35 lines
998 B
Rust
35 lines
998 B
Rust
use crate::particle::Particle;
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use std::cell::RefCell;
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use std::rc::Rc;
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pub struct Link {
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p1: Rc<RefCell<Particle>>,
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p2: Rc<RefCell<Particle>>,
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length: f32,
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}
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impl Link {
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pub fn new(p1: Rc<RefCell<Particle>>, p2: Rc<RefCell<Particle>>, length: f32) -> Self {
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Link { p1, p2, length }
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}
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pub fn solve(&mut self) {
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let vec = self.p2.borrow().pos - self.p1.borrow().pos;
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let vec_len = (vec.x * vec.x + vec.y * vec.y).sqrt();
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if vec_len > self.length {
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let vec_norm = vec / vec_len;
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let max_stretch = 0.5;
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let clamped_len = vec_len.min(self.length + max_stretch);
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let displacement = clamped_len - vec_len;
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let stiffness = 999.;
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let vec_scaled = vec_norm * displacement * stiffness;
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let damping = 0.99;
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self.p1.borrow_mut().apply_force(-vec_scaled * damping);
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self.p2.borrow_mut().apply_force(vec_scaled * damping);
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}
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}
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}
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