From bea625a42c9aa0d854ae98e55a8a55945709730d Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@zdoom.fake>
Date: Sun, 23 Oct 2016 20:42:48 +0200
Subject: [PATCH] - added an ATTENUATE flag to dynamic lights, this is set by
 default for attached lights. For placed lights this is off, because it'd
 interfere with many existing maps that depend on unattenuated lights.

---
 src/gl/dynlights/gl_dynlight.cpp   |  1 +
 src/gl/dynlights/gl_dynlight.h     |  1 +
 src/gl/dynlights/gl_dynlight1.cpp  |  2 +-
 wadsrc/static/shaders/glsl/main.fp | 17 ++++++++++-------
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/gl/dynlights/gl_dynlight.cpp b/src/gl/dynlights/gl_dynlight.cpp
index ae19ecf608..40008e3ad5 100644
--- a/src/gl/dynlights/gl_dynlight.cpp
+++ b/src/gl/dynlights/gl_dynlight.cpp
@@ -1082,6 +1082,7 @@ void gl_AttachLight(AActor *actor, unsigned int count, const FLightDefaults *lig
 		light->target = actor;
 		light->owned = true;
 		light->ObjectFlags |= OF_Transient;
+		light->flags4 |= MF4_ATTENUATE;
 		actor->dynamiclights.Push(light);
 	}
 	light->flags2&=~MF2_DORMANT;
diff --git a/src/gl/dynlights/gl_dynlight.h b/src/gl/dynlights/gl_dynlight.h
index 84965e3185..c51e0c79d8 100644
--- a/src/gl/dynlights/gl_dynlight.h
+++ b/src/gl/dynlights/gl_dynlight.h
@@ -50,6 +50,7 @@ enum
 #define MF4_SUBTRACTIVE MF4_MISSILEEVENMORE
 #define MF4_ADDITIVE MF4_MISSILEMORE
 #define MF4_DONTLIGHTSELF MF4_SEESDAGGERS
+#define MF4_ATTENUATE MF4_INCOMBAT
 
 enum ELightType
 {
diff --git a/src/gl/dynlights/gl_dynlight1.cpp b/src/gl/dynlights/gl_dynlight1.cpp
index d20f5c01b1..2f8ef44edc 100644
--- a/src/gl/dynlights/gl_dynlight1.cpp
+++ b/src/gl/dynlights/gl_dynlight1.cpp
@@ -116,7 +116,7 @@ bool gl_GetLight(int group, Plane & p, ADynamicLight * light, bool checkside, FD
 	data[4] = r;
 	data[5] = g;
 	data[6] = b;
-	data[7] = 0;
+	data[7] = !!(light->flags4 & MF4_ATTENUATE);
 	return true;
 }
 
diff --git a/wadsrc/static/shaders/glsl/main.fp b/wadsrc/static/shaders/glsl/main.fp
index fb1983fc73..36db31f681 100644
--- a/wadsrc/static/shaders/glsl/main.fp
+++ b/wadsrc/static/shaders/glsl/main.fp
@@ -142,16 +142,19 @@ float diffuseContribution(vec3 lightDirection, vec3 normal)
 //
 //===========================================================================
 
-float pointLightAttenuation(vec4 lightpos)
+float pointLightAttenuation(vec4 lightpos, float attenuate)
 {
 	float attenuation = max(lightpos.w - distance(pixelpos.xyz, lightpos.xyz),0.0) / lightpos.w;
-	#if 0
+	if (attenuate == 0.0)
+	{
 		return attenuation;
-	#else
+	}
+	else
+	{
 		vec3 lightDirection = normalize(lightpos.xyz - pixelpos.xyz);
 		float diffuseAmount = diffuseContribution(lightDirection, normalize(vWorldNormal.xyz));
 		return attenuation * diffuseAmount;
-	#endif
+	}
 }
 
 //===========================================================================
@@ -229,7 +232,7 @@ vec4 getLightColor(float fogdist, float fogfactor)
 				vec4 lightpos = lights[i];
 				vec4 lightcolor = lights[i+1];
 				
-				lightcolor.rgb *= pointLightAttenuation(lightpos);
+				lightcolor.rgb *= pointLightAttenuation(lightpos, lightcolor.a);
 				dynlight.rgb += lightcolor.rgb;
 			}
 			//
@@ -240,7 +243,7 @@ vec4 getLightColor(float fogdist, float fogfactor)
 				vec4 lightpos = lights[i];
 				vec4 lightcolor = lights[i+1];
 				
-				lightcolor.rgb *= pointLightAttenuation(lightpos);
+				lightcolor.rgb *= pointLightAttenuation(lightpos, lightcolor.a);
 				dynlight.rgb -= lightcolor.rgb;
 			}
 		}
@@ -322,7 +325,7 @@ void main()
 						vec4 lightpos = lights[i];
 						vec4 lightcolor = lights[i+1];
 						
-						lightcolor.rgb *= pointLightAttenuation(lightpos);
+						lightcolor.rgb *= pointLightAttenuation(lightpos, lightcolor.a);
 						addlight.rgb += lightcolor.rgb;
 					}
 					frag.rgb = clamp(frag.rgb + desaturate(addlight).rgb, 0.0, 1.0);