Struct Light 

pub struct Light {
    pub kind: LightType,
    pub position: Vector3D,
    pub direction: Vector3D,
    pub intensity: f64,
    pub falloff: f64,
    pub spot_cos: f64,
    /* private fields */
}

A light source contributing illumination to a shaded point.

The fields have meanings that depend on LightType. Directions point toward the light source except for the spot cone axis, which points outward along the beam; see LightType for the full convention.

• For LightType::Directional, position is unused and direction is the unit vector from the surface toward the light.
• For LightType::Point, position is the world position of the light and direction is unused.
• For LightType::Spot, position is the lamp position, direction is the cone axis pointing outward along the beam, and spot_cos carries cos(half_angle) of the cone.

A light is never mutated during shading: LightingUniforms::shade_with_visibility reads it and derives per-point quantities into locals.

Fields

kind: LightType

The kind of light source (directional, point, or spot).

position: Vector3D

The world position of the light.

direction: Vector3D

Unit direction. Toward the light for LightType::Directional; the outward cone axis for LightType::Spot; unused for LightType::Point.

intensity: f64

Overall intensity scalar in the range 0.0..=infinity.

falloff: f64

Inverse-square falloff factor for point and spot lights.

pub rather than pub(crate): the getter is an out-of-crate consumer’s entry point (tests/, and the ray tracer’s data stage), and a narrowed field behind a public getter would silently re-expose it.

spot_cos: f64

cos(half_angle) for spot lights; zero for other kinds.

Implementations

impl Light

Implements factory constructors and shading for Light, Material, and LightingUniforms.

pub fn new_directional(direction: Vector3D, color: Vector3D) -> Light

Creates a new directional light pointing in direction with color.

The direction is normalized internally; intensity defaults to 1.0. Falloff and spot half-angle are unused for directional lights.

Arguments

• Vector3D - The unit direction toward the light source.
• Vector3D - The RGB intensity multiplier.

Returns

• Light - The new directional light.

pub fn new_point(position: Vector3D, color: Vector3D, intensity: f64) -> Light

Creates a new point light at position with color and intensity.

Falloff defaults to 1.0 (inverse-square). The direction field is unused for point lights and is set to the zero vector.

Arguments

• Vector3D - The world-space position of the light.
• Vector3D - The RGB intensity multiplier.
• f64 - The intensity scalar.

Returns

• Light - The new point light.

pub fn new_spot( position: Vector3D, direction: Vector3D, color: Vector3D, intensity: f64, half_angle_rad: f64, ) -> Light

Creates a new spotlight at position shining in direction.

The cone is defined by half_angle_rad; the cosine of that angle is stored for fast cone-test comparisons during shading.

Arguments

• Vector3D - The world-space position of the light.
• Vector3D - The unit direction the cone opens along.
• Vector3D - The RGB intensity multiplier.
• f64 - The intensity scalar.
• f64 - The half-angle of the cone in radians.

Returns

• Light - The new spotlight.

impl Light

pub fn get_kind(&self) -> LightType

pub fn get_position(&self) -> Vector3D

pub fn get_direction(&self) -> Vector3D

pub fn get_intensity(&self) -> f64

pub fn get_falloff(&self) -> f64

pub fn get_mut_falloff(&mut self) -> &mut f64

pub fn set_falloff(&mut self, val: f64) -> &mut Self

pub fn get_spot_cos(&self) -> f64

impl Light

pub fn new( kind: LightType, position: Vector3D, direction: Vector3D, color: Vector3D, intensity: f64, falloff: f64, spot_cos: f64, ) -> Self

Trait Implementations

impl Clone for Light

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Light

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Light

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Light