zoomie/src/controller.rs

use winit::{
	event::{ElementState, KeyEvent, MouseButton, MouseScrollDelta, WindowEvent},
	keyboard::{KeyCode, PhysicalKey},
};

use crate::camera::Camera;

pub struct CameraController {
	speed: f32,
	forward: f32,
	cursor_start: (f32, f32),
	movement: (f32, f32),
	is_moving: bool,
}

impl CameraController {
	pub fn new(speed: f32) -> Self {
		Self {
			speed,
			forward: 0.0,
			cursor_start: (0.0, 0.0),
			movement: (0.0, 0.0),
			is_moving: false,
		}
	}

	pub fn process_events(&mut self, event: &WindowEvent) -> bool {
		match event {
			WindowEvent::MouseInput { state, button, .. } => {
				if state.is_pressed() && *button == MouseButton::Left {
					self.is_moving = true;
					return true;
				}
				else {
					self.is_moving = false;
					self.movement = (0.0, 0.0);
				}
				false
			}
			WindowEvent::CursorMoved { position, .. } => {
				if !self.is_moving {
					self.cursor_start = (position.x as f32, position.y as f32);
				}
				else {
					let x = -self.cursor_start.0 + position.x as f32;
					let x = x * 0.000001;
					let y = self.cursor_start.1 - position.y as f32;
					let y = y * 0.000001;

					self.movement = (x, y);
				}
				true
			}
			WindowEvent::MouseWheel { delta, .. } => match delta {
				MouseScrollDelta::LineDelta(_, y) => {
					self.forward = *y;
					true
				}
				_ => false,
			},
			_ => false,
		}
	}

	pub fn update_camera(&mut self, camera: &mut Camera) {
		use cgmath::InnerSpace;

		let forward = camera.target - camera.eye;
		let forward_norm = forward.normalize();

		if self.forward > 0.0 {
			camera.eye += forward_norm * self.speed;
		}
		else if self.forward < 0.0 {
			camera.eye -= forward_norm * self.speed;
		}

		if self.is_moving {
			camera.eye.x += self.movement.0;
			camera.eye.y += self.movement.1;

			camera.target.x += self.movement.0;
			camera.target.y += self.movement.1;
		}

		self.forward = 0.0;
	}
}