWrapper,
@@ -26,7 +29,7 @@ struct MyEmulator {
 }
 
 impl MyEmulator {
-    pub fn with_core(core: impl AsRef<Path>) -> Self {
+    pub fn with_core(core: impl AsRef<Path>) -> Pin<Box<Self>> {
         let lib = libloading::Library::new(core.as_ref()).unwrap();
         let raw_retro = retro::loading::LibretroApi::from_library(lib).unwrap();
         let retro = retro::wrapper::LibretroWrapper::from(raw_retro);
@@ -36,11 +39,12 @@ impl MyEmulator {
         let av_info = retro.as_ref().get_system_av_info();
 
         let pixel_format = sdl2::pixels::PixelFormatEnum::ABGR1555;
-        let mut result = MyEmulator { retro, av_info, pixel_format, texture: None };
+        let mut emu = MyEmulator { retro, av_info, pixel_format, texture: None };
+        let mut pin_emu = Box::pin(emu);
 
-        retro::wrapper::register_handler(&mut result);
-        result.retro.as_ref().init();
-        result
+        retro::wrapper::register_handler(pin_emu.as_mut());
+        pin_emu.retro.as_ref().init();
+        pin_emu
     }
 
     pub fn run(&self) {
@@ -58,20 +62,9 @@ impl MyEmulator {
 
 impl retro::convert::Handler for MyEmulator {
     fn video_refresh(&mut self, data: &[u8], width: u32, height: u32, pitch: u32) {
-        println!("self ref: {:?}", self as *mut Self);
-        //println!("video_refresh {}x{}", width, height);
-        //let rect = Rect::new(0, 0, width, height);
+        let rect = Rect::new(0, 0, width, height);
         if let Some(tex) = self.texture.as_mut() {
-            tex.with_lock(None, |tex_buffer: &mut [u8], tex_pitch: usize| {
-                let src_pitch = pitch as usize;
-                let src_width = width as usize;
-                for y in 0..(height as usize) {
-                    let src_slice = (y * src_pitch)..((y * src_pitch) + src_width);
-                    let tex_slice = (y * tex_pitch)..((y * tex_pitch) + src_width);
-                    tex_buffer[tex_slice].copy_from_slice(&data[src_slice]);
-                }
-            }).unwrap();
-            //tex.update(None, data, pitch as usize).unwrap();
+            tex.update(rect, data, pitch as usize).unwrap();
         }
     }
 
@@ -85,6 +78,14 @@ impl retro::convert::Handler for MyEmulator {
     }
 }
 
+impl Drop for MyEmulator {
+    fn drop(&mut self) {
+        if let Some(x) = self.texture.take() {
+            unsafe { x.destroy(); }
+        }
+    }
+}
+
 pub fn main() -> failure::Fallible<()> {
     let opt: Opt = Opt::from_args();
     let mut emu = MyEmulator::with_core(&opt.core);
@@ -102,11 +103,12 @@ pub fn main() -> failure::Fallible<()> {
     let texture_creator = canvas.texture_creator();
     emu.texture = texture_creator.create_texture_streaming(emu.pixel_format, width, height).ok();
 
-    let mut x: u8 = 1;
-    println!("emu ref: {:?}", &emu as *const MyEmulator);
+    let target_frame_time = Duration::from_secs_f64(1.0 / emu.av_info.timing.fps);
 
     let mut event_pump = sdl_context.event_pump().map_err(failure::err_msg)?;
     'running: loop {
+        let frame_begin = Instant::now();
+
         for event in event_pump.poll_iter() {
             match event {
                 Event::Quit {..}
@@ -116,22 +118,14 @@ pub fn main() -> failure::Fallible<()> {
                 _ => {}
             }
         }
-        if let Some(tex) = emu.texture.as_mut() {
-            tex.with_lock(None, |tex_buffer: &mut [u8], tex_pitch: usize| {
-                for i in 0..tex_buffer.len() {
-                    tex_buffer[i] = x;
-                    x = (x + 1) % 255;
-                }
-            }).unwrap();
-            //tex.update(None, data, pitch as usize).unwrap();
-        }
 
         // The rest of the game loop goes here...
         emu.run();
         canvas.clear();
         canvas.copy(emu.texture.as_ref().unwrap(), None, Some(Rect::new(0, 0, width, height))).map_err(failure::err_msg)?;
         canvas.present();
-        ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));
+
+        target_frame_time.checked_sub(frame_begin.elapsed()).map(sleep);
     }
     Ok(())
 }

src/retro/convert.rs

@@ -189,7 +189,7 @@ pub enum EnvCmd {
     // SetSerializationQuirks = ENVIRONMENT_SET_SERIALIZATION_QUIRKS,
 }
 
-pub trait Handler: 'static {
+pub trait Handler: Unpin + 'static {
     fn video_refresh(&mut self, data: &[u8], width: c_uint, height: c_uint, pitch: c_uint) {}
     fn audio_sample(&mut self, left: i16, right: i16) {}
     fn audio_sample_batch(&mut self, stereo_pcm: &[i16]) -> usize { stereo_pcm.len() }
@@ -235,3 +235,5 @@ pub trait Handler: 'static {
     fn get_language(&mut self) -> Option<Language> { None }
     // fn set_serialization_quirks(&mut self, quirks: &mut u64) -> bool { false }
 }
+
+// impl<T: Handler> Unpin for T {}

src/retro/loading.rs

@@ -1,13 +1,10 @@
-use std::convert::TryInto;
 use std::os::raw::{c_char, c_void};
 use std::path::Path;
-use std::marker::PhantomData;
 
 use failure::Fallible;
 use libloading;
 
 use super::ffi::*;
-use super::convert::*;
 
 pub struct LibretroApi {
     lib: libloading::Library, // for tying our lifetime to its own

src/retro/wrapper.rs

@@ -4,10 +4,12 @@ use core::slice::from_raw_parts;
 
 use std::ffi::CString;
 use std::os::raw::{c_uint, c_char};
+use std::ops::DerefMut;
 use std::path::Path;
+use std::pin::Pin;
 
 use libretro_sys::{Message, PixelFormat, SystemAvInfo, GameGeometry};
-use num_enum::{IntoPrimitive, TryFromPrimitive};
+use num_enum::TryFromPrimitive;
 
 use super::convert::*;
 use super::loading::*;
@@ -18,7 +20,7 @@ static mut CB_SINGLETON: StaticCallbacks = StaticCallbacks {
 
 #[derive(Default)]
 struct StaticCallbacks {
-    handler: Option<&'static mut dyn Handler>,
+    handler: Option<Pin<&'static mut dyn Handler>>,
 }
 
 unsafe impl Sync for StaticCallbacks {}
@@ -135,11 +137,6 @@ impl StaticCallbacks {
             None => 0,
         }
     }
-    pub(crate) fn register(cb: &'static mut dyn Handler) {
-        unsafe {
-            CB_SINGLETON.handler.replace(cb);
-        }
-    }
     pub(crate) fn reset() {
         unsafe {
             CB_SINGLETON.handler.take();
@@ -177,7 +174,9 @@ impl Drop for LibretroWrapper {
 
 // a note on lifetimes: we explicitly lie about them here because as long as they live as long as
 //  the library wrapper itself we're good (we wipe our 'static references on drop() too)
-pub fn register_handler(handler: &mut dyn Handler) {
-    let ptr: *mut dyn Handler = handler;
-    StaticCallbacks::register(unsafe { ptr.as_mut() }.unwrap());
+pub fn register_handler(handler: Pin<&'_ mut (dyn Handler + '_)>) {
+    unsafe {
+        let mut ptr = handler.get_unchecked_mut() as *mut dyn Handler;
+        CB_SINGLETON.handler.replace(Pin::new_unchecked(ptr.as_mut().unwrap()));
+    }
 }