From 86e41652647cec8efd2dd0c8a0e4076f85548288 Mon Sep 17 00:00:00 2001
From: Victor Giers <mail@victorgiers.com>
Date: Tue, 28 Apr 2026 14:16:31 +0200
Subject: [PATCH] Update light input structure and implement dominant light
 resolution for god rays

---
 src/rendering/screen-space-god-rays.ts | 39 ++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/src/rendering/screen-space-god-rays.ts b/src/rendering/screen-space-god-rays.ts
index de573205..32ff5be0 100644
--- a/src/rendering/screen-space-god-rays.ts
+++ b/src/rendering/screen-space-god-rays.ts
@@ -22,8 +22,7 @@ import { Pass } from "postprocessing";
 import type { Vec3 } from "../core/vector";
 import type {
   AdvancedRenderingGodRaysSettings,
-  AdvancedRenderingSettings,
-  WorldSunLightSettings
+  AdvancedRenderingSettings
 } from "../document/world-settings";
 
 const MIN_CELESTIAL_LIGHT_INTENSITY = 1e-4;
@@ -61,6 +60,12 @@ export interface ScreenSpaceGodRaysLightSource {
   intensity: number;
 }
 
+export interface ScreenSpaceGodRaysLightInput {
+  direction: Vec3;
+  colorHex: string;
+  intensity: number;
+}
+
 export interface ScreenSpaceGodRaysLightProjection {
   screenPosition: {
     x: number;
@@ -112,7 +117,7 @@ export function createScreenSpaceGodRaysLightSource(): ScreenSpaceGodRaysLightSo
 
 export function syncScreenSpaceGodRaysLightSource(
   target: ScreenSpaceGodRaysLightSource,
-  light: WorldSunLightSettings | null
+  light: ScreenSpaceGodRaysLightInput | null
 ) {
   if (
     light === null ||
@@ -134,6 +139,34 @@ export function syncScreenSpaceGodRaysLightSource(
   target.intensity = light.intensity;
 }
 
+export function resolveDominantScreenSpaceGodRaysLightInput(
+  sun: ScreenSpaceGodRaysLightInput | null,
+  moon: ScreenSpaceGodRaysLightInput | null
+): ScreenSpaceGodRaysLightInput | null {
+  const sunVisible =
+    sun !== null &&
+    sun.intensity > MIN_CELESTIAL_LIGHT_INTENSITY &&
+    isFiniteVec3(sun.direction);
+  const moonVisible =
+    moon !== null &&
+    moon.intensity > MIN_CELESTIAL_LIGHT_INTENSITY &&
+    isFiniteVec3(moon.direction);
+
+  if (sunVisible && moonVisible) {
+    return sun.intensity >= moon.intensity ? sun : moon;
+  }
+
+  if (sunVisible) {
+    return sun;
+  }
+
+  if (moonVisible) {
+    return moon;
+  }
+
+  return null;
+}
+
 export function resolveGodRaysParameters(
   settings: AdvancedRenderingGodRaysSettings
 ): ResolvedGodRaysParameters {