fps lock and integer pixel scaling and letterboxing

examples/test.rs

@@ -1,7 +1,7 @@
 use skunk2d::*;
 
-const WIDTH: i32 = 1280 / 2;
-const HEIGHT: i32 = 720 / 2;
+const WIDTH: i32 = 1920 / 3;
+const HEIGHT: i32 = 1080 / 3;
 
 struct World {
     img: Image,

src/window.rs

@@ -1,13 +1,16 @@
 use crate::image::Image;
 use crate::vec2::Vec2;
 use rand::Rng;
+use std::cmp::{max, min};
 use std::num::NonZeroU32;
+use std::time::{Duration, Instant};
 use winit::dpi::LogicalSize;
 use winit::event::VirtualKeyCode::Escape;
 use winit::event::{
     ElementState, Event as WinitEvent, MouseButton as WinitMouseButton, WindowEvent,
 };
 use winit::event_loop::{ControlFlow, EventLoop};
+use winit::platform::run_return::EventLoopExtRunReturn;
 use winit::window::WindowBuilder;
 
 pub enum MouseButton {
@@ -61,15 +64,15 @@ impl WindowState {
 }
 
 pub fn run<T: Game + 'static>(width: i32, height: i32) {
-    let event_loop = EventLoop::new();
+    let mut event_loop = EventLoop::new();
     let window = {
         let size = LogicalSize::new(width as f64, height as f64);
         WindowBuilder::new()
             .with_title("Skunk 2D")
             .with_inner_size(size)
             .with_min_inner_size(size)
-            //.with_decorations(false)
-            //.with_maximized(true)
+            .with_decorations(false)
+            .with_maximized(true)
             .build(&event_loop)
             .unwrap()
     };
@@ -84,7 +87,26 @@ pub fn run<T: Game + 'static>(width: i32, height: i32) {
     let mut window_state = WindowState::new();
     let mut game = T::new(&mut window_state);
 
-    event_loop.run(move |event, _, control_flow| {
+    let mut frames_since_last_second = 0;
+    let mut last_second = Instant::now();
+
+    let mut last_frame = last_second;
+    let target_fps = 60;
+    let target_frame_duration = Duration::from_secs(1) / target_fps;
+
+    let mut scale = 1usize;
+    let mut off_x = 0usize;
+    let mut off_y = 0usize;
+
+    event_loop.run_return(move |event, _, control_flow| {
+        let mut scale = &mut scale;
+        let mut off_x = &mut off_x;
+        let mut off_y = &mut off_y;
+        if Instant::now() - last_second > Duration::from_secs(1) {
+            println!("fps: {}", frames_since_last_second);
+            frames_since_last_second = 0;
+            last_second += Duration::from_secs(1);
+        }
         match event {
             WinitEvent::NewEvents(_) => {}
             WinitEvent::WindowEvent {
@@ -108,16 +130,15 @@ pub fn run<T: Game + 'static>(width: i32, height: i32) {
                                 *control_flow = ControlFlow::Exit;
                             }
                         };
-                        if *control_flow == ControlFlow::Exit {
-                            return;
-                        }
                     }
                     WindowEvent::ModifiersChanged(_) => {}
                     WindowEvent::Ime(_) => {}
                     WindowEvent::CursorMoved { position, .. } => {
+                        let x = (position.x as i32 - *off_x as i32) / *scale as i32;
+                        let y = (position.y as i32 - *off_y as i32) / *scale as i32;
                         window_state.mouse_pos = Vec2 {
-                            x: position.x as i32,
-                            y: position.y as i32,
+                            x: min(width - 1, max(0, x)),
+                            y: min(height - 1, max(0, y)),
                         }
                     }
                     WindowEvent::CursorEntered { .. } => {}
@@ -156,32 +177,47 @@ pub fn run<T: Game + 'static>(width: i32, height: i32) {
             WinitEvent::UserEvent(_) => {}
             WinitEvent::Suspended => {}
             WinitEvent::Resumed => {}
-            WinitEvent::MainEventsCleared => {}
-            WinitEvent::RedrawRequested(_) => {
-                game.draw(&mut screen);
+            WinitEvent::MainEventsCleared => {
+                if Instant::now() - last_frame >= target_frame_duration {
+                    game.update(&mut window_state);
+                    game.draw(&mut screen);
 
-                let (width, height) = {
                     let size = window.inner_size();
-                    (size.width, size.height)
-                };
-                surface
-                    .resize(
-                        NonZeroU32::new(width).unwrap(),
-                        NonZeroU32::new(height).unwrap(),
-                    )
-                    .unwrap();
+                    surface
+                        .resize(
+                            NonZeroU32::new(size.width).unwrap(),
+                            NonZeroU32::new(size.height).unwrap(),
+                        )
+                        .unwrap();
 
-                let mut buf = surface.buffer_mut().unwrap();
-                for i in 0..(width * height) as usize {
-                    buf[i] = window_state.palette[screen.data()[i] as usize];
+                    *scale = min(size.width / width as u32, size.height / height as u32) as usize;
+                    *off_x = (size.width as usize - width as usize * *scale) / 2;
+                    *off_y = (size.height as usize - height as usize * *scale) / 2;
+
+                    let mut buf = surface.buffer_mut().unwrap();
+                    for y in 0..height as usize {
+                        for x in 0..width as usize {
+                            let p = window_state.palette
+                                [screen.data()[x + y * width as usize] as usize];
+                            for iy in 0..*scale {
+                                for ix in 0..*scale {
+                                    let tx = x * *scale + ix + *off_x;
+                                    let ty = y * *scale + iy + *off_y;
+                                    buf[tx + ty * size.width as usize] = p;
+                                }
+                            }
+                        }
+                    }
+                    buf.present().unwrap();
+                    frames_since_last_second += 1;
+                    last_frame += target_frame_duration;
+                } else {
+                    std::thread::sleep(Duration::from_millis(1));
                 }
-                buf.present().unwrap();
             }
+            WinitEvent::RedrawRequested(_) => {}
             WinitEvent::RedrawEventsCleared => {}
             WinitEvent::LoopDestroyed => {}
         }
-
-        game.update(&mut window_state);
-        window.request_redraw();
     });
 }