Encapsulate camera location

src/bin/wireframe/main.rs

@@ -1,6 +1,6 @@
 use std::{collections::HashSet, time::Instant};
 
-use glam::{mat4, vec2, vec3, vec4, Mat4, Quat, Vec3};
+use glam::{mat4, vec2, vec3, vec4, Mat4, Vec3};
 use glium::{
 	backend::{glutin::SimpleWindowBuilder, Facade},
 	glutin::config::ConfigTemplateBuilder,
@@ -69,6 +69,39 @@ fn prepare_scene(display: &impl Facade) -> Vec<Wireframe> {
 		.collect()
 }
 
+mod camctl {
+	use glam::{vec3, Mat4, Quat, Vec3};
+
+	pub struct CameraLocation {
+		pos: Vec3,
+		rot: Quat,
+	}
+
+	impl CameraLocation {
+		pub fn new() -> CameraLocation {
+			let rot = Quat::from_euler(glam::EulerRot::ZYX, std::f32::consts::FRAC_PI_4, 0., 0.);
+			let pos = rot * vec3(-200., 0., 50.);
+			CameraLocation { pos, rot }
+		}
+
+		pub fn view_mtx(&self) -> Mat4 {
+			Mat4::from_quat(self.rot.inverse()) * Mat4::from_translation(-self.pos)
+		}
+
+		pub fn move_rel(&mut self, offset: Vec3) {
+			self.pos += self.rot * offset;
+		}
+
+		pub fn rotate_rel_ypr(&mut self, ypr: Vec3) {
+			self.rotate_rel_quat(Quat::from_euler(glam::EulerRot::XYZ, ypr.x, ypr.y, ypr.z));
+		}
+
+		pub fn rotate_rel_quat(&mut self, rot: Quat) {
+			self.rot *= rot;
+		}
+	}
+}
+
 static KEYS_MOVE: &'static [(PhysicalKey, Vec3)] = &[
 	(PhysicalKey::Code(KeyCode::KeyW), vec3(1., 0., 0.)),
 	(PhysicalKey::Code(KeyCode::KeyS), vec3(-1., 0., 0.)),
@@ -103,10 +136,7 @@ fn main() {
 
 	let scene = prepare_scene(&display);
 
-	let rot = Quat::from_euler(glam::EulerRot::ZYX, std::f32::consts::FRAC_PI_4, 0., 0.);
+	let mut cam = camctl::CameraLocation::new();
-	let mut cam_pos = rot * vec3(-200., 0., 50.);
-	let mut cam_rot = rot;
-
 	let mut t1 = Instant::now();
 
 	#[allow(deprecated)]
@@ -124,13 +154,12 @@ fn main() {
 						.iter()
 						.filter_map(|(key, dir)| keys_pressed.contains(key).then_some(dir))
 						.sum();
-					cam_pos += 100. * dt * (cam_rot * v);
 					let vroll: Vec3 = KEYS_ROTATE
 						.iter()
 						.filter_map(|(key, dir)| keys_pressed.contains(key).then_some(dir))
 						.sum();
-					let vroll = 2. * dt * vroll;
+					cam.move_rel(100. * dt * v);
-					cam_rot *= Quat::from_euler(glam::EulerRot::XYZ, vroll.x, vroll.y, vroll.z);
+					cam.rotate_rel_ypr(2. * dt * vroll);
 
 					let size = window.inner_size();
 					let size = vec2(size.width as f32, size.height as f32).normalize()
@@ -143,10 +172,7 @@ fn main() {
 						vec4(0., 1., 0., 0.),
 						vec4(0., 0., 0., 1.),
 					);
-
+					let view = my_to_gl * cam.view_mtx();
-					let view = my_to_gl
-						* Mat4::from_quat(cam_rot.inverse())
-						* Mat4::from_translation(-cam_pos);
 
 					let mut target = display.draw();
 					target.clear_color(0.0, 0.0, 0.0, 0.0);