SpringMass

SpringMotion::new(stiffness, mass, x0, seconds) lets a block go from rest x0 meters from its rest position, and SpringMotion::damped(stiffness, mass, damping, x0, seconds) adds friction. SpringMass draws the block on a spring from a wall. With plot set to the map of axes you show (time along x, displacement up y), the displacement so far draws on them with a dot at the current value, so the block and its graph move together. trace(until, per_second) gives the same points for a plot of your own. Gallery scene: SpringMass.

SpringMass 5.5 sPlayUnmuteCopy render command

use std::sync::OnceLock;

use fframes_kit::prelude::*;

fn figure<'a>(ui: &mut Ui<'a, '_, '_>) -> Svgr<'a> {
    static MOTION: OnceLock<SpringMotion> = OnceLock::new();
    let motion = MOTION.get_or_init(|| SpringMotion::damped(20.0, 1.0, 0.6, 1.0, 6.0));
    let axes = Axes {
        x_range: Range::new(0.0, 6.0, 1.0),
        y_range: Range::new(-1.0, 1.0, 0.5),
        x_length: 9.0,
        y_length: 2.6,
        center: (0.0, -2.0),
        tips: false,
        ..ui.defaults()
    };
    let spring = ui.show(SpringMass {
        motion: Some(motion),
        wall: (-5.5, 1.6),
        rest_length: 3.5,
        plot: Some(axes.map(ui)),
        ..ui.defaults()
    });
    let axes = ui.show(axes);
    svgr!(<g>{axes}{spring}</g>)
}

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).

SpringMass

Field	Type	Default	Description
motion	Option<&SpringMotion>	None	The simulated oscillation to draw, built once in the video’s constructor; None draws nothing.
wall	(f64, f64)	(-6.0, 1.5)	Where the spring is fixed to the wall (the middle of its end), in units of ui.space.
rest_length	f64	3.0	Meters from the wall to the block’s near side at rest; the dashed line marks it.
scale	f64	1.0	Units of ui.space per meter.
delay	f32	0.0	Seconds after the local start before the block is let go.
time_scale	f32	1.0	Speed of the motion over local time; 2 runs twice as fast, 1 is real time.
coils	usize	10	Number of turns of the zigzag that draws the spring.
block_size	f32	110.0	Side of the square block in pixels.
plot	Option<AxesMap>	None	Axes to plot the displacement on as the block moves (time in seconds along x, meters along y); None for no plot. Draw the axes yourself.
color	Color	theme.colors.text	Colour of the spring, the wall and the floor.
block_color	Color	theme.colors.accent	Colour of the block.
plot_color	Color	theme.colors.highlight	Colour of the displacement plot and its dot.
guide_color	Color	theme.colors.muted	Colour of the dashed rest line.
stroke_width	f32	theme.stroke.regular	Width of the spring, the wall, the floor and the plot in pixels.
enter	Option<EnterAnim>	None	How the wall, floor and rest line draw in; None shows them from the start.
exit	Option<ExitAnim>	None	How the wall, floor and rest line leave at the end of the container; None stays.
parts_enter	Option<FadeIn>	None	How the spring, block and plot fade in; None for none.
parts_exit	Option<FadeOut>	None	How the spring, block and plot fade out before the end; None for none.

Feature physics · Source