LightManager

filament::Engine* engine = filament::Engine::create();
utils::Entity sun = utils::EntityManager::get().create();

filament::LightManager::Builder(LightManager::Type::SUN)
    .castShadows(true)
    .build(*engine, sun);

engine->getLightManager().destroy(sun);

LightManager::Builder builder(LightManager::Type::POINT);

builder.lightChannel(1, true).lightChannel(2, false);

builder.castShadows(true);

LightManager::ShadowOptions options;
options.mapSize = 2048;
options.shadowCascades = 3;
builder.shadowOptions(options);

// Create a light that only casts shadows but doesn't illuminate
builder.castLight(false).castShadows(true);

builder.position({0.0f, 5.0f, 0.0f});

builder.direction({0.0f, -1.0f, 0.0f}); // Pointing downward

builder.color({1.0f, 0.9f, 0.8f}); // Warm white

// Sun's illuminance is about 100,000 lux
LightManager::Builder(LightManager::Type::SUN)
    .intensity(100000.0f)
    .build(*engine, sunEntity);

// Point light with 800 lumens (typical LED bulb)
LightManager::Builder(LightManager::Type::POINT)
    .intensity(800.0f)
    .build(*engine, bulbEntity);

// 60W incandescent bulb
builder.intensity(60.0f, LightManager::EFFICIENCY_INCANDESCENT);

// 10W LED bulb
builder.intensity(10.0f, LightManager::EFFICIENCY_LED);

builder.intensityCandela(1000.0f);

builder.falloff(10.0f); // 10 meter radius of influence

// 30 degree inner cone, 45 degree outer cone
float innerAngle = 30.0f * (M_PI / 180.0f);
float outerAngle = 45.0f * (M_PI / 180.0f);
builder.spotLightCone(innerAngle, outerAngle);

// The Sun as seen from Earth: 0.526° to 0.545°
builder.sunAngularRadius(0.545f);

builder.sunHaloSize(10.0f);

builder.sunHaloFalloff(80.0f);

utils::Entity lightEntity = utils::EntityManager::get().create();
auto result = builder.build(*engine, lightEntity);
if (result == LightManager::Builder::Result::Success) {
    // Light created successfully
}

LightManager::ShadowOptions options;
options.mapSize = 2048;
options.shadowCascades = 4;
options.constantBias = 0.001f;
options.screenSpaceContactShadows = true;

LightManager::ShadowCascades::computeUniformSplits(
    options.cascadeSplitPositions, 4
);

builder.shadowOptions(options);

float splits[3];
LightManager::ShadowCascades::computeUniformSplits(splits, 4);

float splits[3];
LightManager::ShadowCascades::computeLogSplits(splits, 4, 0.1f, 100.0f);

float splits[3];
LightManager::ShadowCascades::computePracticalSplits(splits, 4, 0.1f, 100.0f, 0.5f);

auto instance = lightManager.getInstance(lightEntity);
lightManager.setPosition(instance, {0.0f, 10.0f, 0.0f});

lightManager.setDirection(instance, {0.0f, -1.0f, 0.0f});

lightManager.setColor(instance, {1.0f, 0.9f, 0.8f});

lightManager.setIntensity(instance, 50000.0f);

lightManager.setShadowCaster(instance, true);

#include <filament/Engine.h>
#include <filament/LightManager.h>
#include <utils/EntityManager.h>

using namespace filament;
using namespace utils;

// Create engine and entity
Engine* engine = Engine::create();
Entity sunEntity = EntityManager::get().create();

// Configure shadow options
LightManager::ShadowOptions shadowOptions;
shadowOptions.mapSize = 2048;
shadowOptions.shadowCascades = 3;
LightManager::ShadowCascades::computePracticalSplits(
    shadowOptions.cascadeSplitPositions, 3, 0.1f, 100.0f, 0.5f
);

// Create a sun light
LightManager::Builder(LightManager::Type::SUN)
    .color({1.0f, 0.95f, 0.9f})
    .intensity(100000.0f)  // 100,000 lux
    .direction({0.3f, -1.0f, -0.3f})
    .sunAngularRadius(0.545f)
    .castShadows(true)
    .shadowOptions(shadowOptions)
    .build(*engine, sunEntity);

// Create a point light (street lamp)
Entity lampEntity = EntityManager::get().create();
LightManager::Builder(LightManager::Type::POINT)
    .color({1.0f, 0.9f, 0.7f})
    .intensity(800.0f)  // 800 lumens
    .position({5.0f, 3.0f, 0.0f})
    .falloff(10.0f)  // 10 meter radius
    .build(*engine, lampEntity);

// Create a spot light
Entity spotEntity = EntityManager::get().create();
float innerAngle = 20.0f * (M_PI / 180.0f);
float outerAngle = 30.0f * (M_PI / 180.0f);

LightManager::Builder(LightManager::Type::SPOT)
    .color({1.0f, 1.0f, 1.0f})
    .intensity(1000.0f)
    .position({0.0f, 5.0f, 0.0f})
    .direction({0.0f, -1.0f, 0.0f})
    .falloff(15.0f)
    .spotLightCone(innerAngle, outerAngle)
    .build(*engine, spotEntity);