Zooming out crashes egui_plot

[danielfaust]

Describe the bug

In the demo located at https://www.egui.rs/#Demo, when fully zooming out from the "Custom Axes" plot example in the "Plot" window, egui will crash with a "The egui app has crashed." message

To Reproduce

Steps to reproduce the behavior:

1. Go to https://www.egui.rs/#Demo
2. Click on Plot in the left pane
3. Click on Custom Axes in the Plot window
4. Fully scroll out with the mouse wheel while pressing Ctrl

Desktop

• Windows 11
• Google Chrome
• Version 119.0.6045.160 (Offizieller Build) (64-Bit)

Desktop

• Ubuntu 22.04
• Firefox
• Version 120.0 (64-Bit) canonical-002-1.0 (Mozilla Firefox Snap for Ubuntu)

Smartphone

Not reproducible due to pinch and zoom not being able to fully zoom out

[Firepal]

Relevant:

egui/crates/egui_demo_lib/src/demo/plot_demo.rs

Lines 478 to 510 in 8d4de86

	fn x_grid(input: GridInput) -> Vec<GridMark> {
	// Note: this always fills all possible marks. For optimization, `input.bounds`
	// could be used to decide when the low-interval grids (minutes) should be added.
	let mut marks = vec![];
	let (min, max) = input.bounds;
	let min = min.floor() as i32;
	let max = max.ceil() as i32;
	for i in min..=max {
	let step_size = if i % Self::MINS_PER_DAY as i32 == 0 {
	// 1 day
	Self::MINS_PER_DAY
	} else if i % Self::MINS_PER_H as i32 == 0 {
	// 1 hour
	Self::MINS_PER_H
	} else if i % 5 == 0 {
	// 5min
	5.0
	} else {
	// skip grids below 5min
	continue;
	};
	marks.push(GridMark {
	value: i as f64,
	step_size,
	});
	}
	marks
	}

It's very much possible that this is trying to draw many, many grid marks

[emilk]

Very similar to:

• Panic when zooming out a plot too far #3462

[Tweoss]

It does seem like the custom axes demo tries to draw many grid marks when zoomed out.

In the normal plot demo, when zooming out, I get the below. Presumably, NaN is compared against another floating point number, and the inequality doesn't hold in line 1916.

egui/crates/egui_plot/src/lib.rs

Lines 1915 to 1925 in 520b28c

	fn fill_marks_between(out: &mut Vec<GridMark>, step_size: f64, (min, max): (f64, f64)) {
	assert!(max > min);
	let first = (min / step_size).ceil() as i64;
	let last = (max / step_size).ceil() as i64;
	let marks_iter = (first..last).map(|i| {
	let value = (i as f64) * step_size;
	GridMark { value, step_size }
	});
	out.extend(marks_iter);
	}

[emilk]

I think this is fixed now

[danielfaust]

I can no longer find any plots in the demo. Have they been removed?