Add proximity dimming feature

Also overhaul brightness clamping code. It now occurs in HSV space.

5 files changed, 76 insertions, 14 deletions

diff --git a/Editor/tooner.cs b/Editor/tooner.cs
index e0a8bfc..53bdc46 100644
--- a/Editor/tooner.cs
+++ b/Editor/tooner.cs
@@ -1495,9 +1495,32 @@ public class ToonerGUI : ShaderGUI {
         "Mipmap multiplier");
     bc.floatValue = (float) Math.Max(1E-6, bc.floatValue);
 
+    bc = FindProperty("_Proximity_Dimming_Enable_Static");
+    bool enabled = bc.floatValue > 1E-6;
+    EditorGUI.BeginChangeCheck();
+    enabled = EditorGUILayout.Toggle("Proximity dimming", enabled);
+    EditorGUI.EndChangeCheck();
+    bc.floatValue = enabled ? 1.0f : 0.0f;
+    SetKeyword("_PROXIMITY_DIMMING", enabled);
+
+    if (enabled) {
+      EditorGUI.indentLevel += 1;
+
+      bc = FindProperty("_Proximity_Dimming_Min_Dist");
+      editor.FloatProperty(bc, "Min distance");
+
+      bc = FindProperty("_Proximity_Dimming_Max_Dist");
+      editor.FloatProperty(bc, "Max distance");
+
+      bc = FindProperty("_Proximity_Dimming_Factor");
+      editor.FloatProperty(bc, "Dimming factor");
+
+      EditorGUI.indentLevel -= 1;
+    }
+
 #if LTCGI_INCLUDED
     bc = FindProperty("_LTCGI_Enabled");
-    bool enabled = bc.floatValue > 1E-6;
+    enabled = bc.floatValue > 1E-6;
     EditorGUI.BeginChangeCheck();
     enabled = EditorGUILayout.Toggle("Enable LTCGI", enabled);
     EditorGUI.EndChangeCheck();
diff --git a/feature_macros.cginc b/feature_macros.cginc
index 8f15a6d..432a29d 100644
--- a/feature_macros.cginc
+++ b/feature_macros.cginc
@@ -138,6 +138,7 @@
 #pragma shader_feature_local _ _CLEARCOAT
 #pragma shader_feature_local _ _CLEARCOAT_MASK
 #pragma shader_feature_local _ _CLEARCOAT_MASK2
+#pragma shader_feature_local _ _PROXIMITY_DIMMING
 
 #endif  // __FEATURE_MACROS_INC
 
diff --git a/globals.cginc b/globals.cginc
index 9a5a130..e294bd6 100644
--- a/globals.cginc
+++ b/globals.cginc
@@ -45,6 +45,12 @@ float3 shadowedReflections;
 float3 _ReflShadows;
 float3 _ReflShadowStrength;
 
+#if defined(_PROXIMITY_DIMMING)
+float _Proximity_Dimming_Min_Dist;
+float _Proximity_Dimming_Max_Dist;
+float _Proximity_Dimming_Factor;
+#endif
+
 #if defined(_CLEARCOAT)
 float _Clearcoat_Enabled;
 float _Clearcoat_Strength;
diff --git a/pbr.cginc b/pbr.cginc
index 9fc9fa4..ef8b1d4 100644
--- a/pbr.cginc
+++ b/pbr.cginc
@@ -236,26 +236,53 @@ float4 getLitColor(
   }
 #endif
 
+  direct_light.color = RGBtoHSV(direct_light.color);
+  indirect_light.specular = RGBtoHSV(indirect_light.specular);
+  indirect_light.diffuse = RGBtoHSV(indirect_light.diffuse);
+
   if (_Reflection_Probe_Saturation < 1.0) {
-    direct_light.color = RGBtoHSV(direct_light.color);
     direct_light.color[1] *= _Reflection_Probe_Saturation;
-    direct_light.color = HSVtoRGB(direct_light.color);
-    indirect_light.specular = RGBtoHSV(indirect_light.specular);
     indirect_light.specular[1] *= _Reflection_Probe_Saturation;
-    indirect_light.specular = HSVtoRGB(indirect_light.specular);
-    indirect_light.diffuse = RGBtoHSV(indirect_light.diffuse);
     indirect_light.diffuse[1] *= _Reflection_Probe_Saturation;
-    indirect_light.diffuse = HSVtoRGB(indirect_light.diffuse);
   }
 
-  direct_light.color = clamp(direct_light.color, _Min_Brightness, _Max_Brightness);
-  indirect_light.diffuse = clamp(indirect_light.diffuse, _Min_Brightness, _Max_Brightness);
-  indirect_light.specular = clamp(indirect_light.specular, _Min_Brightness, _Max_Brightness);
+#if defined(_PROXIMITY_DIMMING)
+  {
+    float cam_dist = length(_WorldSpaceCameraPos - worldPos);
+    cam_dist = clamp(cam_dist, _Proximity_Dimming_Min_Dist,
+        _Proximity_Dimming_Max_Dist);
+    // Map onto [0, 1]
+    cam_dist = (cam_dist - _Proximity_Dimming_Min_Dist) /
+      (_Proximity_Dimming_Max_Dist - _Proximity_Dimming_Min_Dist);
+    float dim_factor = lerp(_Proximity_Dimming_Factor, 1, cam_dist);
+    direct_light.color[2] *= dim_factor;
+    indirect_light.diffuse[2] *= dim_factor;
+    indirect_light.specular[2] *= dim_factor;
+  }
+#endif
 
-  // TODO move back before clamping
-  direct_light.color *= _Lighting_Factor * _Direct_Lighting_Factor * enable_direct;
-  indirect_light.specular *= _Lighting_Factor * _Indirect_Specular_Lighting_Factor;
-  indirect_light.diffuse *= _Lighting_Factor * _Indirect_Diffuse_Lighting_Factor;
+  direct_light.color[2] *= _Lighting_Factor * _Direct_Lighting_Factor * enable_direct;
+  indirect_light.specular[2] *= _Lighting_Factor * _Indirect_Specular_Lighting_Factor;
+  indirect_light.diffuse[2] *= _Lighting_Factor * _Indirect_Diffuse_Lighting_Factor;
+
+  float2 brightnesses = float2(
+      direct_light.color[2],
+      indirect_light.diffuse[2]);
+  // Do this to avoid division by 0. If both light sources are black,
+  // sum_brightness could be 0;
+  brightnesses = max(brightnesses, min(_Min_Brightness, .001));
+  float sum_brightness = brightnesses[0] + brightnesses[1];
+  float2 brightness_proportions = brightnesses / sum_brightness;
+  sum_brightness = clamp(sum_brightness, _Min_Brightness, _Max_Brightness);
+  direct_light.color[2] = sum_brightness * brightness_proportions[0];
+  indirect_light.diffuse[2] = sum_brightness * brightness_proportions[1];
+
+  // Specular has to be clamped separately to avoid artifacting.
+  indirect_light.specular[2] = clamp(indirect_light.specular[2], _Min_Brightness, _Max_Brightness);
+
+  direct_light.color = HSVtoRGB(direct_light.color);
+  indirect_light.specular = HSVtoRGB(indirect_light.specular);
+  indirect_light.diffuse = HSVtoRGB(indirect_light.diffuse);
 
   // Apply AO
   indirect_light.diffuse *= ao;
diff --git a/tooner.shader b/tooner.shader
index 7ae6a85..9ab319b 100644
--- a/tooner.shader
+++ b/tooner.shader
@@ -164,6 +164,11 @@ Shader "yum_food/tooner"
     _Ambient_Occlusion("Ambient occlusion", 2D) = "white" {}
     _Ambient_Occlusion_Strength("Ambient occlusion", Range(0,1)) = 1
 
+    _Proximity_Dimming_Enable_Static("Enable proximity dimming", Float) = 0
+    _Proximity_Dimming_Min_Dist("Proximity dimming min distance", Float) = 0
+    _Proximity_Dimming_Max_Dist("Proximity dimming max distance", Float) = 1
+    _Proximity_Dimming_Factor("Proximity dimming max distance", Float) = 0
+
     _Shading_Mode("Shading mode", Range(0, 1)) = 0
     _Mesh_Normals_Mode("Normals mode", Float) = 0.0
     _Flatten_Mesh_Normals_Str("Flatten mesh normals strength", Float) = 100.0