lj_rust/src/transformer/rotate.rs

use crate::transformer::Transformers;
use crate::point::Point;
use crate::worldstate::WorldState;

use serde::{Serialize,Deserialize};
//use std::f32::consts::PI;

/// Rotate

#[derive(Serialize,Deserialize,Debug,Clone,Copy)]
pub struct Rotate {
    cx: f32,
    cy: f32,
    angle: f32,

}

impl Transformers for Rotate {
    fn apply(&self, point_list: &[Point], _ws: &WorldState) -> Vec<Point> {
    point_list.iter()
        .map(| pt | {
            let dx = pt.x - self.cx;
            let dy = pt.y - self.cy;
            let cos = self.angle.cos();
            let sin = self.angle.sin();
            let x = (dx * cos - dy * sin) + self.cx; 
            let y = (dx * sin + dy * cos) + self.cy; 
            Point { x,
                y,
                ..*pt
            }
        }).collect()
    }
}