From a4e527979d51066b748b94184dfda57c8a6fc2e6 Mon Sep 17 00:00:00 2001
From: nashmuhandes <nashbackslash@gmail.com>
Date: Wed, 25 Dec 2024 18:22:43 +0800
Subject: [PATCH] Allow setting a dynamic light's alpha to influence its
 brightness. This brings it in parity with VKDoom

---
 src/rendering/hwrenderer/hw_dynlightdata.cpp      | 3 +++
 src/rendering/hwrenderer/scene/hw_spritelight.cpp | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/rendering/hwrenderer/hw_dynlightdata.cpp b/src/rendering/hwrenderer/hw_dynlightdata.cpp
index 044d34d3d..0c264a1f7 100644
--- a/src/rendering/hwrenderer/hw_dynlightdata.cpp
+++ b/src/rendering/hwrenderer/hw_dynlightdata.cpp
@@ -92,6 +92,9 @@ void AddLightToList(FDynLightData &dld, int group, FDynamicLight * light, bool f
 		cs = 1.0f;
 	}
 
+	if (light->target)
+		cs *= (float)light->target->Alpha;
+
 	float r = light->GetRed() / 255.0f * cs;
 	float g = light->GetGreen() / 255.0f * cs;
 	float b = light->GetBlue() / 255.0f * cs;
diff --git a/src/rendering/hwrenderer/scene/hw_spritelight.cpp b/src/rendering/hwrenderer/scene/hw_spritelight.cpp
index f9998398a..ca67296d7 100644
--- a/src/rendering/hwrenderer/scene/hw_spritelight.cpp
+++ b/src/rendering/hwrenderer/scene/hw_spritelight.cpp
@@ -176,6 +176,15 @@ void HWDrawInfo::GetDynSpriteLight(AActor *self, float x, float y, float z, FLig
 					lr = light->GetRed() / 255.0f;
 					lg = light->GetGreen() / 255.0f;
 					lb = light->GetBlue() / 255.0f;
+
+					if (light->target)
+					{
+						float alpha = (float)light->target->Alpha;
+						lr *= alpha;
+						lg *= alpha;
+						lb *= alpha;
+					}
+
 					if (light->IsSubtractive())
 					{
 						float bright = (float)FVector3(lr, lg, lb).Length();