Galactica/src/game/game.rs

use cgmath::{Deg, InnerSpace, Point2};
use content::SystemHandle;
use std::time::Instant;
use winit::event::{ElementState, MouseButton, MouseScrollDelta, TouchPhase, VirtualKeyCode};

use super::camera::Camera;
use crate::{content, inputstatus::InputStatus};
use galactica_constants;
use galactica_gameobject as object;
use galactica_render::{AnchoredUiPosition, ObjectSprite, UiSprite};
use galactica_shipbehavior::{behavior, ShipBehavior};
use galactica_world::{util, ShipPhysicsHandle, World};

struct Ui {}

impl Ui {
	fn new() -> Self {
		Self {}
	}

	fn build_radar(
		&self,
		player: &ShipPhysicsHandle,
		physics: &World,
		ct: &content::Content,
	) -> Vec<UiSprite> {
		let mut out = Vec::new();

		let radar_range = 2000.0;
		let radar_size = 300.0;

		out.push(UiSprite {
			texture: ct.get_texture_handle("ui::radar"),
			pos: AnchoredUiPosition::NorthWest(Point2 { x: 10.0, y: -10.0 }),
			dimensions: Point2 {
				x: radar_size,
				y: radar_size,
			},
			angle: Deg(0.0),
		});

		let (_, pr) = physics.get_ship_body(player).unwrap();
		let pr = util::rigidbody_position(pr);
		for (s, r) in physics.iter_ship_body() {
			if s.physics_handle == *player {
				continue;
			}
			let r = util::rigidbody_position(r);
			let d = r - pr;
			let m = d.magnitude() / radar_range;
			if m < 0.8 {
				out.push(UiSprite {
					texture: ct.get_texture_handle("ui::blip"),
					pos: AnchoredUiPosition::NorthWest(
						Point2 {
							x: radar_size / 2.0 + 10.0,
							y: radar_size / -2.0 - 10.0,
						} + (d / radar_range * 150.0),
					),
					dimensions: Point2 { x: 1.0, y: 1.0 } * 5.0f32.min((0.8 - m) * 50.0),
					angle: Deg(0.0),
				});
			}
		}

		return out;
	}
}

pub struct Game {
	pub input: InputStatus,
	pub last_update: Instant,
	pub player: ShipPhysicsHandle,
	pub system: object::System,
	pub camera: Camera,
	paused: bool,
	pub time_scale: f32,

	ui: Ui,
	physics: World,
	shipbehaviors: Vec<Box<dyn ShipBehavior>>,
	content: content::Content,
}

impl Game {
	pub fn new(ct: content::Content) -> Self {
		let mut physics = World::new();
		let ss = ct.get_ship(content::ShipHandle { index: 0 });

		let mut o1 = object::OutfitSet::new(ss);
		o1.add(&ct, content::OutfitHandle { index: 0 });
		o1.add_gun(&ct, content::GunHandle { index: 0 });
		o1.add_gun(&ct, content::GunHandle { index: 0 });

		let s = object::Ship::new(
			&ct,
			content::ShipHandle { index: 0 },
			content::FactionHandle { index: 0 },
			o1,
		);

		let h1 = physics.add_ship(&ct, s, Point2 { x: 0.0, y: 0.0 });

		let s = object::Ship::new(
			&ct,
			content::ShipHandle { index: 0 },
			content::FactionHandle { index: 0 },
			object::OutfitSet::new(ss),
		);
		let h2 = physics.add_ship(&ct, s, Point2 { x: 300.0, y: 300.0 });

		let mut o1 = object::OutfitSet::new(ss);
		o1.add(&ct, content::OutfitHandle { index: 0 });
		o1.add_gun(&ct, content::GunHandle { index: 0 });

		let s = object::Ship::new(
			&ct,
			content::ShipHandle { index: 0 },
			content::FactionHandle { index: 0 },
			o1,
		);

		let h3 = physics.add_ship(
			&ct,
			s,
			Point2 {
				x: -300.0,
				y: 300.0,
			},
		);

		let mut shipbehaviors: Vec<Box<dyn ShipBehavior>> = Vec::new();
		shipbehaviors.push(behavior::Player::new(h1));
		shipbehaviors.push(behavior::Dummy::new(h2));
		shipbehaviors.push(behavior::Point::new(h3));

		Game {
			last_update: Instant::now(),
			input: InputStatus::new(),
			player: h1,

			camera: Camera {
				pos: (0.0, 0.0).into(),
				zoom: 500.0,
			},
			system: object::System::new(&ct, SystemHandle { index: 0 }),

			paused: false,
			time_scale: 1.0,
			physics,
			shipbehaviors,
			content: ct,
			ui: Ui::new(),
		}
	}

	pub fn process_key(&mut self, state: &ElementState, key: &VirtualKeyCode) {
		self.input.process_key(state, key)
	}

	pub fn process_click(&mut self, state: &ElementState, key: &MouseButton) {
		self.input.process_click(state, key)
	}

	pub fn process_scroll(&mut self, delta: &MouseScrollDelta, phase: &TouchPhase) {
		self.input.process_scroll(delta, phase)
	}

	pub fn set_paused(&mut self, pause: bool) {
		if pause {
			self.paused = true;
			self.input.release_all()
		} else {
			self.paused = false;
		}
	}

	pub fn update(&mut self) {
		let t: f32 = self.last_update.elapsed().as_secs_f32() * self.time_scale;

		self.shipbehaviors.retain_mut(|b| {
			if self.physics.get_ship_mut(&b.get_handle()).is_none() {
				false
			} else {
				b.update_controls(&mut self.physics, &self.content);
				true
			}
		});

		self.physics.step(t, &self.content);

		if self.input.v_scroll != 0.0 {
			self.camera.zoom = (self.camera.zoom + self.input.v_scroll)
				.clamp(galactica_constants::ZOOM_MIN, galactica_constants::ZOOM_MAX);
			self.input.v_scroll = 0.0;
		}

		// TODO: Camera physics
		let r = self
			.physics
			.get_ship_mut(&self.player)
			.unwrap()
			.physics_handle;
		let r = self.physics.get_rigid_body(r.0); // TODO: r.0 shouldn't be public
		let ship_pos = util::rigidbody_position(r);
		self.camera.pos = ship_pos;
		self.last_update = Instant::now();
	}

	pub fn get_object_sprites(&self) -> Vec<ObjectSprite> {
		let mut sprites: Vec<ObjectSprite> = Vec::new();

		sprites.append(&mut self.system.get_sprites());
		sprites.extend(self.physics.get_ship_sprites(&self.content));

		// Make sure sprites are drawn in the correct order
		// (note the reversed a, b in the comparator)
		//
		// TODO: maybe use a gpu depth buffer instead?
		// I've tried this, but it doesn't seem to work with transparent textures.
		sprites.sort_by(|a, b| b.pos.z.total_cmp(&a.pos.z));

		// Don't waste time sorting these, they should always be on top.
		sprites.extend(self.physics.get_projectile_sprites());

		return sprites;
	}

	pub fn get_ui_sprites(&self) -> Vec<UiSprite> {
		return self
			.ui
			.build_radar(&self.player, &self.physics, &self.content);
	}
}