Hm… these changes seem to regress rendering by a lot. The guides lag behind the mouse so much, at least on my machine.

This does the trick for me:

diff --git a/src/main.rs b/src/main.rs
index edff83a..1eb0143 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -131,6 +131,10 @@ fn main() -> Result<(), String> {
     let mut in_selection = false;
     let mut ignore_next_release = false;
 
+    use std::time::{Instant, Duration};
+    let mut last_draw = Instant::now();
+    const DRAW_DELTA: Duration = Duration::from_millis(8);
+
     // TODO draw rectangle around window under cursor
     loop {
         let ev = conn
@@ -158,6 +162,12 @@ fn main() -> Result<(), String> {
                 return Err("Exiting due to ESC key press".into());
             }
             xcb::MOTION_NOTIFY => {
+                let now = Instant::now();
+                if now - last_draw < DRAW_DELTA {
+                    continue;
+                }
+                last_draw = now;
+
                 let motion: &xcb::MotionNotifyEvent = unsafe { xcb::cast_event(&ev) };
 
                 let (left_x, right_x) = min_max(motion.event_x(), start_pt.x());

Not that's the best code but it works.

@Lonami That should be in another patch from what I will say since it fixes another problem.

by the way @Lonami in your patch, your subtraction of Instants should be saturating_sub since I think they panic if they go negative

they panic if they go negative

They can't be negative because Instant is monotonic:

A measurement of a monotonically nondecreasing clock.

@Lonami But rust does not know that, bound checks might still be there.

they panic if they go negative

They can't be negative because Instant is monotonic:

A measurement of a monotonically nondecreasing clock.

Ah you're right, I was confusing it with a different situation

@Lonami That should be in another patch

Most likely because it affects previous code, I only mentioned it because it makes this change-set usable.

@Lonami But rust does not know that, bound checks might still be there.

That's micro-optimization compared to the rest of things we're doing :)

This TODO should be removed: https://github.com/neXromancers/hacksaw/pull/22/files#diff-639fbc4ef05b315af92b4d836c31b023R140 (// TODO draw rectangle around window under cursor)

@Lonami That's what I think it's best, just don't release before we update the other parts, I would also like to do more refactorings, especially the state of current functions. Also, I will plan out a public API for libraries then if I have the time I can help out improving the performance.

Note that there is a bug here when keys are pressed, windows changes. The border still stick to the old changes, we should listen to keyboard events now too but propagate them, I am not sure how to do this yet.

@pickfire How about we create a branch to work on this, and merge it into master when it's performant and the bugs are worked out?

I like this idea personally.

@expectocode Of course, that's good.

The most debated PR on the history of neXromancers so far has been merged 🎉