SpotLight

Represents a light that emits in a specific direction with a cone-shaped area of influence.

A spotlight combines directional and point light behavior: intensity diminishes with distance (via attenuation) and with the angle from the central axis of the cone. This is commonly used to simulate focused light sources such as flashlights or stage spotlights.

When the target parameter is set to nullptr, the light will point toward the world origin.

auto spot = vglx::SpotLight::Create({
  .color = 0xFFFFFF,
  .intensity = 1.0f,
  .angle = vglx::math::DegToRad(10.0f),
  .penumbra = 0.3f,
  .target = nullptr,
  .attenuation = {
    .base = 1.0f,
    .linear = 0.0f,
    .quadratic = 0.0f
  }
});

INFO

Derives from Light and inherits all public properties and methods.

Construction

Constructors

SpotLight()

Constructs a spotlight.

SpotLight::SpotLight(const Parameters& params);

Parameter	Description
params	Initialization parameters for constructing the light.

Factories preferred

SpotLight::Create() auto

Creates a shared instance of SpotLight.

static auto SpotLight::Create(const Parameters& params);

Parameter	Description
params	Initialization parameters for constructing the light.

Types

SpotLight::Parameters struct

Parameters for constructing a SpotLight object.

Parameter	Description
color Color	Light color.
intensity float	Light intensity multiplier.
angle float	Cone angle (in radians) for spotlight cutoff.
penumbra float	Softness of the spotlight edge.
target std::shared_ptr<Node>	Node the light is directed toward.
attenuation Attenuation	Attenuation parameters controlling distance-based falloff.

Properties

angle float

Cone angle, in radians, of the spotlight.

float angle {};

attenuation Attenuation

Attenuation parameters controlling distance-based falloff.

Attenuation attenuation {};

penumbra float

Penumbra controlling the softness of the spotlight’s edge.

float penumbra {};

target std::shared_ptr<Node>

Node that the light is oriented toward.

std::shared_ptr<Node> target {nullptr};

Functions

Direction() Vector3

Returns the normalized direction vector of the light.

The direction is derived from the light’s position and its target node. If no target is set, the light will point toward the origin.

Vector3 SpotLight::Direction();

GetType() Light::Type virtual

Identifies this light as Light::Type::Spot.

Type vglx::SpotLight::GetType() const override;

OnUpdate() void virtual

Called once per frame to update the light state.

Currently used to generate or dispose of debug geometry when debug mode is enabled.

void SpotLight::OnUpdate(float delta) override;

Parameter	Description
delta	Time in seconds since the last frame.

SetDebugMode() void virtual

Enables or disables debug visualization for this light.

When enabled, the renderer will visualize the spotlight cone and influence region using helper line geometry.

void SpotLight::SetDebugMode(bool is_debug_mode) override;

Parameter	Description
is_debug_mode	true to enable debug mode; false to disable.