scissor attempt

uidev/src/main.rs

@@ -23,7 +23,7 @@ use wgui::{
 		EventListenerCollection, MouseButtonIndex, MouseDownEvent, MouseMotionEvent, MouseUpEvent,
 		MouseWheelEvent,
 	},
-	gfx::WGfx,
+	gfx::{WGfx, cmd::WGfxClearMode},
 	renderer_vk::{self},
 };
 use winit::{
@@ -32,12 +32,16 @@ use winit::{
 	keyboard::{KeyCode, PhysicalKey},
 };
 
-use crate::testbed::{
-	TestbedUpdateParams, testbed_dashboard::TestbedDashboard, testbed_generic::TestbedGeneric,
+use crate::{
+	rate_limiter::RateLimiter,
+	testbed::{
+		TestbedUpdateParams, testbed_dashboard::TestbedDashboard, testbed_generic::TestbedGeneric,
+	},
 };
 
 mod assets;
 mod profiler;
+mod rate_limiter;
 mod testbed;
 mod timestep;
 mod vulkan;
@@ -117,6 +121,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 	let mut timestep = Timestep::new();
 	timestep.set_tps(60.0);
 
+	let mut limiter = RateLimiter::new();
+
 	#[allow(deprecated)]
 	event_loop.run(move |event, elwt| {
 		elwt.set_control_flow(ControlFlow::Poll);
@@ -291,6 +297,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 				log::trace!("drawing frame {frame_index}");
 				frame_index += 1;
 
+				limiter.start(120); // max 120 fps
 				profiler.start();
 
 				{
@@ -301,7 +308,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 								recreate = true;
 								return;
 							}
-							Err(e) => panic!("failed to acquire next image: {e}"),
+							Err(e) => {
+								log::error!("failed to acquire next image: {e}");
+								return;
+							}
 						};
 
 					let tgt = images[image_index as usize].clone();
@@ -309,7 +319,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 					let mut cmd_buf = gfx
 						.create_gfx_command_buffer(CommandBufferUsage::OneTimeSubmit)
 						.unwrap();
-					cmd_buf.begin_rendering(tgt).unwrap();
+					cmd_buf
+						.begin_rendering(tgt, WGfxClearMode::Clear([0.0, 0.0, 0.0, 0.1]))
+						.unwrap();
 
 					let primitives = wgui::drawing::draw(&testbed.layout().borrow_mut()).unwrap();
 					render_context
@@ -334,6 +346,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 				}
 
 				profiler.end();
+				limiter.end();
 			}
 			Event::AboutToWait => {
 				// should be limited to vsync

uidev/src/profiler.rs

@@ -1,10 +1,4 @@
-use std::{sync::LazyLock, time::Instant};
-
-static TIME_START: LazyLock<Instant> = LazyLock::new(Instant::now);
-
-pub fn get_micros() -> u64 {
-	TIME_START.elapsed().as_micros() as u64
-}
+use crate::timestep::get_micros;
 
 pub struct Profiler {
 	interval_us: u64,

uidev/src/rate_limiter.rs

@@ -0,0 +1,37 @@
+use crate::timestep::get_micros;
+
+#[derive(Default)]
+pub struct RateLimiter {
+	rate: u16,
+	start_us: u64,
+	end_us: u64,
+}
+
+impl RateLimiter {
+	pub fn new() -> Self {
+		Self {
+			rate: 0,
+			end_us: 0,
+			start_us: 0,
+		}
+	}
+
+	pub fn start(&mut self, rate: u16) {
+		self.rate = rate;
+		self.start_us = get_micros();
+	}
+
+	pub fn end(&mut self) {
+		if self.rate == 0 {
+			return;
+		}
+
+		self.end_us = get_micros();
+		let microseconds = self.end_us - self.start_us;
+		let frametime_microseconds = ((1000.0 / self.rate as f32) * 1000.0) as u64;
+		let delay = frametime_microseconds as i64 - microseconds as i64;
+		if delay > 0 {
+			std::thread::sleep(std::time::Duration::from_micros(delay as u64));
+		}
+	}
+}