From 4af65ed961165156862d1e2bdd050df4ae36856a Mon Sep 17 00:00:00 2001
From: lisk77 <lisk77@protonmail.com>
Date: Sat, 8 Mar 2025 02:04:50 +0100
Subject: [PATCH] feat: implemented a priority camera system that searches for
 the `Entity` with the `Camera2D` component with the smallest priority

---
 crates/comet_ecs/src/component.rs       | 23 +++++++++++++++++++++--
 crates/comet_renderer/src/camera.rs     | 11 +++++++----
 crates/comet_renderer/src/renderer2d.rs | 25 +++++++++++++++++++++----
 3 files changed, 49 insertions(+), 10 deletions(-)

diff --git a/crates/comet_ecs/src/component.rs b/crates/comet_ecs/src/component.rs
index f77b99b..bb47b1c 100644
--- a/crates/comet_ecs/src/component.rs
+++ b/crates/comet_ecs/src/component.rs
@@ -54,6 +54,7 @@ pub struct Render2D {
 pub struct Camera2D {
 	zoom: f32,
 	dimensions: Vec2,
+	priority: u8
 }
 
 // ##################################################
@@ -275,10 +276,20 @@ impl Transform3D {
 }
 
 impl Camera2D {
-	pub fn new(dimensions: Vec2, zoom: f32) -> Self {
+	/// Creates a Camera2D component.
+	///
+	/// # Parameters
+	/// - `dimensions`: The dimensions of the camera as a `Vec2` (width, height).
+	/// - `zoom`: The zoom level of the camera.
+	/// - `priority`: The priority of the camera, with lower numbers indicating higher priority.
+	///
+	/// # Returns
+	/// - Returns a `Camera2D` instance.
+	pub fn new(dimensions: Vec2, zoom: f32, priority: u8) -> Self {
 		Self {
 			dimensions,
-			zoom
+			zoom,
+			priority
 		}
 	}
 
@@ -298,6 +309,14 @@ impl Camera2D {
 		self.dimensions = dimensions;
 	}
 
+	pub fn priority(&self) -> u8 {
+		self.priority
+	}
+
+	pub fn set_priority(&mut self, priority: u8) {
+		self.priority = priority;
+	}
+
 	pub fn in_view_frustum(&self, camera_pos: Position2D, entity: Position2D) -> bool {
 		let left = camera_pos.x() - self.zoom;
 		let right = camera_pos.x() + self.zoom;
diff --git a/crates/comet_renderer/src/camera.rs b/crates/comet_renderer/src/camera.rs
index d3ad19c..86606eb 100644
--- a/crates/comet_renderer/src/camera.rs
+++ b/crates/comet_renderer/src/camera.rs
@@ -30,10 +30,13 @@ impl Camera {
 	}
 
 	pub fn build_view_projection_matrix(&self) -> cgmath::Matrix4<f32> {
-		OPENGL_TO_WGPU_MATRIX * cgmath::ortho(self.position.x() - self.dimension.x() / 2.0,
-											  self.position.x() + self.dimension.x() / 2.0,
-											  self.position.y() - self.dimension.y() / 2.0,
-											  self.position.y() + self.dimension.y() / 2.0,
+		let zoomed_width = self.dimension.x() / self.zoom;
+		let zoomed_height = self.dimension.y() / self.zoom;
+
+		OPENGL_TO_WGPU_MATRIX * cgmath::ortho(self.position.x() - zoomed_width / 2.0,
+											  self.position.x() + zoomed_width / 2.0,
+											  self.position.y() - zoomed_height / 2.0,
+											  self.position.y() + zoomed_height / 2.0,
 											  1.0,
 											  0.0)
 	}
diff --git a/crates/comet_renderer/src/renderer2d.rs b/crates/comet_renderer/src/renderer2d.rs
index f232049..d04f476 100644
--- a/crates/comet_renderer/src/renderer2d.rs
+++ b/crates/comet_renderer/src/renderer2d.rs
@@ -730,6 +730,17 @@ impl<'a> Renderer2D<'a> {
 		todo!()
 	}
 
+	fn find_priority_camera(&self, cameras: Vec<Camera2D>) -> usize {
+		let mut priority = 0;
+		let mut position = 0;
+		for (i, camera) in cameras.iter().enumerate() {
+			if camera.priority() < priority {
+				position = i;
+			}
+		}
+
+		position
+	}
 	/// A function to automatically render all the entities of the `World` struct.
 	/// The entities must have the `Render2D` and `Transform2D` components to be rendered as well as set visible.
 	pub fn render_scene_2d(&mut self, world: &World) {
@@ -739,8 +750,14 @@ impl<'a> Renderer2D<'a> {
 			return;
 		}
 
-		let camera_component = world.get_component::<Camera2D>(cameras[0]).unwrap();
-		let camera_position = world.get_component::<Transform2D>(cameras[0]).unwrap().position();
+		let cam = cameras.get(
+			self.find_priority_camera(
+				cameras.iter().map(|e| *world.get_component::<Camera2D>(*e).unwrap()
+				).collect::<Vec<Camera2D>>())
+		).unwrap();
+
+		let camera_component = world.get_component::<Camera2D>(*cam).unwrap();
+		let camera_position = world.get_component::<Transform2D>(*cam).unwrap().position();
 
 		let camera = OldCam::new(
 			camera_component.zoom(),
@@ -791,11 +808,11 @@ impl<'a> Renderer2D<'a> {
 		for entity in world.get_entities_with(ComponentSet::from_ids(vec![Transform2D::type_id(), Render2D::type_id()])) {
 			let entity_id = entity as usize;
 
-			/*if !camera_component
+			if !camera_component
 				.in_view_frustum(*camera_position, *world.get_component::<Transform2D>(entity_id).unwrap().position())
 			{
 				continue;
-			}*/
+			}
 
 			match world.get_component::<Render2D>(entity_id) {
 				Some(render) => {