From e77cba1fd8ad45809d207a7c281af3e6baabef36 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 18 Apr 2018 22:15:06 +0200
Subject: [PATCH] - added a 'lightsizefactor' command to gldefs.

This is for mitigating the recently discovered problem with attenuated lights getting reduced in size, even on OpenGL 3+. The intent of the shrinking was to account for higher brightness of non-attenuated lights on OpenGL 2 and was never meant to be active on more modern versions.
The factor will apply to any attenuated light defined after it and will be inherited by included sub-lumps, but it will only last for the lunp it is set in.

If you have a definition for the broken behavior, AddLightAssociation

'lightsizefactor 0.667' at the top of your GLDEFS.
---
 src/r_data/a_dynlightdata.cpp |  7 ++++++-
 src/r_data/gldefs.cpp         | 22 ++++++++++++++--------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/r_data/a_dynlightdata.cpp b/src/r_data/a_dynlightdata.cpp
index b9c09a6908..6cab5d02c0 100644
--- a/src/r_data/a_dynlightdata.cpp
+++ b/src/r_data/a_dynlightdata.cpp
@@ -137,7 +137,7 @@ void FLightDefaults::ApplyProperties(ADynamicLight * light) const
 
 extern int ScriptDepth;
 
-void AddLightDefaults(FLightDefaults *defaults)
+void AddLightDefaults(FLightDefaults *defaults, double attnFactor)
 {
    FLightDefaults *temp;
    unsigned int i;
@@ -153,6 +153,11 @@ void AddLightDefaults(FLightDefaults *defaults)
          break;
       }
    }
+   if (defaults->GetAttenuate())
+   {
+	   defaults->SetArg(LIGHT_INTENSITY, int(defaults->GetArg(LIGHT_INTENSITY) * attnFactor));
+	   defaults->SetArg(LIGHT_SECONDARY_INTENSITY, int(defaults->GetArg(LIGHT_SECONDARY_INTENSITY) * attnFactor));
+   }
 
    LightDefaults.Push(defaults);
 }
diff --git a/src/r_data/gldefs.cpp b/src/r_data/gldefs.cpp
index 92c7a91d76..c01b905d9d 100644
--- a/src/r_data/gldefs.cpp
+++ b/src/r_data/gldefs.cpp
@@ -52,7 +52,7 @@
 #include "textures/skyboxtexture.h"
 #include "gl/shaders/gl_postprocessshader.h"
 
-void AddLightDefaults(FLightDefaults *defaults);
+void AddLightDefaults(FLightDefaults *defaults, double attnFactor);
 void AddLightAssociation(const char *actor, const char *frame, const char *light);
 void InitializeActorLights(TArray<FLightAssociation> &LightAssociations);
 
@@ -193,6 +193,7 @@ static const char *CoreKeywords[]=
    "detail",
    "#include",
    "material",
+   "lightsizefactor",
    nullptr
 };
 
@@ -215,7 +216,8 @@ enum
    TAG_HARDWARESHADER,
    TAG_DETAIL,
    TAG_INCLUDE,
-   TAG_MATERIAL
+   TAG_MATERIAL,
+   TAG_LIGHTSIZEFACTOR,
 };
 
 //==========================================================================
@@ -230,6 +232,7 @@ class GLDefsParser
 	int workingLump;
 	int ScriptDepth = 0;
 	TArray<FLightAssociation> &LightAssociations;
+	double lightSizeFactor = 1.;
 
 	//==========================================================================
 	//
@@ -470,7 +473,7 @@ class GLDefsParser
 					sc.ScriptError("Unknown tag: %s\n", sc.String);
 				}
 			}
-			AddLightDefaults(defaults);
+			AddLightDefaults(defaults, lightSizeFactor);
 		}
 		else
 		{
@@ -565,7 +568,7 @@ class GLDefsParser
 			}
 			defaults->OrderIntensities();
 
-			AddLightDefaults(defaults);
+			AddLightDefaults(defaults, lightSizeFactor);
 		}
 		else
 		{
@@ -660,7 +663,7 @@ class GLDefsParser
 				}
 			}
 			defaults->OrderIntensities();
-			AddLightDefaults(defaults);
+			AddLightDefaults(defaults, lightSizeFactor);
 		}
 		else
 		{
@@ -760,7 +763,7 @@ class GLDefsParser
 				defaults->SetArg(LIGHT_SECONDARY_INTENSITY, defaults->GetArg(LIGHT_INTENSITY));
 				defaults->SetArg(LIGHT_INTENSITY, v);
 			}
-			AddLightDefaults(defaults);
+			AddLightDefaults(defaults, lightSizeFactor);
 		}
 		else
 		{
@@ -846,7 +849,7 @@ class GLDefsParser
 					sc.ScriptError("Unknown tag: %s\n", sc.String);
 				}
 			}
-			AddLightDefaults(defaults);
+			AddLightDefaults(defaults, lightSizeFactor);
 		}
 		else
 		{
@@ -1427,7 +1430,6 @@ class GLDefsParser
 			}
 		}
 	}
-
 	
 
 public:
@@ -1461,6 +1463,7 @@ public:
 						sc.ScriptError("Lump '%s' not found", sc.String);
 
 					GLDefsParser newscanner(lump, LightAssociations);
+					newscanner.lightSizeFactor = lightSizeFactor;
 					newscanner.DoParseDefs();
 					break;
 				}
@@ -1508,6 +1511,9 @@ public:
 			case TAG_DETAIL:
 				ParseDetailTexture();
 				break;
+			case TAG_LIGHTSIZEFACTOR:
+				lightSizeFactor = ParseFloat(sc);
+				break;
 			case TAG_DISABLE_FB:
 				{
 					/* not implemented.