resphys 0.1.0

use glam::Vec2;
use macroquad::*;
use resphys::{Collider, ColliderState, AABB};

extern crate log;

const FPS_INV: f32 = 1. / 60.;

type PhysicsWorld = resphys::PhysicsWorld<TagType>;

#[macroquad::main("Raycast/Overlap Test demonstration")]
async fn main() {

    let ray = resphys::Ray {
        origin: Vec2::new(750.0, 50.0),
        dir: Vec2::new(-400., 500.),
        toi: 1.,
    };

    let mut physics = PhysicsWorld::new();
    let mut bodies = resphys::BodySet::new();
    let mut colliders = resphys::ColliderSet::new();

    let body1 = resphys::builder::BodyDesc::new()
        .with_position(Vec2::new(360., 285.))
        .self_collision(false)
        .build();
    let collider1 = resphys::builder::ColliderDesc::new(
        AABB {
            half_exts: Vec2::new(16., 32.),
        },
        TagType::Player,
    )
    .with_category(1);

    let player_bhandle = bodies.insert(body1);
    let _player_chandle = colliders
        .insert(collider1.build(player_bhandle), &mut bodies, &mut physics)
        .unwrap();

    for x in (0..=768).step_by(32) {
        add_tile(
            &mut physics,
            &mut bodies,
            &mut colliders,
            Vec2::new(16. + x as f32, 16.),
        );
    }
    for y in (32..=544).step_by(32) {
        add_tile(
            &mut physics,
            &mut bodies,
            &mut colliders,
            Vec2::new(16., 16. + y as f32),
        );
    }
    for y in (32..=544).step_by(32) {
        add_tile(
            &mut physics,
            &mut bodies,
            &mut colliders,
            Vec2::new(768. + 16., 16. + y as f32),
        );
    }
    for x in (32..=768 - 32).step_by(32) {
        add_tile(
            &mut physics,
            &mut bodies,
            &mut colliders,
            Vec2::new(16. + x as f32, 544. + 16.),
        );
    }

    let mut remaining_time = 0.;
    loop {
        remaining_time += get_frame_time();
        while remaining_time >= FPS_INV {
            let player_body = &mut bodies[player_bhandle];

            player_body.velocity += Vec2::new(0., 64. * FPS_INV);

            player_body.velocity = controls(player_body.velocity);

            physics.step(FPS_INV, &mut bodies, &mut colliders);
            remaining_time -= FPS_INV;
        }

        clear_background(Color::new(0., 1., 1., 1.));
        for (_, collider) in colliders.iter() {
            let body = &bodies[collider.owner];
            draw_collider(&collider, body.position);
        }

        let overlap_pos = Vec2::new(150., 150.);
        let overlap_halfexts = Vec2::new(200., 200.);
        draw_rectangle_lines(
            overlap_pos.x() - overlap_halfexts.x(),
            overlap_pos.y() - overlap_halfexts.y(),
            overlap_halfexts.x() * 2.,
            overlap_halfexts.y() * 2.,
            3.,
            VIOLET,
        );

        // tiles have collision_mask set to 1, player rectangle to 2
        for collider_handle in
            physics.overlap_test(overlap_pos, overlap_halfexts, 1, &bodies, &colliders)
        {
            let collider = &colliders[collider_handle];
            let body = &bodies[collider.owner];
            draw_overlap_test_collider(collider, body.position);
        }

        // tiles have collision_mask set to 1, player rectangle to 2
        let ray_toi = physics
            .project_ray(&ray, 1 | 2, &bodies, &colliders)
            .min_by(|(_, a), (_, b)| {
                a.toi
                    .partial_cmp(&b.toi)
                    .unwrap_or(std::cmp::Ordering::Less)
            })
            .map(|(collider_handle, raycast)| {
                let collider = &colliders[collider_handle];
                let body = &bodies[collider.owner];
                draw_overlap_test_collider(collider, body.position);
                raycast.toi
            })
            .unwrap_or(1.);

        draw_line(
            ray.origin.x(),
            ray.origin.y(),
            ray.origin.x() + ray.dir.x() * ray_toi,
            ray.origin.y() + ray.dir.y() * ray_toi,
            1.,
            PURPLE,
        );

        next_frame().await
    }
}

// 32 is tile per second
fn controls(mut velocity: Vec2) -> Vec2 {
    let input: f32 = {
        if is_key_down(KeyCode::Left) {
            -1.
        } else if is_key_down(KeyCode::Right) {
            1.
        } else {
            0.
        }
    };

    velocity += Vec2::new(input * 32. * 8. * FPS_INV, 0.);

    // if movement pressed

    let damped = (1f32 - 0.2).powf(5. * FPS_INV);
    *velocity.x_mut() *= damped;
    // println!("vel: {}", velocity.x());

    *velocity.x_mut() = velocity.x().max(-32. * 4.).min(32. * 4.);

    if is_key_pressed(KeyCode::Up) {
        velocity += Vec2::new(0., -128.);
    }
    velocity
}

fn add_tile(
    physics: &mut PhysicsWorld,
    bodies: &mut resphys::BodySet,
    colliders: &mut resphys::ColliderSet<TagType>,
    position: Vec2,
) {
    let body3 = resphys::builder::BodyDesc::new()
        .with_position(position)
        .make_static()
        .build();
    let collider3 = resphys::builder::ColliderDesc::new(
        AABB {
            half_exts: Vec2::new(16., 16.),
        },
        TagType::Tile,
    )
    .with_category(2);
    let body3_handle = bodies.insert(body3);
    colliders.insert(collider3.build(body3_handle), bodies, physics);
}

fn draw_collider(collider: &Collider<TagType>, position: Vec2) {
    let mut color = match collider.state {
        ColliderState::Solid => BLUE,
        ColliderState::Sensor => YELLOW,
    };
    // Quickly change color's alpha
    let fill_color = color;

    color.0[3] = (0.3 * 255.) as u8;

    let wh = collider.shape.half_exts;
    let x_pos = position.x() - wh.x() + collider.offset.x();
    let y_pos = position.y() - wh.y() + collider.offset.y();
    draw_rectangle(x_pos, y_pos, wh.x() * 2., wh.y() * 2., color);
    draw_rectangle_lines(x_pos, y_pos, wh.x() * 2., wh.y() * 2., 3., fill_color);
}

fn draw_overlap_test_collider(collider: &Collider<TagType>, position: Vec2) {
    let mut color = match collider.state {
        ColliderState::Solid => GREEN,
        ColliderState::Sensor => ORANGE,
    };
    // Quickly change color's alpha
    let fill_color = color;

    color.0[3] = (0.3 * 255.) as u8;

    let wh = collider.shape.half_exts;
    let x_pos = position.x() - wh.x() + collider.offset.x();
    let y_pos = position.y() - wh.y() + collider.offset.y();
    draw_rectangle(x_pos, y_pos, wh.x() * 2., wh.y() * 2., color);
    draw_rectangle_lines(x_pos, y_pos, wh.x() * 2., wh.y() * 2., 3., fill_color);
}

#[derive(Clone, Copy, Debug)]
enum TagType {
    Tile,
    Player,
}