camera.rs

use bevy::{
	core_pipeline::clear_color::ClearColorConfig,
	prelude::{Bundle, Component, GlobalTransform, Transform, Vec2},
	render::{
		camera::{Camera, CameraProjection, CameraRenderGraph},
		extract_component::ExtractComponent,
		primitives::Frustum,
		view::VisibleEntities,
	},
};

use crate::{context::KayakRootContext, event_dispatcher::EventDispatcher};

use super::ortho::UIOrthographicProjection;

/// Kayak UI's default UI camera.
#[derive(Component, ExtractComponent, Clone, Default)]
pub struct CameraUIKayak {
	pub clear_color: ClearColorConfig,
	pub custom_viewport: Option<Vec2>,
}

/// Kayak UI's default UI camera bundle.
#[derive(Bundle)]
pub struct UICameraBundle {
	pub camera: Camera,
	// pub camera_2d: Camera2d,
	pub camera_render_graph: CameraRenderGraph,
	pub orthographic_projection: UIOrthographicProjection,
	pub visible_entities: VisibleEntities,
	pub frustum: Frustum,
	pub transform: Transform,
	pub global_transform: GlobalTransform,
	pub camera_ui: CameraUIKayak,
	pub context: KayakRootContext,
	pub event_disaptcher: EventDispatcher,
}

impl Default for UICameraBundle {
	fn default() -> Self {
		Self::new(KayakRootContext::default())
	}
}

impl UICameraBundle {
	pub const UI_CAMERA: &'static str = "KAYAK_UI_CAMERA";
	pub fn new(kayak_root_context: KayakRootContext) -> Self {
		// we want 0 to be "closest" and +far to be "farthest" in 2d, so we offset
		// the camera's translation by far and use a right handed coordinate system
		let far = 1000.0;

		let orthographic_projection = UIOrthographicProjection {
			far,
			window_origin: Vec2::new(0.0, 0.0),
			..Default::default()
		};

		let transform = Transform::from_xyz(0.0, 0.0, far - 0.1);

		let view_projection =
			orthographic_projection.get_projection_matrix() * transform.compute_matrix().inverse();
		let frustum = Frustum::from_view_projection(&view_projection);
		UICameraBundle {
			camera: Camera {
				order: isize::MAX - 1,
				..Default::default()
			},
			camera_render_graph: CameraRenderGraph::new(bevy::core_pipeline::core_2d::graph::NAME),
			orthographic_projection,
			frustum,
			visible_entities: VisibleEntities::default(),
			transform,
			// camera_2d: Camera2d::default(),
			global_transform: Default::default(),
			camera_ui: CameraUIKayak {
				clear_color: ClearColorConfig::None,
			},
			context: kayak_root_context,
			event_disaptcher: EventDispatcher::new(),
		}
	}
}