Projectile

A ball thrown at speed and angle without drag. Its path draws behind it, and it carries its velocity and the velocity’s two components. Once it passes them, the top of the arc and the landing point are marked with the height and the range. flight_time, position, velocity, apex and range give the numbers. Gallery scene: Projectile.

Projectile 3.5 sPlayUnmuteCopy render command

use fframes_kit::prelude::*;

fn figure<'a>(ui: &mut Ui<'a, '_, '_>) -> Svgr<'a> {
    ui.show(Projectile {
        origin: (-6.0, -2.5),
        speed: 11.0,
        angle: 0.9,
        scale: 0.9,
        delay: 0.5,
        enter: Some(Create::default().into()),
        ..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).

Projectile

Field	Type	Default	Description
origin	(f64, f64)	(-6.0, -2.5)	Where the ball is launched from, in units of ui.space.
speed	f64	10.0	Launch speed in m/s.
angle	f64	std::f64::consts::FRAC_PI_4	Launch angle above the horizontal in radians.
gravity	f64	GRAVITY	Downward acceleration in m/s²; 0 or less gives no flight.
scale	f64	1.0	Units of ui.space per meter.
delay	f32	0.0	Seconds after the local start before the ball is launched.
time_scale	f32	1.0	Speed of the flight over local time; 2 runs twice as fast, 1 is real time.
trace	bool	true	Draws the path flown so far as a dashed line behind the ball.
vectors	bool	true	Draws the ball’s velocity and its horizontal and vertical components as arrows until it lands.
peak	bool	true	Marks the top of the arc with a dot and a dashed drop line once the ball has passed it.
labels	bool	true	Writes the height of the top and the range at the landing point (with peak).
vector_scale	f64	0.12	Units of ui.space per m/s for the velocity arrows.
radius	f32	14.0	Radius of the ball in pixels.
color	Color	theme.colors.title	Colour of the ball.
velocity_color	Color	theme.colors.accent	Colour of the velocity arrow.
component_color	Color	theme.colors.highlight	Colour of the horizontal and vertical component arrows and the marks.
trace_color	Color	theme.colors.muted	Colour of the dashed path.
ground_color	Color	theme.colors.muted	Colour of the ground line and the dashed drop line.
stroke_width	f32	theme.stroke.regular	Width of the velocity arrow in pixels; the other arrows and lines use the theme’s thin width.
enter	Option<EnterAnim>	None	How the ground draws in; None shows it from the start.
exit	Option<ExitAnim>	None	How the ground leaves at the end of the container; None stays.
parts_enter	Option<FadeIn>	None	How the ball, path, arrows and labels fade in; None for none.
parts_exit	Option<FadeOut>	None	How the ball, path, arrows and labels fade out before the end; None for none.

Methods:

• fn flight_time(&self) -> f64: Seconds from the launch until the ball is back at the launch height; 0 when it is not thrown upward or there is no gravity.
• fn position(&self, t: f64) -> (f64, f64): Meters from the launch point after t seconds of flight (y up), stopping at the landing.
• fn velocity(&self, t: f64) -> (f64, f64): Velocity in m/s after t seconds of flight.
• fn apex(&self) -> (f64, f64, f64): The time, horizontal distance and height of the top of the arc.
• fn range(&self) -> f64: Meters from the launch point to the landing point.

Feature physics · Source