From 0393ab02635441701b428613d3bc82017267656f Mon Sep 17 00:00:00 2001
From: drewcassidy <drewcassidy@me.com>
Date: Mon, 8 Jun 2020 00:03:26 -0700
Subject: [PATCH] Decal shader changes, try to fix lighting additive pass

---
 Assets/Shaders/DecalsCommon.cginc             | 31 ++++++++++++++-----
 .../ConformalDecals/Assets/decal-blank.mu     |  2 +-
 .../Resources/conformaldecals.shab            |  4 +--
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/Assets/Shaders/DecalsCommon.cginc b/Assets/Shaders/DecalsCommon.cginc
index 128e67d..1f8994b 100644
--- a/Assets/Shaders/DecalsCommon.cginc
+++ b/Assets/Shaders/DecalsCommon.cginc
@@ -79,6 +79,22 @@ inline void decalClipAlpha(float alpha) {
     #endif
 }
 
+// modifed version of the KSP BlinnPhong because it does some weird things
+inline fixed4 LightingBlinnPhongDecal(SurfaceOutput s, fixed3 lightDir, half3 viewDir, fixed atten)
+{
+	s.Normal = normalize(s.Normal);
+	half3 h = normalize(lightDir + viewDir);
+
+	fixed diff = max(0, dot(s.Normal, lightDir));
+
+	float nh = max(0, dot(s.Normal, h));
+	float spec = pow(nh, s.Specular*128.0) * s.Gloss;
+
+	fixed4 c = 0;
+	c.rgb = (s.Albedo * _LightColor0.rgb * diff + _LightColor0.rgb * _SpecColor.rgb * spec) * (atten);
+	return c;
+}
+
 // declare surf function, 
 // this must be defined in any shader using this cginc
 void surf (DecalSurfaceInput IN, inout SurfaceOutput o);
@@ -221,7 +237,9 @@ fixed4 frag_forward(v2f IN) : SV_Target
     surf(i, o);
    
     #ifdef DECAL_PREVIEW
-        o.Albedo = lerp(_Color.rgb,o.Albedo, o.Alpha);
+        if (any(IN.uv_decal > 1) || any(IN.uv_decal < 0)) o.Alpha = 0;
+
+        o.Albedo = lerp(_Color.rgb, o.Albedo, o.Alpha);
         o.Normal = lerp(float3(0,0,1), o.Normal, o.Alpha);
         o.Gloss = lerp(_Color.a, o.Gloss, o.Alpha);
         o.Emission = lerp(0, o.Emission, o.Alpha);
@@ -239,21 +257,20 @@ fixed4 frag_forward(v2f IN) : SV_Target
     WorldNormal = normalize(WorldNormal);
     o.Normal = WorldNormal;
     
-    //KSP lighting function
-    c += LightingBlinnPhongSmooth(o, lightDir, worldViewDir, atten);
+    //call modified KSP lighting function
+    c += LightingBlinnPhongDecal(o, lightDir, worldViewDir, atten);
     
     // Forward base emission and ambient/vertex lighting
     #ifdef UNITY_PASS_FORWARDBASE
         c.rgb += o.Emission;
         c.rgb += o.Albedo * IN.vlight;
-        c.a = saturate(c.a);
+        c.a = o.Alpha;
     #endif //UNITY_PASS_FORWARDBASE
     
     // Forward add multiply by alpha
     #ifdef UNITY_PASS_FORWARDADD
-        c.rgb *= c.a;
-        c.a = 0.0;
-    #endif
+        c.rgb *= o.Alpha;
+    #endif 
     
     return c;
 }
diff --git a/Distribution/GameData/ConformalDecals/Assets/decal-blank.mu b/Distribution/GameData/ConformalDecals/Assets/decal-blank.mu
index ea50654..5a0984f 100644
--- a/Distribution/GameData/ConformalDecals/Assets/decal-blank.mu
+++ b/Distribution/GameData/ConformalDecals/Assets/decal-blank.mu
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:41e91c40e21638fcf49f2c5cede4acf1d0b6706fc8b1ac1d7211edc47fb6635a
+oid sha256:9d7714407c3b6b0bde5cd830e9789f837d44310db16272c6b42299e9af9f2907
 size 3273
diff --git a/Distribution/GameData/ConformalDecals/Resources/conformaldecals.shab b/Distribution/GameData/ConformalDecals/Resources/conformaldecals.shab
index 6ed0ecd..634aa4d 100644
--- a/Distribution/GameData/ConformalDecals/Resources/conformaldecals.shab
+++ b/Distribution/GameData/ConformalDecals/Resources/conformaldecals.shab
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:680b0c8662bace934a133136cdb52efd484afe1e22806b36d68796a89cdf153a
-size 123968
+oid sha256:6f9ec40c787677e390877fe37b5957e06b8ca2caea690c64f96789bfe70ccd2d
+size 126198