const PI: f32 = 3.14159265359

const LUMINANCE_WEIGHTS: vec3<f32> = vec3(0.2126, 0.7152, 0.0722)

const GODOT_NORMAL_FADE_RATE: f32 = 0.0175

const GODOT_NORMAL_MINIMUM_STRENGTH: f32 = 0.015

const GODOT_WATER_ALBEDO: vec3<f32> = vec3( 0.010022826, 0.01960665, 0.02721178, )

const GODOT_SSS_MODIFIER: vec3<f32> = vec3(0.9, 1.15, 0.85)

fn smith_masking_shadowing ( ) -> f32

fn ggx_distribution ( ) -> f32

fn safe_normalize ( ) -> vec3<f32>

fn sample_local_light ( ) -> LocalLightSample

fn local_light_contribution ( ) -> LocalLightContribution

fn quat_rotate ( ) -> vec3<f32>

fn view_direction ( ) -> vec3<f32>

fn sample_environment ( ) -> vec3<f32>

fn sample_diffuse_environment ( ) -> vec3<f32>

fn filtered_primary_light_color ( ) -> vec3<f32>

fn resolve_primary_light ( ) -> PrimaryLightState

fn strongest_incident_directional_light ( ) -> IncidentDirectionalLight