pub mod camera;
pub mod debug;
pub mod figure;
pub mod lod;
pub mod math;
pub mod particle;
pub mod simple;
pub mod smoke_cycle;
pub mod terrain;
pub mod tether;
pub mod trail;

pub use self::{
    camera::{Camera, CameraMode},
    debug::{Debug, DebugShape, DebugShapeId},
    figure::FigureMgr,
    lod::Lod,
    particle::ParticleMgr,
    terrain::{SpriteRenderContextLazy, Terrain},
    tether::TetherMgr,
    trail::TrailMgr,
};
use crate::{
    audio::{ambience, ambience::AmbienceMgr, music::MusicMgr, sfx::SfxMgr, AudioFrontend},
    render::{
        create_skybox_mesh, CloudsLocals, Consts, CullingMode, Drawer, GlobalModel, Globals,
        GlobalsBindGroup, Light, Model, PointLightMatrix, PostProcessLocals, RainOcclusionLocals,
        Renderer, Shadow, ShadowLocals, SkyboxVertex,
    },
    session::PlayerDebugLines,
    settings::Settings,
    window::{AnalogGameInput, Event},
};
use client::Client;
use common::{
    calendar::Calendar,
    comp::{
        self, item::ItemDesc, ship::figuredata::VOXEL_COLLIDER_MANIFEST, slot::EquipSlot,
        tool::ToolKind,
    },
    outcome::Outcome,
    resources::{DeltaTime, TimeOfDay, TimeScale},
    terrain::{BlockKind, TerrainChunk, TerrainGrid},
    vol::ReadVol,
    weather::WeatherGrid,
};
use common_base::{prof_span, span};
use common_state::State;
use comp::item::Reagent;
use hashbrown::HashMap;
use num::traits::{Float, FloatConst};
use specs::{Entity as EcsEntity, Join, LendJoin, WorldExt};
use vek::*;

const ZOOM_CAP_PLAYER: f32 = 1000.0;
const ZOOM_CAP_ADMIN: f32 = 100000.0;

// TODO: Don't hard-code this.
const CURSOR_PAN_SCALE: f32 = 0.005;

pub(crate) const MAX_LIGHT_COUNT: usize = 20; // 31 (total shadow_mats is limited to 128 with default max_uniform_buffer_binding_size)
pub(crate) const MAX_SHADOW_COUNT: usize = 24;
pub(crate) const MAX_POINT_LIGHT_MATRICES_COUNT: usize = MAX_LIGHT_COUNT * 6 + 6;
const NUM_DIRECTED_LIGHTS: usize = 1;
const LIGHT_DIST_RADIUS: f32 = 64.0; // The distance beyond which lights may not emit light from their origin
const SHADOW_DIST_RADIUS: f32 = 8.0;
const SHADOW_MAX_DIST: f32 = 96.0; // The distance beyond which shadows may not be visible
/// The minimum sin γ we will use before switching to uniform mapping.
const EPSILON_UPSILON: f64 = -1.0;

const SHADOW_NEAR: f32 = 0.25; // Near plane for shadow map point light rendering.
const SHADOW_FAR: f32 = 128.0; // Far plane for shadow map point light rendering.

/// Above this speed is considered running
/// Used for first person camera effects
const RUNNING_THRESHOLD: f32 = 0.7;

/// The threashold for starting calculations with rain.
const RAIN_THRESHOLD: f32 = 0.0;

/// is_daylight, array of active lights.
pub type LightData<'a> = (bool, &'a [Light]);

struct EventLight {
    light: Light,
    timeout: f32,
    fadeout: fn(f32) -> f32,
}

struct Skybox {
    model: Model<SkyboxVertex>,
}

pub struct Scene {
    data: GlobalModel,
    globals_bind_group: GlobalsBindGroup,
    camera: Camera,
    camera_input_state: Vec2<f32>,
    event_lights: Vec<EventLight>,

    skybox: Skybox,
    terrain: Terrain<TerrainChunk>,
    pub debug: Debug,
    pub lod: Lod,
    loaded_distance: f32,
    /// x coordinate is sea level (minimum height for any land chunk), and y
    /// coordinate is the maximum height above the mnimimum for any land
    /// chunk.
    map_bounds: Vec2<f32>,
    select_pos: Option<Vec3<i32>>,
    light_data: Vec<Light>,

    particle_mgr: ParticleMgr,
    trail_mgr: TrailMgr,
    figure_mgr: FigureMgr,
    tether_mgr: TetherMgr,
    pub sfx_mgr: SfxMgr,
    pub music_mgr: MusicMgr,
    ambience_mgr: AmbienceMgr,

    integrated_rain_vel: f32,
    wind_vel: Vec2<f32>,
    pub interpolated_time_of_day: Option<f64>,
    last_lightning: Option<(Vec3<f32>, f64)>,
    local_time: f64,

    pub debug_vectors_enabled: bool,
}

pub struct SceneData<'a> {
    pub client: &'a Client,
    pub state: &'a State,
    pub viewpoint_entity: specs::Entity,
    pub mutable_viewpoint: bool,
    pub target_entity: Option<specs::Entity>,
    pub loaded_distance: f32,
    pub terrain_view_distance: u32, // not used currently
    pub entity_view_distance: u32,
    pub tick: u64,
    pub gamma: f32,
    pub exposure: f32,
    pub ambiance: f32,
    pub mouse_smoothing: bool,
    pub sprite_render_distance: f32,
    pub particles_enabled: bool,
    pub weapon_trails_enabled: bool,
    pub flashing_lights_enabled: bool,
    pub figure_lod_render_distance: f32,
    pub is_aiming: bool,
    pub interpolated_time_of_day: Option<f64>,
}

impl<'a> SceneData<'a> {
    pub fn get_sun_dir(&self) -> Vec3<f32> {
        TimeOfDay::new(self.interpolated_time_of_day.unwrap_or(0.0)).get_sun_dir()
    }

    pub fn get_moon_dir(&self) -> Vec3<f32> {
        TimeOfDay::new(self.interpolated_time_of_day.unwrap_or(0.0)).get_moon_dir()
    }
}

/// Approximate a scalar field of view angle using the parameterization from
/// section 4.3 of Lloyd's thesis:
///
/// W_e = 2 n_e tan θ
///
/// where
///
/// W_e = 2 is the width of the image plane (for our projections, since they go
/// from -1 to 1) n_e = near_plane is the near plane for the view frustum
/// θ = (fov / 2) is the half-angle of the FOV (the one passed to
/// Mat4::projection_rh_zo).
///
/// Although the widths for the x and y image planes are the same, they are
/// different in this framework due to the introduction of an aspect ratio:
///
/// y'(p) = 1.0 / tan(fov / 2) * p.y / -p.z
/// x'(p) = 1.0 / (aspect * tan(fov / 2)) * p.x / -p.z
///
/// i.e.
///
/// y'(x, y, -near, w) = 1 / tan(fov / 2) p.y / near
/// x'(x, y, -near, w) = 1 / (aspect * tan(fov / 2)) p.x / near
///
/// W_e,y = 2 * near_plane * tan(fov / 2)
/// W_e,x = 2 * near_plane * aspect * W_e,y
///
/// Θ_x = atan(W_e_y / 2 / near_plane) = atanfov / t()
///
/// i.e. we have an "effective" W_e_x of
///
/// 2 = 2 * near_plane * tan Θ
///
/// atan(1 / near_plane) = θ
///
/// y'
/// x(-near)
/// W_e = 2 * near_plane *
///
/// W_e_y / n_e = tan (fov / 2)
/// W_e_x = 2 n
fn compute_scalar_fov<F: Float>(_near_plane: F, fov: F, aspect: F) -> F {
    let two = F::one() + F::one();
    let theta_y = fov / two;
    let theta_x = (aspect * theta_y.tan()).atan();
    theta_x.min(theta_y)
}

/// Compute a near-optimal warping parameter that helps minimize error in a
/// shadow map.
///
/// See section 5.2 of Brandon Lloyd's thesis:
///
/// [http://gamma.cs.unc.edu/papers/documents/dissertations/lloyd07.pdf](Logarithmic Perspective Shadow Maps).
///
/// η =
///     0                                                         γ < γ_a
///     -1 + (η_b + 1)(1 + cos(90 (γ - γ_a)/(γ_b - γ_a)))   γ_a ≤ γ < γ_b
///     η_b + (η_c - η_b)  sin(90 (γ - γ_b)/(γ_c - γ_b))    γ_b ≤ γ < γ_c
///     η_c                                                 γ_c ≤ γ
///
/// NOTE: Equation's described behavior is *wrong!*  I have pieced together a
/// slightly different function that seems to more closely satisfy the author's
/// intent:
///
/// η =
///     -1                                                        γ < γ_a
///     -1 + (η_b + 1)            (γ - γ_a)/(γ_b - γ_a)     γ_a ≤ γ < γ_b
///     η_b + (η_c - η_b)  sin(90 (γ - γ_b)/(γ_c - γ_b))    γ_b ≤ γ < γ_c
///     η_c                                                 γ_c ≤ γ
///
/// There are other alternatives that may have more desirable properties, such
/// as:
///
/// η =
///     -1                                                        γ < γ_a
///     -1 + (η_b + 1)(1 - cos(90 (γ - γ_a)/(γ_b - γ_a)))   γ_a ≤ γ < γ_b
///     η_b + (η_c - η_b)  sin(90 (γ - γ_b)/(γ_c - γ_b))    γ_b ≤ γ < γ_c
///     η_c                                                 γ_c ≤ γ
fn compute_warping_parameter<F: Float + FloatConst>(
    gamma: F,
    (gamma_a, gamma_b, gamma_c): (F, F, F),
    (eta_b, eta_c): (F, F),
) -> F {
    if gamma < gamma_a {
        -F::one()
        /* F::zero() */
    } else if gamma_a <= gamma && gamma < gamma_b {
        /* -F::one() + (eta_b + F::one()) * (F::one() + (F::FRAC_PI_2() * (gamma - gamma_a) / (gamma_b - gamma_a)).cos()) */
        -F::one() + (eta_b + F::one()) * (F::one() - (F::FRAC_PI_2() * (gamma - gamma_a) / (gamma_b - gamma_a)).cos())
        // -F::one() + (eta_b + F::one()) * ((gamma - gamma_a) / (gamma_b - gamma_a))
    } else if gamma_b <= gamma && gamma < gamma_c {
        eta_b + (eta_c - eta_b) * (F::FRAC_PI_2() * (gamma - gamma_b) / (gamma_c - gamma_b)).sin()
    } else {
        eta_c
    }
    // NOTE: Just in case we go out of range due to floating point imprecision.
    .max(-F::one()).min(F::one())
}

/// Compute a near-optimal warping parameter that falls off quickly enough
/// when the warp angle goes past the minimum field of view angle, for
/// perspective projections.
///
/// For F_p (perspective warping) and view fov angle θ,the parameters are:
///
/// γ_a = θ / 3
/// γ_b = θ
/// γ_c = θ + 0.3(90 - θ)
///
/// η_b = -0.2
/// η_c = 0
///
/// See compute_warping_parameter.
fn compute_warping_parameter_perspective<F: Float + FloatConst>(
    gamma: F,
    near_plane: F,
    fov: F,
    aspect: F,
) -> F {
    let theta = compute_scalar_fov(near_plane, fov, aspect);
    let two = F::one() + F::one();
    let three = two + F::one();
    let ten = three + three + three + F::one();
    compute_warping_parameter(
        gamma,
        (
            theta / three,
            theta,
            theta + (three / ten) * (F::FRAC_PI_2() - theta),
        ),
        (-two / ten, F::zero()),
    )
}

impl Scene {
    /// Create a new `Scene` with default parameters.
    pub fn new(
        renderer: &mut Renderer,
        lazy_init: &mut SpriteRenderContextLazy,
        client: &Client,
        settings: &Settings,
    ) -> Self {
        let resolution = renderer.resolution().map(|e| e as f32);
        let sprite_render_context = lazy_init(renderer);

        let data = GlobalModel {
            globals: renderer.create_consts(&[Globals::default()]),
            lights: renderer.create_consts(&[Light::default(); MAX_LIGHT_COUNT]),
            shadows: renderer.create_consts(&[Shadow::default(); MAX_SHADOW_COUNT]),
            shadow_mats: renderer.create_shadow_bound_locals(&[ShadowLocals::default()]),
            rain_occlusion_mats: renderer
                .create_rain_occlusion_bound_locals(&[RainOcclusionLocals::default()]),
            point_light_matrices: Box::new(
                [PointLightMatrix::default(); MAX_POINT_LIGHT_MATRICES_COUNT],
            ),
        };

        let lod = Lod::new(renderer, client, settings);

        let globals_bind_group = renderer.bind_globals(&data, lod.get_data());

        let terrain = Terrain::new(renderer, &data, lod.get_data(), sprite_render_context);

        let camera_mode = match client.presence() {
            Some(comp::PresenceKind::Spectator) => CameraMode::Freefly,
            _ => CameraMode::ThirdPerson,
        };

        let calendar = client.state().ecs().read_resource::<Calendar>();

        Self {
            data,
            globals_bind_group,
            camera: Camera::new(resolution.x / resolution.y, camera_mode),
            camera_input_state: Vec2::zero(),
            event_lights: Vec::new(),

            skybox: Skybox {
                model: renderer.create_model(&create_skybox_mesh()).unwrap(),
            },
            terrain,
            debug: Debug::new(),
            lod,
            loaded_distance: 0.0,
            map_bounds: Vec2::new(
                client.world_data().min_chunk_alt(),
                client.world_data().max_chunk_alt(),
            ),
            select_pos: None,
            light_data: Vec::new(),
            particle_mgr: ParticleMgr::new(renderer),
            trail_mgr: TrailMgr::default(),
            figure_mgr: FigureMgr::new(renderer),
            tether_mgr: TetherMgr::new(renderer),
            sfx_mgr: SfxMgr::default(),
            music_mgr: MusicMgr::new(&calendar),
            ambience_mgr: AmbienceMgr {
                ambience: ambience::load_ambience_items(),
            },
            integrated_rain_vel: 0.0,
            wind_vel: Vec2::zero(),
            interpolated_time_of_day: None,
            last_lightning: None,
            local_time: 0.0,
            debug_vectors_enabled: false,
        }
    }

    /// Get a reference to the scene's globals.
    pub fn globals(&self) -> &Consts<Globals> { &self.data.globals }

    /// Get a reference to the scene's camera.
    pub fn camera(&self) -> &Camera { &self.camera }

    /// Get a reference to the scene's terrain.
    pub fn terrain(&self) -> &Terrain<TerrainChunk> { &self.terrain }

    /// Get a reference to the scene's lights.
    pub fn lights(&self) -> &Vec<Light> { &self.light_data }

    /// Get a reference to the scene's particle manager.
    pub fn particle_mgr(&self) -> &ParticleMgr { &self.particle_mgr }

    /// Get a reference to the scene's trail manager.
    pub fn trail_mgr(&self) -> &TrailMgr { &self.trail_mgr }

    /// Get a reference to the scene's figure manager.
    pub fn figure_mgr(&self) -> &FigureMgr { &self.figure_mgr }

    pub fn music_mgr(&self) -> &MusicMgr { &self.music_mgr }

    /// Get a mutable reference to the scene's camera.
    pub fn camera_mut(&mut self) -> &mut Camera { &mut self.camera }

    /// Set the block position that the player is interacting with
    pub fn set_select_pos(&mut self, pos: Option<Vec3<i32>>) { self.select_pos = pos; }

    pub fn select_pos(&self) -> Option<Vec3<i32>> { self.select_pos }

    /// Handle an incoming user input event (e.g.: cursor moved, key pressed,
    /// window closed).
    ///
    /// If the event is handled, return true.
    pub fn handle_input_event(&mut self, event: Event, client: &Client) -> bool {
        match event {
            // When the window is resized, change the camera's aspect ratio
            Event::Resize(dims) => {
                self.camera.set_aspect_ratio(dims.x as f32 / dims.y as f32);
                true
            },
            // Panning the cursor makes the camera rotate
            Event::CursorPan(delta) => {
                self.camera.rotate_by(Vec3::from(delta) * CURSOR_PAN_SCALE);
                true
            },
            // Zoom the camera when a zoom event occurs
            Event::Zoom(delta) => {
                let cap = if client.is_moderator() {
                    ZOOM_CAP_ADMIN
                } else {
                    ZOOM_CAP_PLAYER
                };
                // when zooming in the distance the camera travelles should be based on the
                // final distance. This is to make sure the camera travelles the
                // same distance when zooming in and out
                let player_scale = client
                    .state()
                    .read_component_copied::<comp::Scale>(client.entity())
                    .map_or(1.0, |s| s.0);
                if delta < 0.0 {
                    self.camera.zoom_switch(
                        // Thank you Imbris for doing the math
                        delta * (0.05 + self.camera.get_distance() * 0.01) / (1.0 - delta * 0.01),
                        cap,
                        player_scale,
                    );
                } else {
                    self.camera.zoom_switch(
                        delta * (0.05 + self.camera.get_distance() * 0.01),
                        cap,
                        player_scale,
                    );
                }
                true
            },
            Event::AnalogGameInput(input) => match input {
                AnalogGameInput::CameraX(d) => {
                    self.camera_input_state.x = d;
                    true
                },
                AnalogGameInput::CameraY(d) => {
                    self.camera_input_state.y = d;
                    true
                },
                _ => false,
            },
            // All other events are unhandled
            _ => false,
        }
    }

    pub fn handle_outcome(
        &mut self,
        outcome: &Outcome,
        scene_data: &SceneData,
        audio: &mut AudioFrontend,
    ) {
        span!(_guard, "handle_outcome", "Scene::handle_outcome");
        self.particle_mgr
            .handle_outcome(outcome, scene_data, &self.figure_mgr);
        self.sfx_mgr
            .handle_outcome(outcome, audio, scene_data.client);

        match outcome {
            Outcome::Lightning { pos } => {
                self.last_lightning = Some((*pos, scene_data.state.get_time()));
            },
            Outcome::Explosion {
                pos,
                power,
                is_attack,
                reagent,
                ..
            } => self.event_lights.push(EventLight {
                light: Light::new(
                    *pos,
                    match reagent {
                        Some(Reagent::Blue) => Rgb::new(0.15, 0.4, 1.0),
                        Some(Reagent::Green) => Rgb::new(0.0, 1.0, 0.0),
                        Some(Reagent::Purple) => Rgb::new(0.7, 0.0, 1.0),
                        Some(Reagent::Red) => {
                            if *is_attack {
                                Rgb::new(1.0, 0.5, 0.0)
                            } else {
                                Rgb::new(1.0, 0.0, 0.0)
                            }
                        },
                        Some(Reagent::Phoenix) => Rgb::new(1.0, 0.8, 0.3),
                        Some(Reagent::White) => Rgb::new(1.0, 1.0, 1.0),
                        Some(Reagent::Yellow) => Rgb::new(1.0, 1.0, 0.0),
                        None => Rgb::new(1.0, 0.5, 0.0),
                    },
                    power
                        * if *is_attack || reagent.is_none() {
                            2.5
                        } else {
                            5.0
                        },
                ),
                timeout: match reagent {
                    Some(_) => 1.0,
                    None => 0.5,
                },
                fadeout: |timeout| timeout * 2.0,
            }),
            Outcome::ProjectileShot { .. } => {},
            _ => {},
        }
    }

    /// Maintain data such as GPU constant buffers, models, etc. To be called
    /// once per tick.
    pub fn maintain(
        &mut self,
        renderer: &mut Renderer,
        audio: &mut AudioFrontend,
        scene_data: &SceneData,
        client: &Client,
        settings: &Settings,
    ) {
        span!(_guard, "maintain", "Scene::maintain");
        // Get player position.
        let ecs = scene_data.state.ecs();

        let dt = ecs.fetch::<DeltaTime>().0;

        self.local_time += dt as f64 * ecs.fetch::<TimeScale>().0;

        let positions = ecs.read_storage::<comp::Pos>();

        let viewpoint_pos = if let Some(viewpoint_pos) =
            positions.get(scene_data.viewpoint_entity).map(|pos| pos.0)
        {
            let viewpoint_ori = ecs
                .read_storage::<comp::Ori>()
                .get(scene_data.viewpoint_entity)
                .map_or(Quaternion::identity(), |ori| ori.to_quat());

            let viewpoint_look_ori = ecs
                .read_storage::<comp::CharacterActivity>()
                .get(scene_data.viewpoint_entity)
                .and_then(|activity| activity.look_dir)
                .map(|dir| {
                    let d = dir.to_vec();

                    let pitch = (-d.z).asin();
                    let yaw = d.x.atan2(d.y);

                    Vec3::new(yaw, pitch, 0.0)
                })
                .unwrap_or_else(|| {
                    let q = viewpoint_ori;
                    let sinr_cosp = 2.0 * (q.w * q.x + q.y * q.z);
                    let cosr_cosp = 1.0 - 2.0 * (q.x * q.x + q.y * q.y);
                    let pitch = sinr_cosp.atan2(cosr_cosp);

                    let siny_cosp = 2.0 * (q.w * q.z + q.x * q.y);
                    let cosy_cosp = 1.0 - 2.0 * (q.y * q.y + q.z * q.z);
                    let yaw = siny_cosp.atan2(cosy_cosp);

                    Vec3::new(-yaw, -pitch, 0.0)
                });

            let viewpoint_scale = ecs
                .read_storage::<comp::Scale>()
                .get(scene_data.viewpoint_entity)
                .map_or(1.0, |scale| scale.0);

            let (is_humanoid, viewpoint_height, viewpoint_eye_height) = ecs
                .read_storage::<comp::Body>()
                .get(scene_data.viewpoint_entity)
                .map_or((false, 1.0, 0.0), |b| {
                    (
                        matches!(b, comp::Body::Humanoid(_)),
                        b.height(),
                        b.eye_height(1.0), // Scale is applied later
                    )
                });

            if scene_data.mutable_viewpoint || matches!(self.camera.get_mode(), CameraMode::Freefly)
            {
                // Add the analog input to camera if it's a mutable viewpoint
                self.camera
                    .rotate_by(Vec3::from([self.camera_input_state.x, 0.0, 0.0]));
                self.camera
                    .rotate_by(Vec3::from([0.0, self.camera_input_state.y, 0.0]));
            } else {
                // Otherwise set the cameras rotation to the viewpoints
                self.camera.set_orientation(viewpoint_look_ori);
            }

            let viewpoint_offset = if is_humanoid {
                let viewpoint_rolling = ecs
                    .read_storage::<comp::CharacterState>()
                    .get(scene_data.viewpoint_entity)
                    .map_or(false, |cs| cs.is_dodge());

                let is_running = ecs
                    .read_storage::<comp::Vel>()
                    .get(scene_data.viewpoint_entity)
                    .zip(
                        ecs.read_storage::<comp::PhysicsState>()
                            .get(scene_data.viewpoint_entity),
                    )
                    .map(|(v, ps)| {
                        (v.0 - ps.ground_vel).magnitude_squared() > RUNNING_THRESHOLD.powi(2)
                    })
                    .unwrap_or(false);

                let on_ground = ecs
                    .read_storage::<comp::PhysicsState>()
                    .get(scene_data.viewpoint_entity)
                    .map(|p| p.on_ground.is_some());

                let player_entity = client.entity();
                let holding_ranged = client
                    .inventories()
                    .get(player_entity)
                    .and_then(|inv| inv.equipped(EquipSlot::ActiveMainhand))
                    .and_then(|item| item.tool_info())
                    .is_some_and(|tool_kind| {
                        matches!(
                            tool_kind,
                            ToolKind::Bow | ToolKind::Staff | ToolKind::Sceptre
                        )
                    });

                let up = match self.camera.get_mode() {
                    CameraMode::FirstPerson => {
                        if viewpoint_rolling {
                            viewpoint_height * 0.42
                        } else if is_running && on_ground.unwrap_or(false) {
                            viewpoint_eye_height
                                + (scene_data.state.get_time() as f32 * 17.0).sin() * 0.05
                        } else {
                            viewpoint_eye_height
                        }
                    },
                    CameraMode::ThirdPerson if scene_data.is_aiming && holding_ranged => {
                        viewpoint_height * 1.16 + settings.gameplay.aim_offset_y
                    },
                    CameraMode::ThirdPerson if scene_data.is_aiming => viewpoint_height * 1.16,
                    CameraMode::ThirdPerson => viewpoint_eye_height,
                    CameraMode::Freefly => 0.0,
                };

                let right = match self.camera.get_mode() {
                    CameraMode::FirstPerson => 0.0,
                    CameraMode::ThirdPerson if scene_data.is_aiming && holding_ranged => {
                        settings.gameplay.aim_offset_x
                    },
                    CameraMode::ThirdPerson => 0.0,
                    CameraMode::Freefly => 0.0,
                };

                // Alter camera position to match player.
                let tilt = self.camera.get_orientation().y;
                let dist = self.camera.get_distance();

                Vec3::unit_z() * (up * viewpoint_scale - tilt.min(0.0).sin() * dist * 0.6)
                    + self.camera.right() * (right * viewpoint_scale)
            } else {
                self.figure_mgr
                    .viewpoint_offset(scene_data, scene_data.viewpoint_entity)
            };

            match self.camera.get_mode() {
                CameraMode::FirstPerson | CameraMode::ThirdPerson => {
                    self.camera.set_focus_pos(viewpoint_pos + viewpoint_offset);
                },
                CameraMode::Freefly => {},
            };

            // Tick camera for interpolation.
            self.camera
                .update(scene_data.state.get_time(), dt, scene_data.mouse_smoothing);
            viewpoint_pos
        } else {
            Vec3::zero()
        };

        // Compute camera matrices.
        self.camera.compute_dependents(&scene_data.state.terrain());
        let camera::Dependents {
            view_mat,
            view_mat_inv,
            proj_mat,
            proj_mat_inv,
            cam_pos,
            ..
        } = self.camera.dependents();

        // Update chunk loaded distance smoothly for nice shader fog
        let loaded_distance =
            (0.98 * self.loaded_distance + 0.02 * scene_data.loaded_distance).max(0.01);

        // Reset lights ready for the next tick
        let lights = &mut self.light_data;
        lights.clear();

        // Maintain the particles.
        self.particle_mgr.maintain(
            renderer,
            scene_data,
            &self.terrain,
            &self.figure_mgr,
            lights,
        );

        // Maintain the trails.
        self.trail_mgr.maintain(renderer, scene_data);

        // Update light constants
        let max_light_dist = loaded_distance.powi(2) + LIGHT_DIST_RADIUS;
        lights.extend(
            (
                &scene_data.state.ecs().read_storage::<comp::Pos>(),
                scene_data
                    .state
                    .ecs()
                    .read_storage::<crate::ecs::comp::Interpolated>()
                    .maybe(),
                &scene_data
                    .state
                    .ecs()
                    .read_storage::<comp::LightAnimation>(),
                scene_data
                    .state
                    .ecs()
                    .read_storage::<comp::Health>()
                    .maybe(),
            )
                .join()
                .filter(|(pos, _, light_anim, h)| {
                    light_anim.col != Rgb::zero()
                        && light_anim.strength > 0.0
                        && pos.0.distance_squared(viewpoint_pos) < max_light_dist
                        && h.map_or(true, |h| !h.is_dead)
                })
                .map(|(pos, interpolated, light_anim, _)| {
                    // Use interpolated values if they are available
                    let pos = interpolated.map_or(pos.0, |i| i.pos);
                    Light::new(pos + light_anim.offset, light_anim.col, light_anim.strength)
                })
                .chain(
                    self.event_lights
                        .iter()
                        .map(|el| el.light.with_strength((el.fadeout)(el.timeout))),
                ),
        );
        let voxel_colliders_manifest = VOXEL_COLLIDER_MANIFEST.read();
        let figure_mgr = &self.figure_mgr;
        lights.extend(
            (
                &scene_data.state.ecs().entities(),
                &scene_data
                    .state
                    .read_storage::<crate::ecs::comp::Interpolated>(),
                &scene_data.state.read_storage::<comp::Body>(),
                &scene_data.state.read_storage::<comp::Collider>(),
            )
                .join()
                .filter_map(|(entity, interpolated, body, collider)| {
                    let vol = collider.get_vol(&voxel_colliders_manifest)?;
                    let (blocks_of_interest, offset) =
                        figure_mgr.get_blocks_of_interest(entity, body, Some(collider))?;

                    let mat = Mat4::from(interpolated.ori.to_quat())
                        .translated_3d(interpolated.pos)
                        * Mat4::translation_3d(offset);

                    let p = mat.inverted().mul_point(viewpoint_pos);
                    let aabb = Aabb {
                        min: Vec3::zero(),
                        max: vol.volume().sz.as_(),
                    };
                    if aabb.contains_point(p) || aabb.distance_to_point(p) < max_light_dist {
                        Some(
                            blocks_of_interest
                                .lights
                                .iter()
                                .map(move |(block_offset, level)| {
                                    let wpos = mat.mul_point(block_offset.as_() + 0.5);
                                    (wpos, level)
                                })
                                .filter(move |(wpos, _)| {
                                    wpos.distance_squared(viewpoint_pos) < max_light_dist
                                })
                                .map(|(wpos, level)| {
                                    Light::new(wpos, Rgb::white(), *level as f32 / 7.0)
                                }),
                        )
                    } else {
                        None
                    }
                })
                .flatten(),
        );
        lights.sort_by_key(|light| light.get_pos().distance_squared(viewpoint_pos) as i32);
        lights.truncate(MAX_LIGHT_COUNT);
        renderer.update_consts(&mut self.data.lights, lights);

        // Update event lights
        self.event_lights.retain_mut(|el| {
            el.timeout -= dt;
            el.timeout > 0.0
        });

        // Update shadow constants
        let mut shadows = (
            &scene_data.state.ecs().read_storage::<comp::Pos>(),
            scene_data
                .state
                .ecs()
                .read_storage::<crate::ecs::comp::Interpolated>()
                .maybe(),
            scene_data.state.ecs().read_storage::<comp::Scale>().maybe(),
            &scene_data.state.ecs().read_storage::<comp::Body>(),
            &scene_data.state.ecs().read_storage::<comp::Health>(),
        )
            .join()
            .filter(|(_, _, _, _, health)| !health.is_dead)
            .filter(|(pos, _, _, _, _)| {
                pos.0.distance_squared(viewpoint_pos)
                    < (loaded_distance.min(SHADOW_MAX_DIST) + SHADOW_DIST_RADIUS).powi(2)
            })
            .map(|(pos, interpolated, scale, _, _)| {
                Shadow::new(
                    // Use interpolated values pos if it is available
                    interpolated.map_or(pos.0, |i| i.pos),
                    scale.map_or(1.0, |s| s.0),
                )
            })
            .collect::<Vec<_>>();
        shadows.sort_by_key(|shadow| shadow.get_pos().distance_squared(viewpoint_pos) as i32);
        shadows.truncate(MAX_SHADOW_COUNT);
        renderer.update_consts(&mut self.data.shadows, &shadows);

        // Remember to put the new loaded distance back in the scene.
        self.loaded_distance = loaded_distance;

        // Update light projection matrices for the shadow map.

        // When the target time of day and time of day have a large discrepancy
        // (i.e two days), the linear interpolation causes brght flashing effects
        // in the sky. This will snap the time of day to the target time of day
        // for the client to avoid the flashing effect if flashing lights is
        // disabled.
        const DAY: f64 = 60.0 * 60.0 * 24.0;
        let time_of_day = scene_data.state.get_time_of_day();
        let max_lerp_period = if scene_data.flashing_lights_enabled {
            DAY * 2.0
        } else {
            DAY * 0.25
        };
        self.interpolated_time_of_day =
            Some(self.interpolated_time_of_day.map_or(time_of_day, |tod| {
                if (tod - time_of_day).abs() > max_lerp_period {
                    time_of_day
                } else {
                    Lerp::lerp(tod, time_of_day, dt as f64)
                }
            }));
        let time_of_day = self.interpolated_time_of_day.unwrap_or(time_of_day);
        let focus_pos = self.camera.get_focus_pos();
        let focus_off = focus_pos.map(|e| e.trunc());

        // Update global constants.
        renderer.update_consts(&mut self.data.globals, &[Globals::new(
            view_mat,
            proj_mat,
            cam_pos,
            focus_pos,
            self.loaded_distance,
            self.lod.get_data().tgt_detail as f32,
            self.map_bounds,
            time_of_day,
            scene_data.state.get_time(),
            self.local_time,
            renderer.resolution().as_(),
            Vec2::new(SHADOW_NEAR, SHADOW_FAR),
            lights.len(),
            shadows.len(),
            NUM_DIRECTED_LIGHTS,
            scene_data
                .state
                .terrain()
                .get((cam_pos + focus_off).map(|e| e.floor() as i32))
                .ok()
                // Don't block the camera's view in solid blocks if the player is a moderator
                .filter(|b| !(b.is_filled() && client.is_moderator()))
                .map(|b| b.kind())
                .unwrap_or(BlockKind::Air),
            self.select_pos.map(|e| e - focus_off.map(|e| e as i32)),
            scene_data.gamma,
            scene_data.exposure,
            self.last_lightning.unwrap_or((Vec3::zero(), -1000.0)),
            self.wind_vel,
            scene_data.ambiance,
            self.camera.get_mode(),
            scene_data.sprite_render_distance - 20.0,
        )]);
        renderer.update_clouds_locals(CloudsLocals::new(proj_mat_inv, view_mat_inv));
        renderer.update_postprocess_locals(PostProcessLocals::new(proj_mat_inv, view_mat_inv));

        // Maintain LoD.
        self.lod.maintain(renderer, client, focus_pos, &self.camera);

        // Maintain tethers.
        self.tether_mgr.maintain(renderer, client, focus_pos);

        // Maintain debug shapes
        self.debug.maintain(renderer);

        // Maintain the terrain.
        let (
            _visible_bounds,
            visible_light_volume,
            visible_psr_bounds,
            visible_occlusion_volume,
            visible_por_bounds,
        ) = self.terrain.maintain(
            renderer,
            scene_data,
            focus_pos,
            self.loaded_distance,
            &self.camera,
        );

        // Maintain the figures.
        let _figure_bounds = self.figure_mgr.maintain(
            renderer,
            &mut self.trail_mgr,
            scene_data,
            visible_psr_bounds,
            visible_por_bounds,
            &self.camera,
            Some(&self.terrain),
        );

        let fov = self.camera.get_effective_fov();
        let aspect_ratio = self.camera.get_aspect_ratio();
        let view_dir = ((focus_pos.map(f32::fract)) - cam_pos).normalized();

        // We need to compute these offset matrices to transform world space coordinates
        // to the translated ones we use when multiplying by the light space
        // matrix; this helps avoid precision loss during the
        // multiplication.
        let look_at = math::Vec3::from(cam_pos);
        let new_dir = math::Vec3::from(view_dir);
        let new_dir = new_dir.normalized();
        let up: math::Vec3<f32> = math::Vec3::unit_y();

        // Optimal warping for directed lights:
        //
        // n_opt = 1 / sin y (z_n + √(z_n + (f - n) sin y))
        //
        // where n is near plane, f is far plane, y is the tilt angle between view and
        // light direction, and n_opt is the optimal near plane.
        // We also want a way to transform and scale this matrix (* 0.5 + 0.5) in order
        // to transform it correctly into texture coordinates, as well as
        // OpenGL coordinates.  Note that the matrix for directional light
        // is *already* linear in the depth buffer.
        //
        // Also, observe that we flip the texture sampling matrix in order to account
        // for the fact that DirectX renders top-down.
        let texture_mat = Mat4::<f32>::scaling_3d::<Vec3<f32>>(Vec3::new(0.5, -0.5, 1.0))
            * Mat4::translation_3d(Vec3::new(1.0, -1.0, 0.0));

        let directed_mats = |d_view_mat: math::Mat4<f32>,
                             d_dir: math::Vec3<f32>,
                             volume: &Vec<math::Vec3<f32>>|
         -> (Mat4<f32>, Mat4<f32>) {
            // NOTE: Light view space, right-handed.
            let v_p_orig = math::Vec3::from(d_view_mat * math::Vec4::from_direction(new_dir));
            let mut v_p = v_p_orig.normalized();
            let cos_gamma = new_dir.map(f64::from).dot(d_dir.map(f64::from));
            let sin_gamma = (1.0 - cos_gamma * cos_gamma).sqrt();
            let gamma = sin_gamma.asin();
            let view_mat = math::Mat4::from_col_array(view_mat.into_col_array());
            // coordinates are transformed from world space (right-handed) to view space
            // (right-handed).
            let bounds1 = math::fit_psr(
                view_mat.map_cols(math::Vec4::from),
                volume.iter().copied(),
                math::Vec4::homogenized,
            );
            let n_e = f64::from(-bounds1.max.z);
            let factor = compute_warping_parameter_perspective(
                gamma,
                n_e,
                f64::from(fov),
                f64::from(aspect_ratio),
            );

            v_p.z = 0.0;
            v_p.normalize();
            let l_r: math::Mat4<f32> = if factor > EPSILON_UPSILON {
                // NOTE: Our coordinates are now in left-handed space, but v_p isn't; however,
                // v_p has no z component, so we don't have to adjust it for left-handed
                // spaces.
                math::Mat4::look_at_lh(math::Vec3::zero(), math::Vec3::unit_z(), v_p)
            } else {
                math::Mat4::identity()
            };
            // Convert from right-handed to left-handed coordinates.
            let directed_proj_mat = math::Mat4::new(
                1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, -1.0, 0.0, 0.0, 0.0, 0.0, 1.0,
            );

            let light_all_mat = l_r * directed_proj_mat * d_view_mat;
            // coordinates are transformed from world space (right-handed) to rotated light
            // space (left-handed).
            let bounds0 = math::fit_psr(
                light_all_mat,
                volume.iter().copied(),
                math::Vec4::homogenized,
            );
            // Vague idea: project z_n from the camera view to the light view (where it's
            // tilted by γ).
            //
            // NOTE: To transform a normal by M, we multiply by the transpose of the inverse
            // of M. For the cases below, we are transforming by an
            // already-inverted matrix, so the transpose of its inverse is
            // just the transpose of the original matrix.
            let (z_0, z_1) = {
                let f_e = f64::from(-bounds1.min.z).max(n_e);
                // view space, right-handed coordinates.
                let p_z = bounds1.max.z;
                // rotated light space, left-handed coordinates.
                let p_y = bounds0.min.y;
                let p_x = bounds0.center().x;
                // moves from view-space (right-handed) to world space (right-handed)
                let view_inv = view_mat.inverted();
                // moves from rotated light space (left-handed) to world space (right-handed).
                let light_all_inv = light_all_mat.inverted();

                // moves from view-space (right-handed) to world-space (right-handed).
                let view_point = view_inv
                    * math::Vec4::from_point(
                        -math::Vec3::unit_z() * p_z, /* + math::Vec4::unit_w() */
                    );
                let view_plane = view_mat.transposed() * -math::Vec4::unit_z();

                // moves from rotated light space (left-handed) to world space (right-handed).
                let light_point = light_all_inv
                    * math::Vec4::from_point(
                        math::Vec3::unit_y() * p_y, /* + math::Vec4::unit_w() */
                    );
                let light_plane = light_all_mat.transposed() * math::Vec4::unit_y();

                // moves from rotated light space (left-handed) to world space (right-handed).
                let shadow_point = light_all_inv
                    * math::Vec4::from_point(
                        math::Vec3::unit_x() * p_x, /* + math::Vec4::unit_w() */
                    );
                let shadow_plane = light_all_mat.transposed() * math::Vec4::unit_x();

                // Find the point at the intersection of the three planes; note that since the
                // equations are already in right-handed world space, we don't need to negate
                // the z coordinates.
                let solve_p0 = math::Mat4::new(
                    view_plane.x,
                    view_plane.y,
                    view_plane.z,
                    0.0,
                    light_plane.x,
                    light_plane.y,
                    light_plane.z,
                    0.0,
                    shadow_plane.x,
                    shadow_plane.y,
                    shadow_plane.z,
                    0.0,
                    0.0,
                    0.0,
                    0.0,
                    1.0,
                );

                // in world-space (right-handed).
                let plane_dist = math::Vec4::new(
                    view_plane.dot(view_point),
                    light_plane.dot(light_point),
                    shadow_plane.dot(shadow_point),
                    1.0,
                );
                let p0_world = solve_p0.inverted() * plane_dist;
                // in rotated light-space (left-handed).
                let p0 = light_all_mat * p0_world;
                let mut p1 = p0;
                // in rotated light-space (left-handed).
                p1.y = bounds0.max.y;

                // transforms from rotated light-space (left-handed) to view space
                // (right-handed).
                let view_from_light_mat = view_mat * light_all_inv;
                // z0 and z1 are in view space (right-handed).
                let z0 = view_from_light_mat * p0;
                let z1 = view_from_light_mat * p1;

                // Extract the homogenized forward component (right-handed).
                //
                // NOTE: I don't think the w component should be anything but 1 here, but
                // better safe than sorry.
                (
                    f64::from(z0.homogenized().dot(-math::Vec4::unit_z())).clamp(n_e, f_e),
                    f64::from(z1.homogenized().dot(-math::Vec4::unit_z())).clamp(n_e, f_e),
                )
            };

            // all of this is in rotated light-space (left-handed).
            let mut light_focus_pos: math::Vec3<f32> = math::Vec3::zero();
            light_focus_pos.x = bounds0.center().x;
            light_focus_pos.y = bounds0.min.y;
            light_focus_pos.z = bounds0.center().z;

            let d = f64::from(bounds0.max.y - bounds0.min.y).abs();

            let w_l_y = d;

            // NOTE: See section 5.1.2.2 of Lloyd's thesis.
            // NOTE: Since z_1 and z_0 are in the same coordinate space, we don't have to
            // worry about the handedness of their ratio.
            let alpha = z_1 / z_0;
            let alpha_sqrt = alpha.sqrt();
            let directed_near_normal = if factor < 0.0 {
                // Standard shadow map to LiSPSM
                (1.0 + alpha_sqrt - factor * (alpha - 1.0)) / ((alpha - 1.0) * (factor + 1.0))
            } else {
                // LiSPSM to PSM
                ((alpha_sqrt - 1.0) * (factor * alpha_sqrt + 1.0)).recip()
            };

            // Equation 5.14 - 5.16
            let y_ = |v: f64| w_l_y * (v + directed_near_normal).abs();
            let directed_near = y_(0.0) as f32;
            let directed_far = y_(1.0) as f32;
            light_focus_pos.y = if factor > EPSILON_UPSILON {
                light_focus_pos.y - directed_near
            } else {
                light_focus_pos.y
            };
            // Left-handed translation.
            let w_v: math::Mat4<f32> = math::Mat4::translation_3d(-math::Vec3::new(
                light_focus_pos.x,
                light_focus_pos.y,
                light_focus_pos.z,
            ));
            let shadow_view_mat: math::Mat4<f32> = w_v * light_all_mat;
            let w_p: math::Mat4<f32> = {
                if factor > EPSILON_UPSILON {
                    // Projection for y
                    let near = directed_near;
                    let far = directed_far;
                    let left = -1.0;
                    let right = 1.0;
                    let bottom = -1.0;
                    let top = 1.0;
                    let s_x = 2.0 * near / (right - left);
                    let o_x = (right + left) / (right - left);
                    let s_z = 2.0 * near / (top - bottom);
                    let o_z = (top + bottom) / (top - bottom);

                    let s_y = (far + near) / (far - near);
                    let o_y = -2.0 * far * near / (far - near);

                    math::Mat4::new(
                        s_x, o_x, 0.0, 0.0, 0.0, s_y, 0.0, o_y, 0.0, o_z, s_z, 0.0, 0.0, 1.0, 0.0,
                        0.0,
                    )
                } else {
                    math::Mat4::identity()
                }
            };

            let shadow_all_mat: math::Mat4<f32> = w_p * shadow_view_mat;
            // coordinates are transformed from world space (right-handed)
            // to post-warp light space (left-handed), then homogenized.
            let math::Aabb::<f32> {
                min:
                    math::Vec3 {
                        x: xmin,
                        y: ymin,
                        z: zmin,
                    },
                max:
                    math::Vec3 {
                        x: xmax,
                        y: ymax,
                        z: zmax,
                    },
            } = math::fit_psr(
                shadow_all_mat,
                volume.iter().copied(),
                math::Vec4::homogenized,
            );
            let s_x = 2.0 / (xmax - xmin);
            let s_y = 2.0 / (ymax - ymin);
            let s_z = 1.0 / (zmax - zmin);
            let o_x = -(xmax + xmin) / (xmax - xmin);
            let o_y = -(ymax + ymin) / (ymax - ymin);
            let o_z = -zmin / (zmax - zmin);
            let directed_proj_mat = Mat4::new(
                s_x, 0.0, 0.0, o_x, 0.0, s_y, 0.0, o_y, 0.0, 0.0, s_z, o_z, 0.0, 0.0, 0.0, 1.0,
            );

            let shadow_all_mat: Mat4<f32> = Mat4::from_col_arrays(shadow_all_mat.into_col_arrays());

            let directed_texture_proj_mat = texture_mat * directed_proj_mat;
            (
                directed_proj_mat * shadow_all_mat,
                directed_texture_proj_mat * shadow_all_mat,
            )
        };

        let weather = client
            .state()
            .max_weather_near(focus_off.xy() + cam_pos.xy());
        self.wind_vel = weather.wind_vel();
        if weather.rain > RAIN_THRESHOLD {
            let weather = client.weather_at_player();
            let rain_vel = weather.rain_vel();
            let rain_view_mat = math::Mat4::look_at_rh(look_at, look_at + rain_vel, up);

            self.integrated_rain_vel += rain_vel.magnitude() * dt;
            let rain_dir_mat = Mat4::rotation_from_to_3d(-Vec3::unit_z(), rain_vel);

            let (shadow_mat, texture_mat) =
                directed_mats(rain_view_mat, rain_vel.into(), &visible_occlusion_volume);

            let rain_occlusion_locals = RainOcclusionLocals::new(
                shadow_mat,
                texture_mat,
                rain_dir_mat,
                weather.rain,
                self.integrated_rain_vel,
            );

            renderer.update_consts(&mut self.data.rain_occlusion_mats, &[rain_occlusion_locals]);
        } else if self.integrated_rain_vel > 0.0 {
            self.integrated_rain_vel = 0.0;
            // Need to set rain to zero
            let rain_occlusion_locals = RainOcclusionLocals::default();
            renderer.update_consts(&mut self.data.rain_occlusion_mats, &[rain_occlusion_locals]);
        }

        let sun_dir = scene_data.get_sun_dir();
        let is_daylight = sun_dir.z < 0.0;
        if renderer.pipeline_modes().shadow.is_map() && (is_daylight || !lights.is_empty()) {
            let (point_shadow_res, _directed_shadow_res) = renderer.get_shadow_resolution();
            // NOTE: The aspect ratio is currently always 1 for our cube maps, since they
            // are equal on all sides.
            let point_shadow_aspect = point_shadow_res.x as f32 / point_shadow_res.y as f32;
            // Construct matrices to transform from world space to light space for the sun
            // and moon.
            let directed_light_dir = math::Vec3::from(sun_dir);

            // We upload view matrices as well, to assist in linearizing vertex positions.
            // (only for directional lights, so far).
            let mut directed_shadow_mats = Vec::with_capacity(6);

            let light_view_mat = math::Mat4::look_at_rh(look_at, look_at + directed_light_dir, up);
            let (shadow_mat, texture_mat) =
                directed_mats(light_view_mat, directed_light_dir, &visible_light_volume);

            let shadow_locals = ShadowLocals::new(shadow_mat, texture_mat);

            renderer.update_consts(&mut self.data.shadow_mats, &[shadow_locals]);

            directed_shadow_mats.push(light_view_mat);
            // This leaves us with five dummy slots, which we push as defaults.
            directed_shadow_mats
                .extend_from_slice(&[math::Mat4::default(); 6 - NUM_DIRECTED_LIGHTS] as _);
            // Now, construct the full projection matrices in the first two directed light
            // slots.
            let mut shadow_mats = Vec::with_capacity(6 * (lights.len() + 1));
            shadow_mats.resize_with(6, PointLightMatrix::default);
            // Now, we tackle point lights.
            // First, create a perspective projection matrix at 90 degrees (to cover a whole
            // face of the cube map we're using); we use a negative near plane to exactly
            // match OpenGL's behavior if we use a left-handed coordinate system everywhere
            // else.
            let shadow_proj = camera::perspective_rh_zo_general(
                90.0f32.to_radians(),
                point_shadow_aspect,
                1.0 / SHADOW_NEAR,
                1.0 / SHADOW_FAR,
            );
            // NOTE: We negate here to emulate a right-handed projection with a negative
            // near plane, which produces the correct transformation to exactly match
            // OpenGL's rendering behavior if we use a left-handed coordinate
            // system everywhere else.
            let shadow_proj = shadow_proj * Mat4::scaling_3d(-1.0);

            // Next, construct the 6 orientations we'll use for the six faces, in terms of
            // their (forward, up) vectors.
            let orientations = [
                (Vec3::new(1.0, 0.0, 0.0), Vec3::new(0.0, -1.0, 0.0)),
                (Vec3::new(-1.0, 0.0, 0.0), Vec3::new(0.0, -1.0, 0.0)),
                (Vec3::new(0.0, 1.0, 0.0), Vec3::new(0.0, 0.0, 1.0)),
                (Vec3::new(0.0, -1.0, 0.0), Vec3::new(0.0, 0.0, -1.0)),
                (Vec3::new(0.0, 0.0, 1.0), Vec3::new(0.0, -1.0, 0.0)),
                (Vec3::new(0.0, 0.0, -1.0), Vec3::new(0.0, -1.0, 0.0)),
            ];

            // NOTE: We could create the shadow map collection at the same time as the
            // lights, but then we'd have to sort them both, which wastes time.  Plus, we
            // want to prepend our directed lights.
            shadow_mats.extend(lights.iter().flat_map(|light| {
                // Now, construct the full projection matrix by making the light look at each
                // cube face.
                let eye = Vec3::new(light.pos[0], light.pos[1], light.pos[2]) - focus_off;
                orientations.iter().map(move |&(forward, up)| {
                    // NOTE: We don't currently try to linearize point lights or need a separate
                    // transform for them.
                    PointLightMatrix::new(shadow_proj * Mat4::look_at_lh(eye, eye + forward, up))
                })
            }));

            for (i, val) in shadow_mats.into_iter().enumerate() {
                self.data.point_light_matrices[i] = val
            }
        }

        // Remove unused figures.
        self.figure_mgr.clean(scene_data.tick);

        // Maintain audio
        self.sfx_mgr.maintain(
            audio,
            scene_data.state,
            scene_data.viewpoint_entity,
            &self.camera,
            &self.terrain,
            client,
        );

        self.ambience_mgr
            .maintain(audio, scene_data.state, client, &self.camera);

        self.music_mgr.maintain(audio, scene_data.state, client);
    }

    pub fn global_bind_group(&self) -> &GlobalsBindGroup { &self.globals_bind_group }

    /// Render the scene using the provided `Drawer`.
    pub fn render(
        &self,
        drawer: &mut Drawer<'_>,
        state: &State,
        viewpoint_entity: EcsEntity,
        tick: u64,
        scene_data: &SceneData,
    ) {
        span!(_guard, "render", "Scene::render");
        let sun_dir = scene_data.get_sun_dir();
        let is_daylight = sun_dir.z < 0.0;
        let focus_pos = self.camera.get_focus_pos();
        let cam_pos = self.camera.dependents().cam_pos + focus_pos.map(|e| e.trunc());
        let is_rain = state.max_weather_near(cam_pos.xy()).rain > RAIN_THRESHOLD;
        let culling_mode = if scene_data
            .state
            .terrain()
            .get_key(scene_data.state.terrain().pos_key(cam_pos.as_()))
            .map_or(false, |c| {
                cam_pos.z < c.meta().alt() - terrain::UNDERGROUND_ALT
            }) {
            CullingMode::Underground
        } else {
            CullingMode::Surface
        };

        let camera_data = (&self.camera, scene_data.figure_lod_render_distance);

        // would instead have this as an extension.
        if drawer.pipeline_modes().shadow.is_map() && (is_daylight || !self.light_data.is_empty()) {
            if is_daylight {
                prof_span!("directed shadows");
                if let Some(mut shadow_pass) = drawer.shadow_pass() {
                    // Render terrain directed shadows.
                    self.terrain.render_shadows(
                        &mut shadow_pass.draw_terrain_shadows(),
                        focus_pos,
                        culling_mode,
                    );

                    // Render figure directed shadows.
                    self.figure_mgr.render_shadows(
                        &mut shadow_pass.draw_figure_shadows(),
                        state,
                        tick,
                        camera_data,
                    );
                    self.debug
                        .render_shadows(&mut shadow_pass.draw_debug_shadows());
                }
            }

            // Render terrain point light shadows.
            {
                prof_span!("point shadows");
                drawer.draw_point_shadows(
                    &self.data.point_light_matrices,
                    self.terrain.chunks_for_point_shadows(focus_pos),
                )
            }
        }
        // Render rain occlusion texture
        if is_rain {
            prof_span!("rain occlusion");
            if let Some(mut occlusion_pass) = drawer.rain_occlusion_pass() {
                self.terrain
                    .render_rain_occlusion(&mut occlusion_pass.draw_terrain_shadows(), cam_pos);

                self.figure_mgr.render_rain_occlusion(
                    &mut occlusion_pass.draw_figure_shadows(),
                    state,
                    tick,
                    camera_data,
                );
            }
        }

        prof_span!(guard, "main pass");
        if let Some(mut first_pass) = drawer.first_pass() {
            self.figure_mgr.render_viewpoint(
                &mut first_pass.draw_figures(),
                state,
                viewpoint_entity,
                tick,
                camera_data,
            );

            self.terrain
                .render(&mut first_pass, focus_pos, culling_mode);

            self.figure_mgr.render(
                &mut first_pass.draw_figures(),
                state,
                viewpoint_entity,
                tick,
                camera_data,
            );

            self.lod.render(&mut first_pass, culling_mode);

            // Render the skybox.
            first_pass.draw_skybox(&self.skybox.model);

            // Draws sprites
            let mut sprite_drawer = first_pass.draw_sprites(
                &self.terrain.sprite_globals,
                &self.terrain.sprite_render_state.sprite_atlas_textures,
            );
            self.figure_mgr.render_sprites(
                &mut sprite_drawer,
                state,
                cam_pos,
                scene_data.sprite_render_distance,
            );
            self.terrain.render_sprites(
                &mut sprite_drawer,
                focus_pos,
                cam_pos,
                scene_data.sprite_render_distance,
                culling_mode,
            );
            drop(sprite_drawer);

            // Render tethers.
            self.tether_mgr.render(&mut first_pass);

            // Draws translucent
            self.terrain.render_translucent(&mut first_pass, focus_pos);

            // Render particle effects.
            self.particle_mgr
                .render(&mut first_pass.draw_particles(), scene_data);

            // Render debug shapes
            self.debug.render(&mut first_pass.draw_debug());
        }
        drop(guard);
    }

    pub fn maintain_debug_hitboxes(
        &mut self,
        client: &Client,
        settings: &Settings,
        hitboxes: &mut HashMap<specs::Entity, DebugShapeId>,
        tracks: &mut HashMap<Vec2<i32>, Vec<DebugShapeId>>,
    ) {
        let ecs = client.state().ecs();
        {
            let mut current_chunks = hashbrown::HashSet::new();
            let terrain_grid = ecs.read_resource::<TerrainGrid>();
            for (key, chunk) in terrain_grid.iter() {
                current_chunks.insert(key);
                tracks.entry(key).or_insert_with(|| {
                    let mut ret = Vec::new();
                    for bezier in chunk.meta().tracks().iter() {
                        let shape_id = self.debug.add_shape(DebugShape::TrainTrack {
                            path: *bezier,
                            rail_width: 0.25,
                            rail_sep: 1.0,
                            plank_width: 0.5,
                            plank_height: 0.125,
                            plank_sep: 2.0,
                        });
                        ret.push(shape_id);
                        self.debug
                            .set_context(shape_id, [0.0; 4], [1.0; 4], [0.0, 0.0, 0.0, 1.0]);
                    }
                    for point in chunk.meta().debug_points().iter() {
                        let shape_id = self.debug.add_shape(DebugShape::Cylinder {
                            radius: 0.1,
                            height: 0.1,
                        });
                        ret.push(shape_id);
                        self.debug.set_context(
                            shape_id,
                            point.with_w(0.0).into_array(),
                            [1.0; 4],
                            [0.0, 0.0, 0.0, 1.0],
                        );
                    }
                    for line in chunk.meta().debug_lines().iter() {
                        let shape_id = self
                            .debug
                            .add_shape(DebugShape::Line([line.start, line.end], 0.1));
                        ret.push(shape_id);
                        self.debug
                            .set_context(shape_id, [0.0; 4], [1.0; 4], [0.0, 0.0, 0.0, 1.0]);
                    }
                    ret
                });
            }
            tracks.retain(|k, v| {
                let keep = current_chunks.contains(k);
                if !keep {
                    for shape in v.iter() {
                        self.debug.remove_shape(*shape);
                    }
                }
                keep
            });
        }
        let mut current_entities = hashbrown::HashSet::new();
        if settings.interface.toggle_hitboxes {
            let positions = ecs.read_component::<comp::Pos>();
            let colliders = ecs.read_component::<comp::Collider>();
            let orientations = ecs.read_component::<comp::Ori>();
            let scales = ecs.read_component::<comp::Scale>();
            let groups = ecs.read_component::<comp::Group>();
            for (entity, pos, collider, ori, scale, group) in (
                &ecs.entities(),
                &positions,
                &colliders,
                &orientations,
                scales.maybe(),
                groups.maybe(),
            )
                .join()
            {
                match collider {
                    comp::Collider::CapsulePrism {
                        p0,
                        p1,
                        radius,
                        z_min,
                        z_max,
                    } => {
                        let scale = scale.map_or(1.0, |s| s.0);
                        current_entities.insert(entity);

                        let shape = DebugShape::CapsulePrism {
                            p0: *p0 * scale,
                            p1: *p1 * scale,
                            radius: *radius * scale,
                            height: (*z_max - *z_min) * scale,
                        };

                        // If this shape no longer matches, remove the old one
                        if let Some(shape_id) = hitboxes.get(&entity) {
                            if self
                                .debug
                                .get_shape(*shape_id)
                                .map_or(false, |s| s != &shape)
                            {
                                self.debug.remove_shape(*shape_id);
                                hitboxes.remove(&entity);
                            }
                        }

                        let shape_id = hitboxes
                            .entry(entity)
                            .or_insert_with(|| self.debug.add_shape(shape));
                        let hb_pos = [pos.0.x, pos.0.y, pos.0.z + *z_min * scale, 0.0];
                        let color = if group == Some(&comp::group::ENEMY) {
                            [1.0, 0.0, 0.0, 0.5]
                        } else if group == Some(&comp::group::NPC) {
                            [0.0, 0.0, 1.0, 0.5]
                        } else {
                            [0.0, 1.0, 0.0, 0.5]
                        };
                        //let color = [1.0, 1.0, 1.0, 1.0];
                        let ori = ori.to_quat();
                        let hb_ori = [ori.x, ori.y, ori.z, ori.w];
                        self.debug.set_context(*shape_id, hb_pos, color, hb_ori);
                    },
                    comp::Collider::Voxel { .. }
                    | comp::Collider::Volume(_)
                    | comp::Collider::Point => {
                        // ignore terrain-like or point-hitboxes
                    },
                }
            }
        }
        hitboxes.retain(|k, v| {
            let keep = current_entities.contains(k);
            if !keep {
                self.debug.remove_shape(*v);
            }
            keep
        });
    }

    pub fn maintain_debug_vectors(&mut self, client: &Client, lines: &mut PlayerDebugLines) {
        lines
            .chunk_normal
            .take()
            .map(|id| self.debug.remove_shape(id));
        lines.fluid_vel.take().map(|id| self.debug.remove_shape(id));
        lines.wind.take().map(|id| self.debug.remove_shape(id));
        lines.vel.take().map(|id| self.debug.remove_shape(id));
        if self.debug_vectors_enabled {
            let ecs = client.state().ecs();

            let vels = &ecs.read_component::<comp::Vel>();
            let Some(vel) = vels.get(client.entity()) else {
                return;
            };

            let phys_states = &ecs.read_component::<comp::PhysicsState>();
            let Some(phys) = phys_states.get(client.entity()) else {
                return;
            };

            let positions = &ecs.read_component::<comp::Pos>();
            let Some(pos) = positions.get(client.entity()) else {
                return;
            };

            let weather = ecs.read_resource::<WeatherGrid>();
            // take id and remove to delete the previous lines.

            const LINE_WIDTH: f32 = 0.05;
            // Fluid Velocity
            {
                let Some(fluid) = phys.in_fluid else {
                    return;
                };
                let shape = DebugShape::Line([pos.0, pos.0 + fluid.flow_vel().0 / 2.], LINE_WIDTH);
                let id = self.debug.add_shape(shape);
                lines.fluid_vel = Some(id);
                self.debug
                    .set_context(id, [0.0; 4], [0.18, 0.72, 0.87, 0.8], [0.0, 0.0, 0.0, 1.0]);
            }
            // Chunk Terrain Normal Vector
            {
                let Some(chunk) = client.current_chunk() else {
                    return;
                };
                let shape = DebugShape::Line(
                    [
                        pos.0,
                        pos.0
                            + chunk
                                .meta()
                                .approx_chunk_terrain_normal()
                                .unwrap_or(Vec3::unit_z())
                                * 2.5,
                    ],
                    LINE_WIDTH,
                );
                let id = self.debug.add_shape(shape);
                lines.chunk_normal = Some(id);
                self.debug
                    .set_context(id, [0.0; 4], [0.22, 0.63, 0.1, 0.8], [0.0, 0.0, 0.0, 1.0]);
            }
            // Wind
            {
                let wind = weather.get_interpolated(pos.0.xy()).wind_vel();
                let shape = DebugShape::Line([pos.0, pos.0 + wind * 5.0], LINE_WIDTH);
                let id = self.debug.add_shape(shape);
                lines.wind = Some(id);
                self.debug
                    .set_context(id, [0.0; 4], [0.76, 0.76, 0.76, 0.8], [0.0, 0.0, 0.0, 1.0]);
            }
            // Player Vel
            {
                let shape = DebugShape::Line([pos.0, pos.0 + vel.0 / 2.0], LINE_WIDTH);
                let id = self.debug.add_shape(shape);
                lines.vel = Some(id);
                self.debug
                    .set_context(id, [0.0; 4], [0.98, 0.76, 0.01, 0.8], [0.0, 0.0, 0.0, 1.0]);
            }
        }
    }
}