GasBox

GasMotion::new(GasSetup { .. }) steps count hard balls in a box once, at 240 steps a second: elastic collisions between equal masses and with the walls, with an optional Heat { at, to, over } that brings the temperature to to times its start. The start positions (a grid with jitter) and the directions come from seed. The steps use only + - × ÷ and √, so the same setup gives the same frames on every run and machine. GasBox draws the particles, slow ones in slow_color and those faster than the start’s root mean square speed in fast_color, and a thermometer with the factor T × ... Build the motion in the video’s constructor. particles, temperature and rms_speed give the numbers. Gallery scene: GasBox.

GasBox 7 sPlayUnmuteCopy render command

use fframes_kit::prelude::*;

struct Lesson {
    gas: GasMotion,
}

impl Lesson {
    fn new() -> Self {
        let setup = GasSetup {
            seed: 7,
            count: 60,
            seconds: 7.0,
            heat: Some(Heat { at: 2.5, to: 3.0, over: 1.5 }),
            ..GasSetup::default()
        };
        Self { gas: GasMotion::new(setup) }
    }

    fn figure<'a>(&'a self, ui: &mut Ui<'a, '_, '_>) -> Svgr<'a> {
        ui.show(GasBox {
            motion: Some(&self.gas),
            scale: 1.4,
            ..ui.defaults()
        })
    }
}

API

Components are plain structs. Set the fields you need and fill the rest with ..ui.defaults(): the defaults below come from the current theme (theme. values are fields of Theme).

GasBox

Field	Type	Default	Description
motion	Option<&GasMotion>	None	The simulated particles to draw, built once in the video’s constructor; None draws nothing.
center	(f64, f64)	(0.0, 0.0)	The middle of the box, in units of ui.space.
scale	f64	1.0	Units of ui.space per meter.
delay	f32	0.0	Seconds after the container’s start before the particles start to move.
time_scale	f32	1.0	Speed of the motion over local time; 2 runs twice as fast, 1 is real time.
thermometer	bool	true	Draws a bar right of the box that fills with the temperature, up to the highest one the motion reaches.
labels	bool	true	Writes the temperature factor over the start (T × 1.5) above the thermometer.
box_color	Color	theme.colors.text	Colour of the box walls and the thermometer frame and label.
slow_color	Color	theme.colors.accent	Colour of particles at or below the start’s root mean square speed.
fast_color	Color	theme.colors.highlight	Colour of faster particles and of the thermometer’s level.
stroke_width	f32	theme.stroke.regular	Width of the box walls in pixels.
enter	Option<EnterAnim>	None	How the box and the thermometer frame draw in; None shows them from the start.
exit	Option<ExitAnim>	None	How the box and the thermometer frame leave at the end of the container; None stays.
parts_enter	Option<FadeIn>	None	How the particles and the level fade in; None for none.
parts_exit	Option<FadeOut>	None	How the particles and the level fade out before the end; None for none.

Feature physics · Source