Preallocated the u16 pixel buffer and made the -v output more detailed.

Cargo.lock

@@ -1346,7 +1346,7 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "svc16"
-version = "0.4.0"
+version = "0.4.1"
 dependencies = [
  "anyhow",
  "clap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "svc16"
-version = "0.4.0"
+version = "0.4.1"
 edition = "2021"
 authors = ["Jan Neuendorf"]
 description = "An emulator for a simple virtual computer"

src/engine.rs

@@ -1,7 +1,7 @@
 use std::ops::{BitAnd, BitXor};
 use thiserror::Error;
 
-const MEMSIZE: usize = u16::MAX as usize + 1;
+pub const MEMSIZE: usize = u16::MAX as usize + 1;
 
 const SET: u16 = 0;
 const GOTO: u16 = 1;
@@ -71,10 +71,15 @@ impl Engine {
         self.pos_code = pos_code;
         self.key_code = key_code;
     }
-    pub fn perform_sync(&mut self, pos_code: u16, key_code: u16) -> [u16; MEMSIZE] {
+    pub fn perform_sync(
+        &mut self,
+        pos_code: u16,
+        key_code: u16,
+        buffer: &mut [u16; MEMSIZE],
+    ) -> () {
         self.set_input(pos_code, key_code);
         self.sync_called = false;
-        return self.screen.clone();
+        *buffer = self.screen;
     }
 }
 impl Engine {

src/main.rs

@@ -49,6 +49,8 @@ fn main() -> Result<()> {
         Pixels::new(RES as u32, RES as u32, surface_texture)?
     };
 
+    let mut raw_buffer = [0 as u16; engine::MEMSIZE];
+
     event_loop.run(|event, elwt| {
         let start_time = Instant::now();
         if input.update(&event) {
@@ -65,6 +67,7 @@ fn main() -> Result<()> {
             }
 
             let mut ipf = 0;
+            let engine_start = Instant::now();
             while !engine.wants_to_sync() && ipf <= cli.max_ipf {
                 match engine.step() {
                     Err(_) => {
@@ -75,13 +78,19 @@ fn main() -> Result<()> {
                 }
                 ipf += 1;
             }
+            let engine_elapsed = engine_start.elapsed();
             let (c1, c2) = get_input_code(&input, &pixels);
-            let nb = engine.perform_sync(c1, c2);
+            engine.perform_sync(c1, c2, &mut raw_buffer);
-            update_image_buffer(pixels.frame_mut(), &nb);
+            update_image_buffer(pixels.frame_mut(), &raw_buffer);
 
             let elapsed = start_time.elapsed();
             if cli.verbose {
-                println!("Instructions: {} Frametime: {}ms", ipf, elapsed.as_millis());
+                println!(
+                    "Instructions: {} Frametime: {}ms (Engine only: {}ms)",
+                    ipf,
+                    elapsed.as_millis(),
+                    engine_elapsed.as_millis()
+                );
             }
             if elapsed < FRAMETIME {
                 std::thread::sleep(FRAMETIME - elapsed);