refraction/src/bin/flat/main.rs

250 lines
6.3 KiB
Rust

use std::f32::consts::{FRAC_PI_2, PI};
use flo_canvas::*;
use flo_draw::*;
use glam::*;
use refraction::ifaces::{DebugTraceable, Traceable};
use refraction::tube::metric::Tube;
use refraction::tube::Space;
use refraction::types::{Location, Object, Ray};
use refraction::utils::put_object;
use refraction::DT;
fn draw_loop(gc: &mut Vec<Draw>, mut pts: impl Iterator<Item = Vec3>) {
gc.new_path();
let Some(first) = pts.next() else {
return;
};
gc.move_to(first.x, first.y);
for pt in pts {
gc.line_to(pt.x, pt.y);
}
gc.close_path();
gc.stroke();
}
pub fn main() {
with_2d_graphics(move || {
let canvas = create_drawing_window("Refraction");
canvas.draw(|gc| {
let tube = Tube {
inner_radius: 30.0,
outer_radius: 50.0,
internal_halflength: 100.0,
external_halflength: 300.0,
};
let objs: Vec<_> = [-1.25, -1.00, -0.85, -0.50, 0.00, 0.40, 0.70, 0.95, 1.05]
.iter()
.enumerate()
.map(|(k, &y)| Object {
id: k as i32,
loc: put_object(
&tube,
vec3(0.0, y * tube.external_halflength, 0.0),
Mat3::from_mat2(Mat2::from_angle(y)),
),
r: 20.0,
})
.collect();
let space = Space { tube, objs };
let cam1 = put_object(&space.tube, vec3(-500., 0., 0.), Mat3::IDENTITY);
let cam2 = put_object(
&space.tube,
vec3(
-2.5 * tube.outer_radius,
1.25 * tube.external_halflength,
0.,
),
mat3(vec3(1., -1., 0.), vec3(1., 1., 0.), vec3(0., 0., 1.)),
);
let cam3 = put_object(
&space.tube,
vec3(
0.25 * tube.inner_radius,
0.25 * tube.external_halflength,
0.,
),
mat3(vec3(0., -1., 0.), vec3(1., 0., 0.), vec3(0., 0., 1.)),
);
gc.canvas_height(500.0);
gc.transform(Transform2D::rotate(FRAC_PI_2));
tube.render(gc);
gc.line_width(0.5);
// gc.stroke_color(Color::Rgba(1.0, 0.5, 0.0, 0.5));
// draw_fan(gc, &tube, vec2(-500.0, 0.0), vec2(1.0, 0.0), 1.0);
gc.stroke_color(Color::Rgba(0.0, 0.8, 1.0, 1.0));
draw_fan_2(gc, &space, cam3, 1.0);
gc.stroke_color(Color::Rgba(0.5, 1.0, 0.0, 1.0));
draw_fan_2(gc, &space, cam2, 1.0);
gc.stroke_color(Color::Rgba(1.0, 0.5, 0.0, 1.0));
draw_fan_2(gc, &space, cam1, 1.0);
draw_track(gc, &space, vec2(-500.0, 0.0), vec2(1.0, 0.2));
draw_track(gc, &space, vec2(-500.0, 0.0), vec2(1.0, 0.5));
draw_track(
gc,
&space,
vec2(-0.5 * tube.inner_radius, -1.25 * tube.external_halflength),
vec2(0.1, 1.0),
);
let circle_segments = 47;
for obj in &space.objs {
let pos = obj.loc.pos;
gc.new_path();
gc.circle(pos.x, pos.y, 5.0);
gc.fill_color(Color::Rgba(0.0, 0.5, 1.0, 1.0));
gc.fill();
gc.stroke_color(Color::Rgba(0.0, 0.0, 0.0, 0.5));
draw_loop(
gc,
itertools_num::linspace(0.0, 2.0 * PI, circle_segments)
.skip(1)
.map(|φ| {
let dir = Vec2::from_angle(φ) * obj.r;
let dir = vec3(dir.x, dir.y, 0.);
let dir = obj.loc.rot * dir;
pos + dir
}),
);
gc.stroke_color(Color::Rgba(0.0, 0.5, 1.0, 0.5));
draw_loop(
gc,
itertools_num::linspace(0.0, 2.0 * PI, circle_segments)
.skip(1)
.map(|φ| {
let dir = Vec2::from_angle(φ) * obj.r;
let dir = vec3(dir.x, dir.y, 0.);
let dir = obj.loc.rot * dir;
space.trace_step(Ray { pos, dir }).pos
}),
);
gc.stroke_color(Color::Rgba(0.5, 0.0, 1.0, 1.0));
draw_loop(
gc,
itertools_num::linspace(0.0, 2.0 * PI, circle_segments)
.skip(1)
.map(|φ| {
let n = obj.r.floor();
let d = obj.r / n;
let dir = Vec2::from_angle(φ);
let dir = vec3(dir.x, dir.y, 0.);
let dir = obj.loc.rot * dir * d;
space
.trace_iter(Ray { pos, dir })
.nth(n as usize)
.unwrap()
.pos
}),
);
}
});
});
}
fn draw_cross(gc: &mut Vec<Draw>, pos: Vec2, r: f32) {
gc.move_to(pos.x - r, pos.y - r);
gc.line_to(pos.x + r, pos.y + r);
gc.move_to(pos.x - r, pos.y + r);
gc.line_to(pos.x + r, pos.y - r);
}
fn draw_ray_2(gc: &mut Vec<Draw>, space: &Space, camera: Location, dir: Vec3) {
let pos = vec3(0., 0., 0.);
let (hits, path) = space.trace_dbg(camera, Ray { pos, dir });
let hits2 = space.trace(camera, Ray { pos, dir });
for (a, b) in hits.into_iter().zip(hits2.into_iter()) {
assert_eq!(a.id, b.id);
assert_eq!(a.pos, b.pos);
assert_eq!(a.rel, b.rel);
}
gc.new_path();
gc.move_to(pos.x, pos.y);
for pt in &path.points[1..] {
gc.line_to(pt.x, pt.y);
}
let end_pos = *path
.points
.last()
.expect("the starting point is always in the path");
let dir_pos = end_pos + 1000.0 * path.end_dir;
gc.line_to(dir_pos.x, dir_pos.y);
gc.stroke();
}
fn draw_fan_2(gc: &mut Vec<Draw>, space: &Space, camera: Location, spread: f32) {
for y in itertools_num::linspace(-spread, spread, 101) {
draw_ray_2(gc, space, camera, vec3(1., y, 0.));
}
}
fn draw_track(gc: &mut Vec<Draw>, space: &Space, start: Vec2, dir: Vec2) {
const SCALE: f32 = 5.0;
const STEP: f32 = 2.0 * SCALE;
// let mut loc = Location { pos: start, rot: Mat2::IDENTITY };
// let dir = space.tube.globalize(start, dir);
// let v = space.tube.normalize(start, dir);
let mut loc = Location {
pos: vec3(start.x, start.y, 0.),
rot: mat3(
vec3(dir.x, dir.y, 0.),
vec3(-dir.y, dir.x, 0.),
vec3(0., 0., 1.),
),
};
let v = vec3(1., 0., 0.);
let mut draw = |loc: &Location| {
let p = loc.pos;
let ax = p + loc.rot.x_axis * SCALE;
let ay = p + loc.rot.y_axis * SCALE;
gc.new_path();
gc.stroke_color(Color::Rgba(0.7, 0.0, 0.0, 1.0));
gc.move_to(p.x, p.y);
gc.line_to(ax.x, ax.y);
gc.stroke();
gc.new_path();
gc.stroke_color(Color::Rgba(0.0, 0.7, 0.0, 1.0));
gc.move_to(p.x, p.y);
gc.line_to(ay.x, ay.y);
gc.stroke();
};
draw(&loc);
for _ in 0..1000 {
let N = (STEP / DT).floor() as i32;
for _ in 0..N {
loc = space.move_step(loc, v * DT);
}
draw(&loc);
}
}
trait Renderable {
fn render(&self, gc: &mut Vec<Draw>);
}
impl Renderable for Tube {
fn render(&self, gc: &mut Vec<Draw>) {
gc.new_path();
gc.rect(
-self.outer_radius,
-self.external_halflength,
self.outer_radius,
self.external_halflength,
);
gc.rect(
-self.inner_radius,
-self.external_halflength,
self.inner_radius,
self.external_halflength,
);
gc.winding_rule(WindingRule::EvenOdd);
gc.fill_color(Color::Rgba(0.8, 0.8, 0.8, 1.0));
gc.fill();
}
}